This week's Palomar Observatory History Photo of the Week comes from February 12, 1935. The photo, taken by Ferdinand Ellerman, shows a scene from the Optical Shop at Caltech:
The large machine in the photo is the grinding & polishing machine for the 120-inch mirror, that was ordered from the Corning Glass Works at a test mirror for the 200-inch project. The 120-inch mirror was eventually sold to the Lick Observatory where in 1959 it became the primary mirror for the Shane Reflector.
Several members of the crew of opticians can be seen in the photo, including chief optician Marcus Brown who is standing on the ladder.
In front of the machine is a group of four people. On the right of that group is Dr. Robert Millikan, the Nobel Prize winning physicist who was then president of Caltech. I don't know who the other three people are. They are described merely as being "friends" of Dr. Millikan.