Scientific American — No. 2, July 14, 1877(txt+pdf+epub+mobi电子书下载)

作者：Various

格式: AZW3, DOCX, EPUB, MOBI, PDF, TXT

Scientific American — No. 2, July 14, 1877试读：

BOWER'S PATENT AIR COMPRESSOR.

The new air compressor herewith illustrated may be operated by steam or water power, and is available for work in mines, tunnels, or quarries, for driving rock drills, coal cutters, and hauling and pumping engines, working mining pumps, for use in factories, and in fact for all service where a safe and efficient power is required. The construction of the machine, the capacity of which differs according to the amount of power required, will readily be understood from the illustration. Above the air cylinder are two distinct air chambers, each having two induction or receiving valves, which cushion on rubbers. With the movement of the piston these chambers alternately receive and force the compressed air through check valves placed in the upper part of the air compartment, both compartments being connected with one pipe conveying the air to the ordinary air receiver. These check valves lift alternately, and cushion on water; and as the compressed air is forced into the pipe connecting with the receiver, without a possibility of any of it escaping back into the receiving chambers, it is claimed that there is the smallest possible loss of power, and that the machine will give fully 90 per cent of steam power expended in the shape of compressed air. The compressor is compact in form, strongly made, simple in construction, and not liable to get out of order. One peculiarity in its construction is that no water jacket or hollow piston is used; yet under any of the extreme pressures to which the machine has been tested, no inconvenience, we are informed, from heat has been perceptible.BOWER'S AIR COMPRESSOR.

In connection with the compressor, receivers of various sizes are used, into which the air is pumped and thence conveyed by pipe to the location where required, even if it be a mile or more, the loss by friction between receiver and point of utilization of the air being, it is claimed, under 2 lbs. of the pressure.

The manufacturers also build water-power compressors, one of which, driven by 75 to 100 horse power, they have recently shipped to Utah. The machine is intended to convey the air through iron tubes 5,000 feet to the mouth of a silver mine, where a 50 horse power hoisting and a 25 horse power pumping engine will be driven by air instead of steam, and a tube will be extended into the mine 1,000 feet deep, where the power drills and small pumps will be operated by air also.

The manufacturers submit a number of excellent testimonials from parties using the machine. From one, we learn, that at the Antelope and Prince of Wales mine, near Alta City, Utah, the compressor runs 10 hours per day, and supplies compressed air to two 3 inch drills used in running levels. The distribution terminates at distances of from 1,000 to 2,000 feet from the compressor. The machine also drives one hoisting engine and ventilates the lower part of the mine. The main supply pipe is three inches in diameter, 2,300 feet long, and is tapped by two inch pipe wherever power is required. The expenditure of fuel is one cord of green pine wood and 600 lbs. of bituminous coal per 10 hours. Air pressure in receiver 100 lbs. This pressure is reported to be obtained by 70 lbs. of steam as indicated by the gauges.

For further particulars, address the manufacturers, Messrs. Griffith and Wedge, Zanesville, Ohio.

Death of Professor Santini.

A cable dispatch announces the death of the Italian astronomer, Giovanni Santini. The Professor was born at Tuscany, June 30, 1786, and was in the ninety-first year of his age. He graduated at the University of Pisa. He soon devoted himself to a study of the exact sciences, and in 1814 he had achieved so much distinction that he was appointed to a professorship in the Padowa Observatory in place of Vincenzo Cheminello. In 1825 he was appointed Rector of the University, and up to the time of his death he held the position of Professor of Astronomy and Director of Mathematical Studies. He was generally esteemed by the learned societies of Europe, and held a number of honorary titles and degrees from various leading universities. He was also a correspondent of the French Academy. The principal books published by him are strictly scientific, such as "Decimal Arithmetic" (1808), "Elements of Astronomy" (1820), "Logarithms and Trigonometry," and "Optical Problems" (1821-23). Some of his elementary works on astronomy for beginners are the best ever published in Italy.

John Yule.

