iS4l.J 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



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Sir — In reply to your communication respecting tlie removal of tlie 

 liglit-liouse on the north side of the harbour, I have to state that since 

 it has been brought to its new site I have drawn out the timbers upon 

 which it w.'s conveyed, and the base on its southern side has been 

 underset with two pillars of solid masonry. lam proceeding to do 

 the same on its norlhern side preparatory to striking the supporting 

 braces of timber, which probably may occupy another fortnight. 



The light-house was erected in the year 181)3, by the late Mr. 

 rickernell, then engineer to the harbour commissioners. It is wdiolly 

 composed of stone ; its form is octagonal, 15 feet in breailth across its 

 base, 62 feet in height from the surface of the pier to the top of the 

 cornice, where it is 9 feet in breadth across, and the top of the dome 

 is 16 feet above the cornice, making a total height of 78 feet ; and its 

 calculated weight including the cradle and supporting timbers is 320 

 tons. 



I am, Sir, your obedient servant, 



JOH.M MURR.W. 



Sutidtrland, October IS, 1841. 



It affords us much pleasure in offering our congratulations, wilh 

 which we are sure all the profession will join, to Mr. Murray for the 

 very successful issue of the bold experiment. 



NEW SYPHON GAS VALVES. 



Sir — I beg to forward you herewith a drawing with c 

 two Syphon-valves for the use of Gas Companies, which 1 1 



description of 



V yphon-valves for the use of Gas Companies, which I have intended 



to answer the double purpose of syphon for receiver) and regulatino- 

 valve, and I flatter myself I have succeeded in my object. The cost 

 of either valve and syphon united, will be considerably less than the 

 common slide valve alone. Knowing it to be a subject of interest to 

 many of the readers of your highly esteemed Journal, I have for some 

 time had tliis subject under consideration, and I now place the result 

 in your hands, by an early insertion of which you will oblige. 

 Sir, your very obedient servant, 



Thos. Henry Nimmo. 

 Chartered Gas Company, 

 Westminster Station, 



A, cylinder to receive condensation, .Sc. from mains. 



B, the inlet to be jointed into spigot of pipe. 



C, the outlet to be jointed into socket of pipe. 



D, division plate directing the inlet from the outlet, and bolted to 

 the cylinder. 



E, the tube to convey conde 



F, is a smaller tube placed 

 tion is drawn off. 



G, the valve. 



H, the valve-s at. 



nsation 

 within 



, &c. from main 

 E, through wh 



into cylinder, 

 ch this con lensa- 



KoTE.— The supply of gas will b? regulated in the same manner as ot'icr 

 valves. 



October 15, 1841. 



IMPROVED RAIL AND CHAIR FOR RAILWAYS. 



Sir — Having been practically engaged in the construction of rail- 

 ways for some years, my attention, about three years since, was 

 directed to the designing a rail that should overcome several of the 

 disadvantages, if not failures of the then, as well as the one still used, 

 of intermediately supported rails. 



My observations were then, and are now, with regard to that des- 

 cription of rails at present used. First, that the greatest strength of 

 the rails is not in the direction of the force which they are intended 

 to bear. 



Second/i/, that there is invariably considerable attrition between 

 the rail and chair, and between the joints of the rails, and from which 

 a portion of the useless noise so much complained of on Railways 

 arises. 



Tliirdly, the fixing of the rails is subject to failure, by the loosening 

 of the key or wedge that is used to fix them in the chair from the 

 attrition consequent upon the imperfect connection between two hard 

 surfaces, or from the wooden wedge Iiaving greater force to sustain 

 than it is able without being compressed. 



Fourthly, from the great force required to roll the irregular forms 

 of the present rails, the same are very frequently flawed or frac- 

 tured by the force applied to change the metal to the form so widely 

 different from the bar converted, or otherwise in cooling from the 

 sudden difference in bulk of metal after the rails are rolled. 



From the preceding observations I designed, and have practically 

 proved the following rail, which I shall feel grateful for the indulgence 

 of making it public through the medium of your valuable and widely- 

 circulated Journal. I respectfully submit it to the consideration of 

 the profession, that it claims the following advantages. — First, the 

 equal strength to resist or bear the weight or force of the transit of 

 carriages with one-tenth less metal than intermediately supported 

 rails now in use. 



Secondly, requiring less power to roll the metal, and there being 

 much less possibility of the rails being fractured by the process of 

 rolling. 



Thirdly, the greater security in fixing the rails in the supports, par- 

 ticularly at the joints. 



Fourthly, the simplicity and strength of the supports added to the 



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