File:The fireside university of modern invention, discovery, industry and art for home circle study and entertainment (1902) (14592253588).jpg

Identifier: firesideuniversi01mcgo (find matches)
Title: The fireside university of modern invention, discovery, industry and art for home circle study and entertainment
Year: 1902 (1900s)
Authors: McGovern, John. (from old catalog)
Subjects: Science
Publisher: Chicago, Union pub. house
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
rhead ceases to be au live wire. Tell me about Bigelows demonstration ? In the autumn of 1891, Professor Frank H. Bigelow of Wash-ington, D. C.j announced the successful culmination of hislabors to show scientifically that the Sun is a Magnet; that theEarth is a Dynamo, and generates Electricity by revolving infront of the Sun. Lagrange of Brussels, had conceived thistheory. We now have the big current of electricity in the cables run-ning out of the power-house. Whither does it go ? It goes out by cable and returns through buried wires and byother means to the power-house and the Dynamo. In the olddays of the electric telegraph, the operator sank his wire intothe earth, and this completed a circuit with any person to whomhe was signaling with his key. Whether a line of moleculesarranges itself all the way through the earth, or not, we do notknow. In the case of the trolley cars, when the trolley track islaid—and it is a very good one now-a-days—a thick copper wire ELECTRICITY. 37
Text Appearing After Image:
3g THE FIRESIDE UNIVERSITY, is laid alongside one of the two track-rails. The current passesthrough the car-wheels into the rails, into the copper wire (intothe earth also), and back to the Dynamo. Now for the trolley cars. Why are they called trolleys ? In the old days a trolley was a skid, or railway truck. Whenthe trolley was hung on an overhead wire, it was still called atrolley. The first application of Electricity to a surface car wasthrough a trailing car or trolley that hung on a wire. Thename was a natural outgrowth of the early conditions. Finally,a pole with a small wheel was pressed against th-e wire, and itwas found that Electricity was so quick that it would comedown the pole while the surface of the little wheel touched thewire. This pole is now the trolley-pole. How does the current reach the car-wheels to make them go ? It comes down the pole to the power-switch, over the motor-mans head. (See page 42.) At the power-switch, power istaken off for light and heat in the

Note About Images