IS41.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



435 



the whole world to liattle with these iliiBculties, and adopt a flatheaded rail 

 in spite of them, instead of contenting themselves with the simpler form of 

 •ead that could be had without them. 



Having disposed of the ot)servations, let us examine a few of tlie practical 

 advantages of his " improved rail and chair;" and it will materially assist in 

 the enquiry, if W. B., who has " practically proved the rail himself," will 

 favour us in your next with further information on the following trivial points. 

 As, on W. B.'s lines of railway, the position of the rails is " left entirely to 

 the mercy of the workmen," has he not found that the •' improved" may 

 possibly cut as sorry a figure by the chair not being placed perfectly straight, 

 as the present bungling methods may, by not being sufficiently declined r 

 Most things, I imagine, " left to the mercy of workmen," would have as good 

 a chance of being placed crooked as straight ; and then what might not be 

 the fatal consequence of the one-tenth less metal? 



There is one point however on which the "improved" decidedly bears 

 away the palm from all the present disadvantageous methods that I have ever 

 seen ; which is, the next to impossibility of ever unfixing the line that has 

 once been laid with it. From the method of joining the rails, one faulty one 

 cannot possibly be removed without two others being also taken up, and some 

 fifteen chairs being removed from the sleepers ; just increasing the work in 

 the proportion of three to one of the present disadvantageous methods. I 

 say fifteen chairs removed from the sleepers, for assuredly V/. B. would not 

 attempt to remove the keys and the wooden wedges he has so neatly com- 

 pressed into the notches of the chairs ; these could not possibly be drawn to 

 release the rails without destruction. 



Are \V. B.'s lines of railway in an unknown country of equable tempera- 

 ture, or has the "imjjroved" the additional practical advantage of being of 

 metal unaffected by such sublunary causes .- If not, what becomes in the 

 ■winter time, of the " piece of tliin cast lead," so carefully inserted between 

 the joints .' What service it would do in any season, what noise it would 

 deaden where no noise occurs (except from a loose joint, of which, no one, 

 would accuse the " improved,") I leave to W. B. to explain v.ith the rest. 



Your obedient servant, 



H. A. 



Sir — In the engraving of the improved chair, the ratcliets are shown acute, 

 and on enquiry I find the draftsman sketched them thus, although my direc- 

 tions were for the same to be drawn as shown in the models, or more obtuse, 

 and they should have been like a wave, as I distinctly state there are no 

 internal angles in the chairs, which would be futile if the ratchet or wave 

 was as shewn in diagrams, figs. 3 and 4, and in fact would prevent the with- 

 drawal of the wedge, whereas that shewn in the models I have repeatedly 

 proved will not prevent the wood wedge being drawn or driven out after 

 removing the iron key even without prejudice to its being re-used, ily rea- 

 son for having used the term ratchet was the attaining equal secimty as 

 given by common ratchets 



The preceding correction may seem unnecessary as it would of cotirse be 

 seen by a practical man, and it requires but little penetration to see it is not 

 intended as shewn in diagrams Xos. 3 and 4, but for the benefit of those 

 who may not have seen the models I respectfully request your insertio!i of 

 the above explanation. 



I am, Sir, 



Your obedient servant, 



W. B. 



ON REVERSING ENGINES. 



Sir. — Seeing a plan for reverting engines in your pages, signed Geo. Coe, 

 civil engineer, I take the liberty of sending you a few remarks, which I trust 

 you will give a place in your Journal. 



The plan which Mr. Coe has given is similar to one of which I consider my- 

 self the inventor, only that I have but one-half tlie work which he has shown, 

 to answer the same purpose. He is silent on some of the most essential 

 points ; the lead of the eccentric for instance, if it be set right for going a- 

 head, would be far from being right for going astern ; the engine would be 

 what we call too late and not be able to pass its centres, which every practi- 

 cal man is quite aware would not move in a contrary direction. 



He further states that one man would be able to manage any of tlie largest 

 marine engines that ever navigated the ocean, better than 4 or 6 or even 10 

 men on the present system. Now let alone what I have stated above, I will 

 take two engines of 100 horse power, which is far from being the largest 

 which we have navigating the seas. The steam ways that woidd be required 

 for cylinders of this power should contain 55 superficial inches, 16 inches by 

 Si inches nearly ; the valve that would be required to cover sufficiently, would 

 be 18 inches long and 19 inches broad, containing 112 superficial inches 

 working together. For two engines it will be double the area, excepting one 

 bar less will do, as the centre one acts for both engines, so that will make it 

 equal to 21 7 superficial inches working together. "The pressure which is on 

 a v4ve of this description will be immense, taking it at the lowest figure, say 

 15 lb. on each square inch, 12 lb. by a vacuum being formed in the condenser, 

 and 3 lb. of steam in the valve box or on the back of the valve, making it 

 equal to a weight of one ton nine cwt, to be moved by one individual, which 



is quite impossible, unless multiplied by a long lever, which never can be done 

 to any advantage. 



