NEGLECTED CAUSES OF FIRE. sonal suffering thus occasioned, further mischief seldom results, because the fire is directly extinguished by the party occasioning it. The great danger lies in the discarding of such matches as from having become damp, or from some other cause do not ignite. To explain what I mean, I will suppose the following case:-A number of workmen enter a carpenter's shop on a raw damp morning in November; one of the party, or a lad, proceeds forthwith to light a fire in a proper stove or in a temporary structure of bricks, to afford warmth to the workmen and to heat the glue-pot. The congreve matches are resorted to, but the moisture of the atmosphere has been attracted to the composition; the first two or three matches "miss fire," and are thrown down in front of the grate, at length a light is obtained and the fire kindled. Breakfast time arrives, and one of the workmen, before quitting the shop, goes to see that the fire is all right, or to put on fuel, or it may be to take off the gluepot; on leaving the fire he treads on one of the discarded matches, which, by this time, has become dry from the proximity of the fire, and inflames unperceived. The fire thus kindled finds abundance of food in its vicinity in the shape of dry sawdust, shavings, &c., and in less than a quarter of an hour after the workmen have left the shop, it is enveloped in flames, and the origin of the fire is for ever shrouded in mystery. Or we will suppose that the matches lay drying and unmolested till the evening of that or the following day. After all the workmen have left, the master himself, or a sober careful foreman goes over the shops, and having seen all safe, he approaches the fire-place to see particularly that no lighted embers remain to originate a conflagration. Finding "all right," he leaves, but on leaving, steps on the fatal match, and germinates the very mischief he is so sedulously guarding against. He has scarcely entered his own adjoining dwelling, than the cry of "fire" meets his ear, and running out he finds how little his care has availed, the premises being mysteriously inflamed from one end to the other! Little does he suspect that he himself is the incendiary! 221 I have put this as a suppositive case, but I have good reasons for believing that it has been, in more than one case, a reality. A I cannot help thinking that the "singular case of burning," narrated at page 176, originated from a similar cause. smoker, perhaps, in lighting his muchloved weed, had dropped or discarded a congreve match, which lay on the pavement, in the sun's broad glare, until highly dried and heated; the poor little sufferer trod, with her half sliding step, on the dangerous composition, which inflamed with violence, and set fire to that portion of her apparel which was in close contact with it, and caused her melancholy end. While speaking on the causes of fire, I cannot help adverting to the increasing number of accidents arising from the careless use of candles. Housekeepers would do well entirely to discard the use of open candles, when carried about, or when taken into bed-chambers and the like; if the expense of a neat glass lantern is too much, very safe wire-gauze lanterns are to be had at a very trifling cost, by which the ignition of bed or window curtains, and of apparel, may be prevented. A most dangerous practice prevails amongst females, both young and old, but especially the former, of placing lighted candles on the floor, while kindling fires. Could the amount of personal suffering and the number of deaths produced by this practice be set forth, I think no master of a house or father of a family would allow such a course to be persisted in. The wearing apparel of the offender happening to come in contact with the candle, she is soon enveloped in flames, and such accidents as these generally happening before any other member of the family has risen, she perishes before any assistance can be rendered. By the use of fire and candle guards, the published number of metropolitan fires, last year, might have been reduced in number nearly ONE-THIRD! While there is every reason to believe that the number of unpublished accidents of this kind, which might have been by such means averted, greatly exceeds the whole number of published fires, upwards of one hundred of them being attended with fatal consequences. Under such circumstances, it is im possible to overrate the importance of attention to this subject. I am, Sir, yours respectfully, WM. BADDELEY. 