*2.3. Carotenoids Extraction Methods*

The extraction methods described herein use different categories of solvents, both traditional and green. For traditional solvents, an *n*-hexane-acetone (1:1 % *v*/*v*) (*n*-hexane purchased from Sigma Aldrich, with purity ≥97%, Darmstadt, Germany and acetone purchased from Carlo Erba Reagents, with purity ≥99.8%, Cornaredo, Milan, Italy) mixture was tested (the extracts were coded as "T"), while DES DL-menthol and lactic acid solution (1:8 molar ratio) (code "ML") (DL menthol from Sigma Aldrich, purity ≥98%, Darmstadt, Germany, and lactic acid Sigma Aldrich, purity ≥85 %, Darmstadt, Germany), ethyl acetate (Sigma Aldrich, purity ≥99.8%, Darmstadt, Germany), and ethyl lactate (Sigma Aldrich, purity ≥98%, Darmstadt, Germany) solution (30% of ethyl acetate and 70% of ethyl lactate) (code "G") were used as the DES solvents. The procedure follows previously developed analytical protocols and applied in the literature on the same matrix [50,58].

To compare the three extraction procedures, it is fundamental to adopt the same conditions in terms of temperature, time, and solvent/sample volume/mass ratio: according to the literature, the parameters that favor carotenoid extraction are 63 ◦C for 20 min in ultrasonic bath (2209 S3 Ultrasonic Cleaner, Milan, Italy), with 100 mL/mg solvent/sample, both for *n*-hexane:acetone solution and ethyl acetate:ethyl lactate, but 120 mg/L for the DL-menthol:lactic acid solution [50,58]. As reported by Silva and colleagues [50,58], the solvents were prepared following the following ratios: 1:1 % *v/v n*-hexane:acetone, 70:30 *v/v* ethyl acetate:ethyl lactate, 8:1 mol/mol DL-menthol:lactic acid.

After preparation of the three above-mentioned solvent mixtures, 0.2 g of raw byproduct was weighed for each sample, doubling the quantities suggested by the operation procedures tested by Silva and colleagues [50,58] due to the high moisture content of tomato pomace. When the extraction was performed on treated by-product (freeze-dried, air-dried and heat-dried), 0.1 g of by-product was considered. Next, 10 mL of *n*-hexane:acetone was added to a test tube for a trial, 10 mL of ethyl acetate:ethyl lactate for another, and lastly 12 mL of DL-menthol:lactic acid for another, in three replicates each; each solvent mixture was heated at 60 ◦C before the interaction with the by-product. After this pre-heating, the solvent mixture was mixed with the tomato pomace using a vortex (Vortex agitator Zx3, VELP Scientifica Srl, Monza Brianza, Italy) for 10 s and placed in an ultrasound water bath at 60 ◦C (±1 ◦C) for 20 min.

Finally, the glass tubes were removed from the water bath and centrifuged (MPW M-SCIENCE, MPW Med. Instruments, Warsaw, Poland) at 2916 rpm for 10 min to obtain the separation of the solid and liquid phases. The liquid extract was withdrawn and transferred into another glass tube for spectrophotometric analyses.


**4. Conclusion**

Finally, the ANOVA results (**Table 5**) reveal that the model is significant and the lack-of-fit is not (*p*-value close to 0.05). All coefficients shown in the ANOVA table are significant; the others are not, hence the term of "reduced" cubic model. The multilinear regression coefficients are

thus significant and the final mathematical equation (Eq. (16)) in terms of coded factors is given

The model is determined to be statistically adequate. The study of the residuals did not reveal major inconstancies. It is necessary to check if the model is scientifically adequate and if it can

From the response equation (Eq. (16)), it is clear that the pulse energy (*A*) and the scanning speed (*D*) are the most influent parameters on the scribing depth. Heating a target via laser irradiation depends on the amount of energy brought to the target and the interaction duration. This is why they are the most dominant factors and why the interaction term *AD* appears in

the depth increases with increasing energy input until saturation. It is the classical logarithm trend observed in the literature [37]. The scribing depth also decreases with increasing speed until saturation. Interaction terms such as *AC* (evaluation of the fluence, Eqs. (18) and (19)), *AD* (effect of fluence over time), and *CD* (laser/material interaction over time) appear naturally

( )² ( )²

 pw

() ( )

0 0 2 2

æ öæ ö æö æ ö ç ÷ç ÷ =+ =+ ç÷ ç ÷

² ² () 1 1 *M z M C z* l

 w

0 0

w

èø è ø è øè ø

where *z* is the defocus (m), *O* is the overlap ratio, *f* is the repetition rate (Hz), *v* is the scanning speed (mm/s), λ is the wavelength (nm) and ω0 (cm) is the spot radius at the focal point. The effect of the number of passes *B* varied depending on the delay between two passes and thus on the scanning speed. The effect saturated around three passes for pulse energies below 85

2 2

*E A F* pw

1 1

w

pw

*v D O*

Y = 156.89 + 52A + 22.63B – 3.87C -– 39.2D + 8.78AB – 5.75AC – 13AD – 3.6BD + 3.68CD

+ 6.75D2

adjusted = 0.997, *R*2 predicted = 0.9805). The reduced cubic model is

and *D*2 are conformant with theory as well. Indeed,

*z C* = = ´ ´ (17)

*zf Cf* =- =- ´ ´ (18)

 l

pw

D + 9.05AB2 (16)

(19)

– 3.73ABD + 9.17A2

close to 1 (*R*2

= 0.9986, *R*2

182 Modeling and Simulation in Engineering Sciences

– 9.15B2

the equation. Square terms coefficient *A*2

w

 w

predict response values with additional experiments.

– 5.85C2

in the response equation because they are linked by Eqs. (17)–(19):

using the least-squares method.

– 18.05A2

*3.3.2. Experimental validation*

Whether it is Finite Element Methods, Monte Carlo or Molecular Dynamics, numerical simulation gives the opportunity to better comprehend the physics of laser-material interaction and in many cases to predict results and optimize the parameters for laser processing. In this chapter, numerical simulation was proven to be valuable to both fundamental science and laser applications in the industry. Computer calculation improvement makes it possible to model complex problems when multiphysical phenomena are coupled and allowed important achievements in the field of laser processing. Simplification assumptions are still required but with time and research efforts, models will become more and more realistic giving the possibility of getting a snapshot inside complex physical mechanisms that cannot be observed through experimental means.


**3. Formulation of OMP with an NLS step for CS**

#### **3.1 Mathematical development**

Consider a continuous time signal *X*(*t*) consisting of *K* complex sinusoids of the form

$$X(t) = \sum\_{k=1}^{K} a\_k \exp(2\pi i \, f\_k \, t) \tag{4}$$

where *ak* is the complex valued amplitude and *fk* is the real valued frequency of the *k*th sinusoid. This signal model is broadly applicable [see Duarte and Baraniuk (2010) and 172 Applications of Digital Signal Processing

grid of the time series, OMP can be improved by evaluating the cost function on an overcomplete dictionary (Candes et al. 2011), but as in the ell-1 estimates discussed above, this step becomes computationally intractable long before machine precision can be

Here we follow the development of nonlinear least squares (NLS) given by Stoica and Moses (1997). Their eq. (4.3.1) defines a cost function to be minimized as a function of the

 *f*(ZDM) = 6t **|***y*(*t*) - 6k Dkexp[i(Zk*t*+Mk)]**|**2 (3) where the sums are over the number of sinusoids present in the signal, *k* = 1 to *K* and the time points run from *t* = 0 to *N*-1. Stoica and Moses also show (see their eqs. 4.3.2-4.3.8), that the frequency vector Z is the critical unknown and the amplitude and phase (or complex amplitude) are simply "nuisance" parameters that are obtained from Z. While eq. (3) appears to require simultaneous solution for three real vectors, each of length K, Stoica and Moses (eqs. 4.3.2-4.3.8) show that the problem can be reduced to solving for just the frequency vector Z and that the complex amplitude vector can be calculated directly from

the frequency vector. We use a version of these equations below in eqs. (8) and (13).

In principle, solution of the CS analog of eq. (3) could be performed to directly obtain the parameters of a sparse signal, but in practice, direct solution of eq. (3) is not computationally practical (Stoica and Moses, 1997). The difficulty is that even for a small *K*, eq. (3) is highly multimodal (see for example, Fig. 1 in Li et al., 2000) and the solution requires extremely good first guesses for the vector Z. Even with good initial values for Z, performance guarantees are difficult to find and continue to be the subject of intense investigation (Salzo

Similar two-step model-based approaches to estimating the frequency and amplitude of real and complex sinusoids have been discussed previously in the literature (Stoica et al., 2000: Li et al., 2000; Chan and So, 2004; Christensen and Jensen, 2006). Stoica et al. discuss the use of NLS to obtain the amplitude for complex sinusoidal signals given the frequency; Li et al. and Chan and So discuss a combined matching pursuit NLS approach similar to ours for obtaining the frequencies of complex and real harmonic sinusoidal signals, respectively; and Christensen and Jensen use matching pursuit plus NLS to estimate frequencies in a signal that is the sum of arbitrary frequency real sinusoids. To the best of our knowledge, our paper is the first application of an OMP/NLS algorithm to estimate the frequency and

Consider a continuous time signal *X*(*t*) consisting of *K* complex sinusoids of the form

where *ak* is the complex valued amplitude and *fk* is the real valued frequency of the *k*th sinusoid. This signal model is broadly applicable [see Duarte and Baraniuk (2010) and

(4)

obtained for arbitrary frequencies.

vectors ZDM

**2.3 Nonlinear Least Squares method**

and Villa, 2011 and references therein).

amplitude from CS measurements.

**3.1 Mathematical development**

**3. Formulation of OMP with an NLS step for CS**

references therein]. We take *f*min = 0 and *f*max = 1 to set up our test problem; we sample *X*(*t*) at the Nyquist rate for complex signals, '*t* = 1/*f*max=1, to obtain the sampled time series *X***S** of length *N* from *t* = 0 to *t* = *N***-1** where *N* is the number of time samples. As in all applications of compressive sensing, we make a sparsity assumption, *K* << *N*, and mix the input signal vector *X***S** plus sampled noise *n* down in dimension to the measured vector *y* of dimension *M*:

$$y = \Phi(\,\,\lambda\_S + n),\tag{5}$$

where **Ʒ** is an *M* x *N* mixing matrix and *K*<*M* << *N*. Note that in eq. (5) *n* is added to *X***S** prior to mixing. In other models noise is added to the mixed version of *X***S**, **Ʒ***X***S,** or even to **Ʒ** itself. We generate the elements of **Ʒ** using the pseudo-random number functions in our software (*Mathematica* and *Python*) such that they are taken uniformly from the set of nine complex numbers: {-1 – i, -1, -1 + i, -i, 0, i, 1 – i, 1, 1 + i} or equivalently, the elements are taken from the sum of random integers drawn from {-1,0,1} plus i times different random integers drawn from {-1,0,1}. We use a complex mixing matrix because our signal model is complex. The noise is assumed to be independent and identically distributed (i.i.d.) Gaussian noise with standard deviation V/21/2 and is added to the real and the imaginary part of each element of *X***S**, so that the covariance of *n* is V**2***I* , where *I* is the *N* x *N* identity matrix. If the frequencies lie on the DFT frequency grid associated with the time series *t* = 0 to *t* = *N***-1**, eq. (5) can be solved for the frequencies by writing *s* = **DFT** *X***S**, substituting *X***S** = **IDFT** *s* (**IDFT** = Inverse DFT) in eq. (5), and solving *y* = **Ʒ(IDFT** *s***+***n***)** by minimizing the ell-1 norm of *s* subject to the measurement constraint eq. (5) if *n* = 0 or by minimizing the ell-1 norm penalized by an arbitrary fraction of the constraint (LASSO) in the presence of noise (Candes & Wakin, 2008; Loris, 2008).

