Elementary lessons in electricity & magnetism (1895)
Thompson, Silvanus P. (Silvanus Phillips), 1851-1916 · New York and London, Macmillan and co. · leaf 23
ry point through which they pass. The stress in the medium thus mapped out by the lines of force acts as a tension along them, as though they tended to shorten themselves. In fact in Fig. 8 the tension medium draws the two surfaces together. There a pressure in the medium at right angles to the… … Fig. 10. in theis also Lesson II. — Electroscopes 14. Simple Electroscopes.— An instrument for detect-ing whether a body is electrified or not, and whetherthe electrification is positive or negative, is termed anElectroscope. The feather which was attracted or re-pelled, and the two pith-balls…
Electricity
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