Arizona silver belt., 1899-10-26
CONCENTRATES.
Items of Interest in Regard to Mines
 and Timing.
IFrom Mining and Scientific Press

iNVtit iNNNss titt Hitt'f' N''Ni' saves 9s per cent of the assay values.
 ''Soprolitesn is a term used in Dah lonego, Georgia, district. to designate decomposed bodies of ore in place.
 The value of the mineral output il Tasmania for the first quarter of th' year was fl5 4s Tod per man employed
 The stockholders of the Homestak' NJ. Co. voted m San Francisco to in crease the capital stock from Sl2,50O, GOO to S2l 100000.
 The character of eruptions from tn, interior of the earth has varied at diff ferent geological ages. Those of late tertiary and recent time have beer almost exclusively of a basic type, and include andeSites and basalt
 X good aneroid barometer may be used to measure the depth of q shaft if a number of trips are made and The average taken. These trips should be made without delay, that is. with out stopping at intermediate points.
 Long cross-culS through hard ground to reach vein at great depth, which has only superficial work at the sur face, are not advisable. no matter how rich the vein may be on top. Prove first that the vein has sufficient value and depth to justify the cross-cut.
 Borax minerals where found in place, that is, in the form of q vein as that in the Calico, Cal, mines, may be To- cated the same as lode claims, but where they occur in the basins of dry lakes, etc, they should be located as placers. Deposits of salt are To- cated in the same manner.
 To raise 1000 gallons of water llll miners inchesl per minute to q height of s0 feet would require 40-h.-p. en- zine. With a finch pipe, Q velocity of IS inches per second, a friction heat of .96 inch. there would be friction loss of .04 pounds per square inch, figuring on each loo feet in length.
 Underhand StOping is not commonly followed but is sometimes employed to get ore without the expense of drifting to an ore chute from main shaft. lt is sometimes used in work ing small veins of rich ore. ltrcquires more timber where followed eXten- sively than overhead stOping and the timber cannot be recovered
 The great source of error in working mines by the pillar system is the prlc. tice of leaving pillars in large deposits of the same as those found to answer in similar deposits. X vein feet thick may be supported by pillar ol given size, determined by the char acter of the ground; buta pillar of the same size would not sustain the roof in 20-fuot vein in the same ground.
 The Homcstakc gold mineS at Lead City. in south Dakota, were discoy- cred iy 1876. and now comprise the greater portion of the properties in- cluded in q g0ld-bearing zone coco feet long and 1000 feet wide, extending from Dcadwood gulch on the north to Gold Run on the south. The princi- pal mines are the Homestakc, High land. DeadaOOd-Terra Father De Smet and Caledonia.
 The United States statutes provide. that where mineral veins are pos Sessed, which possession is recognized by local authority. and to the extent so possessed and recognized. the title tO town lots to he acquired shall he subject to Such recognized possession and the necessary use thereof: but nothing contained in this section t23s6 shall be so construed as to re- cognize any color of title iu the pos sessors for mining purposes aN against the United States.
 All minerals excepting coal and iron are reserved from railroad grants. If ihe mineral charactero of land included within railroad grant can be proven prior to issuanre of patent to the rail road the land belongs to the public domain and is open to exploration and purchase under the mining laws, the same aS any other public mincral lands. The supreme court of Cali. fornia has held in several cases that in an actional law patent issued to q railroad company can be attacked by showing that the lands in controversy are mineral lands
 Winzes and man holes cul for pass ing ore or rock from slopes IO level below. should never be driven under an angle of .tj deg. for at lower angle rock will moi nm. and, if there is much fine material and wet. it will mol run well at B deg Where small veins dipat a lower angle than 5 deg, levels should moi be over 75 feet apart. as shoyeling must he rcs0rtcd to, which makes mining expensive. Where broad veins lie ai q lower angle than B deg. the raise may he put iu to better advantage by starting on the foot-wall side and raising toward the hanging.