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APPARATUS 1. 1. Carbon-Zinc Cell. Fig. 1. If you have some rubber bands you can quickly make a cell out of rods of zinc and carbon. The rods are kept apart by putting a band, B, around each end of both rods. The bare wires are pinched under the upper bands. The whole is then bound together by means of the bands, A, and placed in a tumbler of fluid, as given in . This method does not make first-class connections between the wire and rods. ()... more...

THE STEAM-ENGINE. What is steam?—The mechanical energy of steam—The boiler—The circulation of water in a boiler—The enclosed furnace—The multitubular boiler—Fire-tube boilers—Other types of boilers—Aids to combustion—Boiler fittings—The safety-valve—The water-gauge—The steam-gauge—The water supply to a boiler. WHAT IS STEAM? If ice be heated above 32°... more...

HISTORY OF FARMINGThe Land and the People From the most southern point of Ontario on Lake Erie, near the 42nd parallel of latitude, to Moose Factory on James Bay, the distance is about 750 miles. From the eastern boundary on the Ottawa and St Lawrence Rivers to Kenora at the Manitoba boundary, the distance is about 1000 miles. The area lying within these extremes is about 220,000 square miles. In 1912 a northern addition of over 100,000 square... more...

THE FRANCO-AMERICAN CORPS It was on a cool, starlit evening, early in September, 1916, that I first met Drew of Massachusetts, and actually began my adventures as a prospective member of the Escadrille Américaine. We had sailed from New York by the same boat, had made our applications for enlistment in the Foreign Legion on the same day, without being aware of each other's existence; and in Paris, while waiting for our papers, we had... more...

CHAPTER I. EVOLUTION OF TWO-SURFACE FLYING MACHINE. By Octave Chanute. I am asked to set forth the development of the "two-surface" type of flying machine which is now used with modifications by Wright Brothers, Farman, Delagrange, Herring and others. This type originated with Mr. F. H. Wenham, who patented it in England in 1866 (No. 1571), taking out provisional papers only. In the abridgment of British patent Aeronautical Specifications... more...


Induction of Electric Currents. 6. About twenty-six feet of copper wire one twentieth of an inch in diameter were wound round a cylinder of wood as a helix, the different spires of which were prevented from touching by a thin interposed twine. This helix was covered with calico, and then a second wire applied in the same manner. In this way twelve helices were superposed, each containing an average length of wire of twenty-seven feet, and all in... more...

FACTS AND OBSERVATIONS ON THE SALMON. In the following observations I intend to offer some remarks on the various migratory fish of the genus Salmo; and then some facts and opinions which tend to show the importance of some change in the laws which are now in force regarding them. We have first the Salmon; which, in the Ribble, varies in weight from five to thirty pounds. We never see the fish here before May, and then very rarely; a few come... more...

FOREWORD Once in awhile, maybe, twenty-five or thirty years ago, they used to pack you off during the holidays for a visit on Somebody's Farm. Have you forgotten? You went with your little round head close clipped till all the scar places showed white and you came back with a mat of sunbleached hair, your face and hands and legs brown as a nut. Probably you treasure recollections of those boyhood days when a raw field turnip, peeled with a... more...

Advantages of Common-Battery Operation. The advantages of the common-battery system of operation, alluded to in Chapter XIII, may be briefly summarized here. The main gain in the common-battery system of supply is the simplification of the subscribers' instruments, doing away with the local batteries and the magneto generators, and the concentration of all these many sources of current into one single source at the central office. A considerable... more...

CHAPTER I ACOUSTICS Telephony is the art of reproducing at a distant point, usually by the agency of electricity, sounds produced at a sending point. In this art the elements of two general divisions of physical science are concerned, sound and electricity. Sound is the effect of vibrations of matter upon the ear. The vibrations may be those of air or other matter. Various forms of matter transmit sound vibrations in varying degrees, at... more...