The death is announced of Mr. John Yule, of the Hutchestown Engine Works, Rutherglen, N. B., at the age of 66. During early life, Mr. Yule went the round of the best engineers' shops in Scotland and England, and became one of the recognized leaders in engineering progress. His inventiveness took various directions, amongst other fruits being an improved rotary engine, a compensating governor for the steam engine, and a screw tap, drill, and mandrel. For the latter he was awarded the silver medal of the Scottish Society of Arts. For some years Mr. Yule acted as the manager of the boiler department of Messrs. Robert Napier & Son's establishment, but eventually resumed business at the Hutchestown Works, and devoted attention amongst other matters to the improvement of swing bridges and steam cranes and hammers. In the former line two of his most important works are the plate girder bridge over the entrance to one of the docks at Port Glasgow, for the Caledonian Railway, erected from plans by Messrs. Bell and Miller, C.E., Glasgow; and a lattice girder bridge over the entrance to Kingston Dock, Glasgow Harbor. Owing to the angle at which this last bridge crosses the dock, great difficulties were experienced in working out the mechanical details so as to admit of easy motion. These were skillfully overcome, and the bridge was, as finally erected, a monument of his design as well as workmanship. The Blackhill incline on the Monkland Canal, constructed nearly a quarter of a century ago, is a sample of Mr. Yule's mechanical powers. Of late years he was largely engaged as a professional valuator.

Business Prospects.

We have recently taken the pains to make inquiries from the more eminent bankers and merchants in the chief cities of the interior, and the results of our inquiries have tended to confirm the belief we have more than once expressed in this journal, that although, from various causes, there is overhanging a portion of our American industries a cloud of gloom and depression, still throughout the nation at large there is going on a process of growth and recovery from which the best results are anticipated. How long we shall have to wait before the life which is at work silently and secretly beneath the surface will put forth its full power, in the full harvest of productive activity, is, of course, impossible to foretell. What is chiefly important for us to know, however, is that the progress we are making tends upwards and not downwards, and that it promises to lead our industry and commerce to a brighter and not to a darker future.—Financial Chronicle.

To Disinfect Rooms.

The disinfection of a room is not complete unless the walls have been thoroughly cleansed. If they are papered, the paper must be removed and the surface beneath carefully scraped and washed. If the walls are painted, they should be washed with caustic soda. The ceiling should also be subjected to a similar treatment.ESTABLISHED 1845.

MUNN & CO., Editors and Proprietors.

Clubs.—One extra copy of the Scientific American will be supplied gratis for every club of five subscribers at $3.20 each; additional copies at same proportionate rate. Postage prepaid.The Scientific American Supplement

is a distinct paper from the Scientific American. THE Supplement is issued weekly; every number contains 16 octavo pages, with handsome cover, uniform in size with Scientific American. Terms of subscription for Supplement, $5.00 a year, postage paid, to subscribers. Single copies 10 cents. Sold by all news dealers throughout the country.

Combined Rates.—The Scientific American and Supplement will be sent for one year, postage free, on receipt of seven dollars. Both papers to one address or different addresses, as desired.

The safest way to remit is by draft, postal order, or registered letter.

Address MUNN & CO., 37 Park Row, N. Y.

Subscriptions received and single copies of either paper sold by all the news agents.Publishers' Notice to Mail Subscribers.

Mail subscribers will observe on the printed address of each paper the time for which they have prepaid. Before the time indicated expires, to insure a continuity of numbers, subscribers should remit for another year. For the convenience of the mail clerks, they will please also state when their subscriptions expire.

