Batteries are connected by attaching the carbon side of one cell to the zinc side of the next; follow this for any number and there will always remain one carbon pole and one zinc pole to which line wires may be connected. Batteries should be examined occasionally and cleaned. Do not use more salamoniac than will readily dissolve and have a small amount in bottom of cell. Place the batteries so they may not be ex posed to draughts or heat. Use soft rainwater in the solution. Six ounces of salamoniac to a jar is enough. When the batteries appear to be doing too much work or become weak, examine all connections; look for leaks where wires cross or touch. Test each battery separately by connecting it with the two poles of a bell used for that purpose, the amateur Workman—the busy man of affairs—the housekeeper—the farmer, have occasions for useful information about the common materials used in building and repairing and for the tables and measurements used in the different trades and business pursuits, which are seldom found outside of books treating of special trades. These facts and figures also enable one to deal intelligently with the mechanic and tradesman. They are time-savers, and hence are money-makers. Such information is only secured after long and diligent search and comparison of authorities. We give many of the important ones.