[D0014AAN], Letter from John Vincent Miller, Cloyd Mason Chapman to Thomas Alva Edison, August 16th, 1900
https://edisondigital.rutgers.edu/document/D0014AAN
Transcription
Dolores, N. M. Aug. 16, 1900. Mr. T. A. Edison, Orange, N. J. Dear Mr. Edison :- Your letter of Aug. 10th. requesting a sample of concentrate was received yesterday and today we ship you by express about 18 lbs. of the same, the data for which is as follows:- Material from mill excavation Size of material..... .015 to .029 Amount of material separated...... 20000 lbs. Weight of concentrate............. 17.8 lbs. Conc. in material separated...... .91% Rate of material through separator 3700 lbs. We made a run immediately after the run, the concentrate of which we send you, the concentrate of which we send you, under the same conditions the results of which we shall send you as soon as we work them up. Since our last report of Aug. 1st. we have still further incrossed the range of the sizes of screening, dividing the gravel into five sizes as follows:- Under .007, .007 to .015, .015 to .029, .029 to .059, .059 to .119 The results of this system of sizing are fairly satisfactory but the value of the concentrate per ton, we think, can be increased by lowering the percent of the concentrate and still have a high percentage of saving. On another sheet we have tabulated the results of runs made since our last reported upon material screened according to the method explained in our last report and also according to the method explained in our last report and also according to the <illegible text> <E> <process looks very promising> <TAE> [TAE Marginalia] above method, as you will see by referring to the column Size of Material. In our last report a mistake was made in giving the value of concentrate per ton for .018 to .029 material which should be $19.48 instead of $194.80. We are uncertain as to how far we should carry these experiments or rather how far it is best to do so, in regard to increasing range of sizes, percent of saving of gold, and percent of and value of concentrate. We should like very much to have your opinion and some instructions in the matter. Yesterday we started work on one of the shafts Mr. Burn sank before we arrived and which is near the mill. As the material from this was dumped on the ground and more or less mixed with surface material and dumps of old workings, the data for the memo will not be very accurate. Mr. Burn sank two rows of shafts in this locality quite close together and accordingly we thought it best to start with one of those making a complete run, somewhat preliminary, the data for which might be checked by that of another shaft close by, if the run should be unsatisfactory or incomplete for any reason. Yours truly, Cloyd M. Chapman. John V. Miller Table attached to report of Aug. 16, 1900. [FINANCIAL TABLE]