[LB063006], Letter from Thomas Alva Edison to Josiah Custer Reiff, February 4th, 1898
https://edisondigital.rutgers.edu/document/LB063006
Transcription
Friend Reiff – I will answer Mr Smiths letter categorically 1st The gravel should be dry – if not dry it will have to be dried - Our dryer at Edison NJ. dries 6000 Cube yards in 20 hours 2nd, Can handle fine gold best, anything larger than [1/8?] of an inch would not be used, but everything [pruned?] down to size that will pass through the Eye of a needle and can [fire?] is all right, it does not matter if [illegible] is bright or stained so it will not amalgamate, we do not use [illegible] 3rd It is not a machine, but a [mill?], with many [devices?] and for working [6000?] Cube yards per day would cover over an acre of ground, and cost a large sum, [because?] the body must be large to warrant its creation. The grade of the ore is not so important as the quantity – 40 cents per cubic yard is good enough providing the quantity is great. 4th The amount saved will depend upon the condition of the gold. We expect to save at the Ortiz grant 37 cents out of every 40 cents = If the gravel is cemented it is bad, because crushing would be necessary. of course the Cost of crushing cemented gravel is not very expensive, still it would result in loss of gold by the necessary imperfections of crushing — River bed placers are generally cemented, also have clay, also have a large overburden of non auriferous material and I think it unlikely that such [illegible] properties are good business propositions – Best auriferous placers not water bourne like [illegible] in New Mexico leave nothing to be desired — Mr D should put in a little time investigating these dry deposits more thoroughly - so that when my Ortiz mill is [illegible] The question of success or failure will be one of the things that will not be necessary to discuss — P.S. I would like 10 lbs of Anaconda Tailings taken generally to get an average – from my knowledge of their processes, I think the tails will show ½ per cent copper, in the present state of [revenue?] this is too much to [have?], & I want to try & see what my apparatus will do. Yours Edison