over, given by Mr. M'Iver, only differs from my calculated time and velocity in quantity, and not in proportion. The same may be said of the time and velocity of the descent ten times higher than the moon, for that time and velocity acquired are deductions made strictly in accordance with the Newtonian doctrine, and also with Newton's definition of the sesquiplicate ratio. "Rationem vero sesquiplicatem voco triplicatur subduplicatum quæ nempe ex simplici et subduplicato componitur." It now remains for me to show that the method pursued by Newton, in determining the times of descent and the velocity acquired or given, lib. i. sec. 7, Principia," is not in accordance with his " Art of Orbit Building." 46 According to that theory, if a body be projected with a certain velocity, it will revolve in a circle; if the projected velocity be a little greater, it will revolve in an ellipse, &c.; but the dimensions of the ellipse will be greater than the circle. From the same arguments it follows, that if a body be projected with a less velocity than that which would cause it to revolve in a circle, it will also describe an ellipse, but which will be of less dimension than the circle. And this is in accordance with Cor., prop. 15, lib. i. "Principia," which says, Therefore the periodic time in an ellipse is the same as in a circle whose major axis is equal to the diameter of the circle." Suppose, then, two bodies to revolve, one in the circumference of the semicircle ABC, and the other in the ellipse AEC, the lines of description will be equal by the abovementioned corollary, and SO of any two corresponding parts, as AB and AE. And proceeding according to Newton's method, suppose the ellipse to be continually diminished in breadth, then it is evident, if the times of description must continue equal, that the velocity in the ellipse must be diminished in the same ratio at its breadth. Suppose the ellipse to be diminished until it coincide with the right line A, then the line of descent down AC will equal the time of describing ABC, or the descent down AS is equal to the time of describing AB. So long as the ellipse remains a curve it is understood to be composed of the projectile and centripetal forces; but when it changes into the right line AC, it is evident that the projectile force must have vanished, and the body by hypothesis descends down the sole right line simply by the force of gravity. Thus it appears that the projectile force increases the velocity, so that a body will describe one fourth of its orbit in the same time as it would descend to the centre of the body round which it moved simply by the force of gravity, provided that body be placed in the centre of the orbit; and this will be so without respect to the form of the orbit; that is, according to the above-mentioned corollary. I am, sir, Yours respectfully, W. DAVISON. Stockport, Sept. 24, 1845. NOTES AND NOTICES. Native Copper. A letter from Lake Superior states that native copper in large masses, continues to be found. A piece lately discovered near the lake-shore, by Major Campbell, weighs about 16 hundred, is purer than the copper of commerce, and is altogether the most beautiful specimen ever seen. Prevention of Boiler Incrustations.-On board the Echo steam vessel, in this (Portsmouth) harbour, an experiment is being tried of Dr. Ritterbandt's patent method of preventing incrustation in steam boilers. The substance employed is chloride of ammonium, a harmless salt. One of the greatest difficulties with which engineers have to contend in the application of steam is the incrustation of the boiler, producing not only a great expenditure of fuel, but often fatal explosions, especially in tubular boilers, as their peculiar form almost entirely prevents scaling or the application of other mechanical remedies. The experiment has been eminently successful in its application to the boilers of the Echo, under the superintendence of the patentee and Mr. Taplin, of this dockyard. The substance does not discolour the water, nor communicate to it any unt pleasant taste or smell; it has no injurious effect upon the metal of the boiler; does not increase the density of the water, therefore does not produce. "priming;" nor does its application involve any alteration in the boilers now in general use. The action of the ch'oride of ammonium is to change the carbonate of lime into chloride of calcium, which is not deposited by heat; and as the crystallization of other salts, such as the sulphate of lime, depends in a great measure upon contact, the absence of nuclei of solid carbonate prevents, in a great measure, their formation. In marine boilers this is very evident, for after adding chloride of ammonium, and thus preventing the precipitation of insoluble carbonate of lime, it is almost impossible to obtain crystals of common salt, thus "blowing off" is rendered almost unnecessary, in proof of which the George IV. commercial steamer, plying between this port and Southampton, worked 12 days without blowing out, merely by using a small quantity of the material every day, nor when the boiler was afterwards examined was there any exhibition of a tendency to deposit.