1: Organic Chemistry
Organic chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms. Study of structure includes many physical and chemical methods to determine the chemical composition and the chemical constitution of organic compounds and materials. Study of properties includes both physical properties and chemical properties, and uses similar methods as well as methods to evaluate chemical reactivity, with the aim to understand the behavior of the organic matter.
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- 1.1: Prelude to Organic Chemistry
- Early chemists regarded substances isolated from organisms as a different type of matter that could not be synthesized artificially, and these substances were thus known as organic compounds. The widespread belief called vitalism held that organic compounds were formed by a vital force present only in living organisms. Thr defining trait of organic molecules is the presence of carbon as the principal element, bonded to hydrogen and other carbon atoms.
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- 1.2: Hydrocarbons
- Strong, stable bonds between carbon atoms produce complex molecules containing chains, branches, and rings. Hydrocarbons are organic compounds composed of only carbon and hydrogen. The alkanes are saturated hydrocarbons—that is, hydrocarbons that contain only single bonds. Alkenes contain one or more carbon-carbon double bonds. Alkynes contain one or more carbon-carbon triple bonds. Aromatic hydrocarbons contain ring of delocalized π electrons.
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- 1.3: Alcohols and Ethers
- Many organic compounds that are not hydrocarbons can be thought of as derivatives of hydrocarbons. A hydrocarbon derivative can be formed by replacing one or more hydrogen atoms of a hydrocarbon by a functional group, which contains at least one atom of an element other than carbon or hydrogen. The properties of hydrocarbon derivatives are determined largely by the functional group. The –OH group is the functional group of an alcohol. The –R–O–R– group is the functional group of an ether.
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- 1.4: Aldehydes, Ketones, Carboxylic Acids, and Esters
- The carbonyl group, a carbon-oxygen double bond, is the key structure in these classes of organic molecules: Aldehydes contain at least one hydrogen atom attached to the carbonyl carbon atom, ketones contain two carbon groups attached to the carbonyl carbon atom, carboxylic acids contain a hydroxyl group attached to the carbonyl carbon atom, and esters contain an oxygen atom attached to another carbon group connected to the carbonyl carbon atom.
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- 1.5: Amines and Amides
- The addition of nitrogen into an organic framework leads to two families of molecules. Compounds containing a nitrogen atom bonded in a hydrocarbon framework are classified as amines. Compounds that have a nitrogen atom bonded to one side of a carbonyl group are classified as amides.  Amines and carboxylic acids can combine in a condensation reaction to form amides.
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- 1.E: Organic Chemistry (Exercises)
- These are homework exercises to accompany the Textmap created for "Chemistry" by OpenStax. Complementary General Chemistry question banks can be found for other Textmaps and can be accessed here. In addition to these publicly available questions, access to private problems bank for use in exams and homework is available to faculty only on an individual basis; please contact Delmar Larsen for an account with access permission.
Contributors and Attributions
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Paul Flowers (University of North Carolina - Pembroke), Klaus Theopold (University of Delaware) and Richard Langley (Stephen F. Austin State University) with contributing authors. Textbook content produced by OpenStax College is licensed under a Creative Commons Attribution License 4.0 license. Download for free at<EMAIL_ADDRESS>).


4.4: Organizational Designs and Structures
- Identify different types of organizational structures and their strengths and weaknesses.
A 2017 Deloitte source asked, before answering, “Why has organizational design zoomed to the top of the list as the most important trend in the Global Human Capital Trends survey for two years in a row?” 20 The source continued, “The answer is simple: The way high-performing organizations operate today is radically different from how they operated 10 years ago. Yet many other organizations continue to operate according to industrial-age models that are 100 years old or more.” 21
Early organizational theorists broadly categorized organizational structures and systems as either mechanistic or organic. 22 This broad, generalized characterization of organizations remains relevant. Mechanistic organizational structures (Exhibit 4.5) are best suited for environments that range from stable and simple to low-moderate uncertainty (Exhibit 4.4) and are characterized by top-down hierarchies of control that are rule-based. The chain of command is highly centralized and uses formal authority; tasks are clearly defined and differentiated to be executed by specific specialized experts. Bosses and supervisors have fewer people working directly under them (i.e., a narrow span of control), and the organization is governed by rigid departmentalization (i.e., an organization is divided into different departments that perform specialized tasks according to the departments’ expertise). This form of organization represents a traditional type of structure that evolved in environments that were, as noted above, stable with low complexity. Historically, the U.S. Postal Service and other manufacturing types of industries (Exhibit 4.4) were mechanistic. Again, this type of organizational design may still be relevant, as Exhibit 4.4suggests, in simple, stable, low-uncertainty environments.
Organic organizational structures and systems, however, have opposite characteristics from mechanistic ones. AsExhibit 4.4shows, these organizational forms work best in unstable, complex, changing environments. Their structures are flatter, with participatory communication and decision-making flowing in different directions. There is more fluidity and less-rigid ways of performing tasks; there may also be fewer rules. Tasks are more generalized and shared; there is a wider span of control (i.e., more people reporting to managers).Exhibit 4.5offers examples of organically structured industries, such as high tech, computer, aerospace, and telecommunications industries, that must deal with change and uncertainty. Contemporary corporations and firms engaged in fast-paced, highly competitive, rapidly changing, and turbulent environments are becoming more organic in different ways, as we will discuss in this chapter. However, not every organization or every part of most organizations may require an organic type of structure. Understanding different organizational designs and structures is important to discern when, where, and under what circumstances a type of mechanistic system or part of an organization would be needed. The following section discusses five types of structures with variations.
Types of Organizational Structures
Within the context of mechanistic versus organic structures, specific types of organizational structures in the United States historically evolved over at least three eras, as we discuss here before explaining types of organizational designs. During the first era, the mid-1800s to the late 1970s, organizations were mechanistic self-contained, top-down pyramids.23 Emphasis was placed on internal organizational processes of taking in raw materials, transforming those into products, and turning them out to customers.
Early organizational structures were focused on internal hierarchical control and separate functional specializations in order to adapt to external environments. Structures during this era grouped people into functions or departments, specified reporting relationships among those people and departments, and developed systems to coordinate and integrate work horizontally and vertically. As will be explained, the functional structure evolved first, followed by the divisional structure and then the matrix structured.
The second era started in the 1980s and extended through the mid-1990s. More-complex environments, markets, and technologies strained mechanistic organizational structures. Competition from Japan in the auto industry and complex transactions in the banking, insurance, and other industries that emphasized customer value, demand and faster interactions, quality, and results issued the need for more organic organizational designs and structures.
Communication and coordination between and among internal organizational units and external customers, suppliers, and other stakeholders required higher levels of integration and speed of informational processing. Personal computers and networks had also entered the scene. In effect, the so-called “horizontal organization” was born, which emphasized “reengineering along workflow processes that link organizational capabilities to customers and suppliers.” 24 Ford, Xerox Corp., Lexmark, and Eastman Kodak Company are examples of early adopters of the horizontal organizational design , which, unlike the top-down pyramid structures in the first era, brought flattened hierarchical, hybrid structures and cross-functional teams.
The third era started in the mid-1990s and extends to the present. Several factors contributed to the rise of this era: the Internet; global competition—particularly from China and India with low-cost labor; automation of supply chains; and outsourcing of expertise to speed up production and delivery of products and services. The so-called silos and walls of organizations opened up; everything could not be or did not have to be produced within the confines of an organization, especially if corporations were cutting costs and outsourcing different functions of products to save costs. During this period, further extensions of the horizontal and organic types of structures evolved: the divisional, matrix, global geographic, modular, team-based, and virtual structures were created.
In the following discussion, we identify major types of structures mentioned above and discuss the advantages and disadvantages of each, referenced inExhibit 4.6. Note that in many larger national and international corporations, there is a mix and match among different structures used. There are also advantages and disadvantages of each structure. Again, organizational structures are designed to fit with external environments. Depending on the type of environments from our earlier discussion in which a company operates, the structure should facilitate that organization’s capability to achieve its vision, mission, and goals.
Exhibit 4.6 offers a profile of different structures that evolved in our discussion above.
Note the continuum inExhibit 4.6, showing the earliest form of organizational structure, functional, evolving with more complex environments to divisional, matrix, team-based, and then virtual. This evolution, as discussed above, is presented as a continuum from mechanistic to organic structures—moving from more simple, stable environments to complex, changing ones, as illustrated inExhibit 4.6. The six types of organizational structures discussed here include functional, divisional, geographic, matrix, networked/team, and virtual. 25
The functional structure, shown inExhibit 4.7, is among the earliest and most used organizational designs. This structure is organized by departments and expertise areas, such as R&D (research & development), production, accounting, and human resources. Functional organizations are referred to as pyramid structures since they are governed as a hierarchical, top-down control system.
Small companies, start-ups, and organizations working in simple, stable environments use this structure, as do many large government organizations and divisions of large companies for certain tasks.
The functional structure excels in providing for a high degree of specialization and a simple and straightforward reporting system within departments, offers economies of scale, and is not difficult to scale if and when the organization grows. Disadvantages of this structure include isolation of departments from each other since they tend to form “silos,” which are characterized by closed mindsets that are not open to communicating across departments, lack of quick decision-making and coordination of tasks across departments, and competition for power and resources.
