D valve, valve jacket, packing blocks, &c. The steam may be also, by this means, worked expansively to a greater advantage than at present, as it is necessary to have an additional expansion valve for the present D valve, when it is desired to work steam expansively. THOMAS MERITON. Mill Wall, January 27, 1842. Ibid. New Steam Engine erected by Messrs. Rennie, at Mr. Cubitt's Factory, Thames Bank. The two-cylinder, expansive engine, invented by Hornblower, and afterwards, with but slight modifications, brought into extensive use by Woolf, is well known to all persons acquainted with the history of the steam engine. The cause, also, of its subsequently falling into disuse, is no secret; it was found to perform no more duty with two cylinders than could be done, at much less cost, with one. Not that more duty was previously done with one cylinder, but that in the progress of improvement it was discovered, or supposed to be discovered, that steam could be worked expansively as well with one cylinder as with two; and so the cost of the second cylinder, and the extra friction and radiation attending the use of it, saved. Abandoned in Cornwall, where it first found favor, and long maintained a strong hold on public opinion, it has now, strange to say, been re-produced in the metropolis, by engineers of the first eminence; and, stranger still, with a degree of success which, if there be no mistake in the case, shows not only that it has been most undeservedly shelved by its Cornish patrons, but that it is in truth the best sort of engine which has ever yet been constructed. It The engine which has thus taken the engineering world by surprise, is one which has just been erected by the Messrs. Rennie, at the extensive manufactory of Mr. Thomas Cubitt, Thames Bank. differs in no respect, as far as regards details and arrangement, from the ordinary rotative engine of Woolf; nor is any such difference claimed credit for by the makers. There are the two cylinders, side by side, as of old-a small one, into which the steam first passes at a high pressure from the boiler, and a larger one, into which it expands (five times;) also the ponderous beam, fly-wheel, rotating shaft, &c. The only difference we could observe, consists in the workmanship, which is of a very superior description, and in a little better clothing (perhaps) of the cylinders. The effective working power is stated to be equal to sixty horses, and the consumption of fuel to be no more than 2.2 lbs. per horse power per hour. It is this which is the startling result. So small an expenditure of fuel has never been before reached by any rotative engine, of any description; not even by the same sort of engine, when in the friendly and fostering hands of Woolf. That it has been actually realized in the present instance by virtue merely of better workmanship and better clothing, no person can be expected to believe, except on the most indisputable evidence; and such evidence the respectable manufacturers of the engine will, no doubt, themselves allow, still remains to be furnished. We were assured that it was doing the same work which two or three old engines, of the cumulative power of sixty horses, had been in use to perform, and have no reason to question the fact; but that, evidently, is a very uncertain test of its real power. We were also shown indicator diagrams, which exhibited a very small average deficiency of pressure; but the insides of steam cylinders and working shafts, as all the world knows, often tell very different tales. The means taken to keep a correct account of the quantity of fuel consumed (Welsh coal) appeared to be also most unexceptionable; and if we could only admit sixty to be the proper divisor to employ, we make no doubt of 2.2 lbs. per horse power per hour being a true result. Proof, however, of the sixty horses' power is still wanting-such direct and positive proof as actual performance alone can supply, and that not during short trials of an hour or a day at a time, but during trials carried on for several days successively, and under the same circumstances, precisely, in all respects. Ibid. Condensation of Steam by Cold Air. Craddock's Process. The peculiar feature of my invention is, the communication of a rapid motion to the condenser-independent, of course, of the motion. which the vessel or locomotive may have, to which my condenser is attached. It will be unnecessary for me to detail my preliminary experiments, or the various forms which I have given to the condenser during my investigations; I will, therefore, at once, describe the apparatus in that form which, from my present experience, seems to me the best. A hollow axis is supported by proper bearings, in a vertical position. The lower end, or that at which the steam is introduced, is open, and works on a pivot fixed on the bottom of a chamber, on the top of which is a stuffing-box, through which the axis passes. Near the upper or closed end of the