I have by me a working model which I exhibited at the Hull Mechanics' 

 Institution, on the 25ih of Februarv", 1841, and at that time I entered it at 

 the Patent Office, London ; I have since then made working sections. All 

 the different points which I consider in the sketch given in the Journal, as 

 deficient, I have adopted in fidl perfection, and proved by the working model 

 which answers instantaneously forward, backward and stop, with the greatest 

 ease, and can be attached to any engine at a trifling expense. An engine of 

 45 horse power is at the present time being made by Messrs, Overton and 

 Wilson, engineers, Hull, in wliich will be introduced my improvements. I 

 hope in a few weeks to see it in full play on the river Humber, where any 

 one will have an opportunity of judging of its importance. 

 I will send you a sketch of it as soon as time will allow me. 

 I am, cScc, 



Thomas Stather, 

 Foreman to Jlessrs. Overton & Wilson, Hull, 



And an Old Subscriber. 

 Hull, November 15, 1841. 



Sir — Page 330 of your Journal for October last, contains an article pro- 

 fessing to be a new and advantageous plan to facilitate the reversing of steam 

 engines. Although the plan is to me perfectly new, and will I have no doubt 

 be found to change the action of steam very eft'ectually, I do not conceive its 

 peculiar advantage, either as to friction, weight, or cost in construction. On 

 the contrary, it would in the first place cause a very considerable amount of 

 friction, in consequence of the additional slide-valves on the opposite side of 

 the cylinder. Secondly, the boxes for these additional slide-valves, together 

 with the regulating valve-box and those massive pipes which form the com- 

 munications between it and the other valve-boxes, would add very largely to 

 the weight of our marine engines. Thirdly, these additional pipes, valve- 

 boxes, the moveable joints, levers. Jxc, necessary to connect the two pair of 

 double-faced slide-valves, and also those necessary to facilitate the changing 

 and adjusting of the reversing valve, all combined, would add very materially 

 to the cost of an engine. 



However far the above inconveniences may oppose the practical application 

 of Mr. Coe"s system, it has an objection of still greater importance ; which, 

 objection I trust will apologise for my thus intruding upon your pages. 



It is in practice found advantageous (and is now almost universally attended 

 to), to give the slide-valves of all reciprocating steam engines what engineers 

 term lead and cover; the importance of which is very clearly explained in 

 one of your late preceding numbers. Now the valves of Mr. Coe's present 

 system could not be adjusted to produce this effect for one direction without 

 destroying it when reversed. If then we are obliged to neglect the lead and 

 cover, why use the reversing valve and additional double-faced slide-valves 

 proposed by Mr. Coe, when we can obtain exactly the same result from one 

 common single-faced sUde-valve, with the addition of one simple lever merely 

 to change the direction of the motion produced by the fixed eccentric ? 

 With great respect, I am, &e.. 



Vesper. 



P.S. Should Mr. Coe, or any other of your able correspondents, think it 

 worth their trouble to lay before the readers of your Journal a description of 

 a complete apparatus for working steam engines expansively, that is, capable 

 of cutting off the steam at any point between the commencement and termi- 

 nation of the stroke ; such an article would, I presume, be at the present 

 very acceptable. 



Leeds, November 1, 1841. 



ON THE THEORY OF BARS. 



Sir — Mr. Brooks' letter in yotur Journal for the present month purports to 

 be a reply to mine of July last ; in my opinion it is not so. He accuses me 

 of an attempt " to go off on another tack," although he has no authority for 

 such an accusation ; but he flies off, not at a tangent, but in an eccentric 

 movement, and seizes with avidity the bonum magnum found in the Nautical 

 Magazine for 1837. So far from abandoning the law there by me pro- 

 pounded, I adhere to it without qualification or reservation, /. e. to the fact 

 that the rii/kt angle course of egress water charged with matter in suspension, 

 and causing a conflicting action with that water into which it falls, is the 

 cause of a bar. 



He calls on me to adduce proofs of my proposition ; the columns of your 

 Journal and of others alreadv contain a number of facts, demonstrating the 

 accuracy of my thesis. He threatens, if I fail in " duty," to supply the omis- 

 sion by giving proofs " that many rivers are free from bar, notwithstanding 

 their rectangular direction, and of numerous rivers which have bars, although 

 their discharge is at an acute angle." It has been very properly observed 

 that " those who (Uscuss important subjects should be cautious in their choice 

 of facts." 



To the first of these, the rectangular course of river water not causing a bar, 

 the exceptions are explained in ray Treatise, page 5. As to the second I 

 promptly admit that if a river do pass out in an acute angle, and be charged 



3 M 



