1S41.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



237 



One of the girders on each side supports the parapet wall in which it is 

 completely encased, and being faced with cut stone, assumes the appearance 

 of a flat camber arch, 3 feet in depth. 



A detailed drawing, showing minutely the construction, accompanied this 

 communication. 



ARCHITECTURAL SOCIETY. 



Conversazione held Tuesday evening, the 1st of June, 1841, William Tite, 

 Esq., President in the Chair. 



After the report of the proceedings of the Society during tlie session was 

 read, the President delivered a very interesting lecture, " On the researches 

 made in Egypt, at the erperise and under the authority of the Tuscan Go- 

 tiernment." By SiGNOR Rosillini. The lecture was illustrated by a variety 

 of drawings, models, and valuable engravings, which very considerably en- 

 hanced its interest. 



At the completion of the lecture the President announced the agreeable 

 duty which he had to perform, in the distribution of the prizes which had 

 been awarded by the Society for competition during the past session ; at the 

 same time he expressed his regret that the students had not been more active 

 in the other classes of competition, and stated that although prizes had been 

 otfered by the Society for competition in the class of original design, in the '^ 

 class of measured drawings from a public building, and also for the best fairly 

 transcribed notes of the Professor's lectures, yet it became his painful duty 

 to state that no competition whatever had been attempted in either of these 

 classes ; neither was there any competition for the prize otfered for the best 

 drawing of the human figure from a plaster cast in the possession of the So- 

 ciety. Having made these observations, the President proceeded to the dis- 

 tribution of the two prizes which had been awarded, viz., to Mr. Arthur 

 Johnson, for the greatest number of the most approved sketches from sub- 

 jects given by the Architectural Society during the session 1840 and 1841 ; 

 and to Mr. Frederick Johnstone, for having produced the best drawing from 

 a plaster cast in the possession of the Architectural Society, session 1840 and 

 1841. The President called the attention of the meeting to some specimens 

 of a patent which had been obtained for uniting lead and other metals with- 

 out solder, which he was of opinion was worth the consideration of persons 

 connected with building. He then announced that the business of the meet- 

 ing, and of the session was concluded, and in so doing directed the attention 

 of the visitors and other gentlemen present to the various specimens of art 

 contributed for the evening's entertainment ; among which was a very beau- 

 tiful drawing, being a representation of the shield to be presented to Lord 

 Eglinton, in commemoration of the late tournament held under his superin- 

 tendance, both the design and drawing were by Mr. Henry Nixon. Also a 

 newly invented ball-cock patented by Mr. Henry Abraham, the architect ; 

 likewise a cast in bronze of an elaborately chased Roman vase, together with 

 sundry specimens Of Roman tesselated pavement. 



There was also exhibited a very beautiful model in plaster of Mr. Tite's 

 (the President) portico of the New Royal Exchange, as approved and decided 

 by the Gresham Committee, to be erected — it elicited considerable praise 

 and attraction. There was another model of the New Church now erecting 

 at Muswell Hill, under the direction of William Barnes, Esq. Also sundry 

 models by Mr. Samuel Nixon, as well as numerous drawings by Henry 

 Nixon, Clayton, G. B. Moore, Punnett, Meredith, William Barnes, G. 

 Mair, WiUiam Grellier, William Nunn, &c. &c. The meeting was numerously 

 attended, and was favoured by the presence of many of the leading and most 

 ■cientific men of the day. 



ROYAL INSTITUTE OF BRITISH ARCHITECTS. 



June 7. — A paper was read by the Rev. R. Burgess, Hon. Member, on the 

 Roman temples. Mr. Burgess traced, in a most interesting and entertaining 

 narrative, the history of the temples of antiquity, from the rays encircling 

 the heads of the heathen deities, originally applied as a protection to the 

 heads of their statues, and the niches in which they wire subsequently en- 

 sconced, down to the gorgeous edifices of the Roman empire. 



June 21. — Mr. T. L. Donaldson, Fellow, read a description of the column 

 erected at Petersburg in honour of the late Emperor Alexander. The con- 

 struction of this monument rivals that of the best ages of antiquity. The 

 shaft is monolithic, of polished granite, 84 feet in length. The pedestal is 

 also a single block of the same material, and so carefully has the durability 

 of the work been considered, that two vast masses were successively rejected 

 after they had been extricated from the quarry as not being sufficiently per- 

 fect. Possessed as we are in Great Britain of granite quarries capable of 

 supplying stones of almost unlimited dimensions, it is to be regretted that 

 such an example should be lost upon the directors of our public works. Un- 

 fortunately the example is likely to excite nothing but feehngs of horror and 

 contempt for so outrageous a dereliction of the principles of economy ! 



A paper was afterwards read on the open roofs of the middle ages, by T. 

