Descriptive History of the SteamEngine, by ROBERT STUART, Esq. Civil Engineer. 1 vol. 8vo. Illustrated by Engravings of Fortyseven Engines. Price 8s.

WE have much pleasure in bringing under the notice of our readers the volume before us. It is at once the best and the cheapest account of the steam-engine that has yet appeared. Hitherto the facts of its history have lain so widely scattered, or when partially collected, have been retailed at so great an expense, that they have remained quite beyond the reach of those classes who, from being engaged in the construction of machinery, and in directing its operations when applied to manufactures, have naturally a greater interest in a knowledge of such facts, and by knowing them must be more likely to introduce and promote new improvements than any other body of men whatever.

Mr. Stuart remarks, with great truth, that all that has been done by merely learned men, in the applica tion of steam as a moving power, is of no practical" mark or likelihood." Twenty years ago, Hornblower ɔbserved that "the most vulgar stoker may turn up his nose at the acutest mathematician in the world, for (in the action and construction of steamengines) there are cases in which the higher powers of the human mind

must bend to mere mechanical instinct;" and the observation applies with greater force now than it did then. We know not, therefore, how the remark has originated, or what" philosopher" first claimed, for theoretic men, any part of the honour of being instrumental, even indirectly, in the perfecting of the steam-engine; or who gave currency to the phrase of its "invention being one of the noblest gifts that Science ever made to mankind.” The fact is, that science, or scientific men, never had any thing to do in the matter. It was a toy in the hands of all the philosophers who preceded Savery, and it again must become a toy before the speculations of Bossut, the ablest and atest of the philosophers who have

written on the subject, can be made to bear upon it. Indeed there is no machine or mechanism in which the little that theorists have done, is more useless. The honour of bringing it to its present state of perfection, therefore, belongs to a different and more useful class. It arose, was improved, and perfected by working mechanics, and by them only; for tradition has preserved to us, the fact of Savery having begun life as a working miner;-Newcomen was a blacksmith, and his partner, Cawley, was a glazier;-Don Ricardo (Mr Richard) Trevithick, was also an operative mechanic;—and so was the illustrious Watt, when he began and after he had made his grand improvements."

Mr. Stuart commences his historywith an account of Hero, of Alexandria's engine, which is nearly similar to that given of it in our 25th, 26th, and 27th Numbers. "No other notice," he says, "of steam as a first mover occurs in the works of ancient authors, nor in modern writers, until about the year 1563." So it has been customary to state; but we can mention one modern instance, at least of a date more than five hundred years older, where it is distinctly recorded to have been applied to machinery. In Malmesbury's History we meet, under the date of 1002, with the following paragraph: " In the church of Rheims are still extant, as proofs of the knowledge of Gerbert, a public professor in the schools, a clock constructed upon mechanical principles, and an hydraulic organ, in which the air escaping in a surprising manner, by the force of heated water, fills the cavity of the instrument, and the brazen pipes emit modulated tones, through the multifarious apertures. This we incline to think was the earliest modern application of steam; and we are rather surprised that it should have been so long overlooked.

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In 1563, one Mathesius hinted at the possibility of constructing an apparatus similar in its operation and properties to those of the modern steam-engine. About thirty years after that period, a Whirling Oelipile

was described in a book printed at Leipsig. It consisted of a globe with two necks, or outlets on opposite sides; a small quantity of water was introduced into it, and rarefied into steam by a fire made under it ; the vapour issued then at the two necks, and by its reaction a continuous motion was generated.

In 1624, Solomon de Caus, a French engineer, described an engine acting by the elasticity of steam; but the first person who in modern times applied it on any scale, to a useful practical purpose, was Giovanni Branca, who resided at Rome in the beginning of the seventeenth century. A description of his engine (which was only an improved Oelipile) from the pen of Mr. Partington, has already been given in our 9th Number. Mr. Stuart adds, with truth, however, that to the merit of a first idea, assigned to him by Mr. Partington, Branca has no claim.

The elasticity of the vapour of water, which had now become familiar to water-work artists, was applied by them in a variety of ways to their favourite problem of raising water above its level in jets and fountains.

Mr. Stuart describes two of these Air Engines, as they were called, but very prudently, "without vouching for the great effects" said to have been produced by them.

says,

Bishop Wilkins, in his Mathematical Magic, 1648, speaks of the Oelipiles as if in his time, and in England it had been extensively applied to useful purposes. "These are frequently used," he "for exciting and contracting of heat in the melting of glasses or metals.* They may also be contrived for sundry other pleasant uses; as for moving the sails in a chimney corner; the motion of which sails may be applied to the turning of a spit, or the like."

