abroad; and it is no unusual thing to hear of another mining company which has decided to adopt electric power in its mines.

Among recent contracts which have been awarded the Sprague Electric Railway and Motor Company of New York for electricmining apparatus is one which comes from Transvaal, South Africa; and it is interesting to note that the fame for American electric-mining apparatus for durability, economy, and convenience, is recognized in these fields as well as in this country. The company which is now installing Sprague apparatus in Transvaal is the Forbes-Reef Gold-Mining Company, who have ordered through Chester & Gibb, mining engineers of London, Eng., a complete electrical equipment for transmitting power, including four Sprague long-distance motors, and dynamos for transmitting 140 horsepower over a distance of three miles. The primal source of power is a waterfall situated about three miles distant from the mines as the crow flies. These points are connected by insulated wires, which are carried on poles.

At the power-station will be placed three Pelton wheels furnished by Frazer & Chalmers of Chicago. To each of two of these wheels will be belted one long-distance transmission constant potential Edison dynamo of 50,000 watts, or 67 horse-power, capacity each. To the other wheel will be belted a dynamo of the same type and voltage as the others, but of only 40,000 watts, or 55 horse-power, capacity. These dynamos are similar in appearance to the standard Edison dynamo which is used in incandescent lighting; but their winding is modified according to the regular Sprague system, adapting them for the long-distance transmission of power. These machines have an efficiency of over 95 per cent. At the mines are located the four Sprague motors, which are belted direct to the mining-machinery. These motors are divided into two groups; two 20 horse-power Sprague motors and one 80 horse-power motor forming one group, and a single 20 horse-power Sprague motor forming the other group. Each group is supplied with current by a separate set of wires, thus practically insuring a constant flow of electricity under all circumstances.

The method of regulating the motors and keeping up a constant speed in spite of the varying loads thrown on the mining-machinery is accomplished by winding the motors in a special way, so that there is no mechanical governor to get out of order. The governor being in the winding, and consequently acting without making any movement, the motors are more durable, and the use of any complicated mechanical governor is avoided. The motors are to run on a constant potential circuit, and all the motors of each group are connected together from positive to negative wires, thus equalizing the strain on the dynamos when the loads are thrown on the motors. This method of connecting dynamos and motors is in use in all Sprague stations for the transmission of power; and it is much superior in reliability and economy to the series method of putting each motor on a separate connection. In principle it is the same as supplying a city with water by running city mains instead of using a separate conductor for each consumer.

The question of efficiency, or the amount of the primal power which is delivered at the farther end after the transmission, is one which is very important. Upon this point electric transmission compares very favorably with all other methods of transmitting power. In this case the efficiency of the entire system, from the turbine pulley to the mining-machines at the farther end, is about 70 per cent; that is, 70 per cent of the energy which is delivered from the turbine pulleys at the power-station is given off the motor pulleys for work.

New Electric Street-Railways.

DURING the last week there have been a number of street-railway companies which have contracted for electric-railway apparatus in spite of the lateness of the season. The latest contracts closed by the Sprague Electric Railway and Motor Company of New York are for street-railways in Piqua, O., and South Nashville, Tenn.

The road at Piqua is an entirely new road, never having been operated by any power before. The number of cars which will be equipped will be four, and the line will extend for a few miles on the main streets of Piqua.

The South Nashville Street Railway Company will equip eight

cars at present, but it is expected that the entire road will be run by electric power before long.

The Elliott Non-Electric Telephone.

A PATENT was recently issued to Larkin V. Elliott of Moorestown, Ind., for an improved form of mechanical or non-electric telephone, which seems to possess several advantages over other instruments of its class. The general appearance of this telephone is shown in the accompanying illustration. The mouth-piece is bell-shaped, and about four inches in diameter at its larger part, the bore narrowing to about an inch and a quarter where it joins the base. The aperture in the latter is cone-shaped, narrowing from about four inches in diameter where it joins the mouth-piece to half that size at the rear. Between the mouth-piece and the base the diaphragm is securely fastened. The diaphragm consists of two sheets of stretched rawhide, with an interposed layer of soft fibrous material and a covering of some soft fabric. It is made in the following manner. A sheet of thick rawhide is first stretched tightly across the aperture in the base, preferably while wet, so that when it dries it will be still more tightly drawn. Over this is laid a layer of cotton batting or other soft fibrous material. Over this a sheet of thin rawhide is stretched, but not as tightly as the

first sheet. Lastly comes a sheet of velveteen. The whole is secured firmly between the base and mouth-piece.

The line-wire passes through an opening in the centre of the diaphragm, being provided on its end with a button, which bears against the velveteen surface of the diaphragm. The inventor claims that this peculiar construction of the diaphragm, together with the shapes of the apertures in the base and mouth-piece, not only prevent the usual roaring sound in the receiver, but improve the sound by rendering it more distinct, reproducing a clear, natural tone of voice, similar to that which acts upon the diaphragm at the other end of the line-wire.

