Wagner IV, year of origin

[Atarimaster]

Hello,

I just found the file "Corrections compiled by John P. Snyder and Daan Strebe (GeoCART author)
for AN ALBUM OF MAP PROJECTIONS" at
http://www.geography.hunter.cuny.edu/mp/album.txt

It says:

p. 62, title:
PUTNINS P2'
should read
WAGNER IV

UNDER origin
Presented by Reinholds V. Putnins of Latvia in 1934
SHOULD READ
Presented by Karlheinz Wagner of Germany in 1932

But the "Bibliography of Map Projections" by John P. Snyder and Harry Steward, found at
http://pubs.usgs.gov/bul/1856/report.pdf
says on page 96:

Wagner, Karlheinz, 1932, Die unechten Zylinderprojektionen (…)
[Presents two flat-polar pseudocylindrical projections with sinusoidal meridians, one equal-area and one with equally spaced parallels.]

… and that would be Wagner I and Wagner III!

So, if the "Bibliography" would be right, the "Album" was right before you applied the corrections.
Am I right in assuming that the Bibliography is wrong (because it predates the corrections) and it should read "presents two flat-polar pseudocylindrical projections with elliptical meridians"?

Kind regards,
Tobias

[daan]

Hello Tobias.

Interesting. While I would love to take credit for all of those corrections, my own contributions pertained only to typos in text and formulas. None were bibliographic.

I think I can reconstruct what happened, though. Between the list of corrections and the Bibliography of Map Projections, the Bibliography is the earlier work. It’s what Snyder would have used in compiling An Album of Map Projections. Once the Album was completed, he started earnest work on the text for Flattening the Earth: 2,000 Years of Map Projections. While in the course of researching Flattening, he realized the error in attribution, and so he added the Wagner attribution to the list of corrections to be made to the Album.

Why was the Bibliography in error? This is complete conjecture, since I do not have Wagner’s works, but as I recall, Snyder did not read German fluently. If Wagner’s 1932 paper did not illustrate projections II and IV, and if the text did not give explicit formulas for them, then Snyder may well not have realized that the text described them. Meanwhile, projections II and IV did appear in Wagner’s 1949 text, which is where Snyder would have inferred Wagner introduced them. This is borne out by the fact that the original text of the Album states on the Putniṇš P2´ page that Wagner presented an identical projection in 1949. Since Putniṇš presented the projection independently in 1934, Snyder would have assumed Putniṇš was the originator.

In Flattening, Snyder lucidly states that all four projections appeared in Wagner’s 1932 paper. By that time he was confident of the situation. Meanwhile the Bibliography never got corrected, probably because it slipped his mind that the description there only noted two projections.

Best,
— daan

[Atarimaster]

This is complete conjecture

… but sounds pretty reasonable to me.
Thank you very much!

Kind regards,
Tobias