, 1872. 1’r.icE 10 Cents Peb Copy. A Machine for Testing the Strength of Metals, etc.* In order to obtain a very accurate result an inge¬ 2^Fig. 3 represents the form of round test-piece used By Tuomas M. Dbown. nious arrangement has been devised, whereby the in the case of cast iron, etc. Figure 4 the form used The Messrs. Hiehle BnoTnEiis of this city (Phila¬ weights are added automatically toward the end of in case of boiler plate. delphia.) have designed and constructed a machine the operation in the form of small shot. The ar¬ By means of suitable tools and appliances this ma¬ for testing the strength of metals, which without rangement for this purpose consists of a reservoir chine is equally adapted to the application of tor¬ undue complexity, affords results of unusual ac¬ of shot .1, (see fig. 2), attached firmly to the frame sional and crashing strain. curacy. work of the machine. This reservoir is provided It consists essentially of a hydraulic pump and with a valve M at its base, which is opened by a pin Amalgamation of Silver Ores in Pans, with the Aid of Chemicals. The attention of the mining public has, within late years, been largely attracted to the existence of numerous veins and deposits of silver ore, the beneficiation of which was, however, apparently im¬ practicable, as the ores they furnish cannot be worked with any degree of success by the ordinary amalgamation process, and are not sufficiently rich to bear the expense of roasting, even after the im¬ proved and cheaper methods now in vogue. An over- confidence in the adaptability of the ordinary Washoe process to the working of ores of the most different characters has led to numerous failures, while, on the other hand, the caution bred of experience causes many properties to lie idle, which would prove ROUNO TEST PIECE BOILER PLATE TEST PIECE -- 1- • A MACItJNK rOJi TESTING THE STRENGTH OF METALS, ETC jack, by which the Htrain is applied, and a scale beam I on the beam rod when the beam rises, thus allowing remunerative under a method of treatment equal in on which the strain is measured. I shot to run out. When the beam falls the valve thoroughness to the ordinary process, without Fig. 1 represents a machine of 100,000 lbs. capacity. closes by its own weight and the How of shot ceases. greatly exceeding it in expense. The demand for The crane A is suspended from the jack B by a yoke The shot as they flow from the reservoir are received such a process has within the last three years been C, and connected with the small end of the main in a vessel N, suspended from a spring-balance O practically filled, but the suspicion with which all lever by means of a clevis. The piece of metal to hung on a pin on the beam rod. innovations are regarded, and the nninvestigstive be tested is fastened in the clutches D D,and the In operating the machine the slack is first taken spirit of the “ practical ” millman have prevented weights are laid upon a disc H, on a rod suspended up by a screw and nut at E. Htrain is then applied this new method from being more generally known from the end of the scale beam. The pump at the by pumping and the equilibrium maintained by plac¬ and adopted. The facts now set forth should demon¬ base of the machine is connected with the jack by ing weights on the disc H. Wlien a point has been strate its usefulness beyond a question. A test of the tnbe G. All the bearing points of the machine reached within 5,000 to 10,000 lbs. of the supposed its merits can be readily made. Simple as it appears, rest on steel knife edges, and when ready for opera¬ breaking strain of the test piece no more weights it can be made to solve many metallurgical and ting the whole machine is in perfect equipoise, and are placed on the disc, but the additional strain is financial problems in the way of working ores to a so nicely adjusted that a half-ounce weight on the measured by the automatic flow of shot from the fair percentage of their value, and with profit, which disc H is sufficient to turn the beam. reservoir into the receptacle on the beam rod. After hitherto have,by their apparent rebel!ionsneas,proven the rupture of the test piece the strain employed is only sources of loss. ♦ A paper read before the American Institute of Mining I ascertained by adding the weight of shot (shown 1 The first successful attempt at Engineers. Feb. iilst, 1072. ^ on the spring balance) to the weights on the diso. I rebellions silver minerals in pans and without roast* u 258 THE ENGINEERING AND MINING JOURNAL.| [April 23, 1872. iDg waB made ou the CoiiiHtock Kliines. 