axis is an enlargement, or chamber, from which proceed, at right angles to the axis, a number of radial hollow arms, into each of which the ends of a series of small copper tubes are inserted; these, of course, are parallel to the axis; their lower ends are inserted into other radial arms fixed near the bottom of the axis, and similar to those at top, excepting that their ends do not open into it. The radial arms at the bottom are all connected by their ends opening into an annular chamber. A rapid rotary motion is given to the condenser by the steam engine to which it is attached, the result of which is the cooling of the apparatus, and, consequently, the condensation of the steam which has been introduced into the small copper tubes. The condensed steam, or water, falls into the lower radial arms, and is thrown from thence into the annular cham ber by centrifugal force; a small pump is affixed to this chamber, and its piston-rod is attached to the clip of a fixed eccentric, supported round the movable axis of the condenser. As the pump travels about this eccentric, its piston-rod works to and fro, and the water is removed from the condenser. The arrangement of the minor parts of the apparatus, such as the conveyance of the water to the boiler, the connexion of the air-pump, &c., cannot be illustrated without drawings. I may just remark, here, that the force-pump for the removal of the water is not absolutely necessary, as the air-pump may be made to effect that object. My experience, however, demonstrates that it is effected to greater advantage by its use. I have attached a condenser of this kind to a high pressure engine of five horses' power, and, by giving it a velocity of eleven miles per hour, the water is drawn off at a temperature varying, with that of the air, from 90° to 120° Fahr. The column of mercury supported by the vacuum is not quite so high as it should be, according to the temperature of the water; this, however, is owing to the imperfection of some of the joints in the condenser, and will soon be remedied. The power gained is more than double that required to work the condenser and air-pump. The amount of surface required to condense a given number of cubic feet of water per hour, depends on the velocity at which it is intended to work the condenser, and the temperature at which the water is drawn off. It does not appear to me advisable to draw the water off at a temperature lower than 150°, for a given abstraction of heat at lower temperature affects the height of the mercurial column much less than at a higher; and any one familiar with the law according to which heat passes from one body to another, need not be told that the same surface will condense much more steam into water at 150° than at 100°. A condenser having a velocity equal to twenty miles per hour, and the water being drawn off at 150°, will require about twenty square feet of surface per cubic foot of water per hour. The strength of the copper I have hitherto used is one pound to the square foot, but I intend using it much lighter in future. The weight of a condenser equal to condense ten cubic feet of water per hour, will be from eight to ten hundred weight. Besides the advantages which my mode of condensation possesses, in those situations where a supply of water cannot be had, I believe it possesses other, and scarcely less important, ones. By my condenser returning the water to the boiler, I am enabled to use a tubular boiler, without experiencing that inconvenience which almost precludes their use, in combination with the ordinary system of condensation, namely, the liability to become choked up by the deposit from the water. Although the condenser with which I am working is far from being tight in its various joinings, I have worked my engines constantly for four days, without adding any water to the boiler; and I have no doubt that the condenser and engine I am now fitting up, and to which I hope very soon to be able to call the attention of engineers, will give results even more satisfactory than those at present obtained. THOMAS CRADDOCK. Ibid. Mechanics' Register. LIST OF AMERICAN PATENTS WHICH ISSUED IN JUNE, 1841. 1. For improvements in machinery for Hoisting Weights, &c.; John B. Holmes, Boston, Massachusetts, June 7. In this machine the rope, or chain, to which the weight is suspended, winds around two grooved drums, to each of which there is attached a cog wheel, mashing into a pinion that lies between the two, and by which they are actuated, the two cog wheels having the same number of teeth, to insure the same motion to the two drums. These drums, together with their cog wheels, project outside of the frame, one of them turning on a spindle attached to the side of the frame, and the other on a spindle which passes entirely through it— the part of it which is within the frame being adapted to receive one of a train of wheels for multiplying the power. One of the drums has cogs cut upon its outer edge, which take into the teeth of a pinion on the axle of a grooved roller, for the purpose of making pressure upon the rope, or chain, to prevent its slipping. Claim."What I claim as my invention and improvement, and desire to secure by letters patent, are-First, the arrangement of the barrels which hold the rope without an outside framing, as described. Second, the combining there with, in the manner set forth, a grooved roller, to press the rope against the barrel on its passage therefrom, for the purpose of preventing any slipping of the rope which the action of the weight at the other end has a tendency to produce-being constructed and operating as described." 