Arizona silver belt., 1899-10-19

graduate from one variety to another, it is difficult sometimes to draw the line between species. The principal constituents are sanidinc oligoclase, ihornhlcnde, sometimes augite, mag i nesian mica, magnetic and some other minerals. Rhyolite is trachite in which D distinct tiuidal structure may be seen with aid of the micro ] scope, and contains distinct blebS of quartz. Liparite is a dense variety of rhyoiite.
 So far as known. Prof, Tucker, of Columbia university, recently pro duced the greatest heat known Go man. By means of a specially con structcd electrical furnace and cur rent of unusual power temperature was created of sufficient fewency to yaporate steel. hard quartz, and even platinum. The heat obtained was 6500 degrees. Boiling water at sea level means q temperature of al2 deg rees Fahrenheit rcdhot iron 500 deg rees. Steel melts at 5000 and boils like water at 3j00 degrees,
 On the Pacific coast gold is found in beach sands in several counties uI Cal ifornia, Oregon and Washington and on the shores of British Columbia and ! Alaska. In the southern localities many men at various times have i worked the sands ny devious methods and obtained small amount oi gold
 never enough except in q few isu- lated cases to pay for the expense of ! fitting up and the labor required. The gold actually exists, and is found as sociated with layers of black sand, in part magnetic, having been concen- trated by the waves and currents. 1 At one time in the history of the l Grand canyon of the Colorado river in l Arizona volcanic cruptionS occurred on the plateau in the neighborlioud af 1 the canyon and the black basaltic ! hya poured out over the surface and flowed 10 the edge of the canyon, over which it plunged in cascades, filling i the canyon bottom to q considerable !! height Subsequently the river has cut it's way down through this hard, tough rock and through the underiy ing rocks. indicating that the fresh appearing lava flows. which appear tha, they might have been outp1ured recently. are really very old
 The first important discovery Of mines in Utah was made by >qldiets under General Cunnor who estab- lshed the military post al Fort Doug las. east of Salt Lake City. in 1863. His men were the diScoyercrs Of Biug- ham. Stockton, Little Cottonwood iand other camps in Utah. and they also found mines at Pioche. Nevada. The most important mining districts of the Wasatch are ai those places. where the mountains are highest and most massive where the granite has upliftcd the quartziteS and limestones and in the latter porphyries have in. itruded the sedimentary nck~
 A water blast for ycntilatiug a tun- ncl in Guunison county. Colo. k de Mribcd aS follows: The automatic barrel system of ventilation consists of barrel set in the stream outside the tunnel the bottom q few inches below water icvel and open: funnel emplying through q Finch center into the top of the barrel. and beside the funnel. also inserted into the top of the barrel. the air-pipe leading to the tunnel, In this ease Finch pipe was used By q Hume water is conveyed to The funnel mouth. into which it pourS from drop ol about , feet. This fall gathers q great deal of air and drives q constant even current to the breast of the tunnel.
 In sinking shaft on q small vein in granite. the vein dipped out of the shaft; but il being desirable to con tinuc the shaft vertically, this was done: as the vein in its dip gnt several feet from the shaft the granite became extremely hard. 4 crosscllt was run. showing the vein to be about j feet from the shaft and approximately par allcl with il standing vertically. II was then determined to enlarge the shaft by cutting out to the vein. The result was saving of 3o per cent on the cost per foot in sinking during the first week and more than 10 per cent during the succeeding weeks. The vein eventually dipped back into the shaft. This shows that il is often less expensive 10 remove all of the ground to q good breaking crevice as q gouge. vein or iissure. as il facilitates break ing the ground.
 The dctcrminatiOn of ore in place ny the measurement of it's cubic con 1.h tll | .I, tl.