Divisional structures , see Exhibit 4.8, are, in effect, many functional departments grouped under a division head. Each functional group in a division has its own marketing, sales, accounting, manufacturing, and production team. This structure resembles a product structure that also has profit centers. These smaller functional areas or departments can also be grouped by different markets, geographies, products, services, or other whatever is required by the company’s business. The market-based structure is ideal for an organization that has products or services that are unique to specific market segments and is particularly effective if that organization has advanced knowledge of those segments.
The advantages of a divisional structure include the following: each specialty area can be more focused on the business segment and budget that it manages; everyone can more easily know their responsibilities and accountability expectations; customer contact and service can be quicker; and coordination within a divisional grouping is easier, since all the functions are accessible. The divisional structure is also helpful for large companies since decentralized decision-making means that headquarters does not have to micromanage all the divisions. The disadvantages of this structure from a headquarters perspective are that divisions can easily become isolated and insular from one another and that different systems, such as accounting, finance, sales, and so on, may suffer from poor and infrequent communication and coordination of enterprise mission, direction, and values. Moreover, incompatibility of systems (technology, accounting, advertising, budgets) can occur, which creates a strain on company strategic goals and objectives.
A geographic structure , Exhibit 4.9, is another option aimed at moving from a mechanistic to more organic design to serve customers faster and with relevant products and services; as such, this structure is organized by locations of customers that a company serves. This structure evolved as companies became more national, international, and global. Geographic structures resemble and are extensions of the divisional structure.
Organizing geographically enables each geographic organizational unit (like a division) the ability to understand, research, and design products and/or services with the knowledge of customer needs, tastes, and cultural differences. The advantages and disadvantages of the geographic structure are similar to those of the divisional structure. Headquarters must ensure effective coordination and control over each somewhat autonomous geographically self-contained structure.
The main downside of a geographical organizational structure is that it can be easy for decision-making to become decentralized, as geographic divisions (which can be hundreds if not thousands of miles away from corporate headquarters) often have a great deal of autonomy.
Matrix structures, illustrated in Exhibit 4.6 and depicted in Exhibit 4.11, move closer to organic systems in an attempt to respond to environmental uncertainty, complexity, and instability. The matrix structure actually originated at a time in the 1960s when U.S. aerospace firms contracted with the government. Aerospace firms were required to “develop charts showing the structure of the project management team that would be executing the contract and how this team was related to the overall management structure of the organization.” As such, employees would be required to have dual reporting relationships—with the government and the aerospace company. 26 Since that time, this structure has been imitated and used by other industries and companies since it provides flexibility and helps integrate decision-making in functionally organized companies.
Matrix designs use teams to combine vertical with horizontal structures. The traditional functional or vertical structure and chain of command maintains control over employees who work on teams that cut across functional areas, creating horizontal coordination that focuses projects that have deadlines and goals to meet within and often times in addition to those of departments. In effect, matrix structures initiated horizontal team-based structures that provided faster information sharing, coordination, and integration between the formal organization and profit-oriented projects and programs.
As Exhibit 4.11illustrates, this structure has lines of formal authority along two dimensions: employees report to a functional, departmental boss and simultaneously to a product or project team boss. One of the weaknesses of matrix structures is the confusion and conflicts employees experience in reporting to two bosses. To work effectively, employees (including their bosses and project leaders) who work in dual-authority matrix structures require good interpersonal communication, conflict management, and political skills to manage up and down the organization.
Different types of matrix structures, some resembling virtual team designs, are used in more complex environments. 27 For example, there are cross-functional matrix teams in which team members from other organizational departments report to an “activity leader” who is not their formal supervisor or boss. There are also functional matrix teams where employees from the same department coordinate across another internal matrix team consisting of, for example, HR or other functional area specialists, who come together to develop a limited but focused common short-term goal. There are also global matrix teams consisting of employees from different regions, countries, time zones, and cultures who are assembled to achieve a short-term project goal of a particular customer. Matrix team members have been and are a growing part of horizontal organizations that cut across geographies, time zones, skills, and traditional authority structures to solve customer and even enterprise organizational needs and demands.
As part of the next discussed organizational type of structure, networked teams, organizational members in matrix structures must “learn how to collaborate with colleagues across distance, cultures and other barriers. Matrix team members often suffer from the problem of divided loyalties where they have both team and functional goals that compete for their time and attention, they have multiple bosses and often work on multiple teams at the same time. For some matrix team members this may be the first time they have been given accountability for results that are broader than delivery of their functional goals. Some individuals relish the breath and development that the matrix team offers and others feel exposed and out of control.” To succeed in these types of horizontal organizational structures, organizational members “should focus less on the structure and more on behaviors.” 28
Networked team structures are another form of the horizontal organization. Moving beyond the matrix structure, networked teams are more informal and flexible. “[N]etworks have two salient characteristics: clustering and path length. Clustering refers to the degree to which a network is made up of tightly knit groups while path lengths is a measure of distance—the average number of links separating any two nodes in the network.” 29 A more technical explanation can be found in this footnote source. 30 For our purposes here, a networked organizational structure is one that naturally forms after being initially assigned. Based on the vision, mission, and needs of a problem or opportunity, team members will find others who can help—if the larger organization and leaders do not prevent or obstruct that process.
There is not one classical depiction of this structure, since different companies initially design teams to solve problems, find opportunities, and discover resources to do so. Stated another way, “The networked organization is one that is connected together by informal networks and the demands of the task, rather than a formal organizational structure. The network organization prioritizes its ‘soft structure’ of relationships, networks, teams, groups and communities rather than reporting lines.” 31 Exhibit 4.12 is a suggested illustration of this structure.
A Deloitte source based on the 2017 Global Human Capital Trend study stated that as organizations continue to transition from vertical structures to more organic ones, networked global designs are being adapted to larger companies that require more reach and scope and quicker response time with customers: “Research shows that we spend two orders of magnitude more time with people near our desk than with those more than 50 meters away. Whatever a hierarchical organization chart says, real, day-to-day work gets done in networks. This is why the organization of the future is a ‘network of teams.’” 32
Advantages of networked organizations are similar to those stated earlier with regard to organic, horizontal, and matrix structures. Weaknesses of the networked structure include the following: (1) Establishing clear lines of communication to produce project assignments and due dates to employees is needed. (2) Dependence on technology—Internet connections and phone lines in particular—is necessary. Delays in communication result from computer crashes, network traffic errors and problems; electronic information sharing across country borders can also be difficult. (3) Not having a central physical location where all employees work, or can assemble occasionally to have face-to-face meetings and check results, can result in errors, strained relationships, and lack of on-time project deliverables. 33
Virtual structures and organizations emerged in the 1990s as a response to requiring more flexibility, solution-based tasks on demand, fewer geographical constraints, and accessibility to dispersed expertise.34 Virtual structures are depicted in Exhibit 4.13. Related to so-called modular and digital organizations, virtual structures are dependent on information communication technologies (ICTs).
These organizations move beyond network team structures in that the headquarters or home base may be the only or part of part of a stable organizational base. Otherwise, this is a “boundaryless organization.” Examples of organizations that use virtual teams are Uber, Airbnb, Amazon, Reebok, Nike, Puma, and Dell. Increasingly, organizations are using different variations of virtual structures with call centers and other outsourced tasks, positions, and even projects.
Advantages of virtual teams and organizations include cost savings, decreased response time to customers, greater access to a diverse labor force not encumbered by 8-hour workdays, and less harmful effects on the environment. “The telecommuting policies of Dell, Aetna, and Xerox cumulatively saved 95,294 metric tons of greenhouse gas emissions last year, which is the equivalent of taking 20,000 passenger vehicles off of the road.” 35 Disadvantages are social isolation of employees who work virtually, potential for lack of trust among employees and between the company and employees when communication is limited, and reduced collaboration among separated employees and the organization’s officers due to lack of social interaction.
In the following section, we turn to internal organizational dimensions that complement structure and are affected by and affect external environments.
- Why does the matrix structure have a dual chain of command?
- How does a matrix structure increase power struggles or reduce accountability?
- What are advantages of a formal committee structure? Disadvantages?
References
20. Bersin, Josh, et al, “2017 Global Human Capital trends”, Deloitte Insights , February 28, 2017. https://www2.deloitte.com/insights/u...he-future.html
21. Ibid.
22. Burns, T. & Stalker, G. M. (1961), The Management of Innovation, Tavistock, London; Mintzberg, H. 1979. The structuring of organizations. Englewood Cliffs, NJ:Prentice-Hall; Emery, Fred E. and Eric L. Trist, (1965), "The Causal Texture of Organizational Environments", pp 21-32 inHuman Relations, February 1965
23. Anand, N. and R. Daft. (2007). What is the Right Organization Design? Organizational Dynamics , Vol. 36, No. 4, pp. 329–344.
24. Ibid.
25. This section draws on a number of scholarly and practitioner sources, including the following: R. Daft. (2016). Organization Theory & Design, 12th ed. Cengage Learning , Boston, MA; https://blog.hubspot.com/ marketing/team-structure-diagrams; Burton and Obel. (2018).Journal of Organization DesignVol. 7, Issue 5, Devaney, Erik, “7 types of organizational Structure & Whom They’re Suited For [Diagrams],Hubspot, accessed November 18, 2018. https://doi.org/10.1186/s41469-018-0029-2 ; “Matrix Teams”,Global Integration, accessed November 18, 2018. http://www.global-integration.com/gl.../matrix-teams/ ; and Bersin, josh, “The organization of the Future: Arriving Now’, 2017 Global Human Capital Trends,Deloitte Insights, February 28, 2017. https://www2.deloitte.com/insights/u...thefuture.html
26. Brent Durbin. Matrix organization, Encyclopedia Britannica , https://www.britannica.com/topic/matrixorganization
27. “Matrix Teams”, Global Integration , accessed November 18, 2018. http://www.global-integration.com/ glossary/matrix-teams/
28. ibid.
