[LB055258], Letter from Alfred Ord Tate to Joseph Carlos Rich, January 26th, 1892


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[LB055258], Letter from Alfred Ord Tate to Joseph Carlos Rich, January 26th, 1892




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


Jun. 26, 1892.
Jos. C. Rich, Esq., Mayor,
City of Mobile, Alabama.
Dear Sir:-
Your letter of 18th instant has remained unanswered owing to the absence of Mr. Edison, who returned to the Laboratory to-day. In reply to your query as to the percentage of depreciation annually of electric lighting plants, Mr. Edison says that in his opinion the annual depreciation of a large station, incandescent system, should be charged at seven per cent. He also adds the following:
Dynamo (Incandescent) 3%
Engine 8%
General appliances in station 3%
Overhead wires, poles etc. 10%
Underground Edison tubing 4%
Dynamo (Arc) 10%
Boiler (Babcock) 6%
Regarding arc systems, to the above should be added 15 to 18 per cent for depreciation in arc lamps, depending upon the character of the lamps, some of which are so bad as to necessitate the continuous employment of a number of machinists to repair them. Mr. Edison does not consider himself a very good judge of arc light apparatus.
Yours respectfully,
A. O. Tate
Private Secretary,
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