Page:Popular Science Monthly Volume 92.djvu/451

 Popular Science Monthly

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��The Tintinnabulation of the Electric Tubes — Playing Chimes by Electricity

EXPENSE is the principal reason why more church chimes aren't heard - expense and the difficulty of getting heavy bells up into a steeple. A Chicago company, however, is manufacturing chimes made up of heavy tubes instead of the usual bells. A whole set of fifteen or twenty may be stowed away in a small space and erected with comparative ease. Tube chimes may be tuned more closely than bells.

Instead of the customary ropes which actuate hammers, the tube chimes are played by electromagnets controlled from a keyboard. The plungers, forming part of the electromagnets,

��strike their respec- tive tubes sharp and sudden blows when energized.

The keyboard used is about the size of a suitcase. It can be located anywhere inside a church, even next to the pipe-organ keyboard if de- sired. The key- board belonging to the chimes does not carry power currents, relays being in- terposed to per- form this opera- tion.

��Relay

����U. S. Government Tested Much War Machinery in 1917

ACCORDING to an annual report just issued, the U. S. Army's Board of Ordnance and Fortification has experi- mented with a number of interesting ma- chines during the past year.

For instance, the production and trying out of a self-propelled, oil-electric, ar- mored railway car was commenced. Tests are under way of the Hammond radio- dynamic system of torpedo control. For the purchase of this system, if it proves satisfactory to a Board of three Army and three Navy officers, and the President, Congress some time ago appropriated $750,000, and an additional $417,000 to buy material for and make a sample unit. Much is expected from the system when it is finally worked out.

Some experimental gun emplace- ments have been built and put through many tests. Portable searchlights for the field artil- lery have been de\dsed. Flares and star bombs for trench use were decided upon. Pontoon boats are to be propelled by the outboard type of motor in as many cases as possible. This familiar through rowboats. Radio

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The keyboard of the tube chimes may be placed be- side that of the church pipe-organ

��motor is already use on ordinary sets, cameras, turntables for siege artillery, illuminated compasses and many other new conveniences for military use are being developed. Trinitrotoluol, the powerful explosive, gave demonstrations of its powers at the Sandy Hook pro\ang ground. Several submarine detectors are shortly to be tried out on actual sub- marines. Our own U-boats will be used for this purpose and a wide range of experiments and tests will be made. Investigators have been working on the subject all summer, and it is hoped to turn out perfected machines shortly.

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