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action acts alarms apparatus armature arrangement attached axis battery become bobbins bottom brushes cable carbon carbon-holder carries cause cell circuit closed coil commutator conductor connected consists construction containing continuous copper core coupled cylinder derived described diameter direction distance dynamo effect electric light electro-magnet exhibited experiments field figure fixed force four frame give given Gramme incandescent increase insulated intensity iron lamp latter length less lever lower luminous machine magnet means metallic meters mines motor mounted movable move observations obtained opposite pair passes pieces placed plates platinum poles position prevent principle produced quantity range regulator remain resistance rest revolving ring screw separated shown in Fig shows side Siemens solenoid spring terminal thick torpedo traverses tube turn upper vertical weight wheel wire wound zinc
Page 213 - Fio. 18. of eight laminae of steel. The distance apart of the two limbs of each magnet, as well as the distance between the north pole of one magnet and the south pole of the next, is precisely equal to the distance apart, or pitch around the armature, of the pole-pieces and the coils. The details of the magnets, and their method of adjustment and attachment, are shown in Figs.
Page 3 - War. [Indorsement.] The recommendation of the Chief of Engineers is approved. By order of the Secretary of War. HT CROSBY, Chief Clerk.
Page 211 - Serrin, and does away with the use of ratchetwheels, allows the carbons to be placed at any desired height by a slight sliding of the ribbon. Another peculiarity of this lamp is the mode of connecting the different interior parts of the apparatus. The current of the large cable arrives at the upper carbons by the rails and uninsulated portions of the regulator. From the lower carbon, it returns to the two insulated terminals H and H', passing to one by the movable frame, and to the other through...
Page 210 - The connection of the two carbons to the prime mover of the clock is made by means of a steel ribbon, F, attached to the lower ends of the two rods g and I. This ribbon is led over several pulleys, and is wound on a wheel on the axis of the prime mover for a great part of its circumference. The turning of this Fio. 15.
Page 195 - ... varying range. To do this, observations are made during the year on the variations of the range ; the foggiest nights are then omitted, and the minimum range for the remainder of the year represents the range for that portion of the year. If, for example, thirty nights, or one-twelfth of the...
Page 79 - ... the ray traverses twice the thickness of the mirror before taking its final direction. Now, these two surfaces are not parallel, the interior surface being a sphere having a different radius than the other, or in other words the mirror is a concavo-convex lens with the centre thinner than the edge. The different thicknesses which the various rays have to traverse, according to the angle which they make with the axis, so modify them as to bring them rigorously parallel if the radii of the two...
Page 154 - The following are the principal passages from this patent : The invention has for its basis the use of metallic conductors, or of continuous carbons, heated to whiteness by the passage of an electric current. The best metal for this purpose is platinum, the best carbon is retort carbon. When carbon is employed, it is useful on account of its affinity for oxygen at high temperatures to cover it from air and moisture, as indicated in Fig.
Page 191 - She has finally led the way, as usual, in the use of the electric light, which has been definitely adopted for the lighting of her coasts, after many expensive and conclusive experiments ; and, when the plan has been fully carried out, France can boast of having the best and most systematic method of coast-lighting of any country in the world. , The United States has followed France. Our optical apparatus has been almost exclusively imported from that country. We use lamps made after French patterns,...
Page 209 - Fig. 197) with insulated springs. These springs, pressing on two contacts under the lamp, make the appropriate connections. The regulator itself is a combination of the Serrin and Berjot lamps. It comprises the two electro-magnets of the latter lamp, the armatures of which form an internal core, one magnet having coarse wire, and placed direct in the circuit ; the other having fine wire, and mounted in a derived current. The former acts on the articulated frame carrying the lower carbon ; the latter...