29. G. Satell. (June 8, 2015). What Makes an Organization “Networked”, Harvard Business Review , https://hbr.org/2015/06/what-makes-a...tion-networked
30. Satell, Greg, “The Story of Networks”, Digital Tonto , September 26, 2010. https://www.digitaltonto.com/ 2010/the-story-of-networks/; and “Networked Organizations”,Global Integration, accessed November 18, 2018. http://www.global-integration.com/gl.../matrix-teams/ http://www.global-integration.com/glossary/ networked-organization/
31. J. Bersin, T. McDowell, A. Rahnema, and Yves Van Durme. (February 28, 2017), “The organization of the future: Arriving now, 2017” Global Human Capital Trends,Deloitte. https://www2.deloitte.com/insights/us/en/ focus/human-capital-trends/2017/organization-of-the-future.html
32. Lister, Jonathan, “The Disadvantages of Network-based organizational Structure”, Chron , accessed November 18, 2018. http://smallbusiness.chron.com/disad...ure-35988.html
33. Sources in this section include the following: C. Handy. (May–June 1995). Trust and the Virtual Organization, Harvard Business Review , https://hbr.org/1995/05/trust-and-th...l-organization ; M. Ahuja and K. Carley. (1999), Network Structure in Virtual Organizations,Organization Science, Volume 10, Issue 6, June, pp. 741 – 757; http://www.yourarticlelibrary.com/or...nd-types/35533
34. D. Onley. (Apr 29, 2015), Environment , https://www.shrm.org/ResourcesAndToo...cs/technology/ Pages/How-Telecommuting-Helps-the-Environment.aspx
35. I. McCarthy, T. Lawrence, B. Wixted, and B. Gordon. (2010). A Multidimensional Conceptualization of Environmental Velocity, Academy of Management Review 34, no. 4, pp. 604-626


2.12: Shell Frame
|
Frame
American Attributed to the Donald/Sweet Family, c.1890 Wood, snail shells, seeds Gift of Delma Donald Woodburn Estate MHAHS 2002.001.0067 |
The willow plant stand, basket and ornamental frames are surviving examples of the “make-do” endeavors of rural community members around the turn of the 19th Century. By using local resources, they created unique, artistic home decorations with lasting sentimental value. At the same time, the larger British and American Arts and Crafts movement heralded such artistic production in response to the Industrial Revolution. Making hand-crafted items reinforced a return to more ideal economic times and better moral health of communities. Such sentiments survive in today’s non-professional, Do-It-Yourself culture and professional crafts that market the decorative appeal of rustic furnishings and home adornments.
The residence of the Donald family was an emblematic representation of life in the early 20th century Wisconsin through its many objects and artifacts. These are some of the dozens of artifacts that came to the Mt. Horeb Area Historical Society from the estate of Delma Donald Woodburn (1899-2001), who carefully documented and preserved the material heritage of her family’s life in Mount Horeb and Madison, Wisconsin. The artifacts span several generations, beginning with two early pioneer families who came to the rural Mount Horeb area from New York state in 1855–William Sweet and Sally Clark Sweet and Reverend James Donald and Margaret Strong Donald.
The large collection of objects of Delma Donald Woodburn included many objects of different categories, utensils, clothes, and other artifacts.
By this time, in the 19th century, women’s magazines promoted household craft and decorations. Young ladies were expected to learn domestic skills and even common household goods became a pallet for artistic expression. Parlors and family spaces were filled with this kind of craft, making her home more inviting and following the Victorian magazine arts of the time. Vona Donald chose bucolic rural winter scenes to enhance and decorate her environment. With paint and inspiration, the rural landscapes were one of the frequent motifs that brought character to these daily objects.
Objects such as the butter paddle, the wood panel, the picture frames and the cutlery box are examples of the use of daily artifacts as the folk artist’s canvas. Their work added personality to each object making them unique. Some of those artifacts later became a piece of remembrance of a loving relative.
Besides decorative painting, many other elements were used in these craft projects. Norwegian-American folk art went far beyond rosemaling and acanthus wood carving.
SHELL FRAME
Picture frames are objects often connected to sentimental value and, because of that, they were common in the make-do practice. This frame received peculiar natural elements as ornaments: snail shells and watermelon seeds, materials probably abundant in rural communities, glued to a rectangular wooden structure. Make-do was a vivid activity among Norwegian-American self-taught folk-artists. By adding new elements, the pieces were modified and became unique in character. Until today this habit inspires people around the world with the DIY – Do It Yourself- movement.
Sources
For a history of the Donald and Sweet families, see “Settlement” Friends of Donald County Park (accessed December 9, 2008)
For more information on Delma Donald Woodburn, see “Delma Donald Woodburn” in “Pages of the Past” Mt. Horeb Area Historical Society. Accessed December 9, 2008. donaldpark.org/pdf/historyDonaldPark2.pdf
www.mounthoreb.org/ppDelma.htm
Wisconsin Decorative Arts Database


11.3: The NumPy 'ndarray'
The actual data type that the NumPy package provides is called an ndarray , which stands for “n-dimensional array.” If that sounds heady, it kind of is, although in this course we’re only ever going to use a one -dimensional array, which is super simple to understand. In fact, it looks exactly like the examples in Figure 7.1.1.
“One-dimensional” just means that there is a single index number, and the elements are all in a line. 2
Creating ndarray s
There are many different ways to create an ndarray . We’ll learn four of them.
Way 1 : np.array([])
The first is to use the array() function of the NumPy package, and give it all the values explicitly. Here’s the code to reproduce the Figure 7.1.1 examples:
Code \(\PageIndex{1}\) (Python):
followees = np.array(['@katyperry','@rihanna','@TheEllenShow'])
balances = np.array([1526.73, 98774.91, 1000000, 4963.12, 123.19])
It’s simple, but don’t miss the syntactical gotcha: you must include a pair of boxies inside the bananas . Why? Reasons. 3 For now, just memorize that for this function – and this function only – we use “([...stuff...])” instead of “(...stuff...)” when we call it.
By the way, the attentive reader might object to me calling array() a function, instead of a method. Isn’t there a word-and-a-dot before it, and isn’t that a “method thing?” Shrewd of you to think that, but actually no, and the reason is that “ np ” isn’t the name of a variable, but the name of a package. When we say “ np.array() ” what we’re saying is: “Python, please call the array() function from the np package .” The word-and-dot syntax does double-duty.
We can call the type() function, as we did back on p. 17, to verify that yes indeed we have created ndarray s :
Code \(\PageIndex{2}\) (Python):
print(type(followees))
print(type(balances))
| numpy.ndarray
| numpy.ndarray
This is useful, but sometimes we want to know what underlying atomic data type the array is comprised of. To do that, we attach “ .dtype ” (confusingly, without bananas this time) to the end of the variable name. “ .dtype ” stands for “data type.” Here goes:
Code \(\PageIndex{3}\) (Python):
print(followees.dtype)
print(balances.dtype)
| dtype('<U13')
| dtype('float64')
Whoa, what does that stuff mean? It’s a bit hard on the eyes, but let me explain. The underlying data type of followees is (bizarrely) "U13" which in English means “strings of Unicode characters 4 , each of which is 13 characters long or less.” (If you bother to count, you’ll discover that the longest string in our followees array is the last one, ’ @TheEllenShow’ , which is exactly 13 characters long.) The “ float64 ” thing means “ float s, each of which is represented with 64 bits 5 in memory.
You don’t need to worry about any of those details. All you need to know is: if an array’s dtype has "<U" in it, then it’s composed of strings; and if it has the word “ int ” or “ float ” in it, it means one of those two old friends from chapter 3.
Incidentally, you’ll recall from chapter 7 that an array is homogeneous , which means all its elements are of the same type. NumPy enforces this. If you try to combine them:
Code \(\PageIndex{4}\) (Python):
weird = np.array([3, 4.9, 8])
strange = np.array([18, 73.0, 'bob', 22.8])
you’ll discover that NumPy converts them to all be of the same type:
Code \(\PageIndex{5}\) (Python):
print(weird)
print(weird.dtype)
print(strange)
print(strange.dtype)
| [ 3. 4.9 8. ]
| dtype('<U3')
| ['18' '73.0' 'bob' '22.8']
| dtype('float64')
See how the int s 3 and 8 from the first array were converted into the float s 3 . and 8 .; meanwhile, all of the numerical elements of the second array got converted to str s. (If you think about it, that’s the only direction the conversions could go.)
 Among other scenarios, we often need to use a bunch of counter variables to, well, count things. (Recall our incrementing technique from Section 5.1) Suppose, for example, that we had a giant array that held the numbers of likes that each Instagram photo had. When someone likes a photo, that photo’s appropriate element in the array should be incremented (raised in value) by one. Similarly, if someone unlikes it, then its value in the array should be decremented by one.
