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the least possible, and the vacuum the most perfect, it was necessary that the cylinder should remain uniformly at the boiling point; while the water forming the steam was cooled down to the temperature of the atmosphere: to effect this, he employed a separate condensing vessel, between which and the hot cylinder, a communication was formed by means of a pipe and stop-cock.

The high-pressure engine is certainly much more simple than the one we have just described, but the danger attendant upon the use of this valuable prime mover is considerably enhanced by the increased elasticity of the steam employed to give motion to the piston. For a description of this, however, as well as of those invented by Hornblower and Woolf, we must refer our readers to the pages of Mr. Partington's ingenious work, and to the valuable graphic illustrations attached to it. Amongst other useful subjects, he has furnished us with an engraved view of a safety-valve, possessing the essential properties of safety and certainty in its action, and of the apparatus for consuming smoke, an invention of such importance to the health and beauty of our manufacturing towns.

The history and practice of steam navigation is also very fully discussed; and we regret that our limits will not admit of any very extended extracts. We cannot, however, omit the following brief particulars, which fully establish the claim of our own countrymen to this valuable application of the steam-engine.

"In 1698, Savery recommended the use of paddle-wheels, similar to those now so generally employed in steam-vessels, though without in the remotest degree alluding to his engine as a prime mover; and it is probable that he intended to employ the force of men or animals working at a winch for that purpose. About forty years after the publication of this mode of propelling vessels, Mr. Jonathan Hulls obtained a patent for a vessel, in which the paddle-wheels were driven by an atmospheric-engine of considerable power. In describing his mode of producing a force sufficient for towing of vessels, and other purposes, the ingenious patentee says, In some convenient part of the tow-boat there is placed a vessel about twothirds full of water, with the top close shut; this vessel being kept boiling, rarefies the water into a steam; this steam being conveyed through a large pipe into a cylindrical vessel, and there condensed, makes a vacuum, which causes the weight of the atmosphere to press on this vessel, and so presses down a piston that is fitted into this cylindrical vessel, in the same manner as in Mr. Newcomen's engine, with which he raises water by fire. It has been already demonstrated, that when the air is driven out of a vessel of thirty VOL. V. No. 10. 2 B*

inches diameter, (which is but two feet and a half,) the atmosphere will press on it to the weight of 4 tons 16 cwt. and upwards; when proper instruments for this work are applied to it, it must drive a vessel with great force.' Mr. Hulls' patent is dated 1736, and he employed a crank to produce the rotatory motion of his paddlewheels, and this ingenious mode of converting a reciprocating into a rotatory motion was afterwards recommended by the Abbé Arnal, Canon of Alais in Languedoc, who, in 1781, proposed the crank for the purpose of turning paddle-wheels in the navigation of lighters.

It is probable that Mr. Hulls anticipated some objection to his new mode of propelling vessels; and it appears from Capt. Savery's statement, to which we have already alluded, that a strong prejudice had been raised against the use of propelling-wheels in vessels. Mr. Secretary Trenchard, who was at that time at the head of the Admiralty, had also given a decided negative to the proposition. In answer therefore to the objections which might have been anticipated, Mr. Hulls proposed the following queries, which he afterwards solved in the most satisfactory way:

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Query 1.-Is it possible to fix instruments of sufficient strength to move so prodigious a weight as may be contained in a very large vessel?

"Answer. All mechanics will allow it is possible to make a machine to move an immense weight, if there is force enough to drive the same, for every member must be made in a proportionable strength to the intended work, and properly braced with laces of iron, so that no part can give way, or break.

"Query 2.-Will not the force of the waves break any instrument to pieces that is placed to move in the water?

"Answer. First, It cannot be supposed that this machine will be used in a storm or tempest at sea, when the waves are very raging; for if a merchant lieth in a harbour, &c. he would not choose to put out to sea in a storm, if it were possible to get out, but rather stay until it were abated. Secondly, when the wind comes a-head of the tow-boat, the fans will be protected by it from the violence of the waves; and when the wind comes side-ways, the waves will come edge-ways of the fans, and therefore strike them with the less force. Thirdly, there may be pieces of timber laid to swim on the surface of the water on each side of the fans, and so contrived as they shall not touch them, which will protect them from the force of the waves.

"Up inland rivers, where the bottom can possibly be reached, the fans may be taken out, and cranks placed at the hindmost axis to strike a shaft to the bottom of the river, which will drive the vessel forward with the greater force.

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Query 3.-It being a continual expense to keep this machine at work, will the expense be answered?

