BRANCA’S MACHINE.
Hero’s book lay hidden in manuscript and buried in libraries, until the revival of learning in Italy in the sixteenth century, when a translation of it appeared at Bologna in 1547. By that time printing had been invented; and the multiplication of copies being thereby rendered easy, the book was soon brought under the notice of inquiring men throughout Europe. The work must, indeed, have excited an extraordinary degree of interest; in proof of which it may be mentioned that eight different editions, in different languages, were published within a century. The minds of the curious and the scientific were thus directed to the subject of steam as a motive power. But for a long time they never got beyond the idea of Hero’s Æolipile, though they endeavoured to apply the rotary motion produced by it in different ways. Thus, a German writer suggested that it should be used to turn spits, instead of turnspit dogs; and Branca, the Italian architect, used the steam jet projected from a brazen head to drive an apparatus contrived by him for pounding drugs. The jet forced round the vanes of a wheel, so as to produce a rotary motion, and this, being communicated to other wheels, set in motion a rod and stamper, after the manner shown in the preceding cut.
Solomon de Caus was another of the speculative inquirers whose attention was drawn to the subject of steam by the publication of Hero’s book. De Caus was a native of Normandy, and for some time studied the profession of an architect in Italy; from whence he returned to France early in the seventeenth century. Religious persecution was then raging, and, being a Protestant, he was glad to take refuge from it in England. He entered the service of the Prince of Wales, by whom he was for a time employed in designing grottoes, fountains, and hydraulic ornaments for the Palace Gardens at Richmond. While occupied in that capacity he gave lessons in design to the Princess Elizabeth; and on her marriage to the Elector Palatine he accompanied her to Heidelberg, to take charge of the Castle gardens there. It was while residing at Heidelberg that De Caus wrote his well-known book on hydraulics, which was published at Frankfort in 1615.[4]
One of De Caus’s expedients for raising water consisted of an apparatus in which he proposed to employ the expansive power of steam for the purpose. In Hero’s book it is shown how a column of water may be thrown up by means of compressed air; and De Caus merely proposed to employ steam instead of air. His apparatus was very simple. It consisted of a spherical vessel fitted with two pipes, one of them provided with a cock and funnel; the other, which reached down to near the bottom of the vessel, being open at the top to the external air. When the vessel was filled with water and a fire lit underneath, the water was forced up the open tube in a jet, greater or less in proportion to the elasticity of the steam. When both tubes were tightly closed, so that neither steam nor water could escape, the heat, says De Caus, would shortly cause a compression from within so violent that “the ball will burst in pieces, with a noise like a petard.”
DE CAUS’S STEAM APPARATUS.
It will be observed that there was little mechanical contrivance, and no practical use in this apparatus; it merely furnished an illustration of the extraordinary force of pent-up steam, and that was all. Though De Caus made many experiments with his steam-vessel, he never succeeded in making—if, indeed, he ever attempted to make—a working steam-engine of any kind. It is not improbable that he was dismayed, as others were, by the apparent violence of the imprisoned monster; and it needed a more ingenious head than his to contrive a method of rendering him docile, and making him go quietly in harness.[5]
It is probable that the first contriver of a working steam-engine was Edward, second Marquis of Worcester, one of the first and most illustrious of a long line of unfortunate inventors. The career of that nobleman—born though he was to high rank and great estate—was chequered and sad in no ordinary degree. Edward Somerset was the eldest son of Henry Lord Herbert, afterwards Earl of Worcester, and consequently heir to that title. He was born in London in 1601. His early years were principally spent at Raglan Castle, his father’s country seat, where his education was carefully attended to. In the course of his pupilage he made occasional visits to the continent, accompanied by his tutor, for the purpose of acquiring that degree of polish and culture considered necessary for a person of his social position. On the accession of his father to the Earldom of Worcester, in 1627, Edward became Lord Herbert by courtesy; and in the following year he married, and went to reside at Raglan Castle.
From an early period of his life Lord Herbert took especial pleasure in mechanical studies, and in the course of his foreign tours he visited and examined the famous works of construction abroad; for as yet there were none such in England. On settling down at Raglan, he proceeded to set up a laboratory, or workshop, wherein to indulge his mechanical tastes, and perhaps to while away the tedium of a country life. To assist him in his labours, he engaged a clever foreign mechanic, named Caspar Kaltoff, who remained in his service for many years, and materially helped him in his various contrivances. Among the works executed by Lord Herbert and his assistant at Raglan, was the hydraulic apparatus by means of which the castle was supplied with water. From an incidental reference to the “water-works” by a contemporary writer, we learn that they consisted of a series of engines and wheels, by means of which water was raised through pipes to a cistern placed on the summit of the central tower.[6] It is probable that the planning and construction of these works induced Lord Herbert to prosecute the study of hydraulics, and to enter upon that series of experiments as to the power of steam which eventually led to the contrivance of his “Water-commanding Engine.”