This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1885 edition. Excerpt: ...for going down into the cellars, seeing the time at night, consulting the thermometer, &c. A small Plante accumulator may also be used to '"' make a platinum wire glow and set light to a candle or stove as shown in Fig. 99. Three small Callaud cells 3 inches high will maintain the accumulator. In all these applications we have always supposed that the charging battery has a number of elements in tension sufficient to charge the accumulators without changing their coupling. If this is not the case the accumulators must be coupled up in quantity to charge them, and in tension to discharge them. A Plante commutator moved by hand, as described on page 109, may be used, or the Plante-Hospitalier automatic coupler, represented by Fig. 100. The apparatus is intended without any special manoeuvre--beyond switching in or out the lamp or lamps fed by the accumulators--to automatically effect the coupling in quantity to the charging battery and the coupling in tension to the lamps, and to change the accumulators again directly the lamps are put out. It consists of a wooden board carrying a certain number of mercury cups joined to terminals by copper strips; into the cups are plunged jockeys suspended from a horizontal axis turning on pivots. The apparatus represented in Fig. 100 is arranged for three accumulators, the terminals being ten in number, viz. two for the charging circuit; two for the external circuit, including the lamp and contact-breaker; three terminals for the Fig. Ioo. positive poles of the three accumulators A, B, C; three terminals for the negative poles of the three accumulators A, B, C. In the ordinary position, the lamps being out, the plates are in the position as shown in Fig. ioo, that is to say, in the charging...