PRIZE CHRONOMETERS. practical workman, who, in nine cases out of ten, must make his machine expressly for the purpose of competition, has an equal chance with the manufacturer or dealer, who has an opportunity to select from a quantity. If any faith is to be placed in rumour, your Correspondent's men, as he calls them, have joined in the competition, and have been distanced in the chase. As an illustration of your Correspondent's beautiful theory of equality, take the following example :-A. makes a machine on his own account; he does every thing that genius and industry can accomplish to render it as perfect as possible; it turns out to be very good, but is nevertheless found, on comparison, to be inferior, in a trifling degree, to one selected from a number of similar machines which the said A. may have previously made for B. What is then the result? Why, the machine that A. has made for B., and which, by purchase, has become the property of Bi, bears away the prize from the machine that A. has made on his own account; what is worse (and which is the only thing to be complained of), bears away the honours also, it not being known generally, that the merits of this machine belonging to B. are to to be placed entirely to the account of A's genius. If the object of a public competition were to excite emulation and to reward talent, among practical workmen, the end would be quite as well attained, by admitting machines made to the order of carpenters or undertakers (or, indeed, of any person who might choose to incur the expense of procuring them), as it is by the present mode. I do not wish to be understood as censuring that mode-my only object is to place it in its true light, to give to it all the merit to which it is entitled, but no more. Defective as it is, much good has been produced; but it cannot, I think, be denied, that if those machines only were admitted which bore the names of the actual makers, the art, as an art, would be more effectually promoted. I would, however, say, rather than that no stimulus should be given, let the present "real worksystem be continued; men" will, to a certain extent, conti nue to try their powers, notwithstand ing the inequality of the race they must run with the manufacturers; but if they expect any thing more than to give publicity to their qualifications for the art they profess, they will be deceived. I will not hesitate to declare, I that the practical workman who shall 293 send a chronometer to the Royal Observatory, under the impression that he has an equal chance with those who call themselves manufacturers to a large extent, will be a fitter subject for a lunatic asylum, than to be employed as a chronometer maker. He may win, as the purchaser of a lottery ticket may gain a 20,0001. prize, but, on a calculation of chances, the odds will be always against him. I am at a loss to conceive the object of your Correspondent, in ringing the changes so much on the subjects of jealousy, envy, &c. Is he addressing himself covertly to some rival manufacturer? He cannot, surely, mean that the "real workmen" are envious of his talents. Besides, if his having gained a prize of 2001. could excite their envy, those who have gained 3004. must be objects of envy in a still greater degree, as their presumed merits must be proportionably greater. Be this as it may, the application of your Correspondent's very apt quotation from the poet, will not fail to be duly appreciated by all. I am charged by your Correspondent with wishing to insinuate that he is ignorant of the instrument which the term chronometer is intended to express. I have no wish of the kind; I do not deal in insinuations: all that I mean to say, I say openly and fearlessly. I showed that your Correspondent inade a very equivocal use of the term chronometer; and what is his reply? Why, that "had made myself acquainted with the derivation of the word, I should not have risked such an assertion." I can assure this gentleman, that my compendium of useful information had made me acquainted with it some years ago. It happens, however, to have no thing to do with the subject; and a reference to it on my part would have had no other utility than that of proclaiming my kuowledge of two Greek words-a piece of affectation for which your Correspondent, or any other person, might very properly have charged me with pedantry. The word chrono-meter has, in our language, a conventional meaning, and is as capable of as clear a definition as any word we possess. Where then is the necessity of going to derivations? Why, according to your Correspondent's reasoning, an hour-glass might be called a chronometer; but is it so called? If it might not be considered impertinent, I would ask your Correspondent, whether, when a gentleman enters his shop, and desires to look at a chrono 294 PRIZE CHRONOMETERS STEAM ENGINE 2 merits ofthout at into, the wit all subjecting those who make the inquiry to the suspicion of being actuated by malice or envy, or any other uncharitable motive. I am, Sir, ,, G. MUSTON. Fleet-street, Aug. 1, 1825. NEW STEAM ENGINE. he shows him an astronomical or whether be himself, wanting an astronomical clock, would go to a practical clock-maker, and desire him to make him a chronometer? Really, Sir, if there be any truth or reason in your Correspondent's appli-Your obedient servant, cation of terms, it must be admitted, on all hands, that our mechanical nomenclature requires to be reformed, as the chemical one has been; for, in the present acceptation of the term, where is the person carrying a chronometer 543 10 50e dose no in his pocket, who imagines that he WE very lately noticed a newly inwears an astronomical clock? But vented Steam Engine, a patent for your Correspondent ultimately limits which has been obtained by Mr. his application of this term, and tells Eve, in the United States. We have us, that "every machine to which