September 6th, 1899 letter from Nikola Tesla to George Scherff

Colorado Springs, Sept. 6, 1899

Dear Mr. Scherff,

Inclosed forward check for shop expenses $200. Some time ago I wrote about a check book. You acknowledged the receipt of the letter but did not send the book. Have not you more interesting i terns to write about than the pump> There are so many things happening in a great city and so busy are the reporters in the press, you might be able to make your correspondence more interesting. You know of a number of things I take a lively interest in. My work is drawing to a close. I do not know as yet how long I shall remain. Certainly I hope not very long. Please immediately upon receipt of this letter tell Mr. Uhlman to prepare mica condensers as follows. The mica should be of the best quality and say 3" x 3", or better 4" x 4", if the price is not much higher. The sheets should be split very thin. This is important but I can not just now say exactly how many thousandths. Perhaps Mr. Uhlman will find it practicable to make it not more than ~/1000, but perhaps he will find this is too thin. At any rate it must be as thin as possible but still not so that there might be holes in it. The sheets should be as uniform thickness as practicable. Now on each side tinfoil, the thinnest, should be glued with very thin French varnish, slightly warm. The space around should be 1/8" (that is, the mica should be so much larger). On the lapping part, say 1/4". I want 24 condensers, each consisting 6 sheets of mica. To protect the frail structure, Mr. Uhlman may use two sheets of thin brass, one on each side, which will have screws (one each) for fastening the wires to the terminals of the condenser. Mr. Uhlman will devise some practical and inexpensive plan of fastening or keeping the brass plates (not more than 1/32" thick) together. I expect to write again about some other work tomorrow. Mr. Uhlman may keep the workmen busy between times on a fourth break, we shall want it.

Sincerely,
N. Tesla

Note: The above sketches appeared on the typed instructions which Scherff made from Tesla's hand written letter. The sketches were probably made by Mr. Uhlman. - Ed.