The claims of the inventor in regard to the good qualities of these telephones are borne out by the testimonials of many business-men who have had them in use for several months. They are intended only for short lines, from a few rods up to a couple of miles. Proper suspension devices are provided, so that the linewire may be carried around angles without impairing the efficiency of the instruments. An electric call-bell may be used in connection with this telephone if desired.

American Apparatus in Italy.

WORK on the electric-railway apparatus for the Florence and Fiesole Road has been commenced upon at Schenectady, N.Y., which will be ready for shipment before long. This road will be operated entirely by electric power, and Sprague electric cars will be used throughout the entire line.

The road connects the city of Florence with the city of Fiesole, a distance of about five miles. The grades upon this line will be very severe, sufficiently so to have precluded the use of horses upon it. The regular Sprague system of overhead wires, using main conductor with feeders, will be used.

The fact that American railway apparatus have been adopted on this line is extremely flattering to the company to whom the order is given, and gratifying to the patriotism of every American. The fact that the Sprague system was brought into direct competition, in the matter of equipment of this road, with all the systems of electric street-railways in Europe, shows in an additional way the favorable reputation of American apparatus.

16

16

OF NEW YORK.

RICHARD A. MCCURDY, PRESIDENT.

ASSETS

$126,082,153 56

The Largest and best Life Insurance Company in the World. The New Business of the Mutual Life Insurance Company in 1888

Any person seeking a position for which he is qualified by his scientific attainments, or any person seeking some one to fill a position of this character, be it that of a teacher of science, chemist, draughtsman, or what not, may have the Want' inserted under this head FREE OF COST, if he satisfies the publisher of the suitable character of his application. Any person seeking information on any scientific question, the address of any scientific man, or who can in any way use this column for a purpose consonant with the nature of the paper, is cordially invited to do so.

of instruments of precision of experience would be glad of a position where his skill would be valued in connection with some higher educational institution. Address G. J., care of SCIENCE, 47 Lafayette Place, New York.

Readers of Science

Corresponding with or visiting Advertisers, will confer a great favor by mentioning this paper.

Schools.

CONNECTICUT, NEW HAVEN,

LIGHTNING; Ligoncise descriptions of MRS. pares for Smith and Wellesley, and admits to

Vassar by Certificate. Circulars. Early application

the effects of lightning discharges are desired. State whether the object struck was pro- necessary. vided with a lightning rod, the character of the rod, and the way in which it was set up. Beginning at the top, describe briefly the effects. MIC ICHIGAN MINING SCHOOL. - For Catalogues

State whether there was any smoke or dust raised, and whether there was any odor. Any reports of recent and of especially interesting

MICHIGAN, HOUGHTON.

address M. E. Wadsworth, A.M., Ph.D., Director. NEW YORK, ORANGE CO., FLORIDA.

THE LEONARD INSTITUTE, for both sexes, Florida, Orange Co., N. Y., reopens Sept. 11. family of the principal, Mrs. M. S. Parks.

Hundred Thousand new subscribers for The Family Journal and Ladies' Companion wanted. It is the most interesting and instructive paper ever issued Subscribers will receive during the coming twelve

MONTHS

novele written by American Authors, complete in each three numbers. The story of popular works of notion will be retold by a novel reader, the most interesting and unique feature ever introduced in any publication, giving the substance of popular and standard books by famous writers in a space easily read by the busiest people. We have engaged

FOR

this work & widely known and popular writer. Com ments on Current Events, Fashions, New and Origi nal Ideas and Designs for Ladies' Fancy Work and Household Decoration, Letters from Correspondents and their Answers. The colleges and seminaries of the United States will be treated one each month in an illustrated article showing the particular advantage of each, cost of attendance, eto, Invaluable to parents having sons or daughters whom they desire should receive the advantages of a higher edugation than the ordinary school affords. Articles on Painting and Drawing, giving home instruction by s well-known artist. A trial subscription of this ele gant paper will be sent to any address, three months, for

TEN CENTS.

Liberal pay for literary work adapted to our col amns, and for new and original drawings, designs and ideas on any subject which we can use. Premium List the most complete in the world. We offer inducements to club raisers and agents ap proached by no other publishing house. The cele brated Gilbert Cut Waist Linings, which we send post paid to one sending us two yearly sub01 at 60 cents each is alone worth 75 cents.

Bent to any address, post paid one year. 39 frial subscription for only 10 cents. six months, 25 cents, and a three months

TRY IT! TRY IT! TRY IT! and you will become a permanent reader. Address: John L. Douglass, Publisher, 322 Broadway, N. Y

ESTABLISHED 1859.

H. A. DREW,

Commercial Printer,

37 Clinton Place, near Broadwav, New York.

Wedding Orders, Souvenirs, Invitations, Orders of Dance, etc., etc., done in the latest and most elaborate styles, at reasonable prices. All Favors promptly attended to.