Re: coherers

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gary Peterson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <glpeterson-at-tfcbooks-dot-com>

> Materials influence is complex and hard
> to control.  As simple a matter as changing
> to a new file can affect the sensitivity.

The Tesla-Scherff correspondence refer to the following materials for use in
the C/S coherers: aluminum wire chips; aluminum wire nickel-plated cut into
small particles; 10/1000" nickel wire cut into small particles 10/1000"
long; five grades of silver filings, marked No. 1 to No. 5, the former
number being the finest and the latter the coarsest; and bismuth filings.