Page:Incandescent electric lighting- A practical description of the Edison system.djvu/90

 zinc sulphate to vary their respective weights in proportion to the current passing through them. This will be understood by referring to the cut Fig. 25, which shows a three-wire meter with the front of the case removed.

The cut shows the meter case divided by a partition arranged across its centre, the space above it being occupied by the bottles or jars, containing the zinc plates, immersed in the zinc sulphate solution.

. 26—Meter bottle.

These bottles. Fig. 26, are provided with glass tops, held in place by screw ring, the glass tops having holes in them, through which pass the copper stems of the zinc plates, to engage with the spring clips arranged above the bottles, and serving both to hold the bottles in place and to connect the plates with small wires, leading to