422 ASCENDING AND DESCENDING HYDROSTATIC. Carriage. NEW SHIPWRECK SAFETY-MACHINE. An article from Haerlem notices, but very indistinctly, an experiment made at that place with a machine of the singular title of the Sea Phander, which appears to be applied by means of a horse, which, advancing with the machine towards a vessel in distress, conveys ropes to the crew for their preservation. The experiment is said to have been successful. DIFFERENCE BETWEEN HEAT OF Every mode of producing flameof causing economy, by giving the FLAME AND HEAT OF NON-LUMI- greatest approximation and exten NOUS MATTER. SIR,-The study of a poor man, and of a mechanic in particular, should commence with first principles, and the contemplations of the mind will be rendered clear, agreeable, and practical, in the degree that accurate knowledge of first principles may have been established. Solomon, the wisest man, asked for wisdom and knowledge, and the Supreme Ruler added in his grant riches, wealth, and honour. Sir Isaac Newton, the greatest of philosophers, had a character peculiar for mildness, industry, and affability; and relying upon the discovery of first principles, attained honour, power, and affluence, although early educated only at a grammar-school at Grantham. I will, therefore, take this opportunity to repeat a correction of the impression given by our philosophers, that the transmission of solar heat is not interrupted by glass, while that of terrestrial heat is entirely impeded. M. Brande has lately explained the source of error-that the heat of flame resembles solar heat, but that the heat of matter, not luminous, is incapable of penetrating glass. The application of this knowledge is important on a subject occupying many of your pages, viz. the economy of fuel in the furnaces of steam-boilers. The superior power of flame heat can be proved by the fact, that a manufacturer, during a long winter, used some coke; but as it produced no flame, it was found entirely useless. sion of flame towards the boiler, must be very important; and it is only necessary to observe of flame, that it should not be drawn, like that of a blow-pipe, to impinge on one point, as it speedily destroys the boiler, without producing concomitant advantages. First principles point out the way we should go, and the proper exercise of industry gives a peculiar vigour of mind and saving knowledge in all we undertake; which, that you and your readers may long live to enjoy, is the wish of Your very obedient servant, TYRO. ASCENDING AND DESCENDING A Mr. George F. Reeve, of Orange county, New York, has constructed an engine, which not only exhibits an eccentricity of ingenuity in the inventor, and a pleasing novelty to * Steam has been recently applied in this manner, with an advantage of 50 per cent., by Mr. Evans, of Bread-street, Cheapside; but his claim to the first honour of such an application is disputed by Mr. Gilman, and (we believe) by some other individuals. We suspect that the Americans can put in a better title to the discovery than either the one or the other. It is several years ago since the seeming paradox of burning water cut a prominent figure among a number of American wonders newly imported. We intend shortly to give a description of Mr. Evans's apparatus for the pur pose.-EDIT. NEW PRINTING PRESS IMPROVED HARNESS MACHINE. the beholder, but bids very fair to become extensive in its practical utility to the community; the design of the engine is to transport goods or articles by aid of water, any distance, where there is a sufficient quantity and fall for any given distance. Its leading principles consist of a wheel and axis, with floats or buckets, adapted to a race or trough, whose angle of incidence is adapted to the fall, or other circumstantial conveniences. Upon each end of the axis of this wheel is a cog wallow wheel, which works into a rack or cog plate, which is placed upon the top on each side of the race, and which answers for what may not be improperly termed a railway. The engine being situated at the foot of the race, and the water let in, and operating upon the floats, turns the wheel, and by the wallow cog wheels of the axis of the water wheel being geered with the rack on the race, the wheel ascends; and by a more or less partial supply of water, the water-wheel is made to descend with the velocity required. To the engine may be attached any formation or construction of a carriage, adapted to the nature of the articles intended to be transported. -Philadelphia American Daily Ad vertiser.. NEW PRINTING PRESS. I stated some time ago that I had completed a small steam-press, or a press to work with lever power, and with sufficient rapidity to produce 2000 impressions per hour, but could not discover a satisfactory 423 introduction of a heavy fly-wheel. The press is worked by a crank, and with the labour of one hand and two boys to feed the cylinder with paper; thus superseding the necessity of steam, water, or horse power.Noah's American Advocate. IMPROVED HARNESS MACHINE. In the present scarcity of drawboys, it gives us great pleasure to announce, that Claud Wilson and Alexander Lang, weavers, Georgestreet, have made a most important improvement upon the French harness machine, which in many respects will be of the utmost advantage to the trade. The French machine costs 15/. for a harness 400 of a tye; whereas one upon the new principle can be procured for 5l., and of 200 of a tye, for 4l.; the treadle in the former requires to be pressed down nine inches, in the latter only 4. The web which has been selected for a trial is a common imitation shawl; but the inventors are confident that they will be able to work a shawl, plaid, or trimming, with three covers, with one-half of the cards that are required upon the French plan. The machine has been examined by a number of manufacturers, weavers, and mechanics, who have all expressed themselves highly satisfied. It is open for public inspection, and may be seen by applying at No. 139, George-street.