Black and white silent films documenting some of the early days of Caltech's Palomar Observatory are available for viewing at the Internet Archive, a free, nonprofit digital library. The films are the first archival video posted to the web by the Caltech Archives and include original footage of the Observatory's construction, along with images of the 200-inch mirror for the Hale telescope in the astrophysics optical shop on the Caltech campus, being prepared for travel.
Dating from 1936 to 1940, two out of three surviving reels of historical footage have been digitized as part of a project that is managed and funded by the California Audiovisual Preservation Project of the California Digital Library. The third reel will be digitized next year.
A historical timeline of the Palomar Observatory can be found here.