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pairing its power, are circumstances in the use of the machine now familiar to every person. It would be difficult to give a clearer description of the action of a steam-engine in general terms, without a special explanation of its minutiæ and principles. In this case, however, it obviously was the intention of Lord Worcester to conceal both." No drawing of this form of engine is extant, by which a notion of its arrangements can be obtained. Diagrams have, however, been given by various writers, detailing arrangements by which the effects as noticed by the marquis could be obtained. These, of course, are perfectly hypothetical; nevertheless, as a matter of some curiosity, we append a diagram illustrative of an arrangement proposed by Mr. Stuart, in his work Historical and Descriptive Anecdotes of the Steam-engine, a work abounding in interesting matter (in fig. 7). Steam is

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supplied to the receivers ab by a steam-pipe proceeding from a boiler; the steam is admitted alternately to the receivers ab by means of a cock placed at e. The receivers are connected with the deduction pipe i by a pipe m, containing valves opening outwards from each receiver; another pipe nu connects the cistern with the receivers; by means of the cock at n the communication between the cistern and each receiver may be interrupted at pleasure. The steam from the boiler into the receiver a, passes previously filled with water; pressing on its surface, it forces the water through the pipe m up the pipe i, which conveys it to its destination. After the water is expelled from the receiver a, the cock e is turned, which admits the steam into the receiver b; simultaneously the cock n is turned, which admits water from the cistern into a; the steam pressing on the surface of the water in b, forces it up the pipe i; on the whole of the water being expelled, the cock e is turned, shutting off the communication with the boiler from b, but opening it to a. Unless, however, the boiler from which steam is supplied is provided with means for filling it with water at intervals, to compensate for that evaporated during the process of working, it is evident that the continuity of action of the engine would be interrupted. An eminent authority therefore considers that there could not have been in this kind of engine" any feed-pump: in the absence of that instrument, two boilers must have been indispensable to make the action of the engine continuous.” It will be interesting to trace briefly the evidence which has been collected in support of the opinion that the Marquis of Worcester had actually carried his engine into practical effect, this being with many a debatable point. In looking over the preposition of his celebrated work, it will be observed that he speaks of having "seen the water" raised; of "having a way to make his vessels." Again, although the marquis's veracity may be doubted in these incidental notices, it is worthy of note that a manuscript

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found after his death bore this heading: "The Lord Marquis of Worcester's ejaculatory and extemporary thanksgiving prayer, when first with his corporeal eye he did see finished a perfect trial of his water-commanding engine, delightful and useful to whomsoever hath in recommendation either knowledge, profit, or pleasure." Other corroborative evidence might be given, but it is deemed sufficient to append a very conclusive statement of one who was neither influenced by prejudice or interest. The evidence to which we allude is that given by Cosmo de Medicis, Grand Duke of Tuscany, who visited England about the period of the invention, and whose movements during his travels were duly recorded by his secretary. Under date May 28th, 1699, is the following entry: "His Highness, that he might not lose the day uselessly, went again after dinner to the other side of the city, extending his excursion as far as Vauxhall, beyond the palace of the Archbishop of Canterbury, to see an hydraulic machine invented by my Lord Somerset, Marquis of Worcester. It raises water more than forty geometrical feet by the power of one man only; and in a very short space of time will draw up four vessels of water through a tube or channel not more than a span in width, on which account it is considered to be of greater service to the public than the other machine at Somerset House." This, therefore, is superior in its operations to another machine by a different machanic, and applied to the same purpose." The following is the entry in the Duke's journal of the other machine to which allusion was made in the first entry: "His Highness went to see an hydraulic machine raised upon a wooden tower in the neighbourhood of Somerset House, which is used for conveying the water of the river to the greatest part of the city. It is put in motion by two horses, which are continually going round; it not being possible that it should receive its movements from the current of the river, as in many other places where the rivers never vary in their course." "Nothing can be more satisfactory," says Mr. Stuart, "than this last notice. The water in the hydraulic machine at Vauxhall, by the most easy inference, was not elevated by a water-wheel, otherwise the Grand Duke would not have omitted so striking a deviation from that at Somerset House. The effect was equal to that of another worked by two horses; and a tyro in mechanics would at first sight say, that no combination of machinery could accomplish that work by one man which it required the power of twelve men to do in another. From all the circumstances, therefore, it appears to us clear, that this great effect was produced by some sort of a steam-engine: the very identical 'most stupendous water-commanding engine;' 'the semi-omnipotent engine;' the admirable and most forcible way to drive up water by fire.'