-Times Correspondent.-For a ful description of Dr. Ritterbandt's process, see Mech. Mag., vol. xlii. p. 429. Mineral Wealth of the United States.-At a recent meeting of American geologists, Prof. Shepherd expressed his opinion, that both diamonds and platina would be found in abundance in the gold region of Connecticut, also in South Carolina and Georgia. This opinion he predicates upon the fact, that elastic sandstone has been discovered in some of the western counties of that state, Burk and Buncombe, and other states; and, where this is found, it is a geological indication of the presence of the diamonds or platina. In Hall county, Galena, a perfect diamond was found in one of the gold washing deposits, and one other was, unfortunately, broken in pieces by the workmen. LONDON: Printed and Published by James Bounsail, at the Mechanics' Magazine Office, Mechanics', Magazine, MUSEUM, REGISTER, JOURNAL, AND GAZETTE. SATURDAY, NOVEMBER 22, 1845.96 to [Price 3d. • bus ; idro sd1 to 911590 Edited by J. C. Robertson, No. 166, Fleet-Street, Tid esmit ay s ROYLE'S PATENT IMPROVEMENTS IN LOCOMOTIVE, MARINE, STEAM, GAS, AND OTHER TUBES. VOL. XLIII. ROYLE'S PATENT IMPROVEMENTS IN LOCOMOTIVE, MARINE, STEAM, GAS, AND OTHER TUBES. [Patent dated April 15; Specification enrolled October 15, 1845.] THE specification of Mr. Royle recites that "by one mode of manufacturing locomotive, marine, steam, gas, and other tubes which is now in use, and well known,* the piece of iron commonly called a skelp, out of which the tube is made, is first heated to a welding state throughout one half of its length, and then drawn through pincers by an endless chain, in order to weld the edges together, and round and smooth the outer surface of the tube, after which the other half is heated in the same manner, by which mode of operation a considerable waste of time and labour is caused, and perfect uniformity in the tube is rendered difficult of attainment ;" and that by "another mode of manufacturing such tubes which is in use,† the whole of the skelp is heated at once, and welded by passing it between four grooved rollers, the groove of each roller forming one quarter of a circle, and the four grooves forming by their union an entire circle, which gives to the welded skelp its proper circular form;" but that process is also objectionable on account of part of the iron of the skelp being pressed out between the rollers and remaining on the outside in the form of ribs, which must be afterwards removed at great trouble and expense, by chissel, file, or grindstone." 66 "this Mr. Royle proposes to remedy the defects of both these methods by heating the whole of the skelp from end to end at once, and converting it into a perfect tube by welding, rounding, smoothing, and finishing before allowing the metal to cool; whereby he accomplishes what requires by the mode first before described two distinct heating processes, and he avoids altogether the chipping, filing, or grinding, attending the second mode." The following description of the manner in which he effects this important improvement we give in the words of the specification. 66 First, an air furnace is built of sufficient length to contain the entire skelp, or tube. The skelp is then bent by the ordinary bending machinery, so that the edges either touch or lap over each other according to the strength of the tube required. The skelp * Russell's process.-ED. M. M. so bent is next placed in the air furnace and allowed to remain there until it is heated to a welding heat. It is then taken out and passed through a pair of rollers, grooved so as to form a series of six circles at the point of union, as shown in fig. 1 of the drawings hereunto annexed, the grooves of each pair being less than those of the pair immediately preceding it (reckoning from right to left.) If the tube is not sufficiently welded at the first drawing, it is returned to the air furnace, having been necessarily somewhat cooled in passing through the rollers, and when it is again up to the welding heat, the process of passing through the rollers is repeated, and so for a third time if it should be necessary. The tube may either have a mandril inserted or not. After the tube has been passed through the rollers the last time it is drawn through a moveable scraper, of the clamp-like construction represented in figs. 2 and 3, fig. 2 representing it open, and fig. 3 representing it closed. A is the stock of this scraper, and B a cotter for holding it down; C is the working beam, which turns on a hinge attached to one end of the stock; al al are grooves cut out of the upper face of the stock, and a2 a2 corresponding grooves cut out of the under face of the beam, so that on the two sets of grooves being brought together they form two circular holes for the tubes to pass through, one being of larger diameter than the other. The tube is first drawn through the larger