Although the noise is assumed to be i.i.d., the mixing matrix **Ʒ** colors the noise in the observation vector *y*. The covariance of *y* is given by

$$\text{Cov}[y] = \sigma 2 \blacktriangleright \mathbf{Q} \clubsuit \mathbf{H},\tag{6}$$

and the standard maximum likelihood estimator requires definition of a weighting matrix *W*,

$$\mathcal{W} = (\mathbf{Q} \cdot \mathbf{Q}^{\mathrm{Id}})^{-1},\tag{7}$$

where the superscript H indicates the Hermitian conjugate (see Stoica et al., 2000 and Chan and So, 2004, for a discussion of weighted estimators in NLS). If the inverse in eq. (7) is illconditioned or does not exist, this indicates a poor choice of mixing matrix **Ʒ** and another one should be chosen. The maximum likelihood estimator (MLE) for *X***S**, *C***(***Z***)** is solved by finding the vector *Z* that minimizes the weighted square of the residual given by

$$\mathbf{C(Z)} \equiv (\boldsymbol{\Phi}\mathbf{Z} - \boldsymbol{y}) \text{ } \mathbb{H} \text{ } (\boldsymbol{\Phi}\mathbf{Z} - \boldsymbol{y}) \text{ } \tag{8}$$

*Z* is a vector taken from the linear subspace spanned by at most *K* complex sinusoids sampled over *t* = 0 to *N***-1** (see the corresponding equation for determining the amplitude and frequency of a sum of complex sinusoids in a system that does not have compressive sensing, Stoica and Moses, 1997, eq. 4.3.6). CS recovery is equivalent to determining the spectral support (that is, the *K* unknown frequencies) of the input signal *X***S***,* or equivalently determining the vector *Z* that minimizes eq. (8) (Duarte & Baraniuk, 2010). In the absence of noise, weighting with *W* is unnecessary because the solution is exact and both the weighted

Applications of the Orthogonal Matching Pursuit/ Nonlinear

of eq. (11).

**3.2 Algorithm description**

vector *y* to form the first residual *r***1**.

Least Squares Algorithm to Compressive Sensing Recovery 175

 *U* = ) { *x***(** *f***1**), *x*( *f***2**),. . .*x*(*f***K**)} (12) Note that if there is no noise and if all frequencies are known exactly, eq. (11) can be verified by substituting *y* **=** *U A***(***U***),** which is equivalent to eq. (5), on the right hand side

Finally, starting from estimates of the frequencies and amplitudes from OMP as described above, apply weighted NLS to get better values. This is done by finding the frequency or set

 *R*(*f*) = |{*A*[*U*(*f*)]*U*(*f*) - *y*}H *W* {*A*[*U*(*f*)]*U*(*f*) - *y*}|, (13) which is the same as the weighted least squares estimator given by eq. (8) with the substitution of *A***[***U(f)***]** defined by eq. (11) for the amplitude vector and *U***(***f***)** defined by eq. (12) for the mixed sinusoids (see the analogous equations in Stoica and Moses, 1997, eqs.

As described in Table 1, the first step in the first iteration of the Do loop is estimation of the first frequency in the spectral support of the signal *X***s**. This is given by the frequency of the sinusoid whose image after multiplication by **Ʒ** has the maximum correlation with the observation vector *y* (see, for example, Tropp and Gilbert, 2007 Algorithm 3, step 2). Here we use the equivalent form, the argmax of *G***(***f***,** *y***)** with respect to *f* to obtain the first estimate of the frequency of the first sinusoid *f*1 in eq. (4). At this point previous implementations of discrete OMP use the amplitude estimator eq. (11) to estimate the amplitude of the first sinusoid *a*1 = *A*[**Ʒ** *x*(*f*1)], multiply this amplitude estimate times *x***(***f***1)**, given by eq. (9), and by the measurement or mixing matrix **Ʒ** and subtract this vector from the measurement

In our algorithm, we proceed differently by improving the precision of the frequency estimates using NLS before finding the amplitude estimate. We take the frequency *f***1** from the argmax of *G***(***f***,** *y***)** evaluated on a discrete set of frequencies and use that as the starting value to solve the NLS problem given by eq. (13). We have used several methods and several different software packages to solve the NLS problem. A simple decimation routine [i.e., tabulating *R***(***f***)** from *f***1-**'*f* to *f***1+**'*f* ('*f* is the over-complete grid spacing) in 10 steps, finding the argmin, decreasing '*f* by a factor of 10, tabulating and finding the argmin of *R***(***f***)** again until the specified precision is reached] works well but is not very efficient. Powell's method in *Python (*"scipy.optimize.fmin\_powell") and one of the Newton methods, the PrincipalAxis method, and the Conjugate Gradient method in *Mathematica*'s minimizer "FindMinimum" all work and take less time than the decimation routine. A detailed investigation of minimizers for the NLS step in our version of OMP is beyond the scope of this chapter. The oversampling *N***f** required for our method and that required for

Given the better value of *f*1, we compute *a*1 from eq. (11) and a new value of the residual *r*

 *r*1 = *y* – *A*(*U*1)*U*1 = *y* – *a*1 **Ʒ** *x*(*f*1). (14)

conventional OMP are nearly identical as discussed below in Section 6.

with the NLS estimate of the first signal removed from *y* as in OMP

where *U* is the spectral support matrix given that depends on **{***f***1,***f***2,…***f***K}** through

of frequencies *f* **= {** *f***1,** *f***2,…***f***k }** that minimize the functional *R***(***f***)** given by

4.3.7 and 4.3.8). The product *A***[***U(f)***]** *U***(***f***)** in eq. (13) is the same as **Ʒ***Z* in eq. (8).

and un-weighted residuals are zero. Finding the *K* sinusoids that solve eq. (8) is the standard NLS problem and if this were computationally tractable, the problem would be solved. But as pointed out by Li et al. (2000) [see also the discussion in Stoica & Moses (1997)], "the NLS cost function in (3) is usually multimodal with many local minima," and "the minimization of the NLS cost function requires the use of a very fine searching algorithm and may be computationally prohibitive."

One way out of this dilemma is to use NLS in place of least squares within OMP. This has two advantages over using NLS by itself. First, the frequency band over which one has to search in NLS is reduced from the entire frequency band to the frequency grid spacing in the over-complete dictionary used in OMP. Second, the estimates of the frequencies at any given iteration are improved from the values on the grid by using NLS in the previous iteration (see the discussion of a similar continuous version of matching pursuit by Jacques & De Vleeschouwer, 2008).

The first step in our formulation is to define the vector function of frequency, *x*(*f*), as the time series for a unity amplitude complex sinusoid at frequency *f* evaluated at integral sampling times *t* = 0 to *t* = *N -*1,

$$\mathbf{x}(\mathfrak{f}) = \{1, \,\mathbf{e}^{i\mathbf{2}\mathfrak{m}\mathfrak{f}}, \,\mathbf{e}^{i4\mathfrak{m}\mathfrak{f}}, \,\dots, \,\mathbf{e}^{i\mathbf{2}(N-1)\mathfrak{m}\mathfrak{f}}\}.\tag{9}$$

Note that the solution for *X***S** in eq. (5) is a linear combination of *K* vectors *x*(*f***i**), (*i* = 1,*K*). To use OMP, we need an over-complete dictionary (Candes et al., 2010) which means that *x***(***f***)** is evaluated on a fine grid oversampled by the factor *N***f** from the DFT grid. The second step is to define a function that can be evaluated on the fine grid to find a grid frequency close to one of the true frequencies in the input signal *Xs*. Here we use the function *G(f*, *r*) given by

$$G(f,r) = \mathbb{1}\left/\left|r^\* \, W \, r - \frac{\left[\Phi \, \mathbf{x}(f)\right]^\* W \, r}{\sqrt{\left|\Phi \, \mathbf{x}(f)\right|^\* W \left|\Phi \, \mathbf{x}(f)\right|}}\right|\right.\tag{10}$$

where initially *r* = *y* and subsequently, *r* equals the residual of *y* with 1 to *K* components removed as discussed below. We calculate the argmax of *G***(***f***,***y***)** over *f* in the dictionary frequencies to make a first estimate of one of the frequencies present in the input signal *X*(*t*). If there is no noise and if there is only one sinusoid, this procedure provides the dictionary vector whose frequency is nearest that of the input sinusoid. If multiple sinusoids are present, the maximum of *G*(*f*,*y*) occurs at one of the dictionary vectors whose frequency is near one of the input sinusoids provided that the dictionary is sufficiently over-complete and that **Ʒ** possesses the restricted isometry property (Duarte and Baraniuk, 2010). Note that *G*(*f*,*r*) is the inverse square of the distance between *r* and the linear span of *x***(***f***)** in the *W*-normed inner product space (defined by < *a* , *b* > = *a***H***Wb* ). Thus finding the argmax of *G***(***f***,***r***)** is equivalent to finding the argmax of the inner product of the residual with the product of **Ʒ** times the dictionary vectors *x***(***f***j)** for all *f***j** on the over-complete frequency grid (see Tropp and Gilbert, 2007, Algorithm 3, Step 2).

Given estimates of the frequencies **{***f***1,***f***2,…***f***K}** present in the input signal, we can find estimates of the amplitudes of each sinusoid by using the least squares estimator *A***(***U***)** for the amplitude vector **{***a***1,***a***2,…***a***K}** (see Stoica and Moses, 1997, eq. 4.3.8 and Stoica et al., 2000)

$$A(L) = (L^{\text{H}} \mathcal{V} \mathcal{V} \, L)^{-1} \, L^{\text{H}} \, \mathcal{V} \, \mathcal{Y} \, \tag{11}$$

where *U* is the spectral support matrix given that depends on **{***f***1,***f***2,…***f***K}** through

$$\mathcal{U} = \left. \Phi \left( \mathbf{x}(f\_1), \ x(f\_2), \dots, \mathbf{x}(f\_K) \right) \right| \tag{12}$$

Note that if there is no noise and if all frequencies are known exactly, eq. (11) can be verified by substituting *y* **=** *U A***(***U***),** which is equivalent to eq. (5), on the right hand side of eq. (11).

Finally, starting from estimates of the frequencies and amplitudes from OMP as described above, apply weighted NLS to get better values. This is done by finding the frequency or set of frequencies *f* **= {** *f***1,** *f***2,…***f***k }** that minimize the functional *R***(***f***)** given by

$$R(\mathfrak{f}) = |\{A[L\mathcal{U}[f]]L[\mathfrak{f}] - y\}^{\mathrm{H}}\,\mathrm{V}\,\{A[L\mathcal{U}[f]]L[\mathfrak{f}] - y\}|\,\mathrm{}\,\tag{13}$$

which is the same as the weighted least squares estimator given by eq. (8) with the substitution of *A***[***U(f)***]** defined by eq. (11) for the amplitude vector and *U***(***f***)** defined by eq. (12) for the mixed sinusoids (see the analogous equations in Stoica and Moses, 1997, eqs. 4.3.7 and 4.3.8). The product *A***[***U(f)***]** *U***(***f***)** in eq. (13) is the same as **Ʒ***Z* in eq. (8).