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The introduction of this, the first "feasible" scheme for producing useful effects by the power of steam, may be said to be the turning-point in the history of the steam-engine. From this time the march of progressive improvement was rapid and uninterrupted; invention followed invention, improvement succeeded improvement, until the steam-engine arrived at its present potent condition.* From this stage of our labours we shall cease

* Sir Samuel Morland in 1683 submitted to Louis XIV. of France a plan for raising water by the aid of steam. The following notice is extracted from a Ms. in the British Museum. "The principles of the new power of fire invented by the Chevalier Morland in the year 1682, and presented to his most Christian Majesty 1683.-Water being evaporated by the power of fire, the vapour shortly acquires a greater space (near 2000 times)

to record the crude and visionary speculations of the philosopher or enthusiast; but have the more useful and pleasant task of describing the practical results of the application of the labours and ingenuity of our engineers and mechanics.

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It is supposed by some engineers, that the method of raising water by steam, on the principle of atmospheric pressure (or the vacuum), was not unknown to the Marquis of Worcester; and that it is not improbable but that in the engine mentioned by the Grand Duke of Tuscany this agency was taken advantage of. This is, of course, mere conjecture; but in an invention next in chronological order, now to be noticed, atmospheric pressure, or the formation of a vacuum, was a distinguished feature. The engine to which we allude is that so well known as Savery's." The period of the introduction of this engine may be looked upon as the commencement of the practical era; the very mode in which the inventor ushered it into the world, and presented its claims to consideration, proved this. In place of clothing his description in the studied mysticism of words, which up to this period had been the endeavour of all those who had preceded Savery in describing inventions in connexion with the subject, he, on the contrary, fully explained the principles of its action and the details of its arrangements; and instead of giving exaggerated statements of its power and economy, he practically detailed the reasons why he believed it to be a cheaper method of raising water from mines than any other plan then in operation; and earnestly invited parties interested to inspect the machine in operation, and form their own opinion as to its working value. Very little is unfortunately known of this ingenious man. From his title of Captain it has been conjectured that he was a seafaring man; probably this arose from his having been the inventor of an improved method of moving ships in a calm. It is doubtful whether he was or not; indeed, the latter is likely the case, as, in one of his papers describing an invention of his, he remarks: "I believe it may be made useful to ships; but I dare not meddle with that matter, and leave it to the judgment of those who are the best judges of maritime affairs." This does not read like the statement of one who was a practical seaman. Mr. Stuart conjectures, with greater probability, that he was the director or proprietor of a mine, and as such was known by the title which is even now appropriated to the same officer.

than the water occupied before; and were it to be always confined, would burst a piece of cannon; but being well regulated according to the laws of gravity, and reduced by science to measure, to the weights and balance, then it carries its burden peaceably (like good horses), and thus becomes of great use to mankind; particularly for the elevation of water, according to the following table, which marks the number of pounds which may be raised 1800 times per hour, by cylinders half full of water, as well as the different diameters and depths of the said cylinders." Although no account is obtainable of the contrivance for raising water said to have been submitted by Morland to the King of France, the above extract is sufficient evidence of his being acquainted with the power of steam, and as to the value of its application to useful purposes. The table referred to in the above notice need not be given here; it bears with it the evidence of much care having been taken in the experiments necessary to obtain the given results, which may be said to possess considerable accuracy. It is but just, however, to notice that it is quite an open question whether Morland ever really submitted any plan for raising water by steam, as has been said. One historian of authority states that there is no distinct evidence as to his having done so; and in his book published in 1685, describing all sorts of machines for raising water, he makes not the slightest mention of his being in possession of any such plan.

