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Chap. 9.] Vapor Engines — Woisard's Machine.
this cost being as the numbers 11, 4, 2—thus making the scale preponde-rate still more in favor of alcohol and ether. Why then, it may be asked,have they not superseded water 1 Principally because the different vo-lumes of vapor from equal quantities of the three liquid s turn back thescale in favor of steam. A cubic inch of water affords 1800 cubic inchesof steam, while a cubic inch of alcohol produces about 600 and ether only300 inches; hence the expense of producing equal volumes of vapor (andthat is the main point) is actually in favor of steam. It has therefore beendeemed more economical to use this fluid than the others, even if theywere equally cheap—to say nothing of the danger arising from such anemployment of highly inflammable liquids, and the practical difficultiesattending their ap plication.
In 1791, Mr. John Barber obtained a patent for an explosive motiveengine : he used gas or vapor from “ coal, wood, oil, or any other com-bustible matter,” which he distilled in a retort, and “ mixed with a properquantity of atmospheric or common air.” See Repertory of Arts, vol. viii,371. Another patent was issued in 1794 to Robert Street, for an “in-flammable vapor force,” or explosive engine. He exploded spirits oftar or turpentine mixed with common air under a piston, and forced itentirely out of the cylinder, into which it was again returned (bv its ownweight) and guided by grooves in the frame work. Repertory of Arts,vol. i, 154. In 1807, a patent was granted in France to M. De Rivaz, foranother, in which hydrogen änd common air were mixed and exploded.De Rivaz moved a locomotive carriage by the power he thus derived.He also inflamed the gaseous mixture by the electric spark. Dr. Jones,in 1814, made experiments on another. See Journal of the Franklin In stitute , vol. i, 2d series, page 18. Mr. Cecil, in 1820, published in theTransactions of the Cambridge Philc&ophical Society, (Eng.) a descriptionof an explosive engine of considerable merit.
In 1825, Mr. Brown, of London , patented his pneumatic or gas vacuumengine. The very sanguine expectations it excited have now died away.It is figured and described in too many works, both English and Ameri-can, to require insertion here. In 1826, Mr. Morey, of New Hampshire ,patented an explosive engine, and soon after exhibited a large workingmodel in this city, (New York ) which we took several opportunities toexamine. The piston rods of two vertical and open cylinders were con-nected to the opposite ends of a vibrating beam. The pistons were madeof sheet copper, in the form of plungers-, about nine inches diameter, andwere made to work air-tight by means of a Strip of oiled listing or clothtied round the upper ends of the cylinders. This was all the packing.Mr. Morey employed the vapor of spirits of turpentine and common air.A small tin dish contained the spirits, and the only heat he used was froma common table lamp. By means of a crank and fly-wheel a rotary move-ment was obtained, as in the steam-engine.
A singulär device for making the atmospheric changes of temperaturea means for raising water, was devised by M. Woisard. It consisted oftwo vessels, one above the other, connected by a tube. The lower one,having a valve in its bottom, was placed in the water to be raised. Theupper vessei was exposed to the sun’s heat, and within it was a bag orsmall balloon containing air, and a little ether, or other volatile liquid.“ As the atmospheric temperature falls, the balloon will diminish in bulk,the surrounding air will become rarer, and the water will introduce itselfinto the machine through the valve; and when the temperature againrises, the pressure exerted within the machine by the increasing volumeof the balloon, will cause the excess of water to flow out.” With the ex-
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