#### **3.2 Algorithm description**

174 Applications of Digital Signal Processing

and un-weighted residuals are zero. Finding the *K* sinusoids that solve eq. (8) is the standard NLS problem and if this were computationally tractable, the problem would be solved. But as pointed out by Li et al. (2000) [see also the discussion in Stoica & Moses (1997)], "the NLS cost function in (3) is usually multimodal with many local minima," and "the minimization of the NLS cost function requires the use of a very fine searching

One way out of this dilemma is to use NLS in place of least squares within OMP. This has two advantages over using NLS by itself. First, the frequency band over which one has to search in NLS is reduced from the entire frequency band to the frequency grid spacing in the over-complete dictionary used in OMP. Second, the estimates of the frequencies at any given iteration are improved from the values on the grid by using NLS in the previous iteration (see the discussion of a similar continuous version of matching pursuit by Jacques

The first step in our formulation is to define the vector function of frequency, *x*(*f*), as the time series for a unity amplitude complex sinusoid at frequency *f* evaluated at integral

Note that the solution for *X***S** in eq. (5) is a linear combination of *K* vectors *x*(*f***i**), (*i* = 1,*K*). To use OMP, we need an over-complete dictionary (Candes et al., 2010) which means that *x***(***f***)** is evaluated on a fine grid oversampled by the factor *N***f** from the DFT grid. The second step is to define a function that can be evaluated on the fine grid to find a grid frequency close to one of the true frequencies in the input signal *Xs*. Here we use the function *G(f*, *r*) given by

where initially *r* = *y* and subsequently, *r* equals the residual of *y* with 1 to *K* components removed as discussed below. We calculate the argmax of *G***(***f***,***y***)** over *f* in the dictionary frequencies to make a first estimate of one of the frequencies present in the input signal *X*(*t*). If there is no noise and if there is only one sinusoid, this procedure provides the dictionary vector whose frequency is nearest that of the input sinusoid. If multiple sinusoids are present, the maximum of *G*(*f*,*y*) occurs at one of the dictionary vectors whose frequency is near one of the input sinusoids provided that the dictionary is sufficiently over-complete and that **Ʒ** possesses the restricted isometry property (Duarte and Baraniuk, 2010). Note that *G*(*f*,*r*) is the inverse square of the distance between *r* and the linear span of *x***(***f***)** in the *W*-normed inner product space (defined by < *a* , *b* > = *a***H***Wb* ). Thus finding the argmax of *G***(***f***,***r***)** is equivalent to finding the argmax of the inner product of the residual with the product of **Ʒ** times the dictionary vectors *x***(***f***j)** for all *f***j** on the over-complete frequency grid

Given estimates of the frequencies **{***f***1,***f***2,…***f***K}** present in the input signal, we can find estimates of the amplitudes of each sinusoid by using the least squares estimator *A***(***U***)** for the amplitude vector **{***a***1,***a***2,…***a***K}** (see Stoica and Moses, 1997, eq. 4.3.8 and Stoica et al., 2000)

 *A*(*U*) = (*U*H*W U*)-1 *U*H *W y* (11)

, ... , ei2(*N-*1)Ǒ*f*

]. (9)

(10)

algorithm and may be computationally prohibitive."

 *x*(*f*) = [1, ei2Ǒ*f* , ei4Ǒ*f*

(see Tropp and Gilbert, 2007, Algorithm 3, Step 2).

& De Vleeschouwer, 2008).

sampling times *t* = 0 to *t* = *N -*1,

As described in Table 1, the first step in the first iteration of the Do loop is estimation of the first frequency in the spectral support of the signal *X***s**. This is given by the frequency of the sinusoid whose image after multiplication by **Ʒ** has the maximum correlation with the observation vector *y* (see, for example, Tropp and Gilbert, 2007 Algorithm 3, step 2). Here we use the equivalent form, the argmax of *G***(***f***,** *y***)** with respect to *f* to obtain the first estimate of the frequency of the first sinusoid *f*1 in eq. (4). At this point previous implementations of discrete OMP use the amplitude estimator eq. (11) to estimate the amplitude of the first sinusoid *a*1 = *A*[**Ʒ** *x*(*f*1)], multiply this amplitude estimate times *x***(***f***1)**, given by eq. (9), and by the measurement or mixing matrix **Ʒ** and subtract this vector from the measurement vector *y* to form the first residual *r***1**.

In our algorithm, we proceed differently by improving the precision of the frequency estimates using NLS before finding the amplitude estimate. We take the frequency *f***1** from the argmax of *G***(***f***,** *y***)** evaluated on a discrete set of frequencies and use that as the starting value to solve the NLS problem given by eq. (13). We have used several methods and several different software packages to solve the NLS problem. A simple decimation routine [i.e., tabulating *R***(***f***)** from *f***1-**'*f* to *f***1+**'*f* ('*f* is the over-complete grid spacing) in 10 steps, finding the argmin, decreasing '*f* by a factor of 10, tabulating and finding the argmin of *R***(***f***)** again until the specified precision is reached] works well but is not very efficient. Powell's method in *Python (*"scipy.optimize.fmin\_powell") and one of the Newton methods, the PrincipalAxis method, and the Conjugate Gradient method in *Mathematica*'s minimizer "FindMinimum" all work and take less time than the decimation routine. A detailed investigation of minimizers for the NLS step in our version of OMP is beyond the scope of this chapter. The oversampling *N***f** required for our method and that required for conventional OMP are nearly identical as discussed below in Section 6.

Given the better value of *f*1, we compute *a*1 from eq. (11) and a new value of the residual *r* with the NLS estimate of the first signal removed from *y* as in OMP

$$r\_1 = y - A(lL\_1)lL\_1 = y - a\_1 \Phi \ge x(f\_1). \tag{14}$$

Applications of the Orthogonal Matching Pursuit/ Nonlinear

**4. Results for sparse sinusoids without noise**

**4.1 Signal composed of a single sinusoid**

**4.2 Signal composed of a 20 sinusoids**

Least Squares Algorithm to Compressive Sensing Recovery 177

There are two methods to handle the case where the actual number of sinusoids present is unknown, yet still smaller than *K*. The simpler method, applicable for high SNR (V small compared to the smallest signal amplitude), is to perform *K* iterations of the OMP/NLS algorithm, which will incur an additional noise folding penalty, by projecting the additional noise dimensions onto the solution. The second method is to stop when the residual can be explained by noise alone though hypothesis testing. At the solution, the weighted squared residual *r*Hk*W r*k will display a F-squared statistic with 2*k* degrees of freedom, where *k* is the actual number of sinusoids present in the signal. The hypothesis that the residual is caused by noise alone, is accepted when *r***kH***Wr***k <** V**2***T* for some threshold *T* and rejected otherwise. The value for *T* is dependent on a user selectable significance level, the probability of incorrectly rejecting the given hypothesis. For a significance level of D, *T* = CDF-1(1-D), where CDF is the cumulative distribution function of the chi-squared distribution with 2*k* degrees of freedom.

Consider first a signal of the form given by eq. (4) with *K* = 1, *f*1 = 0.44681715350529533 and *a***1** = 0.8018794857541801. Fig. 1 shows a plot of *G***(***f***,** *y***)** for *N* = 1024, *M* = 4. Finding the argmax of *G***(***f***,** *y***)** evaluated for 32,768 frequencies between *f***min** and *f***max** (*N***f** = 32) yields an initial value for the frequency and amplitude of *f*1 = 0.446808 and *a***1** = 0.801070+0.026421i. Minimization of *R*[{)*x(f*1)}] starting at *f***1** = 0.446808 yields a final value *f*1 equal to the input frequency *f*1 with error less than 1x10-16 (machine precision) and the amplitude *a*1 through

Fig. 1. *G*(*f*, *y*) as a function of frequency for a signal composed of a single sinusoid mixed with *N* = 1024x4. Note the appearance of a single strong peak in the estimator that serves as

The algorithm also works for multiple frequencies. More than 20 independent tests were performed for an input signal composed of 20 independent frequencies randomly chosen between 0 and 1; all frequency components have amplitude of 1. In all tests our algorithm recovered the 20 frequencies to machine precision with a 128x1024 mixing matrix. For test 1,

an excellent starting value for minimizing the functional *R*(*f*) given in eq. (13).

We used D = 0.05 in our simulations, but D is an application-specific parameter.

*A*[{) *x(f*1)}] equal to the input amplitude with error less than 4x10-16.

where *U*1 = ) *x***(** *f***1**). The argmax of *G***(***f***,** *r***1)** now yields a first estimate of the frequency of the second sinusoid, *f*2. Next improve the estimates of both *f*1 and *f*2 by again solving the NLS problem by minimizing the functional *R***(***f***)** over *f* **= {***f***1,** *f***2}.** Note that this overwrites the previous estimate of the first frequency *f***1**. The amplitudes *a***1** and *a*2 are recalculated using (8) with *U***2** given by

$$\mathbf{U}\_2 = \begin{bmatrix} \ \mathbf{@x}(f\_1), \ \mathbf{@x}(f\_2) \ \end{bmatrix} \tag{15}$$

for the latest values of *f*1 and *f*2, Finally, in this iteration estimates of the first two sinusoids are removed from *y*:

$$r\_2 = y - A(\text{L2}) \text{ L2}.\tag{16}$$

If *K*, the total number of sinusoids present in the signal, is known, this process is repeated *K* times until *f*K and *a*K are obtained. In the absence of noise, the sum of these sinusoids solves (5) exactly and *r***K** = 0.

Table 1. OMP/NLS Algorithm.

176 Applications of Digital Signal Processing

where *U*1 = ) *x***(** *f***1**). The argmax of *G***(***f***,** *r***1)** now yields a first estimate of the frequency of the second sinusoid, *f*2. Next improve the estimates of both *f*1 and *f*2 by again solving the NLS problem by minimizing the functional *R***(***f***)** over *f* **= {***f***1,** *f***2}.** Note that this overwrites the previous estimate of the first frequency *f***1**. The amplitudes *a***1** and *a*2 are recalculated using

 *U***2** = [ **Ʒ***x***(***f*1), **Ʒ***x***(***f*2) ] (15) for the latest values of *f*1 and *f*2, Finally, in this iteration estimates of the first two sinusoids

 *r*2 = *y* – *A*(*U*2) *U*2. (16) If *K*, the total number of sinusoids present in the signal, is known, this process is repeated *K* times until *f*K and *a*K are obtained. In the absence of noise, the sum of these sinusoids solves

(8) with *U***2** given by

are removed from *y*:

(5) exactly and *r***K** = 0.

 *f***min,** *f***max**

CS Mixing Matrix **Ʒ** Measured data *y*

*f =* **(***f***max***-f***min)/(***N N***f)**

*r***i=** *y***–** *A***(***U***)** *U*

**{***f***1,** *f***2, …***f***KT}**

Table 1. OMP/NLS Algorithm.

*HWri < T:*

If *ri*

 *KT = i* Break End If

*U* = **{Ʒ***x***(***f***1), Ʒ***x***(***f***2)… Ʒ***x***(***f***i)}**

Maximum number of sinusoids *K* or threshold *T*

*f*i = Argmax *G***(***f***,** *r***i-1)** over **{***f***min,** *f***min+**'*f***,…***f***max-**'*f***,***f***max} {***f***1,***f***2,…***f***i} =** Argmin[*R***(***f***)** with initial value *f* = { *f*1, *f*2, …,*f*i} ]

**{***a***1,***a***2,…***a***KT}=** *A* **[{ Ʒ***x* **(***f***1), Ʒ***x* **(***f***2)… Ʒ***x* **(***f***K) }]**

Oversampling ratio for dictionary *N***f**

Inputs:

Initialize  *U* = [ ]  *r0 = y K***T** *= K W =* **(Ʒ ƷH)-1**  '

Do *i* = 1 to *K*

End Do Output of Do: *K***T**

There are two methods to handle the case where the actual number of sinusoids present is unknown, yet still smaller than *K*. The simpler method, applicable for high SNR (V small compared to the smallest signal amplitude), is to perform *K* iterations of the OMP/NLS algorithm, which will incur an additional noise folding penalty, by projecting the additional noise dimensions onto the solution. The second method is to stop when the residual can be explained by noise alone though hypothesis testing. At the solution, the weighted squared residual *r*Hk*W r*k will display a F-squared statistic with 2*k* degrees of freedom, where *k* is the actual number of sinusoids present in the signal. The hypothesis that the residual is caused by noise alone, is accepted when *r***kH***Wr***k <** V**2***T* for some threshold *T* and rejected otherwise. The value for *T* is dependent on a user selectable significance level, the probability of incorrectly rejecting the given hypothesis. For a significance level of D, *T* = CDF-1(1-D), where CDF is the cumulative distribution function of the chi-squared distribution with 2*k* degrees of freedom. We used D = 0.05 in our simulations, but D is an application-specific parameter.