hole, and then through the smaller, and by the two operations is effectually scraped and smoothed. "The method by which the tube is drawn through the scraper is by gripping it in an pincers, which holds the end of the tube fast; instrument, called in the trade, a draught or the instrument, so holding the tube, is then fixed to the link of an endless chain by a bolt, and this chain revolves round a spiked roller driven by a steam engine' or other power at the one side, and by a plain roller at the other. The chain in its passage draws the pipe through the scraper, and when the draught, or pincers, reaches the turn of the chain, the bolt is drawn and the draught released from the chain. The chain and draught are represented in fig. 4. A is the endless chain; B, the tube to be scraped; C, the draught or pincers; D, the spiked wheel; E, the spindle, connected with the steam engine or other moving power; F, the scraper. When, as it sometimes happens, the quality of the iron is such that it is liable to blister. A solid die, with a round hole in it, may be used instead of the move. able scraper." MR. BADDELEY'S ANNUAL REPORT OF LONDON FIRES VINDICATED. It has been quoted often, With a full meed of credit, The maxims wise Wotherspoon taught in his day, "Never to speak till you've something to say, And to stop when you have said it.' Sir,-The "Notes of a Fireman" prepared by five months' laborious incubation, after being recalled, remodelled, and amended, have at last been abruptly concluded by a withdrawal and adjournment sine die-under circumstances which leave little probability of their ever being resumed. I now beg leave therefore, on the principle of "rubbing off as we go," to reply to the "Notes" already before your readers, and furnish such explanations as are necessary to establish the position I have hitherto maintained in your pages; and while I regret the necessity for recapitulating matters of but partial interest, be assured I will endeavour to dispose of the points at issue as briefly as I well can. At the outset, I feel it due to all parties to state that, the signature of my opponent is a nom de guerre assumed for the occasion; that the writer, so far from being " a Fireman" (i. e. one of Mr. Braidwood's men,) is a perfectly free agent in this matter; and that, if the relation of master and man really exists, it is not in the direction implied by the signature of "A Fireman." "A Fireman" then, no matter what colour, whether white, black, or brown, has undertaken the praiseworthy (?) object, of converting the review of a scientific paper, into a personal attack upon Mr. Braidwood and his gallant corps. This has been partly accomplished by mixing up matters having no real connexion with each other, by unwarrantably colouring some facts and misrepresenting others; by taking short sentences, and even parts of stentences from detached papers, placing them in juxtaposition, and thereby eliciting a different meaning from that which, when the context is considered, they were intended to convey; by interpolating quotations, and by the free use of such scurrilous terms and paltry prevariations, as are never resorted to but by desperate men writing in a bad cause. In explanation then, I beg to observe, that no change has taken place in my opinion with regard to the "London Fire-brigade or its respected Chief." As the paid servant of a trading association, Mr. Braidwood's general conduct is not a legitimate subject for public criticism ; it may, however, be matter of commendation, and his well-deserved meed of praise I have ever been, and still continue most anxious to award him. From my first mention of Mr. Braidwood, when I "congratulated the Directors of the Establishment on their good fortune in securing his valuable assistance, to the opening of my last paper which has raised the pseudo "Fireman's" ire, where I stated that "Mr. Braidwood is a gentleman who has for some years discharged the arduous and onerous duties of a semi-public office with satisfaction to his employers and credit to himself :" to these, as well as to the numerous commendatory notices which have appeared between, I now say Amen-nor would I wish to retract or qualify a single laudatory remark. With Mr. Braidwood, the author, however, the position is widely different; his published writings, like those of others, are legitimate subjects of review; and if, on comparison with facts, or with the recorded opinions of others, a difference is found to exist, it lies open to the freest investigation. Mr. Braidwood's statements and opinions will be tested with those of existing authorities, and approved or condemned in proportion as they agree with, or differ from the accepted standard. If Mr. Braidwood's papers are carefully compiled, or truthfully written-if his hypotheses are rational, and his conclusions just, his writings will add to his celebrity. But, on the other hand, if hastily and carelessly compiled, his hypotheses unsupported, and his reasoning incorrect, no official merit can avert the condemnation