An easy way to do this is NumPy’s zeros() function:
Code \(\PageIndex{1}\) (Python):
photo_likes = np.zeros(40000000000)
(although I’ll bet you don’t have enough memory on your laptop to actually store an array this size! Instagram sure has a lot of pics...) When I do this on my Data Science cluster, I get this:
Code \(\PageIndex{2}\) (Python):
print(photo_likes)
print(photo_likes.dtype)
| array([ 0., 0., 0., ..., 0., 0., 0.])
| float64
Don’t miss the “...” in the middle of that first line! It means “there are (potentially) a lot of elements here that we’re not showing, for conciseness.” Also notice that zeros() makes an array of float s, not int s.
Way 3: np.arange()
Sometimes we need to create an array with regularly-spaced values, like “all the numbers from one to a million” or “all even numbers between 20 and 50.” We can use NumPy’s arange() function for this.
Normally we pass this function two arguments, like so:
Code \(\PageIndex{3}\) (Python):
usa_years = np.arange(1776, 2022)
print(usa_years)
print(usa_years.dtype)
| [1776 1777 1778 1779 ... 2018 2019 2020 2021]
| int64
If you read that code and output carefully, you should be surprised. We asked for elements in the range of 1776 to 2022, and we got...1776 through 2021 . Huh?
 When you use arange() you get an array of elements starting with the first argument, and going up through but not including the last number. There’s a reason Python and NumPy decided to do it this way 6 , but for now it’s just another random thing to memorize. If you forget, you’re likely to get an “OBOE” – which stands for “off-by-one error” – a common programming error where you do almost the right thing but perform one fewer, or one more, operation than you meant to.
Anyways, other than that glitch, you can see that the function did a useful thing. We can quickly generate regularly-spaced arrays of any range of values we like. By including a third argument, we can even specify the step size (the interval between each pair of values):
Code \(\PageIndex{4}\) (Python):
twentieth_century_decades = np.arange(1900, 2010, 10)
prez_elections = np.arange(1788, 2024, 4)
print(twentieth_century_decades)
print(prez_elections)
| [1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000]
| [1788 1792 1796 1800 ... 2008 2012 2016 2020]
Notice we had to specify 2010 and 2024 as the second argument to these function calls in order for the arrays to include 2000, and 2020, respectively. This is the same “up to but not including the end point” behavior, but extended to step sizes of greater than one.
Way 4: np.loadtxt()
Most of the data that we analyze will come from external files, rather than being typed in by hand in Python. For one thing, this is how it will be provided by external sources; for another, it’s infeasible to actually type in anything very large.
Let me say a word about files. You probably work with them every day on your own computer, but what you might not realize is that fundamentally, they all contain the same kind of “data.” You might think of a Microsoft Word document as a completely different kind of thing than a GIF image, or an MP3 song file, or a saved HTML page. But they’re actually more alike than they are different.  Those bits are organized to conform to a particular kind of file specification, so that a program (like Word, Photoshop, or Spotify) can recognize and understand them. But it’s still just “information.” The difference between a Word doc and a GIF is like the difference between a book written in English and one written in Spanish; it’s not like the difference between a bicycle and a fish.
In this course, we’ll be working with plain-text files . This is how most of the open data sources on the Internet provide their information. A plain-text file is one that consists of readable characters, but which doesn’t contain any additional formatting (like boldface, colors, margin settings, etc.). You can actually open up a plain-text file in any text editor (including Microsoft Word) and see what it contains.
In your CoCalc account, you have your own little group of files which, like those on your own computer, can be organized into directories (or folders 7 ). It is critically important that the data file you read, and the Jupyter Notebook that reads it, are in the same directory . The #1 trouble students experience when trying to read from a text file is not having the text file itself located in the same directory as the code that reads it. If you make this mistake, Python will simply claim to not recognize the filename you give it.
That doesn’t mean your file doesn’t exist! It’s just not in the right place. An example of doing this correctly is in Figure 8.2.1. We’re in a directory called “ filePractice ” (stare at the middle of the figure until you find those words) which is contained within the home directory that’s denoted by a little house icon. Your home directory is just the starting point of your own private little CoCalc world. The slash mark between the house and the word filePractice indicates that filePractice is contained directly within, or “under,” the home directory.
Figure \(\PageIndex{1}\): A directory (folder) on CoCalc, which contains two files: a plain-text file (called uswnt.txt ) and a Jupyter Notebook which will read from it ( funWithArrays.ipynb ).
The two entries listed are a plain-text file (called uswnt.txt ) and a Jupyter Notebook ( funWithArrays.ipynb ). You can tell that the former is a plain-text file because of the filename extension “ .txt ”. 8 If we clicked on uswnt.txt , we’ll bring up the contents of the file, as shown in Figure 8.2.2. In this case, we have the current roster on the US Women’s National Soccer team, one name per line. Perhaps the most important thing to see is that the file itself, which we will read into Python in a moment, is nothing strange or scary: you could type it yourself into Notepad or Word. 9
This is a good time to mention that spaces and other funny characters in filenames are considered evil . You might think it looks better to call the notebook file “ fun with arrays.ipynb ” and the data file “ US Women’s National Team roster.txt ”, but I promise you it will lead to pain in the end, for a variety of fiddly reasons. It’s better to use camel case for filenames, which is simply capitalizingEachSuccessiveWordInAPhrase.
Figure \(\PageIndex{2}\): The contents of a plain-text file, as rendered by CoCalc.
Okay, finally back to NumPy code. If all the stars are aligned, we can write this code in a funWithArrays.ipynb cell to read the soccer roster into an ndarray :
Code \(\PageIndex{5}\) (Python):
roster = np.loadtxt("uswnt.txt", dtype=object, delimiter="###")
There’s a lot of weird stuff in that line, so follow me here. The first argument is easy enough: the name of the file that contains our data. (Again, I stress that the file must be located in the same directory as the notebook!) The second argument is bizarre: we know what dtype means, but “ object ”? Ugh, another fiddly detail. When you read from a file into a NumPy array, you will be reading one of our three atomic types. Here are the rules:
So basically, you set dtype to the type of data you want in your ndarray ...unless you want strings, in which case you put the word object . Sorry about that.
The last of the three arguments is even nuttier, and you actually don’t need to include it at all if you’re reading ints or floats. If you’re reading strs , however, you need to set the delimiter to something that doesn’t appear in any of the strs . I chose three-hashtags-in-a-row since that rarely appears in any set of text data.
Bottom line: once we’ve done all this, we get:
Code \(\PageIndex{6}\) (Python):
print(roster)
| ['Alyssa Naeher' 'Mallory Pugh' 'Sam Mewis' 'Becky Sauerbrunn' "Kelly O'Hara" 'Morgan Brian' 'Abby Dahlkemper' 'Julie Ertz' 'Lindsey Horan' 'Carli Lloyd' 'Ali Krieger' 'Tierna Davidson' 'Alex Morgan' 'Emily Sonnett' 'Megan Rapinoe' 'Rose Lavelle' 'Tobin Heath' 'Ashlyn Harris' 'Crystal Dunn' 'Allie Long' 'Adrianna Franch' 'Jessica McDonald' 'Christen Press']
which is pretty cool.
Figure \(\PageIndex{3}\): The memory picture of the four arrays we created in section 8.2.


5.7: Suggested Readings
Arcilla, N., L.H. Holbech, and S. O’Donnell. 2015. Severe declines of understory birds follow illegal logging in Upper Guinea forests of Ghana, West Africa. >Biological Conservation 188: 41–49. https://doi.org/10.1016/j.biocon.2015.02.010 Illegal logging is on the increase, and wildlife communities struggle to recover.
Caro, T., J. Darwin, T. Forrester, et al. 2012. Conservation in the Anthropocene. >Conservation Biology 26: 185–88. https://doi.org/10.1111/j.1523-1739.2011.01752.x Even though human activities dominate large areas of the earth, it is important to remember and plan for the many places and ecosystems where human influence is still minimal.
Haddad, N.M., L.A. Brudvig, J. Clobert, et al. 2015. Habitat fragmentation and its lasting impact on Earth’s ecosystems. >Science Advances 1: e1500052. https://doi.org/10.1126/sciadv.1500052 There are many ways that fragmentation hurts biodiversity.
Harris, G., S. Thirgood, J.G.C. Hopcraft, et al. 2009. Global decline in aggregated migrations of large terrestrial mammals. >Endangered Species Research 7: 55–76. https://doi.org/10.3354/esr00173 Habitat loss continues to threaten the world’s remaining mass migrations.
Ibisch, P.L., M.T. Hoffmann, S. Kreft, et al. 2016. A global map of roadless areas and their conservation status. >Science 354: 1423–27. https://doi.org/10.1126/science.aaf7166 Africa still holds large roadless areas; we need to keep it that way.
Laurance, W.F., J. Sayer, and K.G. Cassman. 2014. Agricultural expansion and its impacts on tropical nature. >Trends in Ecology and Evolution 29: 107–16. https://doi.org/10.1016/j.tree.2013.12.001 Agriculture and roads will have severe impacts on Africa’s ecosystems in the coming century.
