Latitude in Snyder (page 15): For the "normal" Mercator projection (on the ellipsoid) this function defines the spacing of the parallels: if the length of the equator on the projection is (units of length or pixels) then the distance, , of a parallel of latitude from the equator is The isometric latitude is closely related to the conformal latitude : The formulae in the previous sections give the auxiliary latitude in terms of the geodetic latitude. The expressions for the geocentric and parametric latitudes may be inverted directly but this is impossible in the four remaining cases: the rectifying, authalic, conformal,
Gaithersburg Latitude Observatory one of the four original observatories built by 1899 — tracking the degree of "wobble" occurring on the earth's north-south axis and resultant variation of latitude. The Observatory — along with observatories in Cincinnati, Ohio; Ukiah, California; Mizusawa, Japan; Charjui in Russian Turkestan; and Carloforte, Sardina, Italy — performed in concert to carry out a coordinated program of star observation designed to investigate and calculate the degree of earth "wobble" or latitude variation. On the grounds of the Gaithersburg Latitude Observatory stands a plaque that reads: This small framed structure played a key role in the scientific investigation of the