We come next to the pretensions of the Marquis of Worcester, who, of "all those whose names are associated with the history of the steam

An authority, by-the-bye, in favour of our Goldsmith's: Apprentice Steam-Soldering Machine.-See p. 275, Vol, II.

engine in its infant stages, is by far the most celebrated."

Mr. Stewart differs from all the writers who nave preceded him in his estimate of the Marquis's merits; he scouts the idea of his having invented the engine, and thinks him merely entitled to " some mention, as the probable projector of an improvement in it.

Since the performances of Hero, De Caus, and Branca have been brought to light, there can now be no doubt that the claims of the Marquis have been overrated; but not certainly to the extent represented by Mr. Stewart, whose acuteness on the subject is inore to be admired than his liberality. Intending in an early Number to enter upon a full review of the whole of the Marquis's Century of Inventions, we shall defer till then the farther remarks we have to make on this part of Mr. Stuart's volume.

The author next describes the suc◄ cessive applications of steam, attempted by Sir Samuel Morland (1682), Papin, Amonton, and Savery, to all of whom, particularly the last, full justice is done.

"In his address and explanations, Savery proceeds with all the candour and earnestness of a man, conscious of having made a discovery of immense importance to mankind; and there is no greater instance of so open and candid an appeal to experiment, and an examiuation of the actual performance of an engine as a test of its merit in the history of mechanical inventions.

*

"This engine Savery applied for raising water for palaces, gentlemen's seats, draining fens, and supplying houses with water in general, and pump ing water from ships; and he erected many of them in different parts of England. The power of his engine the limited only by the strength of the pipes and vessels; for (he says) I will raise you water 500 or 1,000 feet higl., could you find us a way to procure strength enough for such an immense weight as a pillar of water that height.'

*

*

"The advantage derived from the use of Savery's engine, as a substitutefor manual labour, was counterbalanced in public opinion by the great risk of accident from an explosion of the boiler;

for, during the term of his patent, it does not appear that he availed himself of the security arising from the use of Papin's Saftely Valve. * Various attempts were made to strengthen the boilers, by radiating arms fixed in the inside, but without any successful re

It: so that, at this period, the only use to which Savery's apparatus could be applied with safety, was to raise water to heights not exceeding 30 or 32 feet-a virtual abandonment of its preensions as a mine-draining power, which as the grand object of all Savery's exertions"

Then came the improvements of Newcomen the blacksmith, and Cawley the glazier, who "made the experiment of introducing steam under a piston moving in a cylinder and formed a vacuum, by condensing the steam by an effusion of cold water on the outside of the steam-vessel; so that the weight of the atmosphere pressed the piston to the bottom of the cylinder. This was the first form of the atmospheric-engine, the simplest and most powerful machine that had hitherto been constructed."

Still many inconveniences remained to be removed; and not the least was the necessity of employing boys or men to open and shut some of the cocks; for although the risk of accident from the explosion of the boiler might now be considered as obviated, yet the effect of the engine depending much on the condition of its parts, and these being rarely deranged by slight irregularities in their action, the danger of injury to the machine, itself was considerably increased from the ignorance or carelessness of the attendants.

The mechanism for opening and shutting the cocks also remained perplexed by latches and strings until Mr. Henry Beighton, an engineer, extensively employed in the construction of machinery, erected an engine at Newcastle-on-Tyne in 1718, in which all these "cock-boys" and complication of cords were superseded by a rod suspended from the beam which operated as a mechanism invented by him called hand-gear; a contrivance, with some slight modifications, employed in engines of the present day. It would also appear that the steel

yard safety valve was first used in the boiler of this engine, having been suggested to Beighton by Desaguliers.

Mr. Stuart's description of Beighton's engine we shall quote at length; as it will not only give our readers a complete idea of its most approved form of construction at that period, but show more clearly the value of the improvements introduced by that ingenious engineer.

For the use of the illustrative engravings, we are indebted to the kindness of Mr. Stuart, whose ability as a draughtsman is not the least of his merits.

"The cylinder of the Griff Engine was 22 inches in diameter; and Beighton calculated that it contained 113 gallons of steam at every stroke, equal to about 14,464 gallons per minute, which was produced from about five pints of water; and this quantity was equal in its performance to three-fourths of the atmospheric pressure; so that, making ailowance for the friction* of the piston, Ievers, and other parts, about eight pounds of water was raised by each, square inch of the piston.

"In examining the seventeenth (our first) figure, which is a view of the Atmospheric Engine as improved by Beighton, it will be seen, that, in addition to the hand-gear, he gave a better arrangement and form to the parts already in use, and paid more attention to the proportion of the parts among themselves, and to the work which they had to perform; besides introducing greater neatness and accuracy of workmanship into his engines than had been attempted by his predecessors.