In 1698 he obtained a patent from William the Third "for raising water, and occasioning motion to all sorts of mill-work, by the impellant force of fire" and in 1699 he exhibited a model of his engine before the Royal Society, a description and illustration of which is given in their Transactions, vol. xxi. p. 228. In 1702 he published a work entitled The Miner's Friend, written in a lively and interesting style, and containing a full and circumstantial account of the arrangements and operation of the engine. The following is the description, which is worthy of a place here, as an example of mechanical description, and as giving a notion of the merits of Savery as an inventor. In fig. 8, which is a per

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spective view of the whole apparatus, "a a are the furnaces which contain the boilers; b1, b2, the two fire-places; c, the funnel or chimney, which is common to both furnaces. In these two furnaces are placed two vessels of copper, which I call boilers; the one large, as 1, the other small, as d. d, the small boiler contained in the furnace which is heated by the fire at b2; e, the pipe and cock to admit cold water into the small boiler to fill it; f, the screw that covers and confines the cock e to the top of the small boiler; g, a small gauge-cock at the top of a pipe going within eight inches of the bottom of the small boiler; h, a larger pipe, which goes the same depth into the small boiler; i, a clack or valve at the top of the pipe h (opening upwards); k, a pipe going from the box above the said clack or valve in the great boiler, and passing about an inch into it. 71, the great boiler contained in the other furnace, which is heated by the fire

at b1; m, the screw with the regulator which is moved by the handle z, and opens or shuts the apertures at which the steam passes out of the great boiler into the steam pipes oo; n, a small gauge-cock at the top of a pipe which goes halfway down into the great boiler; o, o, steam-pipes, one end of each screwed to the regulator, the other ends to the receivers pl,p2, to convey the steam from the great boiler into these receivers; p1, p 2, copper vessels called receivers, which are to receive the water which is to be raised; q, screw joints by which the branches of the water-pipes are connected with the lower parts of the receivers ; r 1, r 2, r 3, r 4, valves or clacks of brass in the water-pipes, two above the branches o, and two below them; they allow the water to pass upwards through the pipes, but prevent its descent; there are screw-plugs to take out on occasion, to get at the valves r; s, the forcing pipe, which conveys the water upwards to its place of delivery, when it is forced out from the receivers by the impellant steam; t, the sucking pipe, which conveys the water up from the bottom of the pit, to fill the receivers by suction; a square frame of wood, or a box with holes round its bottom in the water, encloses the lower end of the sucking pipe, to keep away dirt and obstructions; x, a cistern with a buoy-cock coming from the force-pipe, so as it shall always be kept filled with cold water; y, a cock and pipe coming from the bottom of the said cistern, with a spout to let the cold water run down on the outside of either of the receivers, p 1, p2; z, the handle of the regulator, to move it by, either open or shut, so as to let the steam out of the great boiler into either of the receivers."

In working the engine, "the first thing is to fix the two boilers of the engine in a good double furnace, so contrived that the flame of the fire may circulate round and encompass the boilers to the best advantage, as you do coppers for brewing. Before you make any fire, unscrew the two small gauge pipes and cocks, g, n, belonging to the two boilers, and at the holes fill the great boiler 7 two-thirds full of water, and the small boiler d quite full; then screw in the said pipes again, as fast and tight as possible, and light the fire under the large boiler at b1, to make the water therein boil; and the steam of it, being quite confined, must become wonderfully compressed, and therefore will, on the opening of a way for it to issue out (which is done by pushing the handle z of the regulator as far as it will go from you), rush with a great force through the steampipe o into the receiver p 1, driving out all the air before it, and forcing it up through the clack r into the force-pipe, as you will perceive by the noise and rattling of that clack; and when all the air is driven out, the receiver p 1 will be very much heated by the steam. When you find it is thoroughly emptied, and is grown very hot, as you may both see and feel, then pull the handle z of the regulator towards you, by which means you will stop the steam-pipe o, so that no more steam can come into the receiver p 1, but you will open a way for it to pass through the other steam-pipe, o, and by that means fill the other receiver, p 2, with the hot steam, until that vessel has discharged its air, through the clack r 2, up the force-pipe, as the other vessel did before.

"While this is doing, let some cold water be poured on the first-mentioned receiver, p1, from the spout y, by which means the steam in it being cooled and condensed, and contracted into a very little room, a vacuum or emptiness is created; and consequently the steam pressing but very little, if

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