A good example of the problems and possibilities implicated in using older archaeological collections for contemporary research is provided by the British Museum's Naukratis project. From 2011, the project set out to examine objects from this famous 'Greek' port city which had been spread across some seventy museums worldwide. The site was first identified by Flinders Petrie in 1884, and he led excavations there for the EEF the following year. It was subsequently investigated under the leadership of Alan Gardiner and then by David Hogarth for the British School at Athens. Thousands of small finds were recovered across these four seasons of British-led work. Amelia Edwards was one of the first to study recovered Naukratis material, and she wrote a paper in 1885, 'Terracottas of Naukratis', taking the opportunity to review the ensemble before individual artefacts were 'distributed among various museums, and, scattered far and wide'. 'Never again', she thought, would 'it be possible to compare them with one another, except in photographs or engravings'.85 The British Museum's ambitious undertaking proved her wrong by surveying the entire distribution of nearly 17,000 individual pieces and assembling an online catalogue bringing together objects and archives. By these means, the project team was able to develop new conclusions about the history of Naukratis, the people who lived there and what their relationships were with sites across Egypt and the Mediterranean.

The Naukratis project revealed the highly selective retention of certain categories of finds for museums, which had skewed the material profile of Naukratis and subsequent interpretations of it.86 While 17,000 artefacts may sound like a lot, records of the original excavations reference several hundred thousand more that remained on site. In particular, Alexandra Villing has noted that undecorated ceramics, though documented as plentiful, were generally not kept, studied or published, meaning that most of the once large corpus of Egyptian pottery from the site is lost. Equally absent in collections are household pottery and trade amphorae of all periods and types, with the exception of stamped amphora handles. In contrast, other classes of finds, such as Egyptian bronzes and amulets, and Ptolemaic and Roman terracotta figurines, are plentiful in many museum collections, but they have remained largely unpublished and therefore outside scholarly discourse. Critical reexamination of this material, together with fresh fieldwork, has provided a corrective to the previous picture of a 'Greek' town, leading to more nuanced insights into the dynamics of what was a multi-ethnic trading community. Tacking back and forth between old collections and new fieldwork has further value in these contexts: it can heighten awareness of recovery strategies, increase critical reflection on how current fieldwork, curation and documentation stands up to historical scrutiny, and allow alternative research questions to be formulated.

Many of these recontextualization projects are reliant upon archaeological archives – photographs, site plans, distribution lists and field notes – through which the discipline took shape. These types of collections have historically ranked low in hierarchies of museum objects, but they equally require curatorial management as distinctive but integral parts of a museum collection. The importance of archival research in animating legacy collections is highlighted by the recent discovery by Campbell Price, curator for Egypt and Sudan at the Manchester Museum, of an Eighteenth Dynasty statue of Senenmut, a famous courtier of Queen Hatshepsut, in that collection.87 The anonymous statue had arrived in 1907, and was originally dispatched to the north of England through the EEF division of finds from Deir el-Bahri. Establishing this fact, and where in the temple it had been recovered from, necessitated archival consultation, which when combined with a fresh review of the inscriptions on the battered base of the statue led to its identification as belonging to Senenmut. Born a commoner, Senenmut, rose to be the chief architect of Queen Hatshepsut's Deir el-Bahri complex, her confidant (some say lover), and tutor to her daughter Princess Neferure. Price's discovery is by no means the only recent example of the potential of archival research to yield surprises. Tony Leahy of the University of Birmingham has established that an EEF-excavated Abydos relief fragment in the collection of the National Museum of Scotland is the only known artefact from the tomb of a twenty-fifth dynasty Kushite prince.88

New scientific techniques, such as isotope analyses and the extraction of ancient DNA, vastly improved approaches in radiocarbon and related absolute dating methods, as well as novel developments in the imaging of objects, such as Reflectance Transformation Imaging (RTI),89 equally hold great promise for eliciting new information from old finds. As a consequence, it has been claimed that archaeology is experiencing a 'third science revolution', permitting the micro-archaeology of material investigations to be meshed with broader theorizing of macroarchaeological problems.90 Such a revolution, it has been said, could mean that 'old collections will suddenly take pole position as the primary source material in archaeology'.91 Given the difficulties of undertaking fieldwork in many parts of the world, this could well be true.

Despite the promise of these technological developments, however, they cannot be applied to museum collections indiscriminately. Many require destructive sampling of small portions of ancient artefacts, creating tensions between the commitment of museums to preserve, display and make accessible objects on the one hand, and the benefits to be gained from scientific investigations on the other. For Egyptian artefacts, in particular, there are additional factors to take into consideration. In many parts of the world a 'curation crisis' has been identified as a result of ongoing archaeological fieldwork, rescue operations and development interventions that have continued to generate archaeological assemblages, but which have not invested in long term plans for their care.92 This has created new pressures on the storage and accessibility of archaeologically procured material, raising questions about the future of collecting from the field. This is not the case for Egyptian material outside Egypt. These collections are unlikely to grow in the near future, nor, as argued above, do they need to. But because of this, they are a finite resource in great demand. Often it is museum objects that provide the only available samples for the application of cutting-edge techniques that are otherwise unavailable in Egypt.

Thankfully, the sample sizes required for many approaches are nowadays very small. For example, in the area of radiocarbon dating one of the most notable advances has been the introduction of Accelerator Mass Spectrometry (AMS), which converts samples to graphite prior to dating, allowing more precise readings from significantly smaller samples. To put that into perspective, a sample of human skin from Naqada excavated by Petrie's teams in 1894–5, tested in 1952, weighed 57 grams and was dated with a margin of error of 300 years;93 human skin from the same site examined with AMS in 201294 weighed less than 0.1 grams, and produced a date with a margin of error of 32 years. Furthermore, new modelling techniques using Bayesian statistics have allowed the construction of ever more precise chronologies, like that published by a team of scientists and archaeologists based at the University of Oxford in 2010.95 Through the acquisition of 211 dates from short-lived plant remains from museum collections (seeds, basketry, plant-based textiles, plant stems, fruits) the team was able to produce a robust absolute chronology for the Pharaonic Era.

The ability to obtain a date from small sample sizes is vital for exceptional objects, such as a tunic in the care of the Petrie Museum. The garment itself was only discovered in 1977 when a dirty bundle of linen that had been brought back from the 1911–12 BSAE season at Tarkhan was sent to the V&A for conservation. The pile of cloth had originally been located outside a large mudbrick tomb (a mastaba) dated to the First Dynasty, but because this was a plundered context, the garment's dating was uncertain. Moreover, on account of the textile's delicacy, only associated linen was able to be analysed in the 1980s, when AMS was in its infancy, and it was then thought to date to the late third millennium BC. In 2015, a single, two-centimetre piece of thread from the garment itself, weighing just 0.002 grammes, was analysed by the University of Oxford's radiocarbon unit. It confirmed not only the First Dynasty date, but also that the item was the world's oldest known piece of tailored clothing.96

Notwithstanding these advances, issues remain. Take, for instance, many types of pottery analysis in which only a centimetre or so of a ceramic is needed for thin sectioning. In contrast to many areas of world archaeology, museum collections rarely have large Egyptian sherd collections. Instead, intact vessels for display purposes are the norm, which are often unsuitable for destructive analysis. Those sherds that were exported were usually acquired because of a distinctive feature, be that a certain type of decoration, a potmark or a characteristic rim. While it is unlikely that single sherds can be reconnected with others, it is nevertheless also the case that joins can be identified. The Deutsches Archäeologisches Institut has been working at Abydos in the region excavated by Petrie's teams, and their archaeologists, such as Andreas Effland, have recovered pottery sherds that connect with fragments in museums recovered a century previously.97 Choosing an area of a pottery sherd to slice through without compromising the integrity of specimens and their contours is therefore not always straightforward, and needs to be subject to considered curatorial research and judgement. Other limitations are the result of unknown conservation treatments applied in earlier periods of museum practice. A recent effort to investigate the lipid content of Badarian era sherds held in the Petrie, for example, was thwarted when it was realized that most of the sherds contained high amounts of plasticizers, a compound called anthraquinone found in synthetic dyes and indicators of petroleum. Their modern museum lives had left an indelible signature rendering their ancient ones elusive for the time being.98

Similar issues surround sampling for the purposes of radiocarbon dating, although these can be mitigated. Nevertheless, the mechanism for modelling chronologies is dependent upon the 'certainty of association' between the object and the event it is aiming to date. An organic sample in a grave could be a later intrusion, and previous generations of fieldworkers rarely provided the kind of documentary resolution needed to determine its contemporaneity with associated objects. Ideally, controlled sampling in the field is needed for robust studies, but there are currently no AMS facilities in Egypt and no legal channels for the export of samples. Such a situation highlights the inherent structural inequalities of practice. There is a continuing disparity between the archaeologically rich nation of Egypt, on the one hand, and the wealthy international institutions through which disciplinary advancement is impelled, on the other. Studying objects outside Egypt's borders can constitute 'scientific colonialism' or 'vestigial colonialism'.99 Training, facilities, language barriers and costs all inhibit equal opportunities for Egyptians to partake in the generation of new knowledge about their country's heritage, while the distribution of research benefits most frequently favours Western scholars. Museum training for international partners has created useful bridges, although the 'best practices' established for European institutions are not necessarily directly transferrable to Egyptian contexts, while international projects can generate rivalries for opportunities and status that undermine the good intentions of sharing expertise. The realities of collaborative work, however, should not detract from efforts to empower disenfranchised groups or individuals. But it takes time, critical awareness, effective communication and ongoing reflection.

#### Old Collections, New Displays

More than a century of partage has ensured that Egyptian antiquities are today considered a staple part of the museum visiting experience, so much so that their tropes – mummies, death, elite culture – are frequently rendered more real than the reality the displays are supposedly meant to illustrate. In other words, these displays constitute a sort of hyperreality100 in which the Egypt that is encountered is conceptual, detached in time and space from the modern country.101 Egypt's self-contained and homogenized representation in the museum is, in part, a product of the disciplinary and social histories that have privileged Pharaonic Egypt (3000 BC–30 BC) above other pasts. It is also a product of deep-seated universalist claims on representing other cultures that disenfranchise counter-claims and complex realities. This has been especially apparent in audience research studies conducted in anticipation of new galleries, which have exposed the lack of public interest in alternative topics beyond very set ideas of what Egypt should look like.102 There have been concerted efforts in the last decade to counter the assumptions on which the popularity of Egyptian displays are based in a series of gallery refurbishment projects and innovative temporary displays. But, as has always been the case, balancing the range of demands on Egypt across intellectual, political and popular imaginations is challenging. Fortunately, that is what the twenty-first century museum platform can offer: a space for contested histories.

