4 PRESCOTT REPORT BANCROFT LIBRARY University of California Berkeley I" I hi; i EEPOET BY WM. C. PRESCOTT, ESQ., MARCH 8, 1868, COMSTOCK LODE IN NEVADA. DEAR SIR : AVhen the mining tide, flowing eastward from the gold placers of the Pacific Coast, swept over the Sierra Nevada, to renew on their eastern slope the search for auriferous treas- ures, the first successful response to the prospector's toil was met in a show of gold from washings in what was then named, and is now known, as Gold Canon. But a short time however elapsed, before it was discovered that the mother ledge, from which this "show" had been derived, was an argentiferous rather than an auriferous vein, and that the method of mining as well as the resulting metal must here entirely change. This vein was the celebrated Comstock Lode. Vast in proportion as in richness, it extends along the flank and beyond the base of Mount Davidson, terminating no one knows where. All along its course for miles assiduous mi- ners have located their respective claims, prospecting their ground with success varying in proportion to the width of the vein at the point of attack, and the proximity of rich sul- phides to the surface of the ground. At this moment its position is very fully established, and, under the concurrent testimony of all geologists, its charac- ter admitted. In no portion of the State of Nevada visited by me, is there any similar metaliferous deposit ; there i> nothing characterized by such peculiar isolation; nothing in gigantic proportions and richness approaching it ; nothing carrying so large a percentage of free metal, or, consequently, so easily worked; nothing that ever has, or probably will, produce tin- iimnt -n>e yield and lar^e proportional profit that this has done and is still doing. It is true that only portions of the Lode are, at <>r near the surface, rich enough tor profitable working, but t! portions comprise the greater part of its superficial extent, and are marked by characteristics no longer doubtful. Tin- vein seems to carry at all points nearly the same absolute amount of silver, and the richness per ton or per cubic foot varies inversely with its width at the point selected. Thu~. where the Lode is narrow or compressed as at Gold Hill, tin ore is very rich, and whore it is very wide, as on the greatest elevation above the latter point and between it and the C'hcl- lar Mine, it is lean and unprofitable. So well are these char- acteristics known that the only practical question, in deter- mining the value of a claim is, what is the relative aggregate width of the Lode at the point selected. Let us apply this test to the property in <jiic~tion. And first of all, lot mo state that the admissibly barren sp.. already alluded to was readily detected, and indeed never long doubtful. North of Cedar Hill and south of Silver City the continuity is broken, and it is uncertain whether it will be found beyond those points; but so thoroughly has it been examined between them that its character may be assumed as fixed for every hundred feet of that entire distance. It is true that the human eye cannot penetrate, at any point, beyond the surface ; but he would be a poor adminis- trator who refused to admit as a fact everything not palpable to his own individual senses. We cannot foresee the com- mercial condition of the country a year hence, yet his would hardly be considered a wise example, who should withdraw his funds from a well established legitimate investment through % the fear that possibly, at some future unknown period, dividends might cease. So in every mining enter- prise. We cannot, by walking along the outcrop of a metallic lead, perceive the stores of precious metals carried beneath, but we may determine, with all the moral certainty possible to inductive reasoning, that they are there, though the eye does not behold them. The following are some of the prin- ciples established by universal observation throughout the argentifei>us regions of both the United States and Mexico, and to them I believe there is no exception. 1st. These leads are neither segregated deposits, nor beds of limited extent, but protracted veins, each having a certain individual and nearly uniform character throughout, never materially modified by chemical, and only occasionally by mechanical forces. 2d. In no case has the quantity of metal been found to diminish as the deeper seated ores were approached, but on the contrary, to increase. 3d. In perpendicular approaches, as in sinking shafts, barren belts have been passed, but in all cases, without, as yet, a single exception, in the whole history of silver mining richer deposits have been found below wherever the works have been driven to the requisite depth. 4th. The operation of atmospheric and other surface phenomena has had a tendency to remove a portion of the 1 above the water line, leaving the balance in different inical combinations from that found at greater depths. ~>th. When two points on a lode have been developed, >ho\ving it to be argentiferous, it may be assumed that it possesses, essentially, the same character at all intermediate p. iiits, varying in richness, possibly, in a slight derive, luit never, taken as a whole, barren. On applying these principle- to the Tncle Sam Senior and Gold Canon Mines we cannot resist the conclusion that, either thi- property is unlike any other yet developed in thy known world, as well as unlike all the other portions of tin .