New subscriptions will be entered from the time the order is received; but the back numbers of either the Scientific American or the Scientific American Supplement will be sent from January when desired. In this case, the subscription will date from the commencement of the volume, and the latter will be complete for preservation or binding.VOL. XXXVII., No. 2. [NEW SERIES.] Thirty-second Year.NEW YORK, SATURDAY, JULY 14, 1877.No. 80,For the Week ending July 14, 1877.I. ENGINEERING AND MECHANICS.—Wrought Iron Bridge Designs; by William O. Douglas. A method of construction whereby the safety of the structure is not dependent on any single member. 2 engravings.—Steel Wire Hawsers.Health and Sewage of Towns; by Alfred Carpenter, M.D., C.S.S. A practical experience of the Dry system.Carlisle Bridge, Dublin, 1 engraving—Extinction of Fires.—Important Dutch Enterprise.Foot Bridge across the River Ness at Inverness; by C. R. Manners, Engineer. 13 illustrations.Radiating Steam Hercules for the St. Heliers' Harbor Works, Jersey. 2 figures.—New Meat Trucks.—New Horseshoe.—Scott's Wheel-Cutting and Moulding Machine. 3 figures.Compound Engine with Rope Driving Gear; by Benjamin Goodfellow, Engineer. 3 engravings.—Differential Screw Pipe Joint. 6 figures.Pipes for Gas and Other Purposes (continued from Supplement No. 77). Main-laying continued, with 4 figures.—Fittings of Gas and Water Pipes; Includes the average "life" of pipes; an account of various soils, and amount of corrosion in each; Professor Barff's new iron-preserving process, and other processes in practical use for preserving iron pipe; proving pipe; the utility of various metals, and directions for pipe-laying: various fittings, illustrated in 16 figures.II. TECHNOLOGY.—The Sizing of Cotton Goods; a paper read before the Society of Arts, by W. Thompson, F.R.S. A very full and clear description, embracing: An account of the process of weaving, explaining the object and utility of size. A table of sizing mixtures in which are enumerated all the substances used, (1) for giving adhesive properties to the size, (2) to give weight and body to the yarn, (3) for softening the size or yarn, and (4) for preserving the size from mildew and decomposition. Tests for these substances and directions for mixing, so as to obtain the results required. Proportions of sizing. Use of flour in size. Weighting materials, China clay and its substitutes. "Softenings" and oils for softening. East winds. Glycerin, grape sugar, mildew preventives, and tape sizing. "Slashing," packing, mildew, damaged goods, etc.—Notes on Garment Dyeing. Giving preparation of garments with cotton warps, green on garments with cotton warps, brown on the same, etc.III. LIGHT, HEAT, ELECTRICITY, ETC.—On the Minute Measurements of Modern Science. By Alfred M. Mayer. Article IX. The dividing engine and methods of making accurate linear scales. 8 illustrations.IV. NATURAL HISTORY, ETC.—Catastrophism, or the Evolution of Environment. An address by Clarence King before the Sheffield Scientific School of Yale College, New Haven, Conn.V. AGRICULTURE, HORTICULTURE.—Pencils of Silver Nitrate.—The Black Poplar.—Tree Leaves as a Fertilizer.—Improving Pastures. —Lawns and Hay.—Thoroughbred Pigs.—Shall Country Houses have Cellars?VI. MISCELLANEOUS.—The New German Patent Law: being the Full Text of the New Law for Patents, passed July 1, 1877, covering all the States of the German Empire.

Terms.—Scientific American Supplement, one year, postpaid, five dollars. One copy of Scientific American and one copy of Scientific American Supplement, one year, postpaid, seven dollars. CLUBS.—One extra copy of the Supplement will be supplied gratis for every club of five Supplement subscribers at $5.00 each.

All the back numbers of the Supplement, from the commencement, January 1, 1876, can be had. Price 10 cents each.

NOW READY.—The Scientific American Supplement for 1876, Complete in two large volumes. Over 800 quarto pages; over 2,000 engravings. Embracing History of the Centennial Exhibition. New Illustrated. Instructions in Mechanical Drawing. Many valuable papers, etc. Price five dollars for the two volumes, stitched in paper; or six dollars and fifty cents, handsomely bound in stiff covers.

Remit by postal order. Address

MUNN & CO. PUBLISHERS, 37 Park Row, New York.

Single copies of any desired number of the Supplement sent to any address on receipt of 10 cents.

CARRYING PEACE INTO AFRICA.

To carry war into Africa has been a proverb ever since Rome vowed the destruction of Carthage. But the Carthagenian invasion was a modern episode in Africa's experiences of that nature. On one of the earlier monuments of Egypt there is figured a slave-hunter's raid upon an Ethiopian village, the horrid details of which are said by travelers to be an accurate picture of a slave raid of to-day. The same murderous work has been going on incessantly for at least 4,000 years: how much longer there is no telling. For all these ages the African borders have known war and war only, and of the most destructive and barbarizing nature.

Recently, under the influence of Sir Samuel Baker, Colonel Gordon, and the civilized world in general, the Khedive of Egypt has carried war into the interior in the interests of peace: a conquest in a measure justified by the suppression of inter-tribal war for the filling of slave pens, and the abolition of the slave trade down the Nile. A similar reform has been effected on the east coast by the pressure of English power on the Sultan of Zanzibar. And the immediate effect of these two movements has been to prevent the butchery or enslavement of not less than half a million negroes annually.