Given public expectations, many institutions with small collections may feel discouraged when reviewing the unassuming archaeological finds that comprise their holdings. Yet Egypt's rich history of reception presents extensive opportunities for lateral thinking that can provide engaging additions to the essential label components that describe an object and identify its ancient use. The concept of object biographies has been an especially productive one for the museum sector, facilitating the incorporation of multi-layered histories into online collections management systems that can map out their relational aspects, and museum displays that may be shaped from several perspectives.103 Combined with the 'narrative turn' in the social sciences, a stronger storytelling approach in museum exhibition design has been encouraged.104 Concomitant developments in curatorial thinking challenge subjective codes of connoisseurship that privilege exceptional pieces. The Toledo Art Museum, for example, has aligned itself more with the principles of the art market than with developing museum practice. The narrative turn enables museums to transcend the narrow confines of art history that assess objects purely on their aesthetic qualities, towards collecting, enabling and sharing meaning. Multi-disciplinary exhibitions are notably geared towards these ends by blending science and art to appeal to a broader range of interests.

This sort of museum work can be characterized as 'bricolage', a term used by Claude Lévi-Strauss and more recently applied to museology by Anwar Tlili.105 Bricolage, as formulated by Lévi-Strauss, constitutes a theory of production that does not privilege the author, artist or artisan, but instead embraces ad hoc combinations and recombinations that create meaning from a diverse range of sources. The bricoleur must navigate heterogeneous assemblages – 'whatever is at hand' – to construct new narratives, rather than generate material afresh. This is not tantamount to suggesting an unbridled bricolage, however, that would dislocate an object's history and cultural contexts. In any such undertaking, the present continues to weigh on dialogues with the past, and interventions are never neutral acts. Bricolage does, however, allow for new forms of re-assemblage, that are not necessarily predicated on fieldwork, but on a broader range of experimental creative acts that facilitate new understandings.106

The exhibition *Origins of the Afro Comb*, developed at the Fitzwilliam Museum in Cambridge in 2013 (Fig. 6.3), is an example of the way in which a simple type of ancient Egyptian object can resonate powerfully with modern times through the alliance of anthropological scholarship, contemporary design and community engagement. The exhibition opened with a striking juxtaposition: a prehistoric Egyptian bone comb decorated with a pair of bull's horns, excavated during Petrie's EEF 1900 mission at Abydos, set beside a black plastic Afro comb with the clenched fist symbol of the Black Power Movement, made in 1972. These alternative associations offered opportunities to explore themes of social identities and beliefs through the symbol of the comb.107 The project built upon previous experience of curating the 2011–12 exhibition, *Triumph, Protection and Dreams, East African Headrests in Context,* which looked

**Fig. 6.3** Poster advertising the 2013 'Afro-combs' exhibition. Reproduced with the kind permission of The Fitzwilliam Museum and the Museum of Archaeology and Anthropology, Cambridge.

at the function, design and development of headrests across cultural and chronological boundaries, including ancient Egypt. More direct still was the travelling *Digging for Dreams* exhibition, curated by Dominic Montserrat in 2000, that explicitly questioned stereotypes of ancient Egypt, foregrounded colonial histories and tackled issues of race and the ethics of human remains display. The agency of Egyptians themselves in the recovery of their past was recognized explicitly in the exhibition *Beyond Beauty: Transforming the Body in Ancient Egypt*, held at London's Two Temple Place in 2015.108

The strategies of these exhibitions uproot Egyptian artefacts from the genealogies that had allied them exclusively with Western modernity, and disrupt universalist claims of representation. Such displays, however, are only temporary interventions. More permanent, longer-term presentations of Egyptian finds are staged in the main galleries only infrequently. Anthropologically styled institutions, such as the Pitt Rivers Museum in Oxford, have long maintained eclectic displays of cross-cultural comparisons, often as much by accident as by design. Nevertheless, in contrast to popular assumptions, the displays of the Pitt Rivers Museum are not 'frozen in time', and the culture-evolutionary underpinnings of the Victorian era have not been retained. They have been replaced by an arrangement scheme that looks at how similar problems across the world's societies have been addressed in a multitude of ways. For galleries devoted exclusively to ancient Egypt, recent museological trends in documenting collecting histories have led to a diversification of the stories that are presented. Since 2008 there have been numerous Egyptian gallery redevelopment programmes in Britain: at the Ashmolean in Oxford (2011), Manchester Museum (2012), World Museum Liverpool (2017) and Edinburgh's National Museum (2019). Several of these renovated displays include introductory panels that acknowledge the activities of archaeologists like Flinders Petrie and curatorial interventions by Margaret Murray and Winifred Compton, albeit often still in one-dimensional heroic terms.

What of collections of Egyptian antiquities in Britain's former colonies? Are these mere relics of colonialism, or can they be deployed for fresh explorations of the present in ways that might be of local relevance? Post-colonial museum initiatives have rightly focused on the self-representation of indigenous stories, regional histories and local artefacts, but where does that leave collections that fall outside this remit? There has been very little cross-cultural dialogue about how collections of 'world culture' in the global south might find new significance. Expertise on the histories and ancient meanings of these objects resides primarily in the Western sphere, and even with the best intentions, how might top-down influences be mitigated given that economic circumstances often dictate and perpetuate unequal relationships? In these instances, future long-term dialogues might be established, encouraging the twoway exchange of ideas rather than the didactic provision of information. Through these means, it may be possible to find ways in which knowledge can benefit local professionals and empower them to develop locally meaningful narratives.

Take, for instance, the archaeological assemblage acquired through Flinders Petrie's BSAE, now in Cape Town in the Iziko Museum. The name 'Iziko' is a Xhosa term for 'centre of cultural activity' or 'hearth', and was adopted as a representation of the re-Africanization of the museum organization. The current dislocation of Egyptian material from this initiative could be addressed within the organization's remit, revealing and liberating Egyptian antiquities from colonial taxonomies. Nelson Mandela, in his 1994 *The Long Walk to Freedom,* himself fantasized about visiting Egypt, and this might be one departure point for future discourse. 'This was not amateur archaeological interest', he said, 'it is important for African nationalists to be armed with evidence to dispute the fictitious claims of whites that Africans are without a civilized past that compares with that of the West'.109 At the time of writing there are ongoing discussions about the future of this material and its display, with much at stake in the choice of what to exhibit. There are also opportunities for the Egyptian collection of the National Museum of Ghana, as its central building undergoes renovation throughout 2015 to 2019, with plans for a reinstallation of its objects.

In India, the last few years have seen an upturn in concern for Egyptian Antiquities. Staff of the Chhatrapatī Shivaji Mahārāj Vastu Saṅgrahālay (CSMVS) in Mumbai, in partnership with the British Museum, curated a show around the mummy in its collections: *Mummy– An Unsolved Mystery: Conserving Mumbai's Egyptian Treasures* from October 2016 to January 2017. The show built on interest generated by the British Museum's touring exhibition *Mummy – the inside story* that was hosted in the city a few years earlier. For CSMVS Museum Director, Sabyasachi Mukherjee, the temporary display of the mummy, together with 21 small Egyptian artefacts (shabtis, amulets and scarabs) was a significant opportunity to challenge the cultural hegemony of Western institutions:

World museums or museums of world culture are a concept mostly associated with the West. It is our endeavour to evolve as a 'world cultures' museum in the East. While we have been realising this motto through collaborative exhibitions with museums across the world, we now want to utilise our own small but significant collection of world artefacts to this effect.110

In these ways Egyptian heritage's prominent status as a touchstone for debates over cultural progress and authority has found new contexts in twenty-first century global discourses. And, as in the nineteenth century, these grand aspirations are frequently still predicated on only a handful of trinkets, trifles and oddments.

\*\*\*

Archaeology's popular reputation is of a profession through which discoveries are made. But it constitutes just one set of interventions in longer-term cycles of loss and recovery, assembly and re-assembly, that are socially embedded and historically produced. The old rejoinder, '*autres temps, autres moeurs'*, cannot be a rationale for claiming uncritical authority over Egypt's cultural heritage. Certainly, there are far greater sensitivities around collection histories than was the case a hundred years ago; a sale of genuine antiquities in museum shops as happened in the 1950s, for instance, would be unthinkable today. Nevertheless, demand for antiquities continues to have a destructive effect on sites in Egypt, just as was the case in the nineteenth century. The beguiling promise of obtaining Egyptian artefacts remains intense, but it is a desire that sits uneasily alongside what is frequently a more prosaic reality. Whether the objects are threadbare textiles or robust statues, the facts of their existence necessitate long-term care, curatorship and interpretation. These are opportunities as much as responsibilities.

#### Notes

### Conclusion

On reaching the third floor of the Liverpool World Museum visitors are confronted with a sign offering two choices: go left to the new Ancient Egypt gallery (opened in 2017), or turn right for the World Cultures gallery. This division neatly captures the exceptionalism that characterizes Egypt's place in world archaeology and in many museum displays globally. It is a product of a range of object habits cultivated over some two centuries. Beyond the geographies explored in the previous chapters, it is clear that emergent axes of wealth and influence are still today seeking cultural authority through an appeal to ancient Egypt. The power of Egyptian artefacts to symbolize early twenty-first century global modernity is evident in their prominence in newly established museums and exhibitions in the Gulf and in Asia. In the Louvre Abu Dhabi, opened in 2017 as 'the first universal museum in the Arab world', one of the primary gateway objects visitors encounter in the introductory Great Vestibule is a bronze figurine of the ancient Egyptian goddess Isis nursing Horus. Meanwhile in China, intense interest in ancient Egypt has been fostered through a flurry of international loans to Chinese museums.1 In both countries, these high profile acts of transculturation have been almost wholly shaped by foreign expertise, and it would be easy to assume that these are largely derivative exhibits, drawing on the tropes of mummies, monuments and royalty constructed in the West. Yet the idea of the object habit, as explored throughout this book, suggests that understanding these ongoing movements of antiquities still requires a sensitivity towards the conditions that enable and shape cultural mediations, and which influence the types of things chosen, the mechanisms of diplomacy, the styles of engagement with artefacts and attitudes to their reception. That these regions are also seeking new fieldwork opportunities in Egypt for themselves further underscores the need to consider how these representations translate into the ongoing construction of archaeological knowledge.

While much of this book has been concerned with the object habits of the past, this concept should not merely encourage museum histories of greater texture and insight. I would suggest that it might additionally facilitate the integration of those histories into contemporary debates, not just those relating to the antiquities trade, as was the focus of Chapter Six. As Murray and Spriggs have argued,2 histories of archaeology assist the formulation and assessment of present day theories, as well as provide insights into the functioning of disciplines. For Egyptology particularly, they offer the prospect of challenging the commonly held view that there exists an ordered set of practices constituting a stable discipline, predicated on the heroic achievements of a few individuals, and the establishment of secure, bounded intellectual tenets.3 Consideration of object habits can provide counter-narratives to such standard display or disciplinary accounts that have become canonical. Chapter One, for instance, addressed an axiomatic principle in archaeology: that small and everyday artefacts are valuable for archaeological inference if finds are well contextualized. This was not a self-evident principle, however, nor one that was simply recognized through an inspired intellectual feat by a man like Flinders Petrie. Establishing archaeological value was a longer-term, historically situated project, an ontological issue as to the status of objects in the politics of collections that was neither essential nor stable, but repeatedly constructed and deconstructed. And because of this, categories continue to be questioned and remain relative. Therefore, while Chapters One to Four charted some of the variegated motivations for collecting 'trinkets', 'trifles' or 'oddments', Chapters Five and Six revealed the shifts in attitudes to those same categories of 'minor antiquities' that were now likely to be disposed of for the very reason that they were, under particular circumstances, deemed to be of 'minor' importance. In the case of material sent to the United States, Chapter Two's discussion of the development of a distinctive fine art museum ethos is instructive today for the increased likelihood of disposing of archaeological finds in the USA, where judgements often continue to be made on art-historical and aesthetics grounds, rather than contextual ones. Egyptian antiquities also clearly still act as significant boundary objects in transnational acts of soft diplomacy and national interest, such as those explored in Chapter Three. The aforementioned Gulf and Chinese attentions are a case in point. For contemporary heritage discourses, the post-Second World War shift in attitudes to foreign objects discussed in Chapter Five has never been more relevant. At the time of writing, in Britain, economic austerity and the decision to leave the European Union (Brexit) are once again fostering more parochial attitudes to transnational acquisitions like those last seen in the 1950s, exerting new pressures on the integrity of museum collections acquired in previous centuries. The widely condemned sale of the ancient Egyptian statue of Sekhemkha in 2014 by Northampton Borough Council from the local museum is just one example. The borough's councillors claimed that the object was irrelevant to local communities. Social histories that demonstrate how entangled Egyptian things are with such towns would argue otherwise, and contingent ethics would foreground the international implications of the inward-looking concerns of British local government.4

