[Proj] Gauss-Schreiber: the continuing story

[Gerald I. Evenden]

Mugnier's Chap. 3  of *The Mathematics of Photogrametry* claims that the 
Gauss-Schreiber projection is just an additional truncation of the Taylor 
series Gauss-Kruger---like the Gauss-Boaga but one step further.

However, referring to p. 163 of *Map Projections---A reference manual* by 
Bugayevskiy and Snyder:

"The Gauss-Schreider projection was developed about 1880 and used for the 
Prussian land survey.  It consists of a double conformal transformation of 
the  ellipse onto the sphere and then of the sphere onto the plane using the 
spherical transverse Mercator projection.  The central merdian varies in 
scale."

And, of course, we have the IGN claim with Laborde in NT/G 73.  I am not sure 
what the timing was but because Laborde's Madegascar efforts were circa 1929 
then the best he can probably claim is rediscovering the projection.  The 
Madagascar should not be confused with the NT/G 73 and I am only  using it as 
a reference to one period where we know he was active as I do not have his 
birth-death dates.

I am now of the opinion that libproj4's original designation of the projection 
is correct and a only a documention note should be made that it may have also 
have been used by Laborde at a later date.

More comments on Gauss-Schreiber's truncated Taylor series later.

-- 
The whole religious complexion of the modern world is due
to the absence from Jerusalem of a lunatic asylum.
-- Havelock Ellis (1859-1939)  British psychologist