[Proj] Links to old papers on geodesics

[Charles Karney]

I added links to a number of C18 and C19 papers on geodesics on

    http://trac.osgeo.org/proj/wiki/GeodesicCalculations#TheHistory

This includes papers and books by Clairaut, Euler, du Séjour, Legendre,
Puissant, Bessel, Gauss, Christoffel, Cayley, Helmert, and Clark,
spanning the period 1733 to 1880.

The links take you to the full text of the works.  Unfortunately, the
book scanning done by Google does not fold out the folded figures.  I
will upload scans of the missing figures I can get hold of.  Please let
me know of errors, omissions, etc.

-- 
Charles Karney <ckarney at sarnoff.com>
Sarnoff Corporation, Princeton, NJ 08543-5300

Tel: +1 609 734 2312
Fax: +1 609 734 2662