These sorts of multi-sited histories connect the field and the museum, meaning that contemporary actions in one space can have consequences for another. Ongoing antiquities looting, conflict and environmental degradation all directly impact field sites around the world, placing greater responsibility on the stewards of collections from those places to reveal the multi-layered histories behind things, connecting past, present and future through the prism of current attitudes. How objects are treated in and by museums affects in turn how objects are valued in other arenas, such as the art market, which itself exerts a pressure on field sites. If, as argued in Chapter Six, ethics are a matter of contingent practice, then these historical currents require future reckoning. More importantly, such appraisals need to be accountable and transparent to a broader range of stakeholders than has previously been the case, something which might be achieved by integrating critical voices and more probing questions about museum displays and disciplinary dialogues. The resources for doing such work are rich, especially if it is remembered that the material subject to dispersal was not simply ancient finds, but, as discussed in several chapters, was part of a larger mixed assemblage of documents, photographs and reproductions that travelled with and among them. Often ranking low in hierarchies of museum collections, these other forms of material culture need not operate simply to authenticate and authorize antiquities, but can work to construct or challenge received wisdom. They are worthy of attention in their own right. Reading 'against the archival grain'5 can allow for a reassessment of the broader agencies behind collections and the vital roles (be they physical or intellectual) played by 'invisible technicians', like those discussed in Chapter Four, such as Egyptians, copyists or women. Encouragingly, important new discoveries are being made in Egypt. This includes the Abydos Temple Paper Archive project,6 which offers the promise of new insights from Egyptian perspectives and which can provide a more nuanced commentary on foreign archaeological activities, their treatment of finds, and local involvement in international processes.

Museums outside Egypt can no longer procure artefacts from the field for their collections. Consequently, most of their holdings represent the archaeological products of particular historical moments, principally the nineteenth and early twentieth centuries when excavation was empowered by modernist, imperialist and colonial agendas. A century on it is imperative that there is reflection on the extent to which these continue to frame Egypt's archaeology, and what sorts of object habits they provoke. Inertia too easily envelops museums, either confining material to static, hyperreal epochs branded as 'ancient Egyptian' or else cushioning it within nostalgia for a so-called 'golden age of discovery'. For twenty-first century museums, the challenge is to re-animate Egyptian heritage within fresh narratives that draw from and make transparent a broader range of histories. And given how scattered finds from Egypt are, there is the opportunity to do so within an extraordinary range of spaces and communities worldwide. Yet if there is anything that the examination of these histories reveals, it is that whichever stories are selected, they are likely to provide just as much insight into more recent and contemporary worlds as they are into any ancient reality.

#### Notes

### Appendix A: Legislation relating to the excavation and export of Egyptian antiquities

The above is a summary of the parts of legislation most relevant to the excavation and distribution of finds.1

### Appendix B: Ancient Egyptian chronology

#### Notes

1 For further information see: Ikram, S. 2011. Collecting and repatriating Egypt's past: toward a new nationalism. In H. Silverman (ed.), *Contested Cultural Heritage. Religion, Nationalism, Erasure, and Exclusion in a Global World*. New York: Springer, 141–54; Khater, A. 1960. *Le regime juridique des fouilles et des antiquités en Égypt*. Cairo: Institut Français d'Archéologie Orientale.

### Bibliography

#### *Abbreviations*

Petrie. In Lazar, I. (ed.) *Egypt and Austria VIII: Meeting point Egypt*. Koper: Univerza na Primorskem, pp. 17–31.

#### Index

Abbott, Henry 72 Aboriginal material culture 124 abstract art 196 Abu Dhabi 253–4 Abu Simbel 200 Abydos 8, 11–14, 19–20, 47–8, 52, 58–61, 84, 92–6, 123, 135–6, 153, 173, 184, 186, 191, 224, 239–43, 255 accelerator mass spectrometry (AMS) 240–1 Actor-Network-Theory (ANT) 3 Adams, Barbara 20 Adams, W.Y. 201 aesthetics 171 Akhenaten 148–9, 153, 169–70 Alberti, Sam 56 Aldred, Cyril 196 Alexandria Graeco-Roman Museum 107 Ali, Muhammed, Khedive of Egypt 219 Allan, Douglas A. 185–6 Alma-Tadema, Lawrence 49 Amarna 146–9, 154–66, 170, 186, 190, 192, 194, 198, 204, 227 America and Britain, circulation of finds between 14, 93, 254 American influence on Egyptian archaeology 91 American museums 69–100, 172, 188–91, 196 ancient texts 11, 32, 108–11 Anglo-American relations 79 Anquandah, James 210 Anthropological Institute of Great Britain and Ireland 42 anthropology 41, 86, 95, 109, 122–3, 200–1 antiquities: assemblages broken up 13–14; legal accountability for 16; *major* and *minor* 36, 38–9, 88, 120, 229, 254; restrictions on export from Egypt of 11, 18, 33–4, 145–6, 151, 171, 175, 221–3; undocumented 226 *Antiquity* (journal) 173–4 Antiquus Mysticus Ordo Rosae Crucis (AMORC) 169–70 Appadurai, Arjun 3 Appiah, Kwame 231 archaeological practices 200, 232 archaeological principles 254 archaeological profession 147, 247 archaeological societies 8 archaeology: as a discipline 32, 37, 137, 199; public reception of 173; status in Britain and in France 29

archival research 14–16, 238–9 Armistead, Emily 119 art market 154, 223–8, 243, 255 artefacts, archaeological: allure of 210; attitudes to 183; central to one's view of the past 111; driving enterprise 7; exclusive focus on 109, 219; research based on 44; shaping of attitudes to 106; status of 201–2, 217; used in education 53; *see also* antiquities 'arts and crafts' movement 40, 49 Ashmolean Museum 48, 159, 169, 197 Astor, John Jacob 157 Aswan Dam 199, 209 auction houses 226–7 audience research by museums 242 Australia 124–5, 138, 150–4 Ayrton, Edward 91

*baksheesh* 19 Baltimore 93 Bankfield Museum 43, 186 Baring, Sir Evelyn 35, 124, 129 Barlow, Annie 57 Bayesian statistics 240 Bell, Larry 198 Belzoni, Giovanni 30 Benjamin, Walter 168, 202 Bennett, Tony 39, 49 the Bible, authority and truth of 52 biblical remains 78 Bicknell, Clarence 112 Bildt, Harald 175 Birch, Samuel 33 Birmingham 40, 183, 186 Bismarck, Otto von 108 black market in artefacts 226 Blackden, Marcus W. 52 Bloomsbury district 202 Boas, Franz 200–1 Bolton 40, 168 Bolton, Herbert 150 bomb damage 181–3 Bombay 130 Borchardt, Ludwig 107 Bordighera 112–13 Boston Museum of Fine Arts (MFA) 20, 36, 70– 2, 75–8, 87, 90, 93–4, 166, 187, 222, 231 Botti, Giuseppe 107 'boundary objects' 106

Bradbury, Kate 82 Bragg, Laura (and 'Bragg boxes') 87–8 Braun, Edmund Wilhelm 116 Breasted, James Henry 83–5, 89, 91, 99, 110 Breccia, Evaristo 107 Brexit 254 'bricolage' 218, 243 Bristol 38, 181, 186 British Academy 199 British Association for the Advancement of Science (BAAS) 120–2 British influence in Egypt 6–7, 29, 128–9, 137, 147, 198 British Museum 28–38, 44–5, 48, 52, 57, 72, 99, 132, 154–5, 158–9, 166–9, 174, 220, 222, 231–5; Department of Egypt and Sudan 234; Naukratis project 237–8 British School of Archaeology in Egypt (BSAE) 11, 45–6, 57, 78, 87, 92–3, 112–14, 118, 123, 131, 135, 161, 173–5, 184, 193, 195, 223–4, 228, 232, 246 Brocklehurst, Marianne 41, 57 Brodie, Neil 116 Brooklyn Museum 17–18, 89–90, 187–91 Broome, Myrtle 169 Broughton Beck School 54 Brown, Percy 130 Brown University 191 Browning, Robert 10 Brugsch, Heinrich 73, 107 Brunton, Guy and Winifred 118, 173–4 Bubastis 26, 108, 218 Buchanan, May 61–2, 185 Buckinghamshire Museum 61, 223 Buckman, Marie 83, 93, 96–7, 150, 163, 165, 169, 173 Bulaq Museum 33–4 Burkitt, Miles 173

Cairo Declaration on the Protection of Cultural Property (2004) 222 Cairo Museum 227 Canada 119–24 Carnarvon, Lord 10, 90, 145–6, 152 Carruthers, William 198–9 Cartailhac, Emile 105 Carter, Howard 130, 145 casts, use of 166–71 Caton-Thompson, Gertrude 173–4 Cedar Rapids Masonic Lodge 93–4 Centre d'Étude et de Documentation sur l'Ancienne Égypte (CEDAE) 199 Cesnola, Luigi 77 Challis, Debbie 54 Charleston Museum 87–8 Charterhouse School 224, 229

Chautauqua Assembly 75, 190–1, 224 Chhatrapatī Shivaji Mahārāj Vastu Sańrahālay (CSMVS) 130–1, 246 Chicago 77, 83–4, 89, 91, 169; Columbian Exposition (1893) 73–4 Childe, Gordon 173–4 China 253–4 Christianity 52–3 Chubb, Mary 165–6, 169–70 circulation of antiquities 14, 93, 254 Cleopatra's Needle, New York 74, 78, 94 Cleveland Museum of Art 171 Cobbe, Frances Power 58 codes of ethics 225–8 Colla, Elliot 5, 82, 230 Colombian National Museum, Bogota 18 colonialism 82, 107, 175, 245 Colorado College 191 commercial sales of artefacts 223–5, 229 Compton, Winifred 245 Conn, Stephen 76, 86–9, 196 conservation 158 contemporary art 234–6 *contexere* 61 context and contextualization 226, 254 Conze, Alexander 111 Cook, Clarence 49 Cook, Thomas (company) 6–7, 42, 223 Cooke, Ashley 183 Copenhagen 114 Coxe, Eckley B. Jr. 87, 91 Croly, Jane Cunningham 82 Crompton, Winifred 56, 162, 170 Crowley, Aleister 52 cultural shifts 201–2 Cuno, James 230–1 'curation crisis' 239 Currelly, Charles Trick 123–4