29, Alfred-street, Islington, March 7, 1842. MESSRS. PALMER AND PERKINS'S PATENT PUMP. Sir,-In your Magazine, No. 967, there is a communication from Mr. Trebor Valentine commenting upon the explanation of Messrs. Palmer and Perkins's Patent Pump, contained in your No. 963. Patentees are always much obliged by the notice of their inventions by scientific gentlemen, and presuming that the reimarks of Mr. Valentine proceed from a kindly, and not a controversial spirit, I have no difficulty in replying to him. Mr. Valentine evidently bases his remarks more upon the drawing than the explanation of this invention, expressing his first doubt to arise from the drawing representing so short a suction pipe. Now it is perfectly understood, that drawings, intended to illustrate descriptions, are made more for that purpose than to provoke criticism. If the action of the pump in question is good, and it produces the requisite vacuum, the suction will follow as a matter of course, notwithstanding the shortness of the pipe in the drawings; and it was the object of the explanation to show that the action was such. Mr. Valentine goes on to say, that the experiments already made do not justify the hopes entertained by the patentees of the utility of their invention for mining purposes. Perhaps not; but still, the description explains that two men worked a 10" pump, raising a column of water 15'4" high. It is therefore an allowable inference, (while it was a conviction with the patentees,) that a greater motive power would have lifted a higher column. Probably Mr. Valentine may himself have been a patentee, and if so, he will have a fellow-feeling for the heavy preliminary expenses attendant on new inventions, and know how unavoidably they form a limit to the actual experiments which would justify every "foregone conclusion." But, as touching both these points, I will, if he wishes it, introduce him to an establishment in London where there is a 7" pump on this principle, which draws the water from a well 365 feet distant, the level of the water in the well being 17 feet below the clack valve; which height, added to 23 feet of rising main, makes a total ver tical lift of 40 feet. This pump has been going night and day, making 25 strokes, and the piston travelling 32 feet per. minute, ever since the 4th of Februarylast, without requiring any attention: eertainly this fact supports the pretensions of the patentees, that their pump will prove a valuable resource for mining purposes. As to the other point, on which Mr. Valentine appears to entertain suspicion, viz., the reduction of friction, I can only say, the experiments were fairly and anxiously conducted with a view of arriving at the truth: the 10" pumps, with which the experiments were conducted, are still standing at Mr. Charles Robinson's, accessible to all the world, and are, in fact, the best reference as to their separate or comparative merits. I remain, Sir, your obedient servant, EDWARD W. PERKINS. 67, Mark-lane, February 28, 1842. AMERICAN MARINE STEAM ENGINE MAKING-THE KAMSCHATKA STEAM FRIGATE. Sir,-In Number 956 of your Journal, I notice a description of the Kamschatka steamer, together with observations reflecting rather severely upon "Brother Jonathan's" attainments in marine engineering. The correctness of your conclusions in regard to the plan of the engines and boilers of that ship, cannot be questioned. That the fault does not rest with American engineers, it is my purpose to show, and I trust these few remarks will find a place in your columns. I would beg leave, however, first to correct your statements in reference to the material used in the hull of the Kamschatka. The frame is of white oak throughout. The plank and ceilings are entirely of white oak, (not " Canada elm," the use of which is here unknown) fastened with bolts, composition spikes and locust treenails. Walls of white oak 5 inches thick, and not "scored on the frame." The frame is further secured inside by diagonal braces of iron, 5 inches wide, 1 inch thick. So far at least as the construction of the hull is concerned, I trust you will allow the builders credit for good workmanship. The history of the building of the The writer has left a blank here for the material of which the bolts are composed.-ED. M. M. ARTIFICIAL FUEL, A MODERN ANTIQUE. Kamschatka is a curious one, and forcibly llustrates the influence of words when Drought into competition with the ordi mary manifestations of practical good sense. The story runs thus: The Russian government sent to this country two officers of their navy, with the power to contract, through the agency of an American citizen, for the building of a steamer of war, and also to superintend its designing and fitting out. These individuals, upon their arrival here, became associated with a gentleman of the legal profession, who, it appears, was somehow interested with the patentee of the half-beam engine, as it is termed, and who became at once their nominal engineer (!) and contractor. The ship was designed and modelled under the direction of the Russian officers; and the quantity and quality of the timber used, likewise submitted to their control. The designing of the machinery was left with the contractor, who brought to his aid such engineering talent as could be obtained in the by-ways of the profession; its construction, from detailed drawings, was given to various establishments in this city. Now, I would ask, what have American engineers to do with this? So far are they from approving the arrangement of the Kamschatka's machinery, that I venture to