{"product_id":"2940149359226","title":"Steam, Its Generation and Use","description":"While the time of man's first knowledge and use of the expansive force\u003cbr\u003eof the vapor of water is unknown, records show that such knowledge\u003cbr\u003eexisted earlier than 150 B. C. In a treatise of about that time entitled\u003cbr\u003e\"Pneumatica\", Hero, of Alexander, described not only existing devices of\u003cbr\u003ehis predecessors and contemporaries but also an invention of his own\u003cbr\u003ewhich utilized the expansive force of steam for raising water above its\u003cbr\u003enatural level. He clearly describes three methods in which steam might\u003cbr\u003ebe used directly as a motive of power; raising water by its elasticity,\u003cbr\u003eelevating a weight by its expansive power and producing a rotary motion\u003cbr\u003eby its reaction on the atmosphere. The third method, which is known as\u003cbr\u003e\"Hero's engine\", is described as a hollow sphere supported over a\u003cbr\u003ecaldron or boiler by two trunnions, one of which was hollow, and\u003cbr\u003econnected the interior of the sphere with the steam space of the\u003cbr\u003ecaldron. Two pipes, open at the ends and bent at right angles, were\u003cbr\u003einserted at opposite poles of the sphere, forming a connection between\u003cbr\u003ethe caldron and the atmosphere. Heat being applied to the caldron, the\u003cbr\u003esteam generated passed through the hollow trunnion to the sphere and\u003cbr\u003ethence into the atmosphere through the two pipes. By the reaction\u003cbr\u003eincidental to its escape through these pipes, the sphere was caused to\u003cbr\u003erotate and here is the primitive steam reaction turbine.\u003cbr\u003e","brand":"Bronson Tweed Publishing","offers":[{"title":"Default Title","offer_id":47068023980272,"sku":"2940149359226","price":0.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0737\/7593\/9824\/files\/2940149359226_p0.jpg?v=1763715375","url":"https:\/\/shop-qa.barnesandnoble.com\/products\/2940149359226","provider":"Barnes \u0026 Noble (DEV)","version":"1.0","type":"link"}