[D0014AAH], Letter from John Vincent Miller, Cloyd Mason Chapman to Thomas Alva Edison, June 6th, 1900


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[D0014AAH], Letter from John Vincent Miller, Cloyd Mason Chapman to Thomas Alva Edison, June 6th, 1900





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


Dolores, N. M.
June 6, 1900.
Mr. T. A. Edison,
Orange, N. J.
Dear Mr. Edison :-
Since our last report of July 9th. we have been carrying on experiments relative to rates of feed and clogging of screens. As the coarse material available here is much larger than that we had in Orange we immediately found it possible to increase the rate of feed over the screens and still keep them clean. Accordingly we have carried on quite extensive experiment in this line occupying the first two weeks since our last report and feel quite certain that it will be practical to at least double the maximum rate we had at the Lab. namely, one ton, half course and half fine, per screen per hour.
The result of these experiments although showing great improvement, were not satisfactory owing to the uneven distribution of coarse and fine over the roller feed of due to the conning of the material in the hopper. We must confess that for some unknown reason we neglected to make any provision to prevent this. We immediately set to work on the problem and found it very hard to solve. Our roller feed extends over four bunks of screens to prevent this. We immediately set to work on the problem and found it very hard to solve. Our roller feed extends over four bunks of someone so that the outer banks received most of the coarse while the inner received the fines. After about two weeks of experimenting we have finally obtained an arrangement which is fairly satisfactory but which we hope to improve whenever we have the opportunity during regular running. We are at present putting in this distributing apparatus or arrangement throughout the screening apparatus and will start again this afternoon on experiments. Just when these experiments will be finished we are unable to state definitely but as we have had the experience of the other tests we think that it will only occupy a few days.
We are intending to wait until these experiments were completed before sending another report but as they are occupying so much time we send this today.
All these experiments have been carried on with material from the excavation for the Mill and we intend using this material throughout all the preliminary runs and tests as there is a large amount of it which must be removed from its present position. We do not intend using any material from the shaft until every thing is in perfect order so that there will be no loss of material or work when the actual tests begin.
In regard to construction work we have lately completed the dryerhouse and a roofing over the runway which we find necessary owing to the frequent rains. The runway, you know, is used for the carting of the fines to the storage bins and the sized material to the separator apparatus.
In regard to the screening of the gravel at the shafts before it is carted to the mill we have decided to hand pick all coarse material down to three inch, then pass remainder over 1" screen, the screenings of this over 1/8th. screen for material to be taken to the Mill, the tailings over a two inch screen, which will give us four sizes- 3" to 2" 2" to 1", 1" to 1/8", and mill size. The material between 1" and 1/8" we shall pass over 3/16" and 3/8" screens to obtain coarse material for use with the fines in the screening apparatus whenever necessary. The two large screens are now being cut out of #18 sheet iron the other screens we have obtained from Frazer and Chalmers.
Mr. Burn has been working on the map for two weeks past. He has laid it out in 500 ft. squares, located the mill, the new shafts and a part of one bonding arroyo, and is now working on the remainder of this and the other bonding arroyo, the Cunningham. He thinks that we can send on the the map by the end of the week.
While over in Santa Fe this week we found it possible to obtain quite complete data from the weather bureau there as to rain and snow fall and velocity of wind at that station. We are rather uncertain as to the value of this data for our purpose as the weather official there thinks there is quite a difference in the the conditions of the two places due to location relative to the surrounding mountains.
Hoping to report the completion of all experimenting in a very short time, we remain,
Yours respectfully,
John V. Miller
Cloyd M. Chapman.
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