EOLIPILE. A name that has been given to an instrument variously modified, for converting in a close vessel water into steam. The first individual who used it, appears to have been Hero the elder, a Grecian mechanic, who settled in Alexandria about 130 years prior to the christian era, whose ingenuity and talents being fostered by the Egyptian monarch, was the probable cause of his interesting discoveries being handed down to us in his work entitled Spiri talia, or Pneusatica. Although in the suite that he has presented it to us in his teolipile, it cannot be regarded as one of his most useful inventions, (his foun tain for raising water by compressed air possessing far more intrinsic merit,) still as being the earliest germ of that great mechanic power which seems destined to change the faee of the entire civilized world, it is well deserving of a description in this place, which we shall give, with reference to the subjoined ftrtre. Over a small furnace was
placed a vase or caldron a, containing water, from the cover of which pro ceeded two arms b c, forming the axis of a hollow globe d. The arm b, is a steam pipe, the other arm c, is solid, having its extremity formed into a conical pivot. At right angles to the axis of the hollow globe, there proceeds from it two tubes e e, bent at their ex tremities, which form the outlets of the steam. Heat being applied to the cal dron, raises the steam, which flowing through the tubular axis b, enters the globe; thence the steam finds its way through the tubes e e into the atmo sphere, the reaction of the latter pro ducing a rotatory motion of the globe, the velocity of which will depend upon _ the strength of the steam.