A still more promising invasion of Africa has just been decided upon in the International Geographical Conference in Brussels: an invasion wholly in the interests of peace and civilization. At the meeting, a year ago, it was declared advisable to establish, by international effort, a line of permanent commercial stations from Bagomoyo, on the coast of Zanzibar, to St. Paul de Loanda, on the opposite Atlantic coast; the first stations to be at Ujiji, where Stanley found Livingstone, on the eastern shore of lake Tanganyika; at Nyangwe, Livingstone's furthest point northward on the Lualaba; and at some point further west on the route of Cameron, to be fixed in the dominions of Muata Yamvo, one of the most powerful chiefs of Central Africa. At the second conference, which ended June 24, arrangements were made for sending out the first expedition toward Tanganyika.

The object of the proposed stations is the development of civilization by commerce, not by religious propaganda. Primarily they will serve as bases of operation for explorers of the interior, a sort of entrepôts, where the explorer may supply himself with provisions, instruments, and goods, and thus save the cost and embarrassment of an army of porters from the coast. They will also serve as places of refuge for explorers in times of sickness and other reverses, which have hitherto so terribly hampered explorers. The heads of these pioneer establishments are to be men of scientific training and proved executive ability; and each will be aided by a physician-naturalist and a few skilled artisans. The points thus far chosen are on a line regularly traveled by the caravans of Arab traders, carrying coffee, tea, sugar, arms, and woven goods to permanent Arab residences and trading stations in the interior. An agent of the London Missionary Society has already begun the survey of a route for ox teams as far as lake Tanganyika; and Cameron has expressed the opinion that a light narrow-gauge railway could be constructed from the coast to the lake at a cost not exceeding four thousand dollars a mile. The traffic along such a road, he thinks, would soon pay interest on the outlay.

The unexplored region thus to be opened up to civilization and commerce (other than in human beings) is larger than the United States east of the Mississippi. Around it is a still larger region of partially explored country of unequalled fertility, abounding in great lakes and navigable rivers, and for the most part so high above the sea that the products of the tropics mingle with those of the temperate zone. The cereals, durah, maize, rice, sugar cane, starch-yielding roots and tubers, cotton, coffee, tobacco, spices, gums and caoutchouc, dye-stuffs and medicinal plants, the banana, fig, date, orange, and the vine are among the known products of this region; and all are capable of becoming important staples of foreign commerce. The country is not less rich in coal, iron, copper, gold, and other valuable minerals. The climate, though moist from abundant rain, is less debilitating than India or Brazil; and everywhere, away from the miasmatic coast regions and the marshes of the lower river courses, European explorers have found small cause for complaining of excessive heat or unhealthiness. On the elevated plateaus which cover so large a part of Central Africa, the climate is like that of the sanitariums of India; while among the mountains the finest climates of the world are fairly rivalled. Stanley found in the mountainous region between the great lakes and within a degree of the equator every climatic condition and every element of landscape beauty that could attract and delight a white colony. It was a perfect alpine country, with mountains rising from twelve to fifteen thousand feet, yet free from alpine cold and snow. Countless torrents from the hills watered ever-verdant valleys as beautiful as those of Tyrol, lying under a brilliant equatorial sun, yet with a climate as cool and equable as any European might desire. Further south, among the mountains about Lake Nyassa, the same features are presented on a grander scale: a country aptly described as a second Switzerland of gigantic proportions.

There can be no question of the ability of Europeans to sustain themselves in the greater part of the interior—certainly on all the higher plateaus—nor of the possibility of building up in Central Africa a great civilized empire. Nature offers every facility, and the native population seem to be well fitted for productive industry. In every respect they are physically and morally superior to the negroes of the coast, and only need protection and the encouragement of legitimate commerce to weld them into a great nation. Already they stand on the borders of civilization. They are intelligent, industrious, and not unskillful in the manufacture of iron and copper ornaments, utensils, and weapons. The arts of tanning, spinning, weaving, dyeing, mat-making, etc., are widely diffused among them, and many of their products are remarkable for their fineness and strength. They carry on agriculture with considerable success; and, notwithstanding the chronic state of insecurity incident to slave-hunting, their wealth in cattle is very great. As soon as the disturbing and impoverishing influence of the slave traffic is abated, and a market provided for the products of peace, the advancement of the people in civilization is likely to go on with great rapidity. As the source of raw materials which we need, and as a market for the surplus manufactures of Europe and America, the country offers, to say the least, many attractions; and it will not be surprising if, within fifty years, thriving commercial stations will be founded on all its great lakes and rivers, and connected with the outer world by telegraphy, railways, and steamship lines.

试读结束[说明：试读内容隐藏了图片]

下载完整电子书