Rudel, T.K. 2013. The national determinants of deforestation in sub-Saharan Africa. >Philosophical Transactions of the Royal Society B 368: 20120405. https://doi.org/10.1098/rstb.2012.0405 One manuscript in a special issue on deforestation in Africa; other manuscripts in this issue are also worth scanning.
van der Hoeven, C.A., W.F. de Boer, and H.H. Prins. 2010. Roadside conditions as predictor for wildlife crossing probability in a Central African rainforest. >African Journal of Ecology 48: 368–77. https://doi.org/10.1111/j.1365-2028.2009.01122.x Some species are highly reluctant to cross roads, even inside protected areas.
Woodborne, S., K.D.A. Huchzermeyer, D. Govender, et al. 2012. Ecosystem change and the Olifants River crocodile mass mortality events. >Ecosphere 3: 1–17. https://doi.org/10.1890/ES12-00170.1 Damming rivers can lead to ecological disasters
Ykhanbai, H., R. Garg, A. Singh, et al. 2014. >Conservation and “>Land Grabbing”> in Rangelands:> Part of the Problem or Part of the Solution? (Rome: International Land Coalition). http://pubs.iied.org/pdfs/G03853.pdf Conservation biologists should work with local communities to prevent land grabs.


10.6: Production and Operations Control
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5. How do operations managers schedule and control production?
Every company needs to have systems in place to see that production and operations are carried out as planned and to correct errors when they are not. The coordination of materials, equipment, and human resources to achieve production and operating efficiencies is called production control . Two of its key aspects are routing and scheduling.
Routing: Where to Next?
Routing is the first step in production control. It sets out a work flow, the sequence of machines and operations through which a product or service progresses from start to finish. Routing depends on the type of goods being produced and the facility layout. Good routing procedures increase productivity and cut unnecessary costs.
One useful tool for routing is value-stream mapping , whereby production managers “map” the flow from suppliers through the factory to customers. Simple icons represent the materials and information needed at various points in the flow. Value-stream mapping can help identify where bottlenecks may occur in the production process and is a valuable tool for visualizing how to improve production routing.
Awning manufacturer Rader Awning & Upholstery used value-stream mapping to automate some of its operations. With the assistance of New Mexico Manufacturing Extension Partnership (MEP), the company evaluated how orders were processed from sales to manufacturing over two days. With the implementation of the processes suggested by MEP, productivity improved by 20 percent per salesperson, production defects decreased by 15 percent, and installation corrections dropped by 25 percent. 8
Scheduling: When Do We Do It?
Closely related to routing is scheduling. Scheduling involves specifying and controlling the time required for each step in the production process. The operations manager prepares timetables showing the most efficient sequence of production and then tries to ensure that the necessary materials and labor are in the right place at the right time.
Scheduling is important to both manufacturing and service firms. The production manager in a factory schedules material deliveries, work shifts, and production processes. Trucking companies schedule drivers, clerks, truck maintenance, and repairs in accordance with customer transportation needs. Scheduling at a college entails deciding when to offer which courses, in which classrooms, with which instructors. A museum must schedule special exhibits, ship works to be displayed, market its offerings, and conduct educational programs and tours. Scheduling can range from simple to complex. Giving numbers to customers waiting to be served in a bakery and making interview appointments with job applicants are examples of simple scheduling. Organizations that must produce large quantities of products or services or service a diverse customer base face more complex scheduling problems.
Three common scheduling tools used for complex situations are Gantt charts, the critical path method, and PERT.
Tracking Progress with Gantt Charts
Named after their originator, Henry Gantt, Gantt charts are bar graphs plotted on a time line that show the relationship between scheduled and actual production.
In the example shown in Exhibit 10.9 , the left side of the chart lists the activities required to complete the job or project. Both the scheduled time and the actual time required for each activity are shown, so the manager can easily judge progress.
Gantt charts are most helpful when only a few tasks are involved, when task times are relatively long (days or weeks rather than hours), and when job routes are short and simple. One of the biggest shortcomings of Gantt charts is that they are static. They also fail to show how tasks are related. These problems can be solved, however, by using two other scheduling techniques, the critical path method and PERT.
The Big Picture: Critical Path Method and PERT
To control large projects, operations managers need to closely monitor resources, costs, quality, and budgets. They also must be able to see the “big picture”—the interrelationships of the many different tasks necessary to complete the project. Finally, they must be able to revise scheduling and divert resources quickly if any tasks fall behind schedule. The critical path method (CPM) and the program evaluation and review technique (PERT) are related project management tools that were developed in the 1950s to help managers accomplish this.
In the critical path method (CPM) , the manager identifies all of the activities required to complete the project, the relationships between these activities, and the order in which they need to be completed. Then, the manager develops a diagram that uses arrows to show how the tasks are dependent on each other. The longest path through these linked activities is called the critical path . If the tasks on the critical path are not completed on time, the entire project will fall behind schedule.
To better understand how CPM works, look at Exhibit 10.10 , which shows a CPM diagram for constructing a house. All of the tasks required to finish the house and an estimated time for each have been identified. The arrows indicate the links between the various steps and their required sequence. As you can see, most of the jobs to be done can’t be started until the house’s foundation and frame are completed. It will take five days to finish the foundation and another seven days to erect the house frame. The activities linked by brown arrows form the critical path for this project. It tells us that the fastest possible time the house can be built is 38 days, the total time needed for all of the critical path tasks. The noncritical path jobs, those connected with black arrows, can be delayed a bit or done early. Short delays in installing appliances or roofing won’t delay construction of the house because these activities don’t lie on the critical path.
Like CPM, the program evaluation and review technique (PERT) helps managers identify critical tasks and assess how delays in certain activities will affect operations or production. In both methods, managers use diagrams to see how operations and production will flow. PERT differs from CPM in one important respect. CPM assumes that the amount of time needed to finish a task is known with certainty; therefore, the CPM diagram shows only one number for the time needed to complete each activity. In contrast, PERT assigns three time estimates for each activity: an optimistic time for completion, the most probable time, and a pessimistic time. These estimates allow managers to anticipate delays and potential problems and schedule accordingly.
CONCEPT CHECK
- What is production control, and what are its key aspects?
- How can value-stream mapping improve routing efficiency?
- Identify and describe three commonly used scheduling tools.


29.1A: Characteristics of Chordata
- Identify the key features of the chordates
Characteristics of Chordata
Animals in the phylum Chordata share four key features that appear at some stage during their development (often, only during embryogenesis) (:
- a notochord
- a dorsal hollow nerve cord
- pharyngeal slits
- post-anal tail
Notochord
The chordates are named for the notochord: a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and also in the adult stage of some chordate species. It is located between the digestive tube and the nerve cord, providing skeletal support through the length of the body. In some chordates, the notochord acts as the primary axial support of the body throughout the animal’s lifetime.
In vertebrates, the notochord is present during embryonic development, at which time it induces the development of the neural tube which serves as a support for the developing embryonic body. The notochord, however, is replaced by the vertebral column (spine) in most adult vertebrates.
Dorsal Hollow Nerve Cord
The dorsal hollow nerve cord derives from ectoderm that rolls into a hollow tube during development. In chordates, it is located dorsally (at the top of the animal) to the notochord. In contrast to the chordates, other animal phyla are characterized by solid nerve cords that are located either ventrally or laterally. The nerve cord found in most chordate embryos develops into the brain and spinal cord, which comprise the central nervous system.
Pharyngeal Slits
Pharyngeal slits are openings in the pharynx (the region just posterior to the mouth) that extend to the outside environment. In organisms that live in aquatic environments, pharyngeal slits allow for the exit of water that enters the mouth during feeding. Some invertebrate chordates use the pharyngeal slits to filter food out of the water that enters the mouth. In vertebrate fishes, the pharyngeal slits develop into gill arches, the bony or cartilaginous gill supports.
In most terrestrial animals, including mammals and birds, pharyngeal slits are present only during embryonic development. In these animals, the pharyngeal slits develop into the jaw and inner ear bones.
Post-anal Tail
The post-anal tail is a posterior elongation of the body, extending beyond the anus. The tail contains skeletal elements and muscles, which provide a source of locomotion in aquatic species. In some terrestrial vertebrates, the tail also helps with balance, courting, and signaling when danger is near. In humans and other apes, the post-anal tail is present during embryonic development, but is vestigial as an adult.
Key Points
- These characteristics are only present during embryonic development in some chordates.
- The notochord provides skeletal support, gives the phylum its name, and develops into the vertebral column in vertebrates.
- The dorsal hollow nerve cord develops into the central nervous system: the brain and spine.
- Pharyngeal slits are openings in the pharynx that develop into gill arches in bony fish and into the jaw and inner ear in terrestrial animals.
- The post-anal tail is a skeletal extension of the posterior end of the body, being absent in humans and apes, although present during embryonic development.
