In 1629 BRANCA, an Italian architect and engineer, published a book, in which he describes a novel application of steam. His illustration is ingenious and pretty ; for, substituting the human head and face in lieu of the cover of Hero's caldron (as shown in the cut), he conducts a tube to and beyond the lips of the figure through which the steam passes, and acts on the vanes of a wheel that is thus made to revolve on its axis by the impetus of the escaping steam, and so give motion to other wheels connected therewith. This certainly conveys the first published idea of employing steam as a prime mover ; but whilst one writer is disposed to concede to him the merit of a first suggestion, another, again, regarding his book as containing a collection of machines invented by others, assumes it to be " an idea of which he is only the mere illustrator." It is obvious that the force obtained from steam so applied, would be very slight, even had the notion been carried into practice.
It will have been seen, then, from this hasty narration, that up to this period,—Branca's publication, in 1629,—none of the experiments made with steam had led to a conception of its gigantic capabilities ; nor, subsequent to that date, until up to the middle of the seventeenth century, have we any further records of its advances.
We now, however, arrive at a new and memorable epoch in the history of the engine; namely, the experiments and disclosures made by the MARQUESS of WORCESTER, about the middle of the seventeenth century. In 1663 that nobleman published his extraordinary book, the Century of Inventions, giving a brief account of one hundred devices of his inventive genius. Amongst these inventions, (numbered 68,) appears the description of a fire tooter-work, which is here transcribed. [Note. The original manuscript of this work, written in the year 1655, is now preserved in the British Museum.] "An admirable and most forcible way to drive up water by fire; not by drawing or sucking it upwards, for that must be as the philosopher calleth tt intro sphevrant activilatis which is but at such a distance. But this way hath no. bounder, if the vessel be strong enough ; for I have taken a piece of a whole cannon, whereof the end was burst, and filled it three quarters full of water, stopping and screwing up the broken end, as also the touchhole, and making a constant fire under it ; within twenty-four hours it burst, and made a great crack : so that, having a way to make my vessels, so that they are strengthened by the force within them, and the one to fill after the other, I have seen the water run like a constant fountain-stream, forty feet high : one vessel of water, rarefied by fire, driveth up forty of cold water, and a man that tends the work, is but to turn two cocks, that one vessel of water being consumed, another begins to force and refill with cold water, and so successively, the fire being tended and kept constant, which the self-same person may likewise abundantly perform in the interim between the necessity of turning the said cocks." It may be supposed that the Marquess, with a mind so ardently disposed to mechanical projects, had made himself acquainted with the attempts of hie predecessors to employ steam as a motive force ; it however, that he must have made advances and discoveries upon the subject far beyond those of other philosophers who had gone before him. Ile speaks of his contrivance as a power inherently WITHOUT SOUNDER, and only limitable by the weakness of the vessels that confine it. Its vastness and docility to human control (of which no experimenter before his time ever appeared to have considered), were evidently well appreciated by him, and must have been demonstrated to him by practical results. This assumption is supported by the manuscript prayer found after his
death among his lordship's papers, entitled by him, "The Lord Marquess of Worcester's ejaculatory and extemporary Thanksgiving Prayer, when first with his corporal eyes he did see finished a perfect trial of his water-commanding engine, delightful and useful to whomsoever bath in recommendation either knowledge, profit, or pleasure." Unless the Marquess's veracity is doubted, it is pretty clear, therefore, that an engine (rude of contrivance it may be,) was actually constructed by him to raise water by the repellant power of steam. He speaks of having "seen the water run like a constant fountain-stream ;" and of the force produced, and int extent—" a stream forty feet high ; one vessel of water rarefied by fire draweth up forty measures of cold water." " His having a way to make his vessels," so that they are strengthened by the force within them, and the one to fill after the other, is not to be regarded u the conjectures of an ardent mind, merely because the results of his experiments are declared to be consequent upon the mode of construction ; " so that having a way, I have seen," and so on. Many attempts have been made to reduce the meaning of this celebrated description into some appreciable form ; but as it, like the greater part of his other descrip tions, is (perhaps purposely) mysterious, designed rather to provoke attraction than to afford a clear conception of a great mechanical invention, no wonder such attempts have been mostly unsatisfactory. The "forcing and refilling," and . the "strengthening of a vessel by the force within," would seem, when taken in an unrestricted sense, to be manifest absurdities, and no conjecture yet offered has sufficed to explain away the error which his inexplicit announcement conveys. An illustration of his possible meaning has been offered by a writer (Mr. Galloway) on this subject in the following figure and description. (Su Galkway and Heberea Hillary and Progress of the Skam-engine.) In this figure a represents the boiler, composed of arched iron plates, with their convex sides turned inwards; they are fastened at the joinings by bolts passing through holes in their Ades, which also pass through the ends of the Tods t t i, a series of which rods extend from end to end of the boiler, being a few inches apart. The ends of the boiler are hemispherical, and are fastened to flanges on the plates h h h h. It will be evident that, each plats being an arch, before the boiler can burst, several, if not nearly all the rods ii, must either be pulled asunder or torn from the bolts at the points of junction ; and as the strength of the rods and bolts may be increased to any extent, without interrupting the action of the fire, there can be no doubt that a boiler might be so constructed as to be perfectly safe under any pressure which could be required for raising water to a given height, because the pressure in such a boiler will never exceed the weight of a column of water equal in height to the elevation of the cistern. b c represent two vessels, which communicate with the boiler a, by means of the pipes f f, and three may-cocks m n, and with the reservoir from which the water is to be drawn by the pipes 11. g g are two tubes, through which the water is elevated to the cistern ; they reach nearly to the bottom of the vessels b c, and are open at each end. The pipe 1, as well as communicate with the vessels b c by means of the three way-cocks m n, which, by moving the handles op, can be so placed, that either the steam from the boiler, or the water from the reservoir, shall instantly have access to the vessels b c.