assert, that there is not one engineer of intelligence to be found in this country, who will approve any one of its features, or who would not blush to own it as an American production, despite the fulsome adulations of the press. As to the progress of steam navigation in this country, I do not mean to speak, except in its defence. The same eagerness to improve the marine engine, by modifying its shape, at length evinced by the English and Scotch engineers, is manifested still more in the efforts of American engineers. On our part, experiments have been conducted mainly with a view to conform to that system, which has obtained, in our river navigation, viz., engines with cylinders small in diameter, and a corresponding decrease in weight of the working parts; in order to do which, various expedients have been resorted to, but as yet, with no very satisfactory results. The inference seems to be gaining strength, that the present form of the English marine engine is the best shape in which steam power can be 223 applied to the purpose of navigation; New York, February, 1842. ARTIFICIAL FUEL A MODERN ANTIQUE. Sir, -The public attention has been recently much drawn to the subject of artificial fuel, and in a historical memoir which I read last month of the various methods which have been patented for the purpose, the earliest is stated to have been one invented by a Mr. Peter Davey, May 20, 1800. Such of the readers of your valuable Magazine as may be curious respecting the history of this manufacture, may be gratified by being referred to a much earlier mention of it to be found in Hugh Platt's Jewel House of Art and Nature, first printed in the year 1594, a copy of which is preserved in Chetham's Library, in the college, Manchester. In this work it is recorded, that a Mr. Gosling, a merchant of London, was at the expense of printing handbills describing how a species of artificial fuel might be manufactured, and distributing them to the poor of every parish in London and its vicinity. The following is copied from his handbill. "Get," says Mr. Gosling, "a load of stiff loam or clay, and take half a peck of it, and with a shovel make it soft with water, then put a peck of small coal to it, and incorporate or mix them all together, until you may roll it or mould it into several parts, like pieces of charcoal or long eggs. As many may be made in a day as will last a quarter of a year. Any other combustible may be mixed up with it, such as peat turf, saw dust, curriers' or shoemakers' threads, tanners' waste bark, and such like." The worthy Mr. Godfrey adds, in a note, that he dispersed freely many thousand of these handbills, "for the good of all people in the land." He left it for the present generation to secure the same thing by patent. I am, Sir, yours respectfully, JOSEPH HENRY REDDELL. Phoenix Chemical Works, Bow Common, March 2, 1842. MR. DAVIES'S ELLIPTOGRAPH. Sir, I am much pleased with Mr. Davies's ingenious instrument mentioned in No. 963, p. 73; but while contemplating it, I felt doubtful whether it would draw an ellipsis; and upon finding points in the curve which an instrument made and set exactly as represented at page 73 would draw, I found the curve too flat near the major axis, and I suspected it would be too much curved about the minor. I must explain that I supposed the upright stem to remain in every respect immovable, and the compass head to move vertically, as well as circularly upon it; and also, the guide i to have a knife edge, which I think will be found necessary, because its positions will coincide with radial lines from the centre of the stem a, and not with the radii of curvature of an ellipsis, such as g would appear if viewed in the direction of the stem. I then submitted the matter to a mathematical friend, who, after investigation, declares that the instrument will only draw an ellipsis when the major axis of that ellipsis is in a certain fixed proportion to the diameter of the plate g, the proportion depending on the lengths, &c. of the other parts of the instrument. If this be correct, as I have no doubt it is, most likely some of your correspondents will furnish you with the investigation and proof; but I beg to say, I do not hold myself responsible for its cor rectness. I mention these facts, because I think they indicate a peculiarity in the instrument which should be made known, and which has probably been overlooked, as it is described at page 74, as being perfect; they may be also useful in directing the construction. But, as it is possible Mr. Davies may fancy these remarks will injure the reputation of his instrument, which I have not the least doubt may be made more than sufficiently correct for its intended purpose, I shall feel obliged by your showing him this letter, that he may have an opportunity of publishing any observations he may wish to make upon it in the same Number in which it appears. Your obedient servant, February 3, 1842. [In compliance with S. Y.'s request, we forwarded a copy of his letter to Mr. Davies, who wrote to us that a present pressure of occupations would prevent him from sending his remarks upon it in time for contemporaneous publication. He feels, however, "not the less obliged to S. Y. for the courtesy of his communication."