that will pass on his productions. In order to give the desired "evil tone" to a 66 Fireman's notes," my strictures on Mr. Braidwood's "Paper" have been hashed up with my last Annual Report of London Fires, so as to give a personal and offensive character to each, not really belonging to either. I will not allow myself to be led away by so bad an example, but confine my remarks on this occasion, to the vindication of my Annual Report of London Fires, de Vide Mech. Mag, vol. xviii. page 269. ferring to future papers a full and entire justification of my strictures on Mr. Braidwood's Pamphlet. In my last Annual Report of London Fires, I had occasion to refer to the very limited usefulness of local experience, and illustrated my position by referring to Mr. Braidwood's experience in Edinburgh, where he found engines with sixinch barrels best adapted to the police requirements of that metropolis; while for Fire-office purposes in London he eventually found engines with seven-inch barrels most advantageous.* "A Fire He man" insinuates that my statement is untrue, by stating that "there were no engines with six-inch barrels used in the northern metropolis, while Mr. Braidwood was there!" True, but the disingenuousness and evasiveness of a "Fireman" will be made apparent by the following extract from Mr. Braidwood's own book on "Fires and Fire-engines," published while he was master of fireengines in Edinburgh. "It has always appeared to me," writes Mr. Braidwood, "that an engine of six-inch barrels, is better suited for all ordinary purposes, than one either larger or smaller." then goes on to explain his reasons for preferring this size, and furnishes a minute account, with detailed drawings, of an engine of that description. Fireman" seems to argue, that considerable obloquy attaches to Mr. Braidwood for this difference of opinion; I can only say that in each case I most cordially agree with him, and must therefore beg to share the obloquy. It is true, that Mr. Braidwood did not employ engines of this size, his opinion was the result of experience with engines both larger and smaller than the approved size; and so it is continually that a person may be satisfied of the superiority of one thing by the use of another, as "A Fireman" may hereafter become convinced of the value of truth, and that honesty is the best policy, without the actual use of either the one or the other. "A The remarks in my last annual report on the "origin of fires" is designated by "a Fireman" as "a chapter of aspersions on the fire-brigade;" these * The alterations in size which "A Fireman" with the most daring effrontry denies, were faithfully chronicled (hitherto unquestioned) in my Annual Reports for 1838--9, vide Mech. Mag., vol. xxx. p. 31, and vol. xxxii. p. 386. aspersions" are met with a tirade of abuse, which, from an anonymous writer, will have no more than their due weight with your readers. What " a Fireman" designates "aspersions," were merely offered as suggestions. When Mr. Braidwood assumed the superintendence of the London fire-establishment he had a mass of incongruous materials to organise and mould to an altered line of duty, and it would have been unreasonable to expect that much attention could be given to minute details, especially in matters not essential to the efficient working of the establishment. After twelve years' experience, however, when the routine duties had become well grounded, there did appear grounds for supposing that it was only to direct attention to subjects requiring improvement to ensure it; especially in matters so glaringly absurd as those to which I adverted, a state of things which "a Fireman" does not affect to deny or to justify. "A Fireman" carps at my objection to the present "manner" of reporting the causes of fire, and catches at the "Sunday working" as so "shocking to Mr. B. from its excessive puritanism." His soreness shows how keenly he felt the force of my remarks. Why, in the name of common sense, should such phrases as Sunday working"-" late hours""old age," &c., be given as explanatory of the cause of fire? If a female is burned to death from her wearing apparel taking fire, why should the cause of fire be put under different heads according to the age of the party? Should the sufferer be young, the cause of accident will probably have been expressed by the unmeaning term of "curtain." But should the unfortunate victim be more advanced in life the cause will be attributed to "old age." Or, if a fire take place from "loose shavings"-" fire sparks"sparks"-" candles," &c.-why should the day of the week, or the hour of the day, take it out of the common category of causes, which must be the same whether the day be Sunday, or Monday— seven o'clock, or eleven. In one case a fire was said to be caused by refusing to admit firemen !" If the fire had not occurred previously to their demanding admittance, what brought the firemen to the house? Are we to infer that the firemen paid a capricious visit to the house, and on being refused admittance," in |