John wins with his 8:33 a.m. Tuesday guess "Andrew Carnegie with George Ellery Hale (arm in arm) visiting Mount Wilson."
Carnegie was a self-made, wealthy industrialist who founded the Carnegie Institution of Washington (now called Carnegie Institution for Science), which funded the Mount Wilson Observatory.
Carnegie also built Carnegie Hall, founded the Carnegie Corporation of New York, Carnegie Mellon University and so much more.
Hale, a force to be reckoned with in Pasadena, founded the observatory and was instrumental in the founding of Caltech, which previously had been Throop University.
As a member of Pasadena's first Planning Commission, Hale guided the master plan for the Civic Center -- which now consists of Pasadena Public Library to the north and Pasadena Civic Auditorium to south, with City Hall, the Post Office, Police Building, Courthouse and other structures in between.
The Hale Building in the Civic Center, which houses the Pasadena Planning Department and the Permit Center, is named in his honor.
I love this more formal photo taken at the Hotel Maryland during Carnegie's visit. Left to right are Hale, J.H. McBride, John Muir, H.F. Osborn, John Daggett Hooker, J.A.B. Scherer and Carnegie.
The elegant headquarters for the Carnegie Institution for Science's Carnegie Observatories is at 813 Santa Barbara Street in a quiet Pasadena neighborhood off North Lake Avenue. It features beautiful grounds; you can explore inside and meet the astronomers during an annual open house every October, which I highly recommend.
I'll leave you with this photo of Carnegie and Hale inside Mount Wilson Observatory in front of the 60-inch telescope.
Many thanks to Caltech, American Institute of Physics, The Carnegie Observatories and Mount Wilson Observatory for the photos.