 Morris, Esq., — many examples were exhibited and described. It appeared 

 to be the general opinion of the meeting, that the scientific skill displayed in 

 these beautiful and picturesque combinations of timber work has been greatly 

 over-rated. Some have signally failed, as at Eltham, while in others, as at 

 Westminster Hall, the principle resolves itself, on examination, into the 

 simplest elements of roofing. The durability of these structures seems rather 

 due to the mechanical construction of the carpentry, in which they are worthy 

 of the greatest admiration. 



MESSRS. COOKE AND WHEATSTONE'S ELECTRIC 



TELEGRAPH. 



(From the Railway Times.) 



We have given many occasional notices of this admirable invention 

 — of its adoption on the Great Western and Blackwall Railways, and 

 its surprising; performances in both instances — but it still remains to 

 us to lay before our readers such a detailed account of the apparatus 

 as may enable them to comprehend fully the mode of its operation, 

 and to estimate duly its great practical efficiency. We cannot help 

 thinking that it must be owing in a great measure to a prevailing 

 paucity of information on the subject of the invention, that it is not 

 making its way more rapidly into use, and believe we shall render 

 good service to the railway interest by doing our best to make its 

 value more clearly, distinctly and generally known. For the following 

 descriptive details, and the numerous engravings by which they are 

 illustrated, we are indebted partly to the evidence given by Professor 

 Wheatstone before the .Select Committee of the House of Commons 

 on Railways, and partly to a set of drawings with explanatory letter- 

 press recently published by the Professor's managing partner in the 

 invention, Mr. Cooke. Some doubts it will be recollected were raised 

 respecting the proportions in which Messrs. Wheatstone and Cooke 

 divided between them the merit of the invention; but these doubts 

 have been for ever removed by the statement on the subject which 

 we published three or four weeks ago, drawn up at the mutual re- 

 quest, and (we believe) to the satisfaction, of these gentlemen, by their 

 friends Sir I. Brunei and Professor Daniell. 



Professor Wheatstone having been requested by the Committee of 

 the House of Commons to explain to them the mode in which he pro- 

 posed to communicate intelligence between two distant points, made 

 the following answer : — 



I have here a copy of the drawing of the specification to the first 

 patent taken out by myself and Mr. Cooke ; in all essential particulars, 

 the instrument here represented resembles the one at the Great Wes- 

 tern Railway. Here is what may be called a dial (see Fig. 1,) with, 

 five vertical magnetic needles. Upon this dial 20 letters of the alpha- 

 bet are marked, and the various letters are indicated by the mutual 

 convergence of two needles when they are caused to move; if the 

 first needle turns to the right and the second to the left, H is indicated. 

 If the first needle deviate to the right, and the fourth to the left, then 

 B is indicated ; if the same needles converge downwards, then V is 

 pointed to. These magnetic needles are acted upon by electrical 

 currents, passing through coi'.s of wire placed immediately behind 

 them ; here is the representation of one of those coils, with the po- 

 sition of the magnetic needle with respect to it (Fig. 6). Each of the 

 coils furms a portion of a communicating wire, which may extend to 

 any distance whatever; these wires, at their termination, are con- 

 nected with an apparatus, which may be called a communicator, 

 (Fig. 1,) because by means of it the signals are communicated ; it con- 

 sists of five longitudinal and two transverse metal bars, fixed in a 

 wooden frame ; the latter are united to the two poles of a voltaic bat- 

 tery, and, in the ordinary condition of the instrument, have no metallic 

 communication with the" longitudinal bars, which are each immediately 

 connected with a different wire of the line; on each of these longi- 

 tudinal bars two stops are placed, forming together two p.irallel rows. 

 When a stop of the upper row is pressed down, the bar upon which 

 it is placed forms a metallic communication with the transverse bar 

 below it, which is connected with one of the poles of the battery ; and 

 when one of the stops of the lower row is touched, another of the 

 longitudinal bars forms a metallic communication with the other pole 

 of the voltaic batterv, and the current flows through the two wires 

 connected with the longitudinal bars, to whatever distance they may 

 be extended, passing up one and down the other, provided they be 

 connected together at their opposite extremities, and affecting mag- 

 netic needles placed before the coils which are interposed in the 

 circuit, there must be a similar complete apparatus at every different 

 station. 



"There is another very essential part of the apparatus I wish to 

 mention, which is, the means we have of ringing a bell before the 

 communication begins, in order to call the attention of the observer. 

 The general principle of the alarum is this; to the detent of an 

 alarum, on tlie ordinary construction of a clock alarum, a piece of soft 

 iron is fixed, and opposite to it there is a bar of soft iron bent to the 

 form of a horse-shoe ; round this bent bar, wire, covered with silk, is 

 w(.und, forming numerous coils ; it is a property o( soft iron to become 

 powerfully magnetic when an electric current passes through a coil 

 thus surrounding it. When the horse-shoe bar thus becomes magnetic, 

 it therefore attracts the detent, and the bell immediately rings; when 

 tlie current ceases the magnetic power ceases also, and the bell 



2 K 



