322 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[September 



mere knowledge in the existence of this style, ortIiiit,or tliat it tiourisli- 

 ed in tliis age, or tliat, cannot improve the architect, though it may the 

 mind ; and unless we can raise ourselves above that pedantry of igno- 

 rance, which covets every thing anticpie, be it dust or marble, we can 

 never rival, nor even faintly imitate, tlie lovely relics of antiquity. 



It is not enough that the column or the pedestal should be brother 

 to some Greek or Roman model, since it is not every one whose brain 

 can swim with the pleasures of a connoisseur. A stranger to Athens 

 or Rome would perhaps turn from the external polish of a modern 

 edifice, however skilfully arranged, and become lost in the strange 

 grandeur of Blenheim, 



FllEDERICK E.\ST. 



Jum 18, 1840. 



TRUSSED BEAMb. 



Sir — In reference to the method of trussing beams, communicated 

 in the 32nd number of your Journal, and said to be invented by Herr 

 Laves of Hanover, I beg to observe that the principle is by no means 

 new to this country, in the practice of Mr. John 13rown of Norwich, 

 I have long had occasion to describe, in specifications, precisely the 

 same method for many purposes, but chiefly for the purlins of roofs, 

 where the transverse trusses have, imavoidably, been at a great dis- 

 tance apart. In order to show you, indeed, how little the method we 

 pursue difters from that of Mr. Laves, I will extract from a speci- 

 tication I have at hand the following: — "All lengths of purlins wliich 

 may exceed 9 feet between the bearings, to be sawn, lengthwise, 

 through the middle of the depth, and trussed as shown by the accom- 

 panying sketch* with a wrought iron collar at each end, and a i screw 

 bolt with broad clasp irons in the centre. 



I remain, 



ifs'oTwich, Your obedient servant, 



June G/A, 1S40 William B. Colling. 



LOCOMOTIVE ALARUM. 



Sir — Various suggestions liave lately appeared in the public prints, rela- 

 tive to the best means of conimnnic.itiiig an alarnm to the eiigine-man in 

 case of fire or other accident in a railway train. — I would suggest a steani- 

 whistlc, wliich should diflfer decidedly in sound from those used by the 

 engine-men. — A light chain attached to the cock of the whistle would enable 

 each guard, .nnd (if thought desirable) the passengers in each carriage to give 

 an alarm in case of an accident occurring, or being likely to occur. 



The advantage which such an alarum would possess over any other, is, 

 that not only the engine-man, hut all the guards and attendants would he 

 immediately on the ywi rive, and prepared to act as circumstances might re- 

 quire. The disadvantage is, that passengers hearing the alarum, might lose 

 their presence of mind, and endanger themselves by attempting to escape 

 from the carriages, instead of doing the only thing, which can tend to ensure 

 their safety, viz., firndy keeping their sittings. 



I am. Sir, your obedient servant, 



Robert Shkppard. 



Horsham, Sutsex, Aug. 19, 1810. 



ON SCREW PILE LIGHTHOUSES. 



Sir — K coiTespondent in your excellent Journal for July, under the signa- 

 ture of " One of the Old School," endeavours to institute a comparison be- 

 tween the patent screw ])ile, and the common driving pile, the latter of which 

 it is evident enjoys his exclusive favour, on the very rational grounds of its 

 antiquity. 



In summing up its superior merits bis readers might reasonably expect to 

 have their attention directed to many lighthouses, and other buildings sup. 

 ported by his favourite pile, and placed upon banks of loose sand covered by 

 the ocean. 



That he has failed to do so, is for the simple reason that no such structure 

 ever did or ever can exist. 



The experiment has indeed been frequently made of driving piles in such 

 positions, and it has hai)pened that owing to the buoyancy of the wood and 

 mobility, and want of tenacity in the sand, they have invariably been found 

 extracted by, and floating on the surface of the succeeding tide. 



If then the old pile or pointed stake, which has been in use for at least 

 20 centuries, has been always found incapable of forming a sound foundation 

 in such positions, how can it reasonably be put in comparison with the screw 



* Me have not given the sketch, as it is very similar in principle to those 

 shown m page IBl, excepting that in tlie above, at the end of the slit, there 

 is a key ot oak with au iron strap passing round the outside, and in the 

 centre there is a block of oak with a nut and screw bolt passing through it 

 and the top and bottom scantlings.— En. C. E. 6c A. JovK. 



pile, which within four years of its being made public, has been successfully 

 applied in submarine sandbanks of the most infirm description, and has more- 

 over received the unqualified approbation of the first engineers of the present 

 day. 



Of these I might furnish an ample list, but feel the impropriety of giving 

 names of the highest respectability to be handed about in idle discussion 

 with your nameless corres|iondent. 