-Ed. M. M.] STEAM-ENGINE IMPROVEMENTS — PILBROW'S CONDENSING CYLINDER ENGINE PRACTICALLY CONSIDEREDCORNISH AND MARINE STEAM-ENGINES. Sir,―The difficulties that surround an inventor's path are sufficient to appal and damp the spirits of all but the most confident and resolute: yet these necessary qualities are apt to produce extreme views of the circumstances in their favour, unless regulated by a desire of the truth, such as has been evinced in Mr. Pilbrow's reduction to a more reasonable amount, of his estimate of the possible advantages due to the principle of his suggested plan for a steam-engine. Amongst these difficulties, that of obtaining a correct standard of comparison is not the least. Unfortunately for patentees, it is seldom sought for with diligence; yet its obvious necessity sufficiently justifies the course that has been adopted by Mr. Pilbrow, in mooting the question of the superiority of the engines made by Watt over those of recent construction. I certainly deemed the evidence inconclusive, and the conclusions inadmissible; but I never intended to impugn, in any way whatever, the accuracy of the experiments reported by Farey, from short trials under favourable circumstances. I communicated my views of the trials under such conditions, in compliance with Mr. Pilbrow's request; but I avoided the practical part of the question, whether this engine would effect the object proposed. Nor should I now again trespass on your pages, but for the expression of regret on his part that I had done so. I will, however, first advert to a misapprehension, by Mr. Pilbrow, of my meaning. I did not, as he supposes, refer to the difference of temperature of the condensing cylinder and the condenser of a marine engine, but to the difference of temperature between the steam cylinder and condensing cylinder of Mr. Pilbrow's engine. I do not urge my estimate of PROGRESS OF STEAM-ENGINE IMPROVEMENTS. lbs. as correct, but I am convinced some difference of pressure will exist, due to the contraction of the valves and steam passages, jointly with the difference of temperature. The use of cold water round the condenser, however difficult its practical application may be, will favour my views. In referring to Farey's tables, I find the pressure due to 96° is about lbs. ; a much closer approximation, I must admit, to lbs. than the 1 lb. I assumed from imperfect recollection. The beam for working Mr. P.'s condensing cylinder is only about 14 of the length of the stroke, and its ends work in an arc of about 115°; while the amount of deviation from the straight line is placed on the inside only. The framing and joints appear adapted for an engine intended to exert a less, rather than a greater power from a cylinder of a given size on the crank; and, further, the valves and steam passages between the cylinders are extremely contracted. The These observations apply in no respect to the principle of the engine, but to arrangements that may be readily altered, though perhaps not without some increase of weight and space occupied. comparison with the beam marine engine is at present perfectly fair: how long the latter will remain the standard is another question; and on these important points of weight and space the Devastation's engines, by Maudslays and Field, and the Virago's, by Boulton and Watt, 225 will be awkward rivals. An inventor has to contend not only with the best engines of recent construction, but with all the improvements that may be effected in them; arising, perhaps, in some cases, from the very competition which his patent has excited. I congratulate Mr. Pilbrow on the accession of a warm friend to his cause in "Scalpel," and on the latter's estimate of the value of the invention. The novelty and ingenuity of it I have always been ready to acknowledge, though perhaps the doubts I have expressed respecting the extent to which it is available, (a point on which all now seem to agree,) may not be considered such an indirect compliment as to bear that interpretation. I shall be glad if my good wishes could give him a fair field and no favour, with plenty of time, and means to use it; and I trust the objection I have made to the arrangements shown in the drawing will be taken in good part, as not intended to injure the patent, but to call attention to the best means of insuring success. So much has been said respecting Cornish engines, and their expansive action, &c., that I deem a comparative statement of the steam and water conditions used in them and their rivals in size and their superiors in power, the larger marine engines, if not of utility, may perhaps be of interest to some of your readers, many of whom are perhaps not accustomed to see the results of expansive action exhibited in the following form. Comparative Statement of the Performances of Cornish and Marine Steam |