Teacher's Hand-Book, to Accomany Avery's Elements of Natural Philosophy; Containing Solutions to Problems, Practical Suggestions, and Additional Matter Concerning Electric Light, Etc., Etc (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1880 Excerpt: ...is polarized, not charged. The + electricity of the outer coat can not escape. The + electricity of the outer coat repels the + of the inner coat about as much as the--electricity of the outer coat attracts it. Thus there is but little "condensation." 3. (a.) See 344, 359. An unpolished surface presents a multitude of little protuberances that act as pointed conductors, (b.) See the Leyden jar with circle of points, p. 77 of Hand-Book. 4. (a.) The charged conductor polarizes or oppositely charges the surrounding objects. The attraction of the opposite electricity of these surrounding bodies would tend to draw the charge to the surface of the electrified insulated conductor. 5. (a.) See Deschanel's Natural Philosophy, 447,449. 6. (a.) See Fig. 142. Place the dozen globes, M, N, etc., in actual contact. They will be polarized. See 339. (b.) Charge one negatively by induction; with it, charge another positively by induction. 7. Connect the knob of the first and the prime-conductor; the outer coats of the first and second; the knobs of the second and third; the outer coats of the third and fourth; the knob of the fourth and the ground. Figure such an arrangement, indicating by the signs + and--, the electrical condition of each coat of each jar. Page 239. See Prick's "Physical Technics," pp. 311-368, and Deschanel's Nat. Philos., Chap. XLV and XLVII. 378. An ohm is the unit of resistance to the passage of an electric current. It is equivalent to the resistance of a wire of pure copper-fa of an inch in diameter and 250 ft. long, or of 330 ft. of No. 9 iron wire. A volt is the unit of electro-motive force (or of power to transmit a current against resistance), and does not differ considerably from the K ...