Key Terms
- notochord : a flexible rodlike structure that forms the main support of the body in the lowest chordates; a primitive spine
- nerve cord : a dorsal tubular cord of nervous tissue above the notochord of a chordate
- pharyngeal slit : filter-feeding organs found in non-vertebrate chordates (lancelets and tunicates) and hemichordates living in aquatic environments


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14: Magnetism and Electromagnetism
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14.1: Permanent Magnets
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Centuries ago, it was discovered that certain types of mineral rock possessed unusual properties of attraction to the metal iron. One particular mineral, called lodestone, or magnetite, is found mentioned in very old historical records (about 2500 years ago in Europe, and much earlier in the Far East) as a subject of curiosity. Later, it was employed in the aid of navigation, as it was found that a piece of this unusual rock would tend to orient itself in a north-south direction if left free to
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14.2: Electromagnetism
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The discovery of the relationship between magnetism and electricity was, like so many other scientific discoveries, stumbled upon almost by accident. The Danish physicist Hans Christian Oersted was lecturing one day in 1820 on the possibility of electricity and magnetism being related to one another, and in the process demonstrated it conclusively by experiment in front of his whole class! By passing an electric current through a metal wire suspended above a magnetic compass, Oersted was able to
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14.3: Magnetic Units of Measurement
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If the burden of two systems of measurement for common quantities (English vs. metric) throws your mind into confusion, this is not the place for you! Due to an early lack of standardization in the science of magnetism, we have been plagued with no less than three complete systems of measurement for magnetic quantities.
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14.4: Permeability and Saturation
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14.5: Electromagnetic Induction
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While Oersted’s surprising discovery of electromagnetism paved the way for more practical applications of electricity, it was Michael Faraday who gave us the key to the practical generation of electricity: electromagnetic induction. Faraday discovered that a voltage would be generated across a length of wire if that wire was exposed to a perpendicular magnetic field flux of changing intensity.
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14.6: Mutual Inductance
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If two coils of wire are brought into close proximity with each other so the magnetic field from one links with the other, a voltage will be generated in the second coil as a result. This is called mutual inductance: when voltage impressed upon one coil induces a voltage in another.


<IP_ADDRESS>.3.2: Signs and Signifiers
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Let’s start with a really simple example. Take a look at these three things:
These signs all ‘stand in’ for the idea of a tree. But they do so in different ways. We generally categorize signs into three types:
- Iconic signs – icons are signs where meaning is based on similarity of appearance. So our drawing of our tree stands in for the notion of ‘tree’ based on a crude similarity of appearance.
- Indexical signs – Indexical signs have a cause-and-effect relationship between the sign and the meaning of the sign. There is a direct link between the two. So a leaf might be an indexical sign.
- Symbolic signs – these signs have an arbitrary or conventional link. The word tree, t-r-e-e only comes to stand in for the notion of tree because of the conventions of our language. In another convention, the symbolic sign for tree might be ‘arbor’ (German) or ‘木’ (Japanese)
In each case, the sign can be broken into two parts, the signifier and the signified . The signifier is the thing, item, or code that we ‘read’ – so, a drawing, a word, a photo. Each signifier has a signified, the idea or meaning being expressed by that signifier. Only together do they form a sign. There is often no intrinsic or direct relationship between a signifier and a signified – no signifier-signified system is ‘better’ than another. Language is flexible, constructed, and changeable. de Saussure uses the word ‘arbitrariness’ to describe this relationship.
A good example is the word ‘cool.’ If we take the spoken word ‘cool’ as a signifier, what might be the signified? In one context or situation, cool might refer to temperature. But in another, it might refer to something as ‘stylish’ or ‘popular’. The relationship between signifier and signified can change over time and in different contexts.
This is important, because signs are understood and encoded in context. As with the words ‘’cool,’ the relationship between signifier and signified is made meaningful in context. This area starts by looking at signs in isolation, but as you become more confident with semiotics, you will start to look at signs as part of a sign system.
Discussion
- What is the relationship between a signifier and the signified?
- What might be an example of an iconic, indexical and symbolic sign for the idea of your pet?


<IP_ADDRESS>: The Yellow Wall-Paper
It is very seldom that mere ordinary people like John and myself secure ancestral halls for the summer.
A colonial mansion, a hereditary estate, I would say a haunted house, and reach the height of romantic felicity—but that would be asking too much of fate!
Still I will proudly declare that there is something queer about it.
Else, why should it be let so cheaply? And why have stood so long untenanted?
John laughs at me, of course, but one expects that in marriage.
John is practical in the extreme. He has no patience with faith, an intense horror of superstition, and he scoffs openly at any talk of things not to be felt and seen and put down in figures.
John is a physician, and perhaps —(I would not say it to a living soul, of course, but this is dead paper and a great relief to my mind)— perhaps that is one reason I do not get well faster.
You see, he does not believe I am sick!
And what can one do?
If a physician of high standing, and one's own husband, assures friends and relatives that there is really nothing the matter with one but temporary nervous depression—a slight hysterical tendency—what is one to do?
My brother is also a physician, and also of high standing, and he says the same thing.
So I take phosphates or phosphites—whichever it is, and tonics, and journeys, and air, and exercise, and am absolutely forbidden to "work" until I am well again.
Personally, I disagree with their ideas.
Personally, I believe that congenial work, with excitement and change, would do me good.
But what is one to do?
I did write for a while in spite of them; but it does exhaust me a good deal—having to be so sly about it, or else meet with heavy opposition.
I sometimes fancy that in my condition if I had less opposition and more society and stimulus—but John says the very worst thing I can do is to think about my condition, and I confess it always makes me feel bad.
So I will let it alone and talk about the house.
The most beautiful place! It is quite alone, standing well back from the road, quite three miles from the village. It makes me think of English places that you read about, for there are hedges and walls and gates that lock, and lots of separate little houses for the gardeners and people.
There is a delicious garden! I never saw such a garden—large and shady, full of box-bordered paths, and lined with long grape-covered arbors with seats under them.
There were greenhouses, too, but they are all broken now.
There was some legal trouble, I believe, something about the heirs and co-heirs; anyhow, the place has been empty for years.
That spoils my ghostliness, I am afraid; but I don't care—there is something strange about the house—I can feel it.
I even said so to John one moonlight evening, but he said what I felt was a draught , and shut the window.
I get unreasonably angry with John sometimes. I'm sure I never used to be so sensitive. I think it is due to this nervous condition.
But John says if I feel so I shall neglect proper self-control; so I take pains to control myself,—before him, at least,—and that makes me very tired.
I don't like our room a bit. I wanted one downstairs that opened on the piazza and had roses all over the window, and such pretty old-fashioned chintz hangings! but John would not hear of it.
He said there was only one window and not room for two beds, and no near room for him if he took another.
He is very careful and loving, and hardly lets me stir without special direction.
I have a schedule prescription for each hour in the day; he takes all care from me, and so I feel basely ungrateful not to value it more.
He said we came here solely on my account, that I was to have perfect rest and all the air I could get. "Your exercise depends on your strength, my dear," said he, "and your food somewhat on your appetite; but air you can absorb all the time." So we took the nursery, at the top of the house.
It is a big, airy room, the whole floor nearly, with windows that look all ways, and air and sunshine galore. It was nursery first and then playground and gymnasium, I should judge; for the windows are barred for little children, and there are rings and things in the walls.
The paint and paper look as if a boys' school had used it. It is stripped off—the paper—in great patches all around the head of my bed, about as far as I can reach, and in a great place on the other side of the room low down. I never saw a worse paper in my life.
One of those sprawling flamboyant patterns committing every artistic sin.

The color is repellant, almost revolting; a smouldering, unclean yellow, strangely faded by the slow-turning sunlight.
It is a dull yet lurid orange in some places, a sickly sulphur tint in others.
No wonder the children hated it! I should hate it myself if I had to live in this room long.
There comes John, and I must put this away,—he hates to have me write a word.
We have been here two weeks, and I haven't felt like writing before, since that first day.
I am sitting by the window now, up in this atrocious nursery, and there is nothing to hinder my writing as much as I please, save lack of strength.

I am glad my case is not serious!
But these nervous troubles are dreadfully depressing.
John does not know how much I really suffer. He knows there is no reason to suffer, and that satisfies him.
Of course it is only nervousness. It does weigh on me so not to do my duty in any way!
I meant to be such a help to John, such a real rest and comfort, and here I am a comparative burden already!
Nobody would believe what an effort it is to do what little I am able—to dress and entertain, and order things.
It is fortunate Mary is so good with the baby. Such a dear baby!
And yet I cannot be with him, it makes me so nervous.
I suppose John never was nervous in his life. He laughs at me so about this wallpaper!
At first he meant to repaper the room, but afterwards he said that I was letting it get the better of me, and that nothing was worse for a nervous patient than to give way to such fancies.
He said that after the wallpaper was changed it would be the heavy bedstead, and then the barred windows, and then that gate at the head of the stairs, and so on.
"You know the place is doing you good," he said, "and really, dear, I don't care to renovate the house just for a three months' rental."
"Then do let us go downstairs," I said, "there are such pretty rooms there."
Then he took me in his arms and called me a blessed little goose, and said he would go down cellar if I wished, and have it whitewashed into the bargain.
But he is right enough about the beds and windows and things.
It is as airy and comfortable a room as any one need wish, and, of course, I would not be so silly as to make him uncomfortable just for a whim.
I'm really getting quite fond of the big room, all but that horrid paper.
Out of one window I can see the garden, those mysterious deep-shaded arbors, the riotous old-fashioned flowers, and bushes and gnarly trees.
Out of another I get a lovely view of the bay and a little private wharf belonging to the estate. There is a beautiful shaded lane that runs down there from the house. I always fancy I see people walking in these numerous paths and arbors, but John has cautioned me not to give way to fancy in the least. He says that with my imaginative power and habit of story-making a nervous weakness like mine is sure to lead to all manner of excited fancies, and that I ought to use my will and good sense to check the tendency. So I try.
