Recently a wonderful cache of old photos was discovered at Palomar. Virtually every image has a date and some accompanying text to go with it. Scanning of this collection has just begun and most of the images have not likely been seen by anyone in decades.
The oldest image in the collection is this one:
The writing on the envelope that contained the glass negative for this shot indicated that the image is from 1929. It was labeled: 4" telescope & stand used for testing seeing.
That means that this telescope is likely one of the ones that was used to evaluate the conditions on various mountain tops as a part of the survey to decide which mountain would be chosen as the home for the 200-inch telescope. Palomar was, of course, finally chosen in 1934. I do not know what became of the site testing telescopes.
The photo was taken by Ferdinand Ellerman.
UPDATE: Thanks to eagle-eyed reader Matt who noticed that there were letters on a box that were backward, meaning that the image was reversed. It has now been corrected. The letters on the box were from a Van Dyck cigar box, shown in full resolution below: