Page:Motors and motor-driving (1902).djvu/324

292 and negative plates, generally an even number of positives and an odd number of negatives, are assembled together in a cell as shown in fig. 9, additional vertical rods of ebonite being there shown in position to give wider separation between the plates. It will be observed that in fig. 9 the plates repose upon two longitudinal prominences at the bottom of the cell, which are technically known as bridges. These serve to keep the plates off the bottom of the vessel, so that if any of the material falls out between them, it shall not bridge across between the plates, causing a conducting connection to be formed, and the plates thereby discharged when not in use and injured. Each of the connecting lugs of each of the positive plates visible on the near top side of fig. 9 is autogenously soldered to a cross-connecting bar of lead, which is brought up vertically to form the positive terminal. The negative plates are similarly connected to another cross bar, this being brought up through the cover on the far side and forming the negative terminal. The process of soldering is carried out either by a hydrogen flame or by an electric welder. When the formed plates are mounted in position as shown in fig. 9, the cover is provided with a central hole for pouring in the acid and allowing the escape of any gases generated when the cell is charged, is put on.

The containing vessel of automobile cells is almost