I think sometimes that if I were only well enough to write a little it would relieve the press of ideas and rest me.
But I find I get pretty tired when I try.
It is so discouraging not to have any advice and companionship about my work. When I get really well John says we will ask Cousin Henry and Julia down for a long visit; but he says he would as soon put fire-works in my pillow-case as to let me have those stimulating people about now.
I wish I could get well faster.
But I must not think about that. This paper looks to me as if it knew what a vicious influence it had!
There is a recurrent spot where the pattern lolls like a broken neck and two bulbous eyes stare at you upside-down.
I get positively angry with the impertinence of it and the everlastingness. Up and down and sideways they crawl, and those absurd, unblinking eyes are everywhere. There is one place where two breadths didn't match, and the eyes go all up and down the line, one a little higher than the other.
I never saw so much expression in an inanimate thing before, and we all know how much expression they have! I used to lie awake as a child and get more entertainment and terror out of blank walls and plain furniture than most children could find in a toy-store.
I remember what a kindly wink the knobs of our big old bureau used to have, and there was one chair that always seemed like a strong friend.
I used to feel that if any of the other things looked too fierce I could always hop into that chair and be safe.
The furniture in this room is no worse than inharmonious, however, for we had to bring it all from downstairs. I suppose when this was used as a playroom they had to take the nursery things out, and no wonder! I never saw such ravages as the children have made here.
The wallpaper, as I said before, is torn off in spots, and it sticketh closer than a brother—they must have had perseverance as well as hatred.
Then the floor is scratched and gouged and splintered, the plaster itself is dug out here and there, and this great heavy bed, which is all we found in the room, looks as if it had been through the wars.
But I don't mind it a bit—only the paper.
There comes John's sister. Such a dear girl as she is, and so careful of me! I must not let her find me writing.
She is a perfect, and enthusiastic housekeeper, and hopes for no better profession. I verily believe she thinks it is the writing which made me sick!
But I can write when she is out, and see her a long way off from these windows.
There is one that commands the road, a lovely, shaded, winding road, and one that just looks off over the country. A lovely country, too, full of great elms and velvet meadows.
This wallpaper has a kind of sub-pattern in a different shade, a particularly irritating one, for you can only see it in certain lights, and not clearly then.
But in the places where it isn't faded, and where the sun is just so, I can see a strange, provoking, formless sort of figure, that seems to sulk about behind that silly and conspicuous front design.
There's sister on the stairs!
Well, the Fourth of July is over! The people are gone and I am tired out. John thought it might do me good to see a little company, so we just had mother and Nellie and the children down for a week.
Of course I didn't do a thing. Jennie sees to everything now.
But it tired me all the same.
John says if I don't pick up faster he shall send me to Weir Mitchell in the fall.
But I don't want to go there at all. I had a friend who was in his hands once, and she says he is just like John and my brother, only more so!
Besides, it is such an undertaking to go so far.
I don't feel as if it was worth while to turn my hand over for anything, and I'm getting dreadfully fretful and querulous.

Of course I don't when John is here, or anybody else, but when I am alone.
And I am alone a good deal just now. John is kept in town very often by serious cases, and Jennie is good and lets me alone when I want her to.
So I walk a little in the garden or down that lovely lane, sit on the porch under the roses, and lie down up here a good deal.
I'm getting really fond of the room in spite of the wallpaper. Perhaps because of the wallpaper.
It dwells in my mind so!
I lie here on this great immovable bed—it is nailed down, I believe—and follow that pattern about by the hour. It is as good as gymnastics, I assure you. I start, we'll say, at the bottom, down in the corner over there where it has not been touched, and I determine for the thousandth time that I will follow that pointless pattern to some sort of a conclusion.
I know a little of the principle of design, and I know this thing was not arranged on any laws of radiation, or alternation, or repetition, or symmetry, or anything else that I ever heard of.
It is repeated, of course, by the breadths, but not otherwise.
Looked at in one way each breadth stands alone, the bloated curves and flourishes—a kind of "debased Romanesque" with delirium tremens —go waddling up and down in isolated columns of fatuity.
But, on the other hand, they connect diagonally, and the sprawling outlines run off in great slanting waves of optic horror, like a lot of wallowing seaweeds in full chase.
The whole thing goes horizontally, too, at least it seems so, and I exhaust myself in trying to distinguish the order of its going in that direction.
They have used a horizontal breadth for a frieze, and that adds wonderfully to the confusion.
There is one end of the room where it is almost intact, and there, when the cross-lights fade and the low sun shines directly upon it, I can almost fancy radiation after all,—the interminable grotesques seem to form around a common centre and rush off in headlong plunges of equal distraction.
It makes me tired to follow it. I will take a nap, I guess.
I don't know why I should write this.
I don't want to.
I don't feel able.
And I know John would think it absurd. But I must say what I feel and think in some way—it is such a relief!
But the effort is getting to be greater than the relief.
Half the time now I am awfully lazy, and lie down ever so much.
John says I musn't lose my strength, and has me take cod-liver oil and lots of tonics and things, to say nothing of ale and wine and rare meat.
Dear John! He loves me very dearly, and hates to have me sick. I tried to have a real earnest reasonable talk with him the other day, and tell him how I wish he would let me go and make a visit to Cousin Henry and Julia.
But he said I wasn't able to go, nor able to stand it after I got there; and I did not make out a very good case for myself, for I was crying before I had finished.
It is getting to be a great effort for me to think straight. Just this nervous weakness, I suppose.
And dear John gathered me up in his arms, and just carried me upstairs and laid me on the bed, and sat by me and read to me till it tired my head.
He said I was his darling and his comfort and all he had, and that I must take care of myself for his sake, and keep well.
He says no one but myself can help me out of it, that I must use my will and self-control and not let any silly fancies run away with me.
There's one comfort, the baby is well and happy, and does not have to occupy this nursery with the horrid wallpaper.
If we had not used it that blessed child would have! What a fortunate escape! Why, I wouldn't have a child of mine, an impressionable little thing, live in such a room for worlds.
I never thought of it before, but it is lucky that John kept me here after all.
Of course I never mention it to them any more,—I am too wise,—but I keep watch of it all the same.
There are things in that paper that nobody knows but me, or ever will.
Behind that outside pattern the dim shapes get clearer every day.
It is always the same shape, only very numerous.
And it is like a woman stooping down and creeping about behind that pattern. I don't like it a bit. I wonder—I begin to think—I wish John would take me away from here!
It is so hard to talk with John about my case, because he is so wise, and because he loves me so.
But I tried it last night.
It was moonlight. The moon shines in all around, just as the sun does.
I hate to see it sometimes, it creeps so slowly, and always comes in by one window or another.
John was asleep and I hated to waken him, so I kept still and watched the moonlight on that undulating wallpaper till I felt creepy.
The faint figure behind seemed to shake the pattern, just as if she wanted to get out.
I got up softly and went to feel and see if the paper did move, and when I came back John was awake.
"What is it, little girl?" he said. "Don't go walking about like that—you'll get cold."
I though it was a good time to talk, so I told him that I really was not gaining here, and that I wished he would take me away.
"Why darling!" said he, "our lease will be up in three weeks, and I can't see how to leave before.
"The repairs are not done at home, and I cannot possibly leave town just now. Of course if you were in any danger I could and would, but you really are better, dear, whether you can see it or not. I am a doctor, dear, and I know. You are gaining flesh and color, your appetite is better. I feel really much easier about you."
"I don't weigh a bit more," said I, "nor as much; and my appetite may be better in the evening, when you are here, but it is worse in the morning when you are away."
"Bless her little heart!"  But now let's improve the shining hours by going to sleep, and talk about it in the morning!"
"And you won't go away?" I asked gloomily.
"Why, how can I, dear? It is only three weeks more and then we will take a nice little trip of a few days while Jennie is getting the house ready. Really, dear, you are better!"
"Better in body perhaps"—I began, and stopped short, for he sat up straight and looked at me with such a stern, reproachful look that I could not say another word.
"My darling," said he, "I beg of you, for my sake and for our child's sake, as well as for your own, that you will never for one instant let that idea enter your mind! There is nothing so dangerous, so fascinating, to a temperament like yours. It is a false and foolish fancy. Can you not trust me as a physician when I tell you so?"
So of course I said no more on that score, and we went to sleep before long. He thought I was asleep first, but I wasn't,—I lay there for hours trying to decide whether that front pattern and the back pattern really did move together or separately.
On a pattern like this, by daylight, there is a lack of sequence, a defiance of law, that is a constant irritant to a normal mind.
The color is hideous enough, and unreliable enough, and infuriating enough, but the pattern is torturing.
You think you have mastered it, but just as you get well under way in following, it turns a back somersault and there you are.  It is like a bad dream.
The outside pattern is a florid arabesque, reminding one of a fungus. If you can imagine a toadstool in joints, an interminable string of toadstools, budding and sprouting in endless convolutions,—why, that is something like it.
That is, sometimes!
There is one marked peculiarity about this paper, a thing nobody seems to notice but myself, and that is that it changes as the light changes.
When the sun shoots in through the east window—I always watch for that first long, straight ray—it changes so quickly that I never can quite believe it.
That is why I watch it always.
By moonlight—the moon shines in all night when there is a moon—I wouldn't know it was the same paper.
At night in any kind of light, in twilight, candlelight, lamplight, and worst of all by moonlight, it becomes bars! The outside pattern I mean, and the woman behind it is as plain as can be.
