1847.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



27 



Lord Dundonald's War Plan. — We understand, says the Hampshire Tele* 

 ijraph, that the secret official trial to ascertain the effect of a continuous 

 evolution of intense gas in projecting shells or shot from a tube, resulted, 

 on an average, in throwing twenty-five six-pounder siiot to the distance of 

 7,000 yards. From this data, it is clear that balls of greater diameter 

 would far exceed the range of common artillery. Another important ad- 

 vantage is said to accrue — namely, that the continuous rush during their 

 emission would prove much less injurious to vessels projecting such missiles 

 than the shock or recoil of single discbarges. Wc learn that Lord Dun- 

 donald's ingredients produce an elastic emission, like that which would be 

 evolved by kindling the end of a hawser or cable formed of hard twisted 

 gun-cotton. 



Some remarks on the Air and Water of Towns^ by Dr. R. A. Smith, read 

 at the Chemical Society^ January 4. — Having given some attention to the 

 inquiry into the health of towns, the author was anxious to find what the 

 real evil in the polluted atmosphere of towns consisted of; and in further- 

 ance of this object commenced a series of examinations on the water used 

 in the town of Manchester for ordinary purposes. Rain-water, collected 

 in cisterns, was first examined ; and on healing tiie solid matter obtained 

 by evaporation, it burnt, giving the odour of fat, and a strong smell of ui- 

 Irogenised organic matter. Rain collected in a clean porcelain dish^ and 

 treated in the same way, gave indications of a similar kind, but in a smaller 

 degree. The moisture condensed from the breath contained organic matter 

 in large quantities; and when collected from tlie windows of crowded 

 rooms, it smelt strongly of human sweat during the evaporation; and 

 when the solid residue was heated, it gave the odour of burning flesh. 

 Water from a great number of wells situated in Manchester was sub- 

 mitted to examination, and in all similar results were obtained. Dr. Smith 

 finds also that the water of riverb and canals becomes contaminated in this 

 way as soon as it reaches a town. The proportion of nitrates is also in 

 many cases remarkable, arising from the rapid oxidation of these nitro- 

 ^enised ingredients. The author conL-Uides by slating lliat he is pursuing 

 this investigation at various seasons, so as to make a more complete exami- 

 natioQ of the subject ; and the ■whole of the analytical results will then be 

 given. 



THE GREAT BRITAIN STEAM-SHIP. 



The following reports were read at a meeting of proprietors of the Great Britain, held 

 lately at Bristol. 



" 18, Dake-street, Westminster, Feb. 27, 184". 



" Gentlemen, — I beg to inclose Captain Claxton's account of the proceedings at Dun- 

 drum Bay, during ilie time that he has been engaged in forming the breakwater or pro- 

 tection to the ship, in the manner recommended by me. Notwithstanding the great diffi- 

 culties he has had to contend with from almost incessant bad weather, with the wind 

 blowing dead on shore nearly the whole of the month of January, and consequently pre- 

 venting the tides from ebbing sufficiently out to allow of the work being properly proceed- 

 ed with ; and notwithstanding the occurrence of more than one slorni at the most critical 

 period of the work, he has, as I fully relied upon his doing, succeeded in so far protecting 

 the ship that she has been comparatively unaffected by violent seas which, there is no 

 doubt whatever, would otherwise have seriously damaged her. We may now calculate 

 with tolerable certainty upon preserving her without further injury until the finer, or at 

 least more settled, weather sets in, lu the work which Captaiu Claxton undertook, and 

 has so successfully completed, he has been compelled to vary very materially the mode of 

 proceeding first laid down ; lie baa, in fact, been obliged to adapt his plans to his means 

 of execution, and almost from day to day to devise modes of proceeding with only the ex- 

 perience of th* past day to guide him. Numerous unforeseen difficulties have occurred, 

 upon which he kept me daily informed ; and simple as my plan might have appeared to 

 others, it required much skill, contrivance, and unwearying perseverance to carry out, and 

 many alterations and improvements as it progressed, I had relied confidently on success 

 when my friend Captaiu Claxton undertook the work, and the result has fully confirmed 

 my expectations. It is now necessary to turn our attention to the best mode of removing 

 the ship. I hope in about a fortnight from the present time to be able to give you some 

 opinion upon this point, but it is one requiring much consideration, and until I had the 

 opportunity of conferring with Captain (Jlaxton on the subject, and also had before me 

 all the measurements and data which he has collected, it was useless to attempt it. 

 " I am, gentlemen, your obedient servant, 



" I. K, BRUNEL." 



" Great Britain, 20th February, 1847. 



