Electrical Ore Reduc- cessantly for hours and even days to ob tion AMERICAN iron workers and elec tricians will watch with considerable interest an extensive experiment in electo-metallurgy which the Canadian government proposes to conduct at Sault Ste. Marie. The Consolidated Lake Superior Power Company is to furnish the building and 400 electrical horse power four months free. The Dominion government wants to find out if ores can be smelted and steel made by the electric process. Canada needs a cheaper method for manufacturing pig iron and steel than is now in use. Ontario is dotted with ore bodies but the lack of cheap fuel prevents their development. There is coal in the eastern and western ends of Canada, but the cost of transportation is prohibitive. There are, however, throughout the provinces many water powers where electricity can be generated and utilized in the manufacture of iron and steel, provided the experiments about to be made prove that the electric process is feasible. High Vacua by New Method FROZEN charcoal has been found to be particularly effective for obtaining high vacua. It long has been known that charcoal possesses the property, in a marked degree, of absorbing gases. Professor Dewar, the eminent English physicist, has demonstrated that this absorptive property increases manifold if the charcoal is cooled to the low temperature of liquid air. This augmented absorption takes place so energetically that if the refrigerated charcoal is contained. in a closed vessel the air in the latter soon becomes entirely absorbed by the charcoal. Professor Dewar immerses charcoal, preferably of cocoanut shell, in liquid air, places the frozen charcoal in a closed vessel connected by a tube with the vessel in which it is purposed to obtain a vacuum. In this manner a vacuum is obtained in a few minutes suitable for producing X rays. When it is remembered. that a mercury pump must be worked in tain such a vacuum the fact that high vacua can be obtained in a few minutes with frozen charcoal is highly interesting. Electricity for Hoists Among the many improvements in shop practice which have been made during the past few years, the adoption of better facilities for transporting the raw material and product has received considerable attention. It has been found that the element of time is a far more important factor in the cost of doing a given piece of work than was formerly suspected. The introduction of high speed steels for machine tool work and the adoption of the motor drive either separately or in groups have quickened the pace of production all along the line and made it more than ever essential that there shall be as little time lost as possible in passing the work through the shop. Hence the growing use of power driven hoists as a part of the improved shop transportation system. The electric hoist has certain peculiar advantages which commend it in a great variety of situations. Leaving aside the traveling crane as a special case, it is worth while to consider the field of use fulness of the small hoist having a single motor and hand propulsion in a horizontal plane. It is decidedly to the advantage of the central station man anxious to increase his day load to encourage the adoption of both small and large electric hoists in many places which as yet do not appreciate them. The universal extension of power circuits in urban communities is a strong point in favor of the motor-driven hoist, which can often be placed in service in localities where handhoisting machinery would be too slow and where no compressed air is available for pneumatic machines. There can be no question as to the relative economy of an electric and a steam-driven hoist; the latter requires in large work a licensed engineer and in point of steam and coal consumption is little better than an escape pipe to the atmosphere. Where compressed air is available. there are many situations in which the pneumatic hoist with its lower first cost meets the requirements admirably, but it is a mistake to assume that the electric hoist is an expensive machine to operate, simply because its first cost is higher than that of its air-driven. competitor. A group of 20 electric hoists recently tested on the Lackawanna Railroad showed an operating and maintenance expense of but 50 cents per hoist per month, which is certainly a most favorable figure. The complication often attributed to electric hoists does not materialize in the later and better designs. Thus, one point in which simplicity has been gained has been through the elimination of the starting rheostat, motors as large as 15 horse power being thrown directly across the line in beginning operation. Although this involves a higher field and armature resistance than would be the case with the rheostat the intermittent character of the service justifies the design. Alcohol for Industrial POTATO alcohol is becoming a large and important factor in German industrial life. The general use of alcohol made from potatoes, grain, and the molasses derived as a secondary product from the manufacture of beet sugar for power purposes is steadily increasing in the Kaiser's domain. From the official statistics for the year ending August 31, 1904, it is shown that in that year alcohol for industrial purposes produced in Germany from potatoes amounted to 80,403,972 gallons; from grain 18,281,551 gallons and from molasses 3,067,970 gallons. Several years ago the German government became impressed with the necessity of building motors which could be operated with some liquid fuel that could be produced in Germany in the event that through the chances of war the supply of imported benzine and other petroleum products should be cut off. Alcohol offered a solution of the problem and under the encouragement of the government the gas-motor builders gave great attention to perfecting alcohol engines. At the same time a powerful organization, the Centrale für Spiritus-Verwertwas established and began a systematic and persistent campaign to encourage and extend the use of alcohol for industrial and economic purposes, particularly