Last Updated: Sep 28, 2016 Views: 23
We don't have any specific records for the Sperry company, although they seem to have been big in the market of beacon manufacture. Their company records are held by the Hagley Museum and Library (http://www.hagley.org/library/collections/manuscripts/findingaids/sperrygyroco.ACC1915.htm). You should definitely contact them to see if they have anything in the company records which describes the type of glass used.
Corning made airfield beacons from Pyrex glass (low-expansion borosilicate glass); I'm not sure if other types of glass might have been used. Pyrex was introduced in 1915 and was often the choice for scientific or industrial glassware.
Our conservator for glass, Steve Koob, might be a good resource for you to contact on subject of ordering glass for repair. Presumably, then you would have to attach it to other glass or to the frame? He may have suggestions for you about how to proceed. His e-mail address is email@example.com.
You can also contact the American Institute for Conservators, if you are looking for someone to do the replacement work. You can search by type of object/material and by geographic area. http://www.conservation-us.org/.
Please let me know if you need additional suggestions. Would love to see a picture of the beacon. We collect information on such objects!