-Paisley Advertiser. OF TANNING. We have pleasure in being enabled to gratify the wishes of many inquiring Correspondents, by the following description of this new method of Tanning mode of supplying my ink-rollers, MR. SPILSBURY'S PATENT METHOD and solicited the co-operation of some of my Yankee brethren. A Mr. W. H. Hale, who comes, I understand, from Boston, and is a silversmith, called upon me, and soon removed the difficulty, by the formation of an ink-trough, which, supplying one roller, communicates the ink rapidly to the other roller, and after a short time, my model was complete, and is so simple and efficacious, and works with so much ease, that 2500 impressions may be thrown off in the hour, by the For Mr. Spilsbury's method of tanning, oblong square frames are provided, with metal hoops fastened round their edges. On one of these a skin or hide is stretched, after being limed, cleansed, and prepared in the usual manner for tanning. Over this hide another of the frames 424 MR. SPILSBURY'S PATENT METHOD OF TANNING. is placed, then a second hide is laid The cock at the top, that communicates with the tan cistern, being opened, and the other near to it being also opened, while that at the bottom is shut, the tan liquor will run down between the hides, driving out the air at the other open cock; which, as soon as any liquor appears in it, being shut, the tan liquor will then distend the hides, and press outwards, with a force proportional to the height which the tan cistern is elevated above the frames. The consequence of which pressure will be, that the tan liquor will ouse through the pores of the hides, appearing at the outside like dew; and by thus bringing fresh portions to act continually on them, will, in the opinion of the patentee, cause them to be tanned much more speedily than happens in the common method, in which the hides lie in the liquor, after it has ceased to operate on them, and are only passed into fresh liquor at intervals by a tedious manual operation. The frames are to be made of wood or copper, and if iron should be used for them, it must be well painted, to prevent its making the hides black. In some cases, two skins or hides may be put at each side of the middle frame; and when the whole are well tanned, the tan cock is to be closed, the liquor is to be run off at the lower cock, and the frames separated from the tan pipe and from each other; and the hides being removed, and having their edges pared off, which were nipped or compressed between the frames, are then to be dried and finished in the usual manner. Nothing further is stated in the specification respecting the time which this process will require, but that it must depend entirely on the nature of the hides or skins. The New Repertory of Inventions has the following remarks on the value of this process : "This method of tanning has attracted much attention; and it is reported that hides of that thickness, to require a year for tanning in the common method, can be finished in this in six weeks; and that some skins can be tanned by it in eight or nine days; it is also said, that a very large sum of money has been offered for the patent right. The theory of the process appears to promise well for quick performance, but on these occasions it is necessary to attend to facts; and we have been informed by some gentlemen in the trade, that the hides are not tanned evenly by this method, but leave spots less acted on by the liquor than the rest; and that leather made in this way is not so durable as the common sort. "The quantity of the hides that must be pared off when they come out of the frames, must certainly diminish the value of the process, and especially when oblong-square frames (such as are represented in the figures of the specification) are used, which, not being of the natural shape of the hides, must cause more waste; which must be worth consideration, even though the parts to be cut away are the least valuable of the hides. "It must, however, be considered that this method of tanning is still in its infancy, and that it will be probably improved in time, so as to diminish some, and totally remove others, of these objections made to it. Let KL be the base of the stand, to be placed on the top of a pedestal parallel to the horizon, by the side of which the arm, NU, is to act. AB is a trough to contain the telescope; at its end, A, a piece of plank or board, GH, is made fast, and is fixed to the base by two hinges, E and R. Near the top of the trough, the arm, NU, is so fixed, by an extended pin, de, as to play in diverse directions. The arm, NU, is to slide in the tube, W, and to be made fast at any desired part by turning the screw at Y until it presses against the arm, and by this means you will fix it very nearly to any desired altitude. Now one side of the tube, W, being made to project, and a hole, X, made through it for the purpose of screwing it to a sliding piece, Za is then capable of sliding in an inlet groove, OP, supported by hinges at S and T; whence, taking hold of the arm at V, and sliding it toward or from P, Za will have an horizontal movement, by which the telescope and trough, AB, will be elevated or depressed, and with a beautiful slow movement. As for the horizontal range, or for turning the whole to any azimuth, the operation is so simple as to require no explanation. The telescope thus supported, and the pedestal resting on sand, I have found by experience that nothing will disturb it but the wind. NOTE. To all telescopes of great power it is better to have two finders, the one of a great field of view. MATHEMATICAL CASE. SIR,-In page 374 I find the question-"Can a straight line touch the circumference of a circle in any point at a less angle than 90o, with the radius drawn from that point to the centre?" I am inclined to doubt the correctness of the conclusion drawn by your plural Correspondents, "Discipuli." It appears feasible at the first "dip;" but I think, if the "bucket" be allowed to sink a little deeper, a different conclusion will be drawn. After a careful investigation of those particular propositions of Euclid which bear upon the point in question, I see no reason to doubt the correctness of the conclusions which Euclid has drawn, and which are the reverse of the one drawn by the "Discipuli." As some of your readers may not have Euclid to refer to, I will quote his 16th Proposition, Book 11., which bears directly on this point. "The straight line drawn at right angles to the diameter of a circle from the extremity of it falls without the circle; and no straight line can be drawn between that straight line and the circumference, from the extremity of the diameter, so as not to cut the circle. "Again, between the straight line, AE, and the circumference, no straight line can be drawn from the point A which does not cut the circle. Let AG be drawn in the angle DAE; from D draw DH at right angles to AG; and because the angle DHA is a right angle, and the angle side DH of the triangle DAH is less DAH less than a right angle, the than the side DA. (Prop. 19, Book 1.) The point H is therefore within the circle, and therefore the straight line AG cuts the circle. "Cor.-Hence it is manifest, that the straight line which is drawn at right angles to the diameter of a circle from the extremity of it touches the circle, and that it touches it only in one point; because, if it did meet the circle in two, it would fall within it. (Prop. 2, Book 111.) Also it is evident that there can be but one straight line which touches the circle in the same point."-Playfair's Geometry. This conclusion appears to me decisive. Suppose the line AG at the smallest imaginable distance from AE, still a line drawn from D, meeting AG at right angles, will form a |