Dall, Caroline Healey 81 Danquah, Joseph B. 207 Darwin, Charles (and Darwinism) 120–3 Davidian people 128 Davies, Norman de Garis 124–5, 208 Davis, Theodore 90–1 Dawson, John William 120–3 'deaccessioning' 188 'decluttering' museums and homes 202 De Forest, Robert W. 172, 188 Deir el-Bahri 54, 108, 123, 130, 133, 155, 157, 239 Dennis, James Tackle 93 department stores 49, 172, 202 Derrida, Jacques 14–16 destructive sampling 239 Detroit 77 Dickens, Charles 82

digs, organisation of 17, 97 Diop, Cheikh Anta 208 dioramas 196–7, 205 dispersal of artefacts from Egypt 7–20, 27, 35, 38, 47–8, 55, 82, 105–8, 150, 183, 217–19, 223–4, 229 disposal of artefacts by museums 183–9 division parties 13 documentation in museums 195 Dominion Museum, Wellington 127 Donati, Vitaliano 107 Doyle, Arthur Conan 50 Doyon, Wendy 97 Droop, John 219 Drovetti, Bernardino 107 Drower, Margaret 223 Duncan, Garrow 17, 53, 223 Dunham, Dows 187 'duplicate' artefacts from digs 33–4, 48, 185, 187, 223 eBay 224–5 Eckenstein, Lina 52, 58 Eckenstein, Oskar 52 Edinburgh 185, 196, 231 Edwards, Amelia 10, 25, 29, 36–8, 50–3, 57–8, 70–1, 238; lectures in America 79–82, 89; opinion of modern-day Egyptians 82–3 Edwards, Elizabeth 97 Edwards, I.E.S. 187, 198 Effland, Andreas 241 Egypt: image of 52; interest in 41–5; infrastructure 6 Egypt Exploration Fund (EEF) 1, 8–11, 14, 19, 27–31, 35–42, 45, 48, 52–8, 69–84, 89–99, 108, 110, 118–21, 1 25–7, 130, 133–4, 148, 155, 183, 195, 218, 223, 237; American branch of 76, 83, 90, 96–7; local honorary secretaries 105 Egypt Exploration Society (EES) 10, 16, 38, 119, 123–4, 146–75, 186, 198–200, 205, 222, 224; American branch of 190; Graeco-Roman branch of 191 Egypt Research Account (ERA) 11, 57, 83–4 Egyptian Antiquities Service 29, 107, 166, 175, 219 Egyptians: collaborating in generation of new knowledge 241–2; foremen 97; workmen 18–20, 112, 146–7 Egyptology 6, 32, 41, 58, 62, 108–12, 135, 137, 201, 254; local societies for 203;

public interest in 184–5 El Gawad, Heba Abd 18 Ellsworth, W.W. 217–19

Elshahed, Mohamed 234 Emery, Walter B. 200 Epstein, Jacob 154–5 Erman, Adolf 84, 105, 109–10 ethics *see* codes of ethics eugenics 54 Evans, Sir Arthur 159 Evans, Christopher 55 Evans, Sir John 32, 100, 224 exhibition design 243–5 experimental archaeology 232

Faenza Museo Internazionale delle Ceramiche 112, 183 Fairman, H.W. 166, 194 Falmouth Museum 192, 232 Fannin, Kate 117 feminism 4, 86–7 field logging methods 92 field notes 18, 163, 200 fieldwork practices 33, 35, 200–1 First World War 94, 98–100 Firth, Cecil 146 Fitzwilliam Museum 243–4 Fletcher, William Roby 124 Fonck, Leopold 112 Foucault, Michel 39, 56 France 107–8 freemasonry 93–4 futurism 203

Galton, Francis 54 Gange, David 6, 52 Ganguli, Babu Ganga Dhar 130 Gardiner, Alan 110, 145–6, 237 Garrod, Dorothy 173 Garstang, John 11–13, 54, 91, 117–18, 130, 194–5, 223 Garstang Museum 16, 194 Geismar, Haidy 236 Geldart, Alice 185 Germany 107–11, 138 Gertzen, Thomas 110 Ghana 207–10, 246 Glanville, Stephen 219 Glasgow 61–2, 181 Gliddon, George 72, 219 global financial crisis 227–8 globalization 138 'golden age' of archaeology 174–5 Goode, G.B. 230 Gorringe, Henry H. 94 Gowland, William 133 Grace, William Russell 74 Great Exhibition (1851) 39 Green, Frederick 91 Grenfell, Bernard P. 10–11, 17

Grenfell, Francis 99, 119, 124 'grey trade' in artefacts 226–7 Gunn, Battiscombe 52 Gustaf VI Adolf, King of Sweden 175

Hafez, Khaled 234 Haffenreffer Museum 191 Haggard, H. Rider 14–15, 50, 55 *hakubutsukan* 132 Hall, Henry 136, 191–2 Hall, Kate Marion 191 Hamada, Kōsaku 133–7 Hamilakis, Yannis 228 Hamilton, Augustus 127 Hamitic hypothesis 208 Hancock Museum, Newcastle 168 Hansard, Freda 58, 61 Harden, Donald H. 187 Harlem Renaissance 155 Harris, Neil 172 Hawass, Zahi 222, 229 Haweis, Mary 49 Haworth, Jesse 11, 56 Hay, Robert 72 Heal's department store 202 Hearst, Phoebe 83, 90–2 Henare, Amiria 44 Henning, Michelle 5 Higgins Museum, Bedford 192 Hill, Kate 37, 57 Hogarth, David 237 Holman, William A.151 Hope, Charles 57 Horniman Museum 192 Hoving, Thomas 188, 221 Howe, Julia Ward 81 Hoyle, William E. 46 Hull Museum 181 Hunt, Arthur 10–11 Hutchinson, Sir Jonathan 54 Huxley, Thomas 10 hyperreality in museum displays 242

*Ideal Home* magazine 202 *Illustrated London News* 153–4 imperialism 132, 136 India 246 India Museum 128–9 'industrial art' 40, 202 'initial art' 114 Institut Français d'Archaéologie Orientale (IFAO) 107 International Museums Office 167 internet market in artefacts 224–5 interpretation of finds 164, 186, 232 Ipswich Museum 195 Italy 107, 111–12

Iziko Museums 246 Iziko Slave Lodge 117–18

Jacobsen, Carl 113–14 Japan 107, 131–8; 'Japanese Exhibition' (London, 1910) 134 Jermyn Street Museum 46 jewellery 98–9 Johnson, Diane 232 Jonas, Mary 153, 162–71 Jones, Sir William 128 *Journal of Egyptian Archaeology* 97–8, 173

Katsumi, Kuroita 136 Kelvingrove Museum, Glasgow 181 Kemp, Barry 194 Kennard, Henry Martyn 11, 56, 105 Kenyon, Frederic 100 Kintore, Earl of 125 Kipling, John Lockwood 130 Kipling, Rudyard 75–6, 130 Kircher, Athanasius 111 Kitchin, J.G. 53 Kohere, Reweti 126 Kopytoff, Igor 3 Korea 136 *Kulturgeschicte* model 46, 78, 200 Kyoto University 131–7

Lacau, Pierre 145–6 Lahore Museum 130 Lambert, George 127 Lange, Julius 114 Lanzone, Rodolfo Vittorio 112 Larson, Frances 194 Latour, Bruno 3, 169 Lawes, Henrietta 58, 61 Lawrence, Arnold W. 207–8 Lawrence, T.E. 17 Layard, Sir Austen Henry 10, 29 Leahy, Tony 239 Le Corbusier 202 Leeds Museum 181 legacy collections 237–9 Leicester 228 Lepsius, Richard 107 Lévi-Strauss, Claude 243 Levy, Joseph M. 155 Lewis, Spencer 169–70 Lieblein, Jens Daniel Carolus 113 Livermore, Mary A. 81 Liverpool Museum 14–15, 38–9, 61, 168–9, 181–6, 194, 253 Livingstone, David 44, 122 local institutions 55; *see also* museums, local and regional Lockyer, Angus 135

'London Season', the 35 looting 227–8 the Louvre, Abu Dhabi 253 the Louvre, Paris 108 Love, A. 169 Lucas, Alfred 158 Lucknow Museum 130 Lutfi, Huda 234 Luxor 28 Lyons, Henry 168, 204–5 Lythgoe, Albert 90, 99

McAlister, Melani 221 McCarthy, Kathleen 88 Macclesfield 41, 57 Mace, Arthur 91 McGill University, Montreal 119–23 McIntosh, Hugh 150–3 MacKenzie, John 5, 129 McLean Museum and Art Gallery, Greenock 56, 186 McLeod, Malcolm 210 McManus Museum and Art Gallery, Dundee 17, 41 Macmillan, Harold 202 Malinowski, Bronislaw 200 Manchester 41, 56, 162, 169, 186, 231 Mandela, Nelson 246 Māori culture 126–7, 138 *Mareotis* (steamship) 25 Mariette, Auguste 6, 42 Markham Report (1938) 172, 174, 186, 195 marking of artefacts 60 Maspero, Gaston 10, 29–35 material culture 50, 124, 127, 255 mementoes acquired by participants in digs 16 metal detecting 220 Metropolitan Museum of Art, New York 76–8, 83–7, 90, 92, 98–9, 167, 171–4, 188–9, 224, 231 Meyerowitz, Eva 207 Midgely, Thomas 169 Miers Report (1928) 172, 174, 186, 195 military operations 25, 30, 198 Minneapolis Institute of Fine Arts 196–8 Mitchell-Furness coterie 85 modern art 196–8 modernism 154–5, 175, 202–3 Mond, Robert 124 Montserrat, Dominic 55, 153, 244–5 Moody, Ronald 155 Moore, Henry 154–5 Moore, Marianne 154 Morgan, Henri de 90 Morris, William 40 Morse, Edward 133 Mortimer, Dunstan 196

Moser, Stephanie 5–6, 28, 147 Mukherjee, Sabyasachi 246 Mullens, Josiah 125 multi-sited projects 2 mummies 11, 16, 34, 42, 72, 89, 114–18, 246 mummy portraits 44, 54, 115 municipal museums 37–40, 43 Murray, Margaret 52, 58, 61–2, 245 Murray, Tim 55, 254 'museum effect' 170 Museum of Modern Art (MoMA), New York 196 museum practices 184, 186, 195–8, 206 museum profession 195 'museum taphonomy' 190 museums: absence of modern Egypt from 233–4; Asian 129–32; colonial 107, 116–17, 120, 138; control of 28, 116, 129; of fine art 70, 168, 254; intellectual prestige of 172–3; local and regional 37–9, 42, 56–7, 126, 138; loss of 190–4; measuring the worth of 236; modernization of 186; professionalism in 28; public enthusiasm for visits to 54, 220; public image of 172; public trust in 227; role of 5, 235–7, 242, 256 Museums Association 202, 227

Naguib, Amgad 234 al-Nahhas, Mostafa 199 Naqada 105, 110, 113 Nasser, Gamal Abdel 209 National Gallery, London 64 nationalism: American 85; Egyptian 9, 145, 171; Japanese 132–6; methodological 106 Natural History Museum 16 Naville, Édouard 30–5, 39, 52–3, 108, 123, 157, 191 Nefertiti 148–9, 153, 155, 229 New Walk Museum, Leicester 228 New Zealand 125–8, 138 Newberry, Percy 91, 205 Newton, Charles 35 Newton, Francis G. 150 Nichols, Catherine 48 Nicholson, Sir Charles 125 Nicholson Museum, Sydney 125 Nile steamers 6 Nkrumah, Kwame 207–9 Nora, Pierre 204 Northampton Borough Council 254–5 Northbrook, Lord 129 Norwich Castle Museum 156, 186 Nunoo, Richard 207

'object biographies' concept 242–3 'object habits' 2–5, 9, 28, 49, 55, 74, 106, 108, 114, 120, 168, 218, 236, 253–4

object-led knowledge 92 object lessons 53–4 Offord, J. 36 Okajima, Seitaro 137 Opava Museum 116 Orientalism 230 Orme, Beatrice 58, 60 'orphaned' collections 183–4, 194–5 Osman, Aly 96–7 Otago Museum 128