"Answer.-The work to be done by this machine will be upon particular occasions, when all other means yet found out are wholly

insufficient. How often does a merchant wish that his ship were on the ocean, when, if he were there, the wind would serve tolerably well to carry him on his intended voyage, but does not serve at the same time to carry him out of the river, &c. he happens to be in, which a few hours' work at this machine would do. Besides, I know engines that are driven by the same power as this is, where materials for the purpose are dearer than in any navigable river in England. Experience, therefore, demonstrates, that the expense will be but a trifle to the value of the work performed by those sort of machines, which any person who knows the nature of those things may easily calculate." [pp. 53-6.]

Such material assistance is now derived from this astonishing power, in navigating not only in our rivers and coasts, but from the British Channel to the American shores of the Atlantic, that we cannot deny ourselves the transcription of the following statement of the progress of this important application of the steam-engine.

"Some idea of the prevalence of steam navigation in the more northern parts of our island, may be formed from the following estimate of the number of passengers who have availed themselves of this species of conveyance in the course of one year. On the Forth and Clyde canal, between Glasgow and Edinburgh, 94,250; between Glasgow and Paisley, by the Ardrassan Canal, 51,700; and from Glasgow, along the Monkland Canal, 18,000. Steam-boats of a large size are now employed in the Adriatic. One (La Carolina) goes regularly every second day from Venice to Trieste; another (L'Eridano) passes between Pavia and Venice, and with such celerity, that the voyage is accomplished in thirty-seven hours.

"We have now to notice the labours of our trans-atlantic brethren in this important branch of naval engineering. Profiting by the hints thrown out both by the Marquis de Jouffroy and Mr. Miller, Fulton, who had also seen Symington's boat, ordered an engine capable of propelling a vessel to be constructed by Messrs. Boulton and Watt. This was sent out to America, and embarked on the Hudson in 1807, and such was the ardour of the Americans in support of this apparently new discovery, that the immense rivers of the new world, whose great width gave them considerable advantages over the canals and narrower streams of Europe, were soon navigated by these vessels. The city of New-York alone possesses seven steam-boats, for commerce and passengers. One of those on the Mississippi passes two thousand miles in twenty-one days, and this too against the current which is perpetually running down. The above boat is 126 feet in length, and carries 460 tons, at a very shallow draft of water, and conveys from New Orleans whole ships' cargoes into the interior of the country, as well as passengers.

The following list of steam-boats now in operation on the river

Mississippi, and its tributary streams, has been published by Mr.

Robinson:

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"In addition to which, there have been lost by accidents of different kinds, the following steam-boats: Orleans, 400 tons; Comet, 15; Enterprise, 45; Dispatch, 25; Franklin, 125; Pike, 25; New Orleans, 300. [pp. 64—7.]

We should have liked to have seen an addition to this enumeration of the number of steam-vessels now in use in Great Britain; satisfied as we are, from our acquaintance with some of our northern ports, that they would cut no inconsiderable figure by the side of those of the United States, where they are unquestionably brought to great perfection. This desideratum, Mr. Partington will probably supply in a new edition of his work, which will soon be called for, if he meets with that encouragement to which the industry and talent displayed in this production so justly entitle him.

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AMERICAN LITERATURE AND
INTELLIGENCE.

ON attentively perusing the "Report on the Penitentiary System in the United States, prepared under a resolution of the Society for the Prevention of Pauperism in the City of New-York," slightly alluded to in our last, we found it so highly interesting and important a document as to require republication in our Journal, almost in an unabbreviated form. On this work we therefore enter without delay, appropriating to it a larger space of our present number than it is our wont to allot to Transatlantic communications, of which we are inclined to think, that we have scarcely received one in which the British public will take a more lively concern; for in speaking of the system of Prison Discipline in America, it depictures in almost every page the errors of our own.

Omitting merely a few introductory sentences, of a local nature, the Report thus begins:

"The history of nations teaches us, that the welfare of empires may be frequently endangered by sudden revolutions in popular opinion, on subjects which embrace the general and individual relations of society. Wild and speculative doctrines will be occasionally started, that strike at the abrogation of existing systems of civil polity, and silently and rapidly acquire strength and stability, until the number and zeal of their votaries become too formidable for the effectual appeals of reason and experience. A period has arrived in this country, which fully illustrates this position. Without a due regard to facts and reflection, there are many in the United States, who advocate the renunciation of the Penitentiary System, and consequently a change in our Criminal Jurisprudence that will increase the severity of its character. Abstaining from all strictures at present, on the tendency and singularity of such an opinion, we would remark, that communities seldom retrace their steps in the trials of experience, until they reach their last extremity; and whether it is now decided to renounce or to retain this system, the determination will probably settle, for ages, the spirit of our laws, in relation to crimes and punishments. It may therefore be expedient for the Committee, in the first place, briefly to advert to the rise of the Penitentiary System in the United States."

To this succeeds a very judicious retrospect of the Criminal Jurisprudence of the principal ancient and modern

VOL. V. NO. 10.

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