[D8123ZBK], Letter from Francis Robbins Upton to Thomas Alva Edison, May 4th, 1881

https://edisondigital.rutgers.edu/document/D8123ZBK

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Title

[D8123ZBK], Letter from Francis Robbins Upton to Thomas Alva Edison, May 4th, 1881

Editor's Notes

Heating clamps gives better results in lamp making; will do so and can make 300 lamps a day that way. If works out, then will make all lamps this way. Haid has sent 75 of the finest bamboos yet for treatment. Bamboo loops instead of paper loops give lamps much longer life, despite of extra 10% cost. Currently turning out about 700-800 lamps daily. Has about 200 pumps currently running. Also working on sockets. Lamp resistance has decreased about 3 ohms in past several weeks due to better carbonizing and pumping. Advises making bamboo thinner to increase resistance from 95-100 ohms. Also, lack of standard resistances make it hard to ascertain accurate lamp resistances. Consider for inclusion: gives good sense of production and development problems. (DH)

Date

1881-05-04

Decade

1880-1889

Type

Folder/Volume ID

D8123-F

Microfilm ID

57:871

Document ID

D8123ZBK

Publisher

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