for heating, cooking, and lighting When one considers that a hoist of 2,000 lbs. capacity, motor driven, may be bought for about $200 or possibly $180 in large numbers, and bears in mind the compactness, lightness, 'cleanliness, and flexibility of the equipment, the fixed. charges of possibly $20 or $25 a year appear a small matter if the production efficiency of the establishment is increased. Newspaper press rooms, shipping departNewspaper press rooms, shipping depart-hung ments, lumber and stone yards, wholesale groceries, coal yards, machine shops and factories are often well supplied with electric power and without compressed air plants. In such cases the electric hoist finds a ready application, and in the long run proves to be a far reaching economy. Its travel is unlimited, in comparison with the pneumatic machine, and it is far more useful for general service than its hydraulic competitor. While no single type of hoist can be prescribed for all conditions of service there is room for a much wider appreciation of motor driven apparatus. The result of this campaign is curious. It was begun to encourage the use of alcohol for motor purposes but so rapidly has the use of alcohol for heating, lighting, and chemical manufacturing purposes been extended that but a small percentage of the whole alcohol consumption has been credited to motors and automobiles. when taken out of the Kimberley and De Beers mines yielded over 1/4 carats of diamonds. In 1902 the yield was 3/4 carat per load. The newer mines have never yielded more than 3-10 carat per load. But lately the company encouraged the trade by reporting that it had the enormous total of 41,000,000 loads of "the blue" in sight, not yet mined. This is even more than the entire quantity taken out of the rich De Beers and Kimberley mines in fifteen years. In the scientific opinion of Geo. F. Kunz, gem expert of the United States mine has been the richest in the world, its annual product having averaged $4,000,000 for over thirty years. Next to this in richness has been the De Beers mine. Then there are three others, larger though less productive. That the two older and richer mines would soon be exhausted has been foreseen. But it has been figured that their diminution would. to a good degree be offset by the three newer but less productive ones. The diamonds of these great mines are found in a volcanic deposit known as "the blue." In 1889 an average load of this Geological Survey, this enormous quantity of unmined "blue" should offer an abundant prospect for the world's diamond supply, regardless of the fact that the new "blue" already mined gives a much lower yield of diamonds per load than did that of the old mines. He says that the De Beers company attributed recent reductions of work in the old mines to a growing scarcity of both labor and coal. The rise in the diamond market seemed at first to be a compensation for this partial shut-down. Discovery of the Mines Fifty years ago Britain's colonial geologist tramped over the diamond fields of South Africa, but saw none of the precious stones. He even walked over the site of Smithfield, where diamonds were afterward picked up on the town commonage. In 1867 a poor Boer farmer's child found, on a bank of the Orange river, a bright pebble, which he brought home. His mother gave it to a neighbor who had admired it, and the neighbor put it into the hands of a traveling trader. The latter showed it to several gem dealers at Hopetown, who pronounced it to be a topaz, not worth buying. The trader finally sent the sparkling stone to a geologist, and was stunned when the word came back California, was made general manager. He at once introduced American methods. He sunk shafts through solid rock outside the mine areas and ran horizontal galleries into the blue ground beneath the fallen masses of the former open pits from which the precious stones had before been taken. Applying his improved system, the vast blue layers were ramified with galleries after galleries at successive depths of thirty to forty feet. As each gallery was worked out he allowed it to fall and set to work beneath it-a process which admitted of being carried on indefinitely, so long as the "blue" was in sight. The story of the diamond from the time it leaves the blue earth until it reaches your jewel box is one which you that it was a diamond worth $2,500; that there were probably plenty more where it came from. The story went abroad and miners began to flock to Hopetown. In '69 a native found "The Star of the South,"-83 carats, which was sold for $60,000. The camps of the inrushing miners stretched as far as Kimberley to the north, where in the seventies the diamond-bearing mud craters were opened and where was located "the blue" of the richest diamond mines on earth. In five months the town of Kimberley grew to be a flourishing center. Out of the desert hotels, shops and houses sprung up in the night like mushrooms. Method of Working The many conflicting interests of the great diamond fields thereabout were finally fused into one dominant organization in 1888. Gardner F. Williams, who had gained his executive ability and general knowledge through experience in have never heard since the very latest mining and cutting methods have been applied. For these facts the writer is indebted to Mr. Williams himself. Under his system the blue ground is now carried up from the deep chambers in cars. It is then spread out in layers about a foot thick, upon open spaces of ground, called "floors" hundreds of acres in extent. Here for several months it is exposed to the air, sun and rain; it is steam harrowed and, in dry weather, watered by sprinklers. Having been thus softened and broken up it is passed through automatic washing machines, crushers and sorters. The lumps containing the diamonds are thus separated and made ready for picking. After many years of hand picking an employe recently discovered that diamonds would adhere to grease, whereas the other minerals in the incasing lumps would not. This simple discovery put hundreds of hand pickers out of work, |