the since had an opportunity of witness compensation for heat and cold is pro-ing the operations of a model, which perly applied, whether it be in the balance or the pendulum, may be strictly termed a chronometer." Now philosophically argumentative as this may be," I would ask, is every machine of the description just given so called? If these machines are not indiscriminately termed chronometers, of what utility is your Correspondent's "may be"? All this floundering about, in the use of vague and indefinite language, can answer no other purpose than that of introducing into our minds the confusion of Babel; by an applications of your Correspondent's logic, the various terms by which differently constructed ships are designated, as also those of various articles of our domestic economy, would be involved in as delightful a disorder as the demon of anarchy could wish. 11 Mr. Eve has had constructed for the purpose of elucidating the principle of his invention Mechanism is ca subject of such importance, and the inventions and theories of the pre sent day are so numerous, that we approach such subjects with diffidence. We will, however, endeavour to explain the construction of this engine; and the first thing deserving notice is the simplicity of the motion, which is rotatory. It consists of but two moving parts, both of which revolve, and are similar to each other, and a steam generator. It has no parts in common with the steam engines in use. No cylinder, piston, valve, cock, fly-wheel, crank, I have not now time to examine this condenser, or any reciprocating parts part of your Correspondent's argument whatever. It is impelled by the diin a way that it would be useful to the rect impulse of the steam acting on public it should be examined. Frauds surfaces at right angles with the moare occasionally practised on the un- tion, so as to appropriate its whole wary by the misapplication of lan- power under the most favourable is in danger of circumstances. guage. No person There is the least having a duplex watch, with a compossible friction, as there are no pensation for heat and cold, imposed on him as a chronometer, by a trades- parts that rub or touch, but the man of your Correspondent's respect- pivots. Its velocity is unlimited, so ability, but his reasoning would justify that, with the smallest conceivable such a proceeding. In conclusion, Sir, force acting, the greatest power, reI have only to observe, that if there are quired can be obtained, by which persons who would excite an undue means an engine of a very small size prejudice against your Correspondent, may be made to perform almost any I am not one of them. My motives given quantity of work. We scarcely were clearly and distinctly stated in my former letter. The competition at need say that it is a high pressure the Royal Observatory is a public mat-engine. We refrain, at present, from ter, and the public interested in pa particular notice of this part of the machine, as a steam generator is knowing the merits of the various com. petitors." Palmam qui meruit ferat," about to be made on a plan of Mr. is my motto; and I presume to think, Eve's, different from any thing used that when the palm has been won, the in this country. Liverpool Courier. 1 Ꭶ WORKING STEAM TWICE-BREWING, ETC. WORKING STEAMATWI STEAM TWICE-BREWING 1st. Page 243. "On Working Steam twice.In the double cylinder steam engine, as as all others, the power is gained by the difference of the pressure of the steam on each side of the piston. For instance suppose the high pressure cylinder has steam in it acting on the piston at 45 pounds per square inch, the steam, on the other side of the piston, counterpoises with a medium pressure of (we will say) 30 pounds per square inch, in consequence of Its being allowed to commence expanding by the motion of the engine, into a large or low pressure cylinder, the moment it has done its duty in the first this expansion is constantly decreasing what I will call the antagonist pressure, during the whole stroke, until it sinks to about 15 or 17 pounds per inch at the end of it, and the steam is their of sufficient elasticity to work the second or larger cylinder, on Bolton and Wate's principle; and this second power is gained by condensing the steam on one side of the piston in this cylinder, whilst the elasticity of 15 or 17 pounds on the other side carries it through the stroke: therefore, the moving power in the first or high pressure cylinder is equal, by supposition, to (45-30) 15 pounds per inch, and the same steam in the second cylinder produces a further power, of nearly equal intensity, per square inch; but as the size of the piston in the second cylinder is much longer than the first, the power of the former may considerably exceed the latter. It is, however, more than probable that if the steam from the "high pressure cylinder were discharged into a separate vessel, sufficiently large to allow it instantly to "expand to about 17 pounds per D square inch (or to its common elasticity in the boilers of condensing engines) before it entered the low pressure cylinder, an extra power might be gamed; that is, the steam, it escapes from a ligh pressure as 295 engine, may be employed to work a condensing engine without further expense; and if these two engines are placed sufficiently near to each other that the same beam, pumprods, &c. &c. may serve for both, it would then become a double-power engine. 2d. Brewing. Page 245.