New York. Checking for flaws in the glass blank of the 200 inch mirror for the Mount Palomar telescope, Corning Glass Works, Ithaca, 1935. 

The Gentleman with the glasses appears to be Dr. George V, McCauley, a physist at Corning who supervised the project for the California Institute of Technology.

The glass blank for what was then the largest telescope in the world, took nearly a year to make. 21 tons of pyrex glass poured into a special oven that kept it molten for a month, then cooled it from 2700 degrees fahrenheit  at a rate of one or 2 degrees a day over 10 months.