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...

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...

CHAPTER I. INTRODUCTION. Our distance from the old world, and the favorable circumstances in which we have been placed with respect to the other nations of the new world, have made it so easy for our government to adhere to a pacific policy, that, in the sixty-two years that have elapsed since the acknowledgment of our national independence, we have enjoyed more than fifty-eight of general peace; our Indian border wars have been too limited... more...

INTRODUCTORY Electricity, like every science, presents two phases to the student, one belonging to a theoretical knowledge, and the other which pertains to the practical application of that knowledge. The boy is directly interested in the practical use which he can make of this wonderful phenomenon in nature. It is, in reality, the most successful avenue by which he may obtain the theory, for he learns the abstract more readily from concrete... 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...

CHAPTER I INTRODUCTORY Fish culture of a certain kind dates from very early times, but its scientific development has only come about quite recently. Most people know that in our own country the monks had stew ponds, where they kept fish, principally carp, and also that the Romans kept fish in ponds. In the latter case we hear more often of the eel than of other fish. The breeding of trout and salmon, and the artificial spawning and hatching of... more...

Agriculture in Virginia, 1607-1699 Various events in the latter years of the sixteenth century did much to shape the future destiny of the English nation. With the destruction of the Spanish Armada in 1588, England rose from a minor position in world affairs to one of major importance. One of the first changes was reflected in her attitude towards trade and commerce. England was no longer penned up on her "tight little isle," and her ships could... more...

PREFACE "Let posterity know, and knowing be astonished, that on the fifteenth day of September, 1784, Vincent Lunardi of Lucca, in Tuscany, the first aerial traveller in Britain, mounting from the Artillery Ground in London, and traversing the regions of the air for two hours and fifteen minutes, on this spot revisited the earth. In this rude monument for ages be recorded this wondrous enterprise successfully achieved by the powers of chemistry... more...