I didn't realize for a long time what the thing was that showed behind,—that dim sub-pattern,—but now I am quite sure it is a woman.
By daylight she is subdued, quiet. I fancy it is the pattern that keeps her so still. It is so puzzling. It keeps me quiet by the hour.
I lie down ever so much now. John says it is good for me, and to sleep all I can.
Indeed, he started the habit by making me lie down for an hour after each meal.
It is a very bad habit, I am convinced, for, you see, I don't sleep.
And that cultivates deceit, for I don't tell them I'm awake,—oh, no!
The fact is, I am getting a little afraid of John.
He seems very queer sometimes, and even Jennie has an inexplicable look.
It strikes me occasionally, just as a scientific hypothesis, that perhaps it is the paper!
I have watched John when he did not know I was looking, and come into the room suddenly on the most innocent excuses, and I've caught him several times looking at the paper! And Jennie too. I caught Jennie with her hand on it once.
She didn't know I was in the room, and when I asked her in a quiet, a very quiet voice, with the most restrained manner possible, what she was doing with the paper she turned around as if she had been caught stealing, and looked quite angry—asked me why I should frighten her so!
Then she said that the paper stained everything it touched, that she had found yellow smooches on all my clothes and John's, and she wished we would be more careful!
Did not that sound innocent? But I know she was studying that pattern, and I am determined that nobody shall find it out but myself!
Life is very much more exciting now than it used to be. You see I have something more to expect, to look forward to, to watch. I really do eat better, and am more quiet than I was.
John is so pleased to see me improve! He laughed a little the other day, and said I seemed to be flourishing in spite of my wallpaper.
I turned it off with a laugh. I had no intention of telling him it was because of the wallpaper—he would make fun of me. He might even want to take me away.
I don't want to leave now until I have found it out. There is a week more, and I think that will be enough.
I'm feeling ever so much better! I don't sleep much at night, for it is so interesting to watch developments; but I sleep a good deal in the daytime.
In the daytime it is tiresome and perplexing.
There are always new shoots on the fungus, and new shades of yellow all over it. I cannot keep count of them, though I have tried conscientiously.
It is the strangest yellow, that wallpaper! It makes me think of all the yellow things I ever saw—not beautiful ones like buttercups, but old foul, bad yellow things.
But there is something else about that paper—the smell! I noticed it the moment we came into the room, but with so much air and sun it was not bad. Now we have had a week of fog and rain, and whether the windows are open or not, the smell is here.
It creeps all over the house.
I find it hovering in the dining-room, skulking in the parlor, hiding in the hall, lying in wait for me on the stairs.
It gets into my hair.
Even when I go to ride, if I turn my head suddenly and surprise it—there is that smell!
Such a peculiar odor, too! I have spent hours in trying to analyze it, to find what it smelled like.
It is not bad—at first, and very gentle, but quite the subtlest, most enduring odor I ever met.
In this damp weather it is awful. I wake up in the night and find it hanging over me.
It used to disturb me at first. I thought seriously of burning the house—to reach the smell.
But now I am used to it. The only thing I can think of that it is like is the color of the paper! A yellow smell.
There is a very funny mark on this wall, low down, near the mopboard. A streak that runs round the room. It goes behind every piece of furniture, except the bed, a long, straight, even smooch , as if it had been rubbed over and over.
I wonder how it was done and who did it, and what they did it for. Round and round and round—round and round and round—it makes me dizzy!
I really have discovered something at last.
Through watching so much at night, when it changes so, I have finally found out.
The front pattern does move—and no wonder! The woman behind shakes it!
Sometimes I think there are a great many women behind, and sometimes only one, and she crawls around fast, and her crawling shakes it all over.
Then in the very bright spots she keeps still, and in the very shady spots she just takes hold of the bars and shakes them hard.
And she is all the time trying to climb through. But nobody could climb through that pattern—it strangles so; I think that is why it has so many heads.
They get through, and then the pattern strangles them off and turns them upside-down, and makes their eyes white!
If those heads were covered or taken off it would not be half so bad.
I think that woman gets out in the daytime!
And I'll tell you why—privately—I've seen her!
I can see her out of every one of my windows!
It is the same woman, I know, for she is always creeping, and most women do not creep by daylight.
I see her on that long shaded lane, creeping up and down. I see her in those dark grape arbors, creeping all around the garden.
I see her on that long road under the trees, creeping along, and when a carriage comes she hides under the blackberry vines.
I don't blame her a bit. It must be very humiliating to be caught creeping by daylight!
I always lock the door when I creep by daylight. I can't do it at night, for I know John would suspect something at once.
And John is so queer now, that I don't want to irritate him. I wish he would take another room! Besides, I don't want anybody to get that woman out at night but myself.
I often wonder if I could see her out of all the windows at once.
But, turn as fast as I can, I can only see out of one at one time.
And though I always see her she may be able to creep faster than I can turn!
I have watched her sometimes away off in the open country, creeping as fast as a cloud shadow in a high wind.
If only that top pattern could be gotten off from the under one! I mean to try it, little by little.
I have found out another funny thing, but I shan't tell it this time! It does not do to trust people too much.
There are only two more days to get this paper off, and I believe John is beginning to notice. I don't like the look in his eyes.
And I heard him ask Jennie a lot of professional questions about me. She had a very good report to give.
She said I slept a good deal in the daytime.
John knows I don't sleep very well at night, for all I'm so quiet!
He asked me all sorts of questions, too, and pretended to be very loving and kind.
As if I couldn't see through him!
Still, I don't wonder he acts so, sleeping under this paper for three months.
It only interests me, but I feel sure John and Jennie are secretly affected by it.
Hurrah! This is the last day, but it is enough. John is to stay in town over night, and won't be out until this evening.
Jennie wanted to sleep with me—the sly thing! but I told her I should undoubtedly rest better for a night all alone.
That was clever, for really I wasn't alone a bit! As soon as it was moonlight, and that poor thing began to crawl and shake the pattern, I got up and ran to help her.
I pulled and she shook, I shook and she pulled, and before morning we had peeled off yards of that paper.
A strip about as high as my head and half around the room.
And then when the sun came and that awful pattern began to laugh at me I declared I would finish it to-day!
We go away to-morrow, and they are moving all my furniture down again to leave things as they were before.
Jennie looked at the wall in amazement, but I told her merrily that I did it out of pure spite at the vicious thing.
She laughed and said she wouldn't mind doing it herself, but I must not get tired.
How she betrayed herself that time!
But I am here, and no person touches this paper but me—not alive!
She tried to get me out of the room—it was too patent! But I said it was so quiet and empty and clean now that I believed I would lie down again and sleep all I could; and not to wake me even for dinner—I would call when I woke.
So now she is gone, and the servants are gone, and the things are gone, and there is nothing left but that great bedstead nailed down, with the canvas mattress we found on it.
We shall sleep downstairs to-night, and take the boat home to-morrow.
I quite enjoy the room, now it is bare again.
How those children did tear about here!
This bedstead is fairly gnawed!
But I must get to work.
I have locked the door and thrown the key down into the front path.
I don't want to go out, and I don't want to have anybody come in, till John comes.
I want to astonish him.
I've got a rope up here that even Jennie did not find. If that woman does get out, and tries to get away, I can tie her!
But I forgot I could not reach far without anything to stand on!
This bed will not move!
I tried to lift and push it until I was lame, and then I got so angry I bit off a little piece at one corner—but it hurt my teeth.
Then I peeled off all the paper I could reach standing on the floor. It sticks horribly and the pattern just enjoys it! All those strangled heads and bulbous eyes and waddling fungus growths just shriek with derision!
I am getting angry enough to do something desperate. To jump out of the window would be admirable exercise, but the bars are too strong even to try.
Besides I wouldn't do it. Of course not. I know well enough that a step like that is improper and might be misconstrued.
I don't like to look out of the windows even—there are so many of those creeping women, and they creep so fast.
I wonder if they all come out of that wallpaper as I did?
But I am securely fastened now by my well-hidden rope—you don't get me out in the road there!
I suppose I shall have to get back behind the pattern when it comes night, and that is hard!
It is so pleasant to be out in this great room and creep around as I please!
I don't want to go outside. I won't, even if Jennie asks me to.
For outside you have to creep on the ground, and everything is green instead of yellow.
But here I can creep smoothly on the floor, and my shoulder just fits in that long smooch around the wall, so I cannot lose my way.
Why, there's John at the door!
It is no use, young man, you can't open it!
How he does call and pound!
Now he's crying for an axe.
It would be a shame to break down that beautiful door!
"John dear!" said I in the gentlest voice, "the key is down by the front steps, under a plantain leaf!"
That silenced him for a few moments.
Then he said—very quietly indeed, "Open the door, my darling!"
"I can't," said I. "The key is down by the front door under a plantain leaf!"
And then I said it again, several times, very gently and slowly, and said it so often that he had to go and see, and he got it, of course, and came in. He stopped short by the door.
"What is the matter?" he cried. "For God's sake, what are you doing!"
I kept on creeping just the same, but I looked at him over my shoulder.
"I've got out at last," said I, "in spite of you and Jane! And I've pulled off most of the paper, so you can't put me back!"
Now why should that man have fainted? But he did, and right across my path by the wall, so that I had to creep over him every time!