VENDING MACHINES. These are more commonly known in the United States as " nickel-in-the-slot " machines—the name arising from the fact that in the earlier appa ratus first put. into public use a five-cent nickel piece was required to operate them. They are all constructed so on the insertion of some definite coin m a locked receptacle some object will be released and made accessible to the payer. or else some information, as, for example, his height, weight, or lung power will be exhibited. The applications of the idea are endless. The invention of the machine dates from the time of Ctesibius, about two centuries before the Christian era, and the first application was to the sale of measured amounts of holy water at the doors of Egyptian temples. (See Ewbauk's _Hydraulics; also Ilero's ,c.-'piritab'rt, Woodcraft's translation.) Its latest development is to the automatic taking of photographs. (See Scientific American Supplement, December 21, 1889, and May 30, 1891.) A large collection of nickel-in-slot machines will be found described and illustrated in Sebentific American Supplement for April 11, 1891.
The Everett Weighing Machine is the type of apparatus of this character in most com mon use. It may at the present time be found in all public places throughout the country. It is an automatic weighing machine. Its construction is such that when the person to be weighed steps on the scale platform, the descent of the latter sets a stop in a certain position. When a coin is inserted in the slot, a lever is tilted, working independent mechanism, which controls an index moving over a dial marked to indicate weight. The dial mechanism is limited in the extent of its operation by the stop which the weight of the person adjusts, as already stated, in definite position. Therefore, by the coaction of the two practically inde pendent mechanisms, one actuated by the coin, and the other by the weight of the user, the range of movement of the index is so limited as to cause it to stop on the dial at the proper indication. A full description of this machine will be found in U. S. Patent No. 336,042, February 9, 1886.