I may however mention tliat a screw pile lighthouse, on a sandbank off the 

 mouth of the Thames, is at present in progress of erection, luider the auspices 

 of a gentleman who deservedly stands at the head of his profession. And, 

 that another upon a sandbank' thirty miles north of Liverpool, was erected 

 during the past winter, at the earnest recommendation of a gentleman well 

 known as an ex]>erienced aiul highly talented marine surveyor, who has no 

 antiquated prejudices staiuling in the way of recent improvements. And I 

 boldly assert, without fear of contradiction, from any pracfical enyincer of 

 I'.rjjerimce, that, to construct such a hgbthouse on either site upon common 

 piles, would be totally impossible. 



As the other objections raised by your correspondent to the scrc?w pile 

 lighthouse, are only supported by bis marvelous gift of prophecy, I sh.ill con- 

 tent myself with requesting him to visit the one at foot of Wyre, where he 

 will have proof positive of the fallacy of Ins conclusions, and when tlierc, if 

 he will drive a common pile into the sand, so as to resist a downward pres- 

 sure or upward strain, equal te that which the screw pile will bear, I shall at 

 once relinquish the latter as a useless expense. 



1 am. Sir, your obliged and huiuble servant, 



Alexander Mitchell. 



Belfast, Auyust 18, 1840. 



THE SAFETY ROT.VTION RAILWAY. 



{A New Method of Construction in Hailwai/s, and in apphjinrj Power to pro- 

 pel Carriages thereon. Patented by Mr. Ranyely. Marcli, 1840.) 



FROM A CORRESPONDENT. 



This invention, of which, in our present number, we can give but a brief 

 description, aims at effecting a complete revolution in the present mode of 

 railway construction and locomotion. In place of having the ordinary rails 

 and wheeled carriages, two series of wheels are fixed along the whole length 

 of the road .It about two yards apart, and at an equal distance from centre 

 to centre of each wheel. These wheels are connected throughout the whole 

 length of the line by bands working in grooved pullies keyed on to the same 

 axle as the wheels, but the .ixlcs of one side of the line are not connected 

 with those of the opposite line. The axles of the wheels are raised about 

 one foot from the ground, the top of the wheel (which is proposed to be of 

 3 feet diameter,) will he therefore elevated 25 feet above the surface. On 

 these wheels is placed a strong framing of timber, having an iron plate 

 fastened on each side in the line of the two series of wheels. A little within 

 this bearing frame, so as just to clear the wheels, is a luggage-box or hold, 

 descending to within a few inches of the ground, in which it is proposed to 

 stow all heavy commodities, for which purpose it is well adapted, ojiening as 

 it does at either end, and its flooring close to the surface of the ground. At 

 each end of the lower part of the framing of this luggage-box, are fixed hori- 

 zontal guide or friction wheels working against the supports 'of the bearing 

 wheels and ])ullie8, by which arrangement cur\es will be traversed with little 

 friction, and it will be impossible for the framing to quit the track. The 

 framing of timber will be about 19 feet in length, so that it will rest alter- 

 nately on six and eight wheels, but never on less than six. On this framing 

 the passenger carriages are erected, which, in its progi-ession forward, it is 

 thought will be kept steady and free from lateral motion by the weight in 

 the luggage box, assisted by the horizontal guide wheels. The method by 

 which locomotion is produced, is by putting the wheels in motion by means 

 of machinery at cither end, which would be eft'ected for an immense distance 

 with a moderate power, as there would be very little more friction due to the 

 wheels than that arising from their own weight ; and the frame, bearing the 

 carriage, would not be run on to the bearing wheels tintil the whole w ere in 

 motion, when its weight woidd act almost after the manner of a fly wheel, 

 resting, as it would, on the periphery of the bearing wheels. It will be per- 

 ceived that, by this plan, the bearings of the wheels must be kept perfectly 

 in the direction of the plane of the road, whether inclined or horizontsl; 

 otherwise serious concussions would occur. But this would not he the case 

 by the depression of one wheel, or even by its entire removal, as the framing 

 will be constructed sufficiently stifl' as not to deflect by having the distance 

 of the hearings doubled. 



If this plan should be found to answer, it will present facibties of trans- 

 port never before thought of, as carriages might be continually despatched 

 without a chance of collision, either by stojjpage or from increased speed of 

 the last beyond the preceding. It also promises to remove the present 

 great drawback to railway progression, viz. the being able to surmount but 

 very slight acclivities by locomotive power with any profitable load ; but by 

 the rotative system, inclines may be surmounted of almost any steepness 

 without the chance of accident. In ease a band should break, tlie action of 

 this railway would not be impeded, as the power being transmitted from 

 either end, rotation would take place throughout its whole length, but the 