"In the seventeenth figure, the cistern, x, for the supply of injection water, is placed as in the previous engravings, and water is pumped into it by a small pump connected with the pipe y y, leading from the mine. (The lever beam, z, is not continued on the pump side beyond its axis A, as this would have required our figure to have been drawn on a scale much too small for being distinct.) To make the piston, d, air-tight, a ring or piece of match† is

"Tallow was used in these engines to lessen the friction, but not to keep them air-tight."

+ “The origin of packing the piston is -Having thus given by Desaguliers:

screwed a large broad piece of leather to the piston which turned up the sides of

laid upon its circumference; which is kept moist by a small stream of water kept constantly running from the pipe, s, upon the piston d: a projecting rin rising above the highest point to which the piston is elevated, prevents the water from flowing over the sides of the cylinder, when the pi-ton has reached its upward stroke. The boiler which is shown as cased in brick-work, is supplied with warm water from this rim by a pipe b; the water falls into a funnel attached to a pipe g, which rises to a convenient height above the top of the brick-work, and descends about a foot into the water in the boiler; the two gauge-pipes i i, are used (as in Savery's Engine) to ascertain the quantity of water in the boiler; the lower end of one is immersed for a short distance in the water-the lower end of the other reaching to within a few inches of its surface. If steam issues from both cocks when they are opened, there is a deficiency of water in the boiler; if both give water, then it shows there is an over-abundant quantity. The cold water is injected into the cylinder through a pipe f; and after it has performed its office of condensation, it is conducted by the pipe tt, and escapes through a valve at its extremity into the well or reservoir. When the water which flows from s, on the top of the piston, is not all used to supply the waste of evapora tion in the boiler, its accumulation would soon fill the rim or cup above the piston, and flow over its edge upon the casing of the boiler. To prevent this overflow, a pipe u u, is inserted at a, which allows the accumulated quantity to fall into the well. The air which is contained in the injected water, and produced by the condensation of the steam under the piston, escapes by a small pipe w, to which is attached a little cup, with a valve opening outwards: when the air is expelled by the descent of the piston, it is shut by the pressure of the

the cylinder two or three inches, in work. ng it wore through, and cut that piece from the other, which, falling flat on the piston, wrought with its edge to the cylin der, and, having been in a long time, was worn very narrow; which being taken out, they had the happy discovery, whereby they found that a bridle-rein, or even a soft thick piece of rope, going round, would make the piston air and water-tight." -Desaguliers' Nut. Phil. Hornblower observes, We need not say any thing to the practical engineer about leathering a steum piston. Nor is it necessary to comment on the Doctor's acquaintance with steam and leather in contact.'-Gregory, Mech. vol. ii., p. 358. 1st edition."

atmosphere; a smal quantity of water is occasionally introduced by the pipe n, to keep it air-tight. This is called the snifting-valve, because the air makes a noise every time it blows through it, like a man snifting with a cold.'

"With the exception of the position of this valve, which Newcomen supplied by the pipe used for conveying the water produced by the condensation of the steam into the well, all the parts that we have particularized have the same operation with those similarly placed in the previous figures. The hand-gear contrived by Beighton, is shown in the eighteenth (our second) figure, on a larger scale than in the preceding engraving, for the purpose of giving a clearer view of its construction and action. The Atmospheric Engine, by its introduction, first properly became a self-acting apparatus.

"Between two perpendicular pieces of wood (not to confuse the figure, one only, B, is shown) there is a square iron axle, o, which has upon it four iron pieces subservient to the turning of the regulator, by shooting forward and drawing back the fork m m, fastened to the handle, V V, of the regulator T. In the perpendicular working beam, called by Beighton the plug-frame, there is a slit, which is contrived so that its pins work on the fore part, middle, and back part, to raise and depress the levers, ry, that move the iron axle o, as much round as is necessary. On the iron axle is fixed a piece called the Y. from its resemblance to that letter, with a moveable weight E, fixed on its upper end. The stirrup, N, is fixed to the hooks s, suspended on the iron axle; the levers ar spanners are also fixed upon this axle, at right angles to the Y piece. The Landle of the horizontal fork has holes near its extremity, for the purpose of keeping any part of the end a, in any part of the regulator lever v v, which moves on a horizontal bar between the pins ta.

"From the situation of the apparatus, the regulator is partly open, which is apparent from the shifting plate or valve, shown by the dotted line y, being turned from under the throat-pipe s, which Communicates with the cylinder: the situation of the piston in the cylinder will be somewhat higher than shown in the seventeenth figure, consequently. the lever-beam and the plug frume are nearly at their greatest elevation; aud the pin or pulley 2, in the slit of the plug-frame, has so raised the lever or