Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity . INCLINED B. EVOLVING BAR. 177. the change produced in the direction of rotation by altering the course of the current. The helix, which ^ ,^^ surrounds the lower end Fig. 116. of the bar, is representedin section, in order to showa wide glass tube within,which can be filled withmercury. The iron barrests in an agate cup atthe bottom of the upper end connectswith a brass cup on anivory arm proceeding fromthe upright brass pillar. This cup may
Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity . INCLINED B. EVOLVING BAR. 177. the change produced in the direction of rotation by altering the course of the current. The helix, which ^ ,^^ surrounds the lower end Fig. 116. of the bar, is representedin section, in order to showa wide glass tube within,which can be filled withmercury. The iron barrests in an agate cup atthe bottom of the upper end connectswith a brass cup on anivory arm proceeding fromthe upright brass pillar. This cup may be united bya bent wire with a similar one on the pillar, as rep-resented in the .cut. When the screw-cups on thebase board are connected with a battery, the currentpasses from one of the cups up the pillar and alongthe bent wire at the top; thence it passes downthe inclined bar. A little mercury in the glass tubeconveys the current to the brass at the bottom of thetube. It then passes through the helix to the otherscrew-cup. The bar now rotates on its axis; a cir-cular card attached to it renders the motion percep-tible at some distance. 284. The course of the current
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectmagnetism, bookyear18
