Although we cannot obtain more than the above-named electromotive force from one cell of either type of storage battery, we can obtain a greater ampère capacity by using large plates instead of small ones, or by using a larger number of small size. The same effects are produced by connecting the cells in series, or multiple, or multiple series, as we showed you in regard to primary batteries; and the storage batteries may be charged as well as discharged when connected in any one of these ways. CHARGING CURRENT The current which is used for charging must always be greater in pressure than that of the storage batteries which are being charged. If it is not, the storage batteries will be the stronger of the two and will overpower the charging current and so discharge themselves. X CONCLUSION We will now bring this little volume to a close, having given you a brief outline of the simplest rudiments of that wonderful power of nature, Electricity. We may compare this subject to a beautiful house the inside of which you would like to examine from top to bottom. We have opened the door for you; now walk in and examine everything. There may be a great many stairs to climb, but what you see and learn will repay for all the trouble. THE END FOOTNOTES: [1] The filaments in modern "Mazda" lamps, as made at the Edison Lamp Works, are strips of metallic tungsten. [2] The batteries we will now describe are for closed-circuit work _only_, and they are never used for open-circuit work. But there is a type of battery made that is available for either open or closed circuit operation. This is the Edison Primary Battery, which will be described later on. [3] Practically, there is always one more negative plate than positive plates in a _regular_ storage-battery cell. Consequently, a standard cell always contains an odd number of plates. TRANSCRIBER'S NOTE -Plain print and punctuation errors fixed. End of Project Gutenberg's ABC of Electricity, by William Henry Meadowcroft