In order to charge the element thus constituted, it is only necessary to fill the lead tube with crystals of sulphate of copper and to pour water into the glass vessel until its level reaches within a centimeter and a half of the upper edge of the zinc. In an hour the copper will have dissolved sufficiently to allow the pile to begin its action.
Experience has demonstrated that, whatever be the supply of copper that is put into the lead tube, the saturated solution will never reach the zinc, even in an open circuit.
In sum, the new arrangement given to the Callaud element presents the following advantages: (1) It permits of the maintenance being confided to anybody, since this consists simply in the introduction into the central tube of crystals of sulphate of copper when it is seen that the blue tint of the lower liquid is disappearing. (2) It permits of proportioning the expense to the work really effected.—La Nature.
SUGGESTIONS IN ARCHITECTURE.—ENGLISH LODGES.
Lodges, Portington Grange, Eastrington.
Walter Hanstock, Architect.
Ground Plan.
Chamber Plan.