[interesting TAE marg on lamp life] Has invention for producing high vac. Also wants date, hour, and place of TAE's birth. TAE marg: "We now use a pump that will reduce the pressure to 1/50 millionth of an atmosphere that costs but [7.50] made of glass. We do not find the lamps last any longer at a very high exhaustion."

Edelen, W R

Edison, Thomas Alva

1884-02-04

1880-1889

Letter

Patent assignments, licenses, and royalties

Vacuum and glass bulb

D8403S

D8403

[D8403S], Letter from W R Edelen to Thomas Alva Edison, February 4th, 1884

71:54

Thomas Edison National Historical Park

Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University