-Your Leominster Correspondent says that he "never met with any malt that would produce one hundred pounds of saccharine matter per quarter." I think the cause of his deception is in his employing a common brewing saccharometer, which merely gives the difference of weight between a barrel (36 gallons) of wort and a barrel of water; but this is a very different thing to the quantity of dry saccharine matter contained in that barrel of wort, which may, however, be at all times discovered by multiplying the indication, per saccharometer, by 2.5; that is, two pounds and a half of the dry saccharine extract of malt, when dissolved in 36 gallons of water, will merely exhibit one degree, or one pound, by the saccharometer. It is true that 200 pounds of saccharine matter from a quarter of malt are rather an excessive produce in country situations, because the maltsters will not clean the malt sufficiently from the roots and dust attaching to it before it is measured; but the London brewers generally buy their malt by weight, or after ascertaining that it is sufficiently screened to weigh from 37 to 40 pounds per bushel. 3d. Ozzanam's Pump, page 252.— I have long had a pump on this principle at work, for the purpose of raising a variety of liquids, and I much approve of it, with this single caution, which I advise all persons to keep in mind who have any intention of employing it; viz. that the pump be always fixed sufficiently low for the fluid to run by its own pressure into the working chamber, or there will be a difficulty in what is technically called fetching it," should the valves at any time leak. 400 Phon by od Lam, Sir, 1 Your obedient servant, Anith of superpol J. HAM. Somersetzen mi 296 WATER CHURN. AO, OB, &c. are the sides of a hexDUCING PENTAGONS, HEPTAGONS, agen that may be inscribed in the - STRMG.A.S., No. 77, page 324, of your valuable Magazine, has said, that he is not in possession of any method, strictly geometrical, to produce the pentagon, heptagon, nonagon, &c." Pbeg methods; not in the least disparage ing his laudable design to simplify geometry, and to reduce it to a level with the practical mechanic, but ra'ther to facilitate the same, should the methods be approved of. Is i bevoltas ar To find the side of any regular poly9b gon, from a trigon to a duodeca29080 that may be inscribed in any sa given circle, suppose ABCD. First, through the centre, O, draw the diameter, AB, dividing the circle into two equal parts. load gaiguid Second, take in your compasses half the diameter, AO or OB, and setting one foot in A, with the other mark Kvand L, and draw the line KL, which will be the side of a triangle that may be inscribed in the circle. Third, draw the line, CD, through the centre, 0, cutting the diameter, AB, at right angles, and then draw AC, the side of a square that may be inscribed in the circle, soiton roa bodFourth, set one foot of the compasses in G, and extend the other to C, and draw the arc and chord, CE, which will be the side of a pentagon, that may be inscribed in the circle. Fifth, any of the semidiameters, SIR, In No. 98 of your valuable Journal, I perceive a new species of Churning Machine invented, which appears to be a useful contrivance; but it has often occurred to me, that running water might be made use of to assist in churning, to great advantage, particularly in large dairies; and and I should consider that a wheel, on the same principle as that of a water mill, would be of infinite service, and save much manual labour. The barrel might be formed after the model of the common barrel churn, and a bolt might be easily contrived to stop the wheel at pleasure. If you consider this hint worth inserting in your columns, I trust that some of your able mechanical Correspondents will put the above machine in motion, or treat more largely on the subject. bu ternam, Sireh eel bas Your most obedient servant, tubeop bro998 91 SRC. to obie odt al sail 9 dai to SIR,I send you the substance of ha chapter in Venturoli's Mechanies, as I think the subject of which it treats has not been noticed in your valuable work eni od The result of a mathematical investigation is, that when a weight is raised by means of a crank, the arm of the lever, at the end of which it acts, may be considered as constant and equal to 7-11ths of the breadth of the crank. The ascent having been completed, the descent follows through are RTF, quently he case in wheels em- which brings back the piston to the ployed for the purpose of raising the pistons of hydraulic pipes. The rod of the piston is attached to the elbow F of the crank. As the wheel turns round, the point Frises to R, deScribing the semicircle FGR; it afterwards returns to F, through the opposite semicircle RTF; and thus the piston rises and sinks by turns. 10 In this movement, even when the moving force is equivalent to a constant weight P. and when also the force of the piston is equivalent to a constant weight Q, hanging from the arm of the crank, the motion cannot be uniformly accelerated; because, whilst the piston ascends through semicircle FGR, the arm of the lever of the weight Q is continually changing it is nothing at the point F, it is greatest at the point. G, where it is equal to the breadth CF of the point whence it set out. In this descent the moving power P does not at all oppose the weight Q. When the crank is employed to raise the pistons of tubes, the piston, after reaching the highest point R, descends by its own weight, and does not exert any force on the machine. Hence, during the whole time employed by the crank in returning and bringing back the elbow to the lowest point, the moving force is idle: to avoid this, a double crank is used, as in the figure. By inserting this you will oblige your constant reader, O. F. F. QUICK TANNING. SIR,-In your first Volume, under the head of "Quick Tanning," you give a short notice of an invention by a Mr. Spilsbury, of Leek, of a new method the motion will be of tanning hides, in a wonderfully short continually accelerated, but by less and less degrees in the first quadrant FG, and then by greater and greater degrees in the second quadrant GR. space of time; but you have said nothing about it ever since, although 1 have been expecting to see some notice of it in almost every Number. I take the liberty, therefore, of requesting |