•SSH 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[ 8 K P T K M B K I 



body in a stato of motiun, until that motion is put a stop to, oillicr 

 suddenly, liy tli>^ inertia of .some greater body it meets, or gradually, 

 by the retarding forci; of friction; which latter force is what really 

 tends to bring ail bodies to a state of rest. 



As to his prime! fack case, that " the vertical pressure upon the rails 

 incTeases as the squares of the velocities decrease," or in other words, 

 that the vertical pressure (vr might) varies inversely as the square of 

 the velocity. I shall not at present enter upon it, further than asking 

 him for </ proof, as it would indeed be a <liscovery ; for we know that 

 the friction of a train varies as the weight or vertical priesiire. If, 

 therefore, the vertical pressiue can be diminished by increasing the 

 velocity, tiie /riftwii can also! 



As I don't think "An Assistant Engineer" 's query has been yet 

 answered, I take the liberty of advising him not to connect the two 

 curves by another of a less radius, but to commence one of them a 

 little farther up on the tangent, (from which I take it for granted it 

 springs,) as in tlie figure 1 subjoin. And to enable him to do so, I 

 think he will find the following approximation to the distance he 

 should go upon the tangent, a useful one. 



Let AD=zd be the distance whicli it is necessary to go upon the 

 tangent, CB:=c the least distance between the curves, (which I suppose 

 to be already described upon the ground,) then c = (nearly) to EF : d 



]• 



: : sin. Z AFB : rad. and .". d^ -. r^rrr. This of course is but 



sni. Z AFB 



an approximation, but it will be found suflficiently correct for all practical 

 purposes, where the distance to be gone on the tangent, or that be- 

 tween the curves, is not very great. The Z AFB may be got from 

 its tangent, which is known, as I svqipose the curve AGB to be laid out 

 by offsets perpendicular to it. The same formula will answer when 

 the curves cut, only then, e should be taken equal to the distance CL; 

 and of course the distance gone upon the tangent should be taken in 

 an opposite direction. It will also apply when it is desired merely to 

 pass through a given point i. 



I am, Sir, 



Your most obedient servant, 



JiiM 18, 1839. R. W. T. 



[This communication not being received until the 8th August, is the 

 reason that it did not appear earlier.] — Editor. 



IMPROVED RUNNING GAUGE, 



FOR ASCEKTAIXING IF THE WIDTH BETWEEN THE RAILS OF A RAILWAY 

 BE IN GUAUE. 



Sir— Observing the notice in your Journal for this month that 

 Messrs. Bramah and Fox are manufacturing the railway gauges in- 

 vented by Mr. Cowper, I take the liberty of suggesting,' through the 

 same medium, what 1 consider will be an impro\ ement, viz. instead of 

 having a man to watch the inilcx, and throw oyster-shells, t*cc. upon 

 the road where it is out of gauge, I would make the machine self- 



acting in this respect by the addition of a lever (A in the annexed 

 sketi'h) having its fulcrum at f ; the sliding axle C should run through 

 the lever at d, and have collars fitting exactly to the sides of the lever, 

 so that while the axle could turn freely on its axis, the least motion 

 in the direction of the axis should be communicated to the lever. To 

 the endy' of the lever should be attached a moveable slide B, having 

 two slits a a in it, and moving close under the bottom of a box or hop- 

 per indicated by the dotted lines ; this box should be filled with Calais 

 sand or powdere<l chalk, and have an o]3ening in the bottom exactly 

 corresponding with the solid part (ft) of the slide B. When the ma- 

 chine is running upon rails of true gauge, the solid part (ft) of the 

 slide will be \mder the opening in the bottom of the box, and prevent 

 the escape of the material within; but on coming to a difi'erent width 

 of rails, one or other of the openings in the slide will be brought under 

 the opening in the bottom of the box, and allow a greater or less 

 quantity of the material in the box to escape, as the width of the rails 

 is greater or less than the true gauge. 



I am. Sir, 

 Barndey, Your obedient servant, 



2nd Jkiig. 1839. W. J. Hindle, Civil Engineer. 



ON PEAT FUEL. 



Sir — Having long known that peat is underrated as a fuel for steam 

 boilers by Tredgold and others, and believing that in various parts of 

 the country, especially in Scotland and Ireland, there is immense store 

 of excellent fuel, which by simple and inexpensive machinery might 

 be so improved as to be of great use not only to thoee living near it 

 but likewise to distant parts. It was with much interest that I 

 read the article in your last number, on Lord Willoughby De Eresby's 

 patent pressing machinery, as constructed by Mr. James White, but 

 however ingenious and effective this plan may be, I fear the first 

 cost and the difficulty of getting repairs done, in the out of the way 

 situation in which the machinery must necessarily be worked, will 

 prevent it from coming into any thing like general use. Another 

 consideration, which I regret to see, is the observation, that the black 

 peat free from fibre is the only kind of any service. Thinking these 

 views have a strong tendency to limit the use of peat, which I believe 

 is directly contrary to his Lordship's wishes, I beg to trouble you with 

 a few observations which are the result of a little experience, and re- 

 gret that circumstances at the time put an end to the operation I was 

 engaged in rather prematurely, and at a time when perseverance only 

 was requisite to produce results useful to the individuals and to the 

 country. Four years ago three gentlemen erected, about 14 miles from 

 Edinburgh, a steam engine of 4 horse power, with edge rollers and 

 hydraulic presses, with the intention of manufacturing an improved 

 fuel from peat, this they did to small extent, but gave up before it 

 was well tried, for reasons that had nothing to do with the business 

 either as to the improvement of the peat as a fuel, or to loss or gain 

 as a commercial transaction ; soon after this was abandoned, the late 

 Michael Linning, Esq., of Edinburgh, one of the parties, erected near 

 Glasgow, alongside of the Gainkirk railway, a manufactory with horse 

 power, which was likewise prematurely stopped by his sudden death, 

 but not before he had shown in some respects the value of his labours, 

 whether this is now carried on or not I do not know, but it was at 

 these works that any knowledge I have was obtained. Like Lord 

 Willoughby, we found that the finer parts of the peat made its escape 

 with the water through the linen cloths with which the boxes were 

 lined, and that the pressing was tedious and slow, and thinking that I 

 saw enough to prove that pressing is both troublesome and needless ; 

 I will state as shortly and clearly as I can, how I should proceed to 

 improve peat, and render it so compact that it would bear a consider- 

 able carriage, and for certain juirposes, such as locomotive machinery, 

 be very valuable. 



As is well known, all common peat when merely weather dried is of 

 a spongy texture, and occupies much room ; this I have seen is entirely 

 owing to the fibres — break them down, as is easy to do, either with 

 edge stones or in a clay mill, and then the peat shrinks upon itself liVe 

 clay, instead of shrinking within and consequently hollow. I have 

 seen a piece of peat, merely molded with the hand till it was well 

 mixed, after a few days drying, so compact and hard that when struck 

 against coal it broke it, and the piece of peat would bear cutting, and 

 take a polish as fine as Cannel coal. All, therefore, which I think re- 

 quisite to make peat an excellent, and for many purposes a better fuel 

 than coal, is to pass it under edge stones or a clay mill, when well 

 broken down, lay it to drain for a short time on a rough boarded or 

 stone floor, with a small slope, and after it has drained, mould it and 

 dry it under low sheds like bricks or tiles, this would be only children 

 or women's work. 