Packard, Alpheus Spring Jr. 191 Paisley Museum 156 'partage' arrangements 7–9, 14, 16, 18, 27, 77, 88, 107, 112, 145, 147, 175, 199, 217–23, 229, 231, 242; returning to 230–2, 236 Pasadena 190, 198 Paterson, Emily 50, 134, 162–3, 188 Peabody Essex Museum, Salem 72 Peet, Eric 201 Peet, Thomas E. 173 Pendlebury, John 165 Pennsylvania 77–8, 85, 90–1 Pepper, William 85–6 Pestalozzi, J.H. 53–4 Petrie, Flinders 1–2, 11, 17–20, 27–8, 31–40, 44–6, 49, 52–60, 73–4, 78–9, 83–91, 98–9, 105, 109–18, 122–3, 128–9, 133–7, 146, 157, 159, 174, 183–4, 187, 190–3, 200–5, 223, 245–6, 254 Petrie, Hilda 11–12, 17, 52, 58–62, 116, 184, 223 Petrie Museum 16, 58, 169, 194, 202, 231–2, 240–1 Philadelphia 86–9; Centennial Exhibition (1876) 73 Philips, Ellen 57 philology 108–11 photographs, use of 163 Picasso, Pablo 154 Pitt-Rivers, A.H. Lane Fox 32, 41–2, 158 Pitt Rivers Museum, Oxford 3, 46, 48, 122, 203–4, 245 Poole, Reginald Stuart 10, 34 Pope, Rachel 203 popularization 147 postage stamps 209 Poynter, Edward 49 preservation of delicate and fragmentary objects 158 Price, Campbell 239 Price, Hugh 17 Prichard, Matthew 96, 166–7 Princess Henry of Battenberg 14 *pro rata* dispersal system 16 Protestantism 53 provenance 187, 226

psychometry 51–2 public schools 54 Quibell, James and Kate 17, 91 Quirke, Stephen 13 Qurna burial group 45 radiocarbon dating 239–41 Ramesses II 70–1 Ransom, Caroline 83–5, 90, 92, 110, 225 Rawnsley, Hardwicke 52 Read, Herbert 202 Reading 61, 186–7 Ready, Augustus P. 158 Ready, William Talbot 158 Redpath Museum 119–23, 138 reflectance transformation imaging 239 Reid, Donald 18 Reisner, George 90–2, 99, 110 'relational museum' model 3 relic culture 51, 55 repatriation claims 229 replica objects 166 reproductions 165–71 restoration 157–62; styles of 160 Rhode Island School of Design 93 Rhodes, Cecil 117 Riggs, Christina 18 Riley, N.T. 32 Roberts, David 30 Robinson, Edward 167 Robson, Eleanor 154 Rochdale 57 Rochester Theological Seminary 75 Rockefeller, John D. 91 Roosevelt, Theodore 69 Rorimer, James 188 Rosetta Stone 229 Roussel, Raphael 196 Rowe, Louis Earle 93 Royal Anthropological Society 174 Royal Archaeological Institute 32, 35 Royal Asiatic Society 130 Royal College of Surgeons 181 Royal Commission on National Museums and Galleries (1928) 167 Royal Ontario Museum (ROM) 123 Rudolf, Cyprian 118 Ruskin, John 40

Saffron Walden Museum 234 St Louis Museum 229 'saloon' style displays 196 San Diego Museum 156 San el-Hagar *see* Tanis Saqqara 198 Sayaji Rao III 129

Sayce, Archibald 134–6 Scandinavia 113, 175 Scheurleer, C.W. Lunsingh 193 Schiaparelli, Ernesto 107 Schliemann, Heinrich 10, 29 Schmidt, Valdemar 114 Schmitz, Jon 190–1 Science Museum, London 168, 204–5 'scientific colonialism' 241 'scientific racism' 208 Scott, John 56 Scripps, Ellen Browning 156 Seddon, Richard 126 seizing of finds 150 Senenmut 239 Service des Antiquités de l'Égypte *see Egyptian Antiquities Service* Sethe, Kurt 109–10 Seymour, Beauchamp 29 *shabtis* 14–15, 54, 83, 184, 223 Shapin, Steven 146–7, 157 Shaw, Charles Thursten 207 Shelton, Anthony 5 Sheppard, Kate 61 Sheppard, Kathleen 85 Sheppard, Thomas 181 sherds of pottery 240–1 Shinnie, Peter 209 Shropshire Museum 186 Simon, Norton 198 Sinker, Caroline 87 Sithathoryunet, Princess 98 Skinner, H.D. 128 Smith, Cecil 46 Somerville College, Oxford 81 Sorosis Club 82 South Africa 117–19, 138 South Kensington Museum 41, 45–6, 78, 89, 99, 132, 166 Spiegelberg, Wilhelm 110 Spriggs, M. 254 Spurrell, Flaxman 113 Staley, David 203 Stead, William T. 52 Steindorff, Georg 110 Stepney Borough Council 192–3 Stevenson, Sara Yorke 83–6 Stockholm 175 Stoker, Bram 50 Stona, Maria 116 Suefi, Ali 18 Suez Canal 6, 198–9 suffrage movement 57–62, 81–2 Sunday School movement 53 Sunday School Teachers' Institute 192–3 Swain, H. 3 Swenson, Astrid 136

#### Sydney 125

Taj-Eddin, Zahed 235 *Tale of Sinuhe* 231 Tanis 31, 36, 38, 40, 125, 181 technological developments affecting museums 239–40 Tell el-Amarna *see* Amarna Tell el-Maskhuta 30, 53 temporary exhibitions 35–6, 114, 200 Tewfik, Muhammed 30 theosophy 52 Thompson, Jason 6 Thomsen, Christian Jürgensen 113 Tlili, Anwar 243 Toledo Museum of Art 225, 243 'tomb cards' 92–3 tools, discovery of 42 Toronto 123–4 trafficking in antiquities 228 transnational analyses 106 Tsuboi, Shōgorō 133 Tufnell, Olga 11 Tully, Gemma 234 Turin Egyptian Museum 107 Tutankhamun, tomb of 9, 145–53, 158, 175, 220–1 Tuthmose III 169 'Tutmania' 175 Twain, Mark 69 Tylor, Edward 44, 120

United Nations Educational, Scientific and Cultural Organization (UNESCO) 195, 199–200, 209; 1970 Declaration on Cultural Property 220, 225, 228 'Universal Museum' declaration (2002) 217–18, 222, 226 universities, role of 172 University College London (UCL) 11, 13–14, 54, 58, 61, 99, 134, 183–4, 202 'Urabi, Ahmad 6 Urlin, Amy 59–62 *ushabtis see shabtis*

Valley of the Kings 145, 148, 151 Vermillion Accord on Human Remains (1989) 230–1 Verne, Jules 203 Victorian culture and the Victorian era 7–8, 40, 48–50, 55, 62, 202, 245 Villing, Alexandra 238

Wainwright, Gerald A. 94–7 Waite, Fred 128 Wallis, Henry 49 Ward, John 224

Ward, Joseph 126 Warhol, Andy 198 Warner, Charles Dudley 69, 77 Warrington Museum 39 Washington Monument 72–3 Wellcome, Sir Henry 193–4 Wellesley College 190 Wellington (New Zealand) 127 Wells, H.G. 203 West Park Museum, Macclesfield 57 Wheeler, Mortimer 173, 201 White, Henry 79 Whitechapel Museum 191 Whitehead, Christopher 44 Whitman, Walt 72 Whittemore, Thomas 94–6, 225 Wiedemann, Alfred 110 Wilkinson, Gardner 41 Willet, Henry 40–1 Willis, Martin 55 Wilmarth, Mary 84 Wilson, Sir Erasmus 10, 31 Wingfield, Chris 3, 201 Winlock, Herbert 171, 174

Winslow, William Copley 70–1, 74–7, 90 Wintle, Clare 206 Witcomb, Andrea 5 women in the home 203 women's contribution to archaeology and museum practice 3–4, 28, 57–61, 83, 88, 109, 203 women's movements 69–70 women's rights 57, 81; *see also* suffrage movement women's status and role 58, 62 World Archaeological Congress 230–1 world culture, collections of 245 world fairs 39 Worringer, Wilhelm 78 Worsaae, Jens 42, 113 Wright, G.E. 175

Yates, Donna 228 Young, William H. 159–62, 169 'Young Turks' 173

Zaghoul, Saad 145 Zionism 75

Alice Stevenson '*Scattered Finds* is a remarkable achievement. In charting how British excavations in Egypt dispersed artefacts around the globe, at an unprecedented scale, Alice Stevenson shows us how ancient objects created knowledge about the past while firmly anchored in the present. No one who reads this timely book will be able to look at an Egyptian antiquity in the same way again.' ‒Professor Christina Riggs, UEA

Between the 1880s and 1980s, British excavations at locations across Egypt resulted in the discovery of hundreds of thousands of ancient objects that were subsequently sent to some 350 institutions worldwide. These finds included unique discoveries at iconic sites such as the tombs of ancient Egypt's first rulers at Abydos, Akhenaten and Nefertiti's city of Tell el-Amarna and rich Roman Era burials in the Fayum.

*Scattered Finds* explores the politics, personalities and social histories that linked fieldwork in Egypt with the varied organizations around the world that received finds. Case studies range from Victorian municipal museums and women's suffrage campaigns in the UK, to the development of some of the USA's largest institutions, and from university museums in Japan to new institutions in post-independence Ghana. By juxtaposing a diversity of sites for the reception of Egyptian cultural heritage over the period of a century, Alice Stevenson presents new ideas about the development of archaeology, museums and the construction of Egyptian heritage. She also addresses the legacy of these practices, raises questions about the nature of the authority over such heritage today, and argues for a stronger ethical commitment to its stewardship.

Alice Stevenson is Associate Professor of Museum Studies at UCL's Institute of Archaeology. She has previously held posts as the Curator of the Petrie Museum of Egyptian Archaeology and as Researcher in World Archaeology at the Pitt Rivers Museum. Her academic specialization is Predynastic and Early Dynastic Egyptian archaeology, but she has a written on a broad range of topics including the history of archaeology, anthropology and museums.

**Cover image:** Courtesy of the Petrie Museum of Egyptian Archaeology, UCL.

> **Cover design:** www.ironicitalics.com

Scattered

Archaeology, Egyptology

Finds

Scattered Finds

Alice Stevenson

and Museums


**Stratigraphic Unconformities: Review of the Concept and Examples from the Middle-Upper Paleozoic and Examples from the Middle-Upper Paleozoic**

**Stratigraphic Unconformities: Review of the Concept**

DOI: 10.5772/intechopen.70373

Pavel Kabanov Pavel Kabanov Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70373

#### **Abstract**

Only about 10% of geologic time is imprinted in sedimentary strata and the rest is hidden in non-depositional or erosional surfaces called unconformities. Stratigraphic unconformities (disconformities) are principal bounding surfaces in sequence stratigraphy, which a geologist would easily identify in the outcrop but frequently overlook in the subsurface unless core is available. The proportion of disconformities that are misidentified or overlooked in subsurface stratigraphy is quite large, which puts a warning sign on simplistic sequence stratigraphic models. The amount of time imprinted in disconformities can be evaluated using relative weathering maturity of the subaerial profile, cyclostratigraphic calibration, absolute dating, and biostratigraphy. However, using biostratigraphy alone is never enough as biostratigraphic gaps tend to fill with increasing data coverage. Identification of paleo-vadose zones and subaerial exposure profiles is regarded as critical for finding stratigraphic unconformities and is the only approach in strata where geophysically mappable fluvial systems are absent. Drowning unconformities are carbonate platform drowning surfaces that usually produce distinct reflection horizons and have better stratigraphic value in the subsurface than platform-embedded subaerial unconformities. This discussion is supported by examples of subaerial disconformities from the Devonian, Carboniferous, and Permian of Canada and Russia and with an example of a geographically extensive mid-Devonian drowning unconformity from Northwestern Canada.

**Keywords:** disconformities, paleosols, paleokarsts, vadose alteration, erosion, drowning unconformities, sequence stratigraphy, subsurface identification

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.