Letter from Nikola Tesla to George Scherff

Date (?)

The trouble in the new break is that the oil in the base does not stand sufficiently below the highest point the mercury can rise in the hollow shaft. It would be desirable to make an overflow hole so that the oil ~7hen it is poured in, can not rise above the mercury. The height of shaft should be so calculated so that when the oil and mercury are poured together in - or when the pulley is taken out and put in again - the oil can never rise into the pulley. This can be done by changing the bottom piece. But first we might try to keep the oil level as low as possible. If the oil will flow in, the bottom piece will have to be changed.

This should be attended to at once, on both the oscillator and independent break. For the oscillator I would advise the use of the discs, say 3/8" diam. (make as other disc) to avoid short circuit.

Teeth same as before.

This is no doubt a letter from Tesla to Scherff. The note was written on letterhead of Auditorium Hotel, Breslin & Southgate, Chicago.