The mighty giant, steam by which we spin, weave, plow through the ocean, drive the rail car, print our newspapers, and perform a thousand other operations, did not attain to its present harmonious and herculean proportion s by a sudden burst of genius, like the flash of a meteor across the darkened ho^^zon. It has had its years of childhood and youth, like all other g^^eat inventions. Its history extends backwards for thousands of years, and is full of romantic incident. We propose, ood now commence, to give a series of sketches illustrative of the lives and efforts of i ts eady inventors. HERO.Egypt has been called " the cradle of the arts and sciences," and perhaps with much justice. Several of hel: ancient ?echanicians constructed marines which afforded evidence If great ingenuity ; and Hero of Alexand^^a was no doubt the inventor of the first steam motor. He was the son of a Greek, and lived 120 years B. C. At an early age, he devoted himself to geometry and mechanical pursuits. He left hehind him a record of his inventions, in ill " r.,1 u-ated manuscript, and therein is described the fountain for raising water by compressed air ; the mode ofform-ing a vacuum by sucking air from a vessel, and also of producing a blast by falling wtiter. He describes thirteen problems in which he operated with heated air and water. In t wo modes the doors of a te m ple were opened and closed by means of rarefied air ; in another, wine was made to flow, by the same means, upon a sacrificial fire, to assist combustion ; and by another method, he m ade a small stage revolve with automata upon it. He describes three modes by wh ich steam was used directly as a mechanical power, viz : to raise water by its elasticity ; to elevate a weight by its expansive power, and to produce a rotary motion by its re-action on the atmosphere.1 rotary steam engine. These three modes of applying steam are illustrated by the accompanying figures. On the lid of the cistern, o, Fig. 1, Hero placed a globe, c, also partly filled with water ; a pipe, e, i-ises from the cistern into the globe ; another pipe, i, proceeds from the globe, terminating over a vase, m, and this commuictites with the cistern by a pipe, n. When the beams of the sun fell upon the globe, they heated the water and generated vapor, which, by its expansion, forced the water through the siphon, i, then it trickled into the vase, and was agsiin conducted into the cistern by the pipe, n. When the beams of the sun were shut out, the su^^ace of the globe became cooled, the vapor within it was condensed, and a vacuum was left in the upper part ; the pressure of the atmosphere then forced the water in the cistern up the pipe, e, to replenish it, and the same operation of forcing water commenced when the rays of the sun were again permitted to fall on t he surface of the globe :ind heat its con ten ts. This apparatus never got beyond the character of a toy, but Hero was operating here with the great powers of nature. In Fig. 2, the heat of a lamp or fire is shown as applied to generate steam. A vase, o, has a pipe, c, inserted into its lid, which is formed at the upper end like a small cup, i, and which contains a hollow ball, o. A fire being made under the vase or boiler, the steam rises from it through the pipe, c, lifts the ball phace d in the basin, and keeps it suspended in the air as long as the steam rises with a proper velocity from the vase, a. This was a very i ngenious s team toy. Fig. 3 represents Hero's steam master-piece. 0 is the vase or boiler contsiining water, and a fire is applied to Its bottom. Two pipes, a c, rise from the cover of the boiler , the one, c, acts as a pivot, and the other as a conduetor of steam into the interior of the hollow sphere, i. Two pipes, m n, bent (It right angles at their extremities, are inserted into the globe. The steam flowing up through the pipe, a, into the globe, and seeking exit ,by the hollow arms, m n, by its re-action " made tho globe revolve with magical celerity, EJS if It were animated within by a living spirit ; " so said the old philosopher. This was the first steam enginea genuine rotaryand it ha^ frequently been imitated withip the past fifty years by suhstituting a hollow wheel for the globe. It is also the parent ot the famous Barker mill, which although operated by water as a substitute for steam, is in all other respgcts Hero's identi-cal engine. It is a great won der that Hero was not led to a practical and useful applic.ation of steam to the saving 0I labor. There is no evidence left that it was ever anything but a toy in his hands. This may be attributed to the bigotry and false notions which the ancient phi-I losophers entertained regarding the dignity of philoso- phy. They considered that such knowledge, when shared by common minds, was degraded ; hence they concealed many of their discoveries rather than expose them to the people, whom they considered ignorant and vulgar. This accounts for the obscurity which hangs over m any of the ancient arts.