Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity . rous cell. The following table gives themagnetizing power obtained : — Table IV. Battery No. 1, 80,000 grs. No. 2, 82,000 Both, as one pair, 88,000 * consecutively, 97,000 Owing to the magnetizing power being so great asnearly to reach the limit of saturation of the electro-magnet, the numbers in this table do not indicate sogreat an increase as really occurs; but they show thatno great advantage is gained by connecting two pairsas a single pair. The
Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity . rous cell. The following table gives themagnetizing power obtained : — Table IV. Battery No. 1, 80,000 grs. No. 2, 82,000 Both, as one pair, 88,000 * consecutively, 97,000 Owing to the magnetizing power being so great asnearly to reach the limit of saturation of the electro-magnet, the numbers in this table do not indicate sogreat an increase as really occurs; but they show thatno great advantage is gained by connecting two pairsas a single pair. The large-sized Smees or Grovesbatteries are not much superior to the small pairs of Smees battery, connected as one, arebut little better than one pair. 467. Separable Helices.—In this instrument,which is represented in Fig. 179, there are twohelices entirely separate from each other. The innerone, composed of several strands of insulated coarsecopper wire, is fixed in a vertical position on the base SEPARABLE HELICES, 287 board. One of its ends is connected with the screw-cup A, and the other with a steel rasp, B. The Fig, exterior helix is of fine insulated wire, and can belifted oiF from the other, which it surrounds. Itsends are enclosed in two brass caps, to which theextremities of the wire are soldered. To these capsare attached the screw-cups C and D. A bundle ofannealed iron wires, of which the ends are seen inthe cut, can be removed from the inner helix whendesired. 468. In Fig. 180, the different parts of the instru-ment are shown separately. The exterior helix, a, isremoved from the inner coil, 6, which is fixed to thebase board. At c is seen a brass tube, within which 288 D A VI s S MANUAL. is the bundle of iron wires, cZ, intended to be intro-duced into the interior helix. For giving the strong- Fig. 180.
Size: 1584px × 1577px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1850, booksubjectmagnetism, bookyear18
