The article did not describe the terms in which the contributors sold their work. Presumably in this case it was for a use in a particular magazine issue.
It would appear in this case in essence NatlG merely reprinted an old issue for which they already compensated the contributor. I don't think contributors are entitled to any extra compensation if the publisher simply issues a reprint of the original work, and that happens often. In other words, if I sell a photo to NatlG and they run it in an issue, and that issue is so popular that they reprint it many times over, I am not entitled to any more compensation than if it was a normal press run.
FWIW, I also want to note that the second hand price of old Natg Geo is very low. My local library has a bookcase full of them for sale at20c each and won't take any more donations to sell. They're not moving very quickly. I like the issues from the 1950s and earliers since the Bell System always had a nice full page ad on the last page (there was a connection between the Bell System and Natlg Geo boards). I got one ad showing "the voice with a smile" which I'm giving to our Centrex operators.
FWIW, a lot of ads from the 1950s are from corporations touting their defense work for the convert, such as missles and atomic energy. Lots of ads had the symbol of an atom in them. In the 1950s companies were proud of that, in the 1960s it became rather controversial.
Actually, some people on e-bay make a business of buying this off stuff, clipping out the ads, and selling the ads. NatlG isn't so good for this since the pages are small, but Fortune and Life magazines have big ads (nice colorful Bell System ads, BTW).
I also picked up a bound volume from the early 1950s with an interesting article on Long Island, but the bound volumes are stripped of all ads, which can be more interesting than the articles themselves.[public replies please] [TELECOM Digest Editor's Note: In the past, I wrote a few articles which I sold, mostly to the Christian Science Monitor for their Home Forum page; also an occasional crossword puzzle. These were in the 1960's, and the Monitor always paid _very well_ for articles and essays and such they purchased, but the conditions were you gave them an _exclusive_ use to the content. No one else could use the articles (including yourself) and _they could use the articles when they pleased and as often as they pleased. I think they paid me fifty dollars for each my Home Forum articles and puzzles. I know it was always sufficient to keep me in beer and cigarettes. PAT]