[D7941ZFX], Letter from Thomas Alva Edison to Edward Hibberd Johnson, October 14th, 1879

https://edisondigital.rutgers.edu/document/D7941ZFX

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Title

[D7941ZFX], Letter from Thomas Alva Edison to Edward Hibberd Johnson, October 14th, 1879

Editor's Notes

"Rough notes only as they fly through my head" about pat situation. TAE 1st to apply carbon variable resistance to practical inst. Use of induction coil novel; fully explained in final. Bell provides no details for HOW to vary resistance. Clerac, Hughes, Thomson lack printed evidence of earlier use of carbon as Brit law requires. Patent is for practical object, not underlying idea. Even if claims upheld narrowly, diaphragm is only practical way to vary resis. Can't understand how any pat lawyer can assert that the micro (eg Blake) isn't the carbon tel. Can phrasing of claims be altered?

Date

1879-10-14

Decade

1870-1879

Type

Folder/Volume ID

D7941-F

Microfilm ID

52:804

Document ID

D7941ZFX

Publisher

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