13y far the for the sake of workiug a greater number of tons per sodium amalgam, cyanide of potassium, etc., are greater portiou of IhcBe blinies was ia former years diem. To ensure good results a charge should very effective in temporarily enlivening the quick¬ allowed to ruu to waste. This loss was prohably not n iiiuin in the iian, subject to the action of silver, their action speedily dies out after the latter looked open as an evil unavoidable in wet crushing quicksilver and chemicals, less than six to seven has been transferred to the pan, and experience has mills, and was partially excused by the fact that not hours. sufficiently demonstrated that when employed in more than 35 per cent, of their gross valne oonld be In working ordinary ores the quicksilver is not practicable quantities they have no effect in aiding extracted by the then known methods of treatment. added until the pulp has been thoroughly the amalgamation. The only thorough method of Thera was consequently but little inducement to ground. This is to prevent the flouring of the cleansing quicksilver is to retort it, and the uso of millmon to save slimes assaying $40 per ton, or quicksilver,. but since slimes require no grinding, proper straining sacks will render a recourse to the tbereabont, os they could barely be worked to a one might supposo that it would be more advan- method uunecessary. profit. Thousands of tons were thus lost, which at Uigeous to put the quicksilver into the pan ou TO BE CONTINUKD. the present day would yield an enormous fortune to charging, thus allowing more time to the amalgama¬ their owner. tion. Metrological Reform. ijome throe years ago a series of experiments were Kxperience has, however, shown that better results made, which clearly proved that these slimes could President Baknauh, of Columbia College, spoke are obtained by i)uttiug in the chemicals—1. e., sul¬ be worked to a high percentage at a cost which, before the Polytechnic Club of the A uerican Insti¬ phate of copper and salt first, and adding the ({uick- though greater than that of ordinary milling, still tute, on Friday evening, April 12, ou “The Present silver from two to three hours later, thus all iwing left a good margin for profit. Mill owners were in¬ State of the (Question of Metrological Iteforui." The the intervening length of time for the decomposition duced to save and sell what they had hitherto allowed following id an outline of his remarks : or “preparation” of the refractory miniTals. The to run waste, and shortly alter the working of When wo spe.-ik of the presenl state of anything, reason of this is not immediabdy apparent, as the slimes became a distinct feature of milling on the we imply that the present state differs from the past. quicksilver charged simultaneously with the chemi¬ Comstock. In order to be iuU lligible, therefore, we must in(|uire cals should attack the chlorodized (V) silver minerals All this was effected simply by adapting to the what the past has been. Accordingly, looking back iu slain nnsi'fnlL The amount per ton of chemicals Washoe pan process certain features of the Mexican upon the condition of the metrology of the worhl as employed varies with the richness of the slimes. paUo- namely, the use of snlplmte of copper and it was a century ago, we find it to have been marked The quantity is olwuys largely in excess of that salt in sufficient quantities to decompose the re¬ by these two characteristics : 1st, Great diversity of called for by the chemical equivalents of the minerals bellious silver minerals and leave them in a favorable systems when diflerent countries, different provinces, to bo acted upon, but in very large pans the relative state for amalgamation. The successful application different districts, or even different towns are com¬ proportions may be diminished. Taking ordinary of these chemicals to the ordinary Washoe process pared. 2ud, Exceeding confusion, when the weights slimes assaying thirty dollars per ton as a basis, the was entirely novel. It is true that in former years average quantities of sulphate of copper and suit and measures of any single country, province, dis¬ many millmon had tried these chemicals among a trict or town are considered by themselve.s. That employed per ton are 10-12 pounds of the former and host of others, but their experiments were invariably 2U-25 pounds of the latter. different political communities should have different carried on with such a want of knowledge that failure systems was a matter of course, considering how en¬ was inevitable.