-ame L >dc, or the explorations made on the Yellow Jacket. Clinton c<. Huhbs, and .Iii-tn- approaches, arc the keys to its character and value. All the experts who ha\.- examined them, of whom none are more entitled to confidence than those whose opinions have been professionally given to you, especially Dr. Veatcli, Prof. Clayton and l>r. Adcllmrgh. concur without a dissenting voice in the decision that the Uncle Sam Senior is on the - Middle Gold Hill* I. identical with the Yellow Jacket and Justus, l>y which it is flanked and its character e-taMi-hed, and the Gold Cafion a continuation of the " Front Gold Hill Lead," whose po.-ition and yield is equally well determined. I need not give the e\idence upon which these opinion- are founded, in my own mind or in the minds of others, mm it would be a needless waste of time, where all partio are veil agreed, that no discussion of them seems pos.-ihle. Finding your property, then, on the Narrow Lead- already proved to be concentrated and rich : finding it identical in surface character and extent with other portions of tho>e leads; finding the ore at various depths in the shaft already sunk ItU feet, identical with that of the flanking properties at corresponding distances, and gradually increasing in richness us the work progressed, until at the greatest depth attained it had reached an average assay almost sufficient to pay the expenses of working it, the conclusion is inevitable that at 250 or 300 feet there will be found ore as rich as any other mine on the Lode has yielded. It is sufficient for you to know that you are on this belt of great depth and richness, indeed one that may never be cut off by even a few feet of barren gangue. PRODUCTION. Let us consider what results this mine is capable of pro- ducing, and at what outlay, as the first cost of the under- taking. To develop the mine to the requisite depth, in- cluding air-shafts, cross-cuts and prospecting adits, timbered complete, would cost, say . . . $25,000 Hoisting works, 15,000 40 stjynp mill, one half of which shall be designed for reduction by the most recent and approved methods for rich ores, with six reverberatory furnaces complete, built in best manner, . . 80,000 $120,000 Such a mill should reduce 30 tons by the humid process, yielding a net profit of $330 per day, and 15 tons by the dry process, yielding a net profit of $825 per day ; total, $1,165, or $35,000 per month, and $420,000 per annum. This, how- ever, is the result of only 50 tons per day, while the mine is capable of producing from 200 to 300 tons per day, for many years. Are these estimates too large ? Let us compare them with the actual experience of the other mining properties on the same Lode. The Gould & Curry Company has paid, since its or- gaui/ation in 1861, in dividends to its stockholders, about $5,000,000, being at the rate ui' about $1,000,0()0 per annum, in coin. The Ophir Company commenced operations in 1861, without a dollar. They made no a < ment upon their stock, which cost the original holders nothing, borrowed f 100,000 on the credit of the Company and its property. They have since that time opened and developed their mine, paid off their debt, erected machinery for hoi pumping, &c., at an expense of probably $150,000, eon- Mnicted the largot mill in the state, save that of the Gould & Curry, at an expense of 8300,000, and made monthly dividends to its stockholders of $50 per foot, or an aggn of 870,000 per month, or $840,000 per annum, while it- ital stock has varied in value from $1,000,000 to $3,000,000, in coin. The Chnllar, Savage, and Yellow Jacket mine-, ha\ exhibited Minilar iv.-ults, varying from $800,000 to $1,JOO,000 per annum, in profits. If any person, therefore, e:m assign a reason why the Uncle Sam, Sr., as soon as the rc<jui>ite capital has been applied t- it. H al">ve otimated, and the deep-seated ores iv\<-alrd. will not exhibit a correspond ing value, I confess he has access to facts and data not yet brought within my knowledge. In the foregoing statement I may seem to ha\c rated the prospects of this property very high, but I eouft>> I | middle ground ; and seeing none, I do not believe it my duty to withhold the fullest expression of an opinion concurr by others, and which I am the happier to express beeau-- i: is almost the only instance in which the result of my exam- inations of any property in Nevada has been so satisfactory a< to enable me to endorse it in the broad and strong terms in the application of which I feel here warranted. The geological characteristics of the Lode I have not thought necessary to discuss, as my opinion would be but a repetition of those so strongly and convincingly stated, by both Dr. Veatch and Dr. Adelburgh. Your obedient servant, WM. C. PRESCOTT.