2. For an improved mode of Block Printing on various kinds of Fabrics, and for Apparatus, &c., for that purpose; Robert Hampson, Manchester, England, June 7. The printing block is attached to a cross frame, which slides on straight edges at the four corners of the main frame, and has a rod attached to its middle that slides through a hole made in a set of arms at the top of the main frame. To the upper end of the rod there is a band attached, which passes over two pulleys, and has appended to it a counter weight, to balance the whole. The fabric to be printed is drawn through the machine, and over the bed on which it rests, to receive the impression, which is given by means of blocks, in a manner well known to machinists. The colors are so arranged in separate sieves as that they can be drawn apart to receive new colors, and then brought together again to apply the colors to the block; the sets of sieves are placed upon a platform provided with wheels, running on rails. The platform, with the colors, is passed under the block, which is then let down to receive that which is wanted. The sieve is then drawn away, and the block de scends upon the fabric, to impress the pattern; and the operation is in this manner repeated. Claim. "I declare that I claim as of my invention the apparatus, or machinery, constructed as set forth, for printing with blocks on woven fabrics of various kinds; that is to say, I claim the combining of a block for printing in various colors with the apparatus, or mechanical agents, for causing said block to descend in a perpendicular direction in order to take up the color from the sieve, or sieves, and to impress the pattern, or design, upon the fabric; said apparatus, or mechanical agents, consisting of the cross frame, the arms, the straight edges at the corners of the main frame, the rod, the band, and counter weight, with their appendages; the whole being so connected as that by raising the counter weight the cross frame and block will descend, and the color be received on the block, or the impression given to the fabric; and I claim the same however the said mechanical agents and contrivances may be modified or varied in size, form, proportion, or other particulars not departing from the principle of my invention; but I do not claim as my invention such mechanical agents, or contrivances, separately, but only as combined to effect the purpose aforesaid; nor do I claim as part of my said invention the apparatus herein before described for traversing the coloring apparatus to and fro, by means of a railway and carriage running thereon-the same, although invented by me, having been by me used and practised previous to the grant of the said letters patent; nor do I claim as of my invention the arrangement of rollers and connected apparatus for causing the fabric to traverse, or be drawn over, the printing table, and conveyed away when printed. And I further declare that I claim as of my invention such coloring apparatus as herein before described, in which several sieves are separated and held apart, to admit of the several colors being distributed and traced, or spread, thereon, without admixture or interference one with another, and whereby the sieves are afterwards closed, or brought into juxta position, in order to the colors being taken up by the block, so as to produce at one impression of the block, or pattern, or design, or parts of a pattern or design, in several colors, arranged contiguous, or near to each other, as hereinbefore described; and which coloring apparatus I claim, whether the same be used in conjunction with the machinery before described, or with the common hand block, or otherwise, and under whatever other modification." 3. For an improved mode of Framing and Bracing the Arms of Paddle Wheels of Steam Vessels; Wm. F. Julian, Hartsville, Bartholomew county, Indiana, June 7. The arms are bolted to a cast iron centre plate, in the usual manner, and kept at equal distances apart, by wedges driven in between them. Two sets of braces are arranged between the arms, the braces being provided with short tenons, fitting into long mortises in their sides, the said mortises being sufficiently long to allow the braces to be drawn in towards the centre of the wheel. The two sets divide |