Show Now that the engineers are sliding their slide-rules slide again they might appreciate a little history of that useful instrument The slide rule was invented by Gunter shortly after his discovery of logarithms in 1620 Gunter placed logarithmic scales on wooden wood wood- en rules and used a pair of dividers to add addor addor addor or subtract the logarithms In 1627 th the 1 log logarithmic scales were drawn by Wingate on two separate lines sliding against each other so as to render the use of dividers i unnecessary and in 1657 Partridge brought slide rule in its present form The I circular form was devised by Leblond in 1 1795 95 if c X jj X is abundant in many of the copp copper r mines of California Large amounts of this iron sulphide sub occur in Shasta county count Also in the quartz veins in granite on the East Lode of California where it is usually auriferous No successful attempt has been made to employ in the west as a source of sulphuric acid c t- t If the drillings from drill holes are to be utilized as a means of determining the value of ore that is being passed through take for samples the drillings from holes crossing crossing crossing cross cross- ing the strike of th the vein not those pointed with it The former will give far more satisfactory satisfactory satisfactory sat sat- results than the latter Holes drilled with the vein may be run their entire distance in a rich streak or they may follow a barren band of rock Neither would give a reliable sample X Th The richest copper ore is cuprite the red oxide the next richest being copper copper cop copper cop cop- per glance N Neither ei ther of these ores often occur occur occur oc oc- cur in large larg masses but it is stated on good authority that near Copper River Alaska there is a mass of copper glance thirty feet thick and at least two hundred feet long Its width has not be been n determined This remarkable mass is owned by the heims T There are dry placers at many places in inthe inthe inthe the Southwest in California Arizona N Nevada Neva Neva- vada va- va da and New Mexico Some of these dry gold-bearing gold gravels are partly cemented There Ther are extensive deposits of this character charac charac- ter along the Colorado river particularly near Ehrenburg and also in New Mexico The absence of sufficient water in their vi vicinity vicinity vicinity vi- vi has pr prevented vented these deposits being worked Y YIt It may be true that it is unwise to make a large investment in a milling plant based upon the results of laboratory tests of ore made on a small scale but it is even more unwise to build an extensive metallurgical plant without having made tests even in the laboratory It is true it is difficult to duplicate duplicate duplicate du du- plicate the conditions obtaining in a comm commercial com acom commercial m mercial plant in a small scale test but by exercising the necessary care and employing the proper paraphernalia a very fair approximation approximation approximation of the commercial results that may mayb maybe maybe b be expected are obtained in the laboratory te test t. t There is very little nickel ore in the west J In n Oregon is one l known locality and andin andin andin in Nevada another Nickel occurs in a gr great at many places in small quantities usually in association with ores of cobalt but the localities localities localities 1 ties in which either nickel or cobalt occur in profitable amount are arc few in number r. r One of the principal sources sources sources' of nickel is on the island of New Caledonia where large deposits deposits deposits de de- posits are b being mined At Sudbury Ontario Ontario Ontario Onta Onta- rio Canada also are nickel mines Most contains more or less nickel x m The pneumatic hammer hamme drill is an excellent excellent excellent excel excel- lent device to be employed in most mines for the purpose of sampling particularly where the rock is hard and it is difficult t to cut even samples This drill can be effectively effective effective- l ly used t to td cut channels t g Certain silver ores which have been successfully successfully successfully suc suc- treated by leaching with solutions of sodium after roasting may usually be tr treated as successfully by the cyanide cyanide cyanide nide process The way to ascertain what may be done is to experiment and learn 1 sU J H HA A high mountain has been discovered discover d so it is stated in Nevada north of Ely that is said to be as high as Mount Shasta California California California Califor Califor- nia about feet Just how this measurement measurement meas meas- was correctly made so quickly a after ter its discovery ry i is not stated t t i I The production of aluminum in the United States has increased according to the United States Geological Sur Survey from om 75 4 tons in 1903 to tons in 1 In this period the price has ind increased ased from 2785 per ton in 1903 to per ton in 1907 t The beach sands of the Pacific coast contain con con- tarn ain gold at many places from Mexico to the Arctic Circle However it t is only in Alaska that th these se beach deposits have been worked at large profit This is no doubt due to the glacial origin of the deposits of the north coast i The occurrence of alunite aluminum sulphate with gold is an unusual thing found at Goldfield Nev It is thought by bysom some som to be a very fair indication that the minerals were deposited by hot ascending solutions On some of the mine dumps at Goldfield the mineral is abundant Some one has r recently truthfully said There is nothing so certain as the uncertainties uncertainties uncertainties of f a sure thing |