" Dear Brunei,— The change in the wind yesterday, and the appearance to-day of more 

 moderate weather, leads me to feel that I may with some comfort meet your wishes, by 

 quitting this in a day or two, for a consultation. I can venture upon this step with some 

 confidence now. in consequence of the very satisfactory result of the late heavy gales and 

 seas wpon the breakwater, after its completion on the 7th instant. I will endeavour to 

 meet your wishes, and embody, as concisely a3 I can, the substance of my various com- 

 munications in one report of my proceedings since my arrival on the 22nd December, 

 when I found Captaiu Hosken using his utmost exertions to carry out your intentions, 

 and I had the benefit of his assistance ia trying to complete the foundation until Chiist- 

 roas-day, after which the tides for some days did not quit the work, and the time of the 

 crew and labourers was entirely occupied in lashing the fagots together, in hoisting them 

 on board whenever the water left the ship's bows sufficiently, in collecting chains and 

 weights, and preparing the holding-down rods. On the 2itth I succeeded in baying back 

 the rivulet, as you beheld it, but which, in the very wet weather, proved to be a rapid and 

 full-bodied stream, and which was greatly annoying us by choosing the ship's bed for its 

 course; on that day the tide ebbed sufficiently to enable me to go on with the work, 

 which it continued to do until the 2nd of January, when it blew a stiff gale from S.E. all 

 Bight, all the next day, and with more or less force for several days after, until the sea 

 ran so high that the surf never left the work at even dead low water and spring tides. , 



"About twenty bundles of fagots broke away, but, as was afterwards the caso, they 

 were picked up after the tide receded, and secured in place. On the oth I found, on get- 

 ting on the work, it had not only very much settled, or diminished in size from the pres- 

 sure of the weights and the nature of the sand, but that the sheer force of the breakers 

 had driven the whole b^dy some feet torward. On the tith, still finding it moving, I 

 communicated with you respecting spars, and gave orders for preparing holding-down 

 tackles, and such spars as belonged to the ship, over forty feet in length, to be got ready. 

 On the 7th, it being still impossible to go on the work for any proHtable purposei the 



crew were employed as usual in packing together the larger bundles of fagote, and in pre- 

 paring tackles, spars, &c. On the 8th, four birch spars, 42 feet long, were pointed 

 through the fotmdation, with binding chains to their heels, at an angle of about 75 degs., 

 and hove tight down with tackles to the cabin scuttles. It blew strong all night— and on 

 the iith, tiudiu< they had stoi>d well, and that the weather was such as to bar us from 

 tagoting, I settled for the delivery of 25 beech trees, of 43 feet in length, and 14 inehes in 

 diameter at the heel, with all despatch. The lOth. 11th, 12ih, and 13th, the weather, 

 wind, and tide, were still unpropitious ; but on the 14tli, we got some of the beech trees 

 in place, in time to test them through a strong gale which blew that night, and all the 

 l.'nh— when the tide having receded sufficiently, we laid about sixty buudles of fagots, 

 and got a few more spars in plate. On the Ifit'h found the larger lot secured between the 

 spars, and weighted with full four tons of iron chains, and other things, besides a quan- 

 tity of large stones, had turned right over, leaving all the weights in a lump together, 

 which I mention to give you an idea of the force of the rollers- they were as before col- 

 lected and put back, and the air pump cover put upon them in addiliou to the other 

 weights. On the 17lh, I8th, and UUh, a little progress was made with the fagoting, but 

 in consequence of the violence of the sea, and the want of atones, although every effort 

 had been made to quarry ami cart, we dared not put a large quantity— found what we 

 did put sunk, shrunk, or settled each time at least three feet — this occurred four different 

 times on leaving off as high as the screw sliaft. Placing the spars still went on, but they 

 did not conquer the inclination of the whole mass to move forward, which by admeasure- 

 ment I found it had full nine feet; to check this, three tackles, with a spanner to each, 

 with four arms lor as many of the spars, were attached and hove tight to the three warps 

 fast to the anchors out astern or on the portquart«jr, all the spars being attached to each 

 other with chains. On the 2i'[h we had a good tide, ntany lagots were laid, and several 

 lighter spars were lashed laterally to the uprights, and stx more beech trees were ordered- 

 21st, both tides liappening in the dark, and the weather being extremely severe, nothing 

 was done bevonJ Lishing at daylight lateral spars as low as the coming-in tide permitted. 

 On thai; night a heavy gale commenced from S.S.E., which only occasionally moderating, 

 cuntinued until the 2rttb, not allowing us the whole time to fagot, iilthough, Ly great ex- 

 ertions, ive were enabled to get the rest of the spars ordered in place. For a few minutes 

 on tbat day we were enabled to examine the work— not a fagot h<id bnikenaway, alihough 

 they were a good deal jambed together — not a spar ha<t moved from its bertli, aud the 

 forward inclination was found to have stopped, although the test was the severest the 

 breakwater had been, up to that period, put to. On the I'Sth the wind shiited to the 

 westward, and afterwards to the northward; the water became pertectly smooth, and the 

 tides excellent for our object. Kvery exertion was made to get on with the fagoting and 

 placing tifteen more beech trees, which had been ordered auU delivered, when it appeared 

 so uncertain as to when we should be able to get on with the fagots. On the 7th, the 

 whole of the fagots ordered, 4,G0U bundles, were in plEce. 



" The weather remained fine, and the water smooth, until the l.Sth of February, when 

 it again changed, a heavv gale springing suddenly up from the south, which lasttd until 

 midnight. High water happening at 10 a.m., as was to be expected after such a sea, 

 about lOli bundles of the fagots, which were only secured with chains and ropes to the 

 screw and spars, or not loaded, similarly to thote on the foundation, broke away, but the 

 mass remained firm, although found to have settled or shrunk, or to have been beat 

 down several feet, and jambed close against the ship. The effect, however, ot the fagots 

 and their spars was almost altogether to do away with the stroke from the sea, and the 

 men were enabled to live on board with comfort. On the 14th it again came on to blow 

 with the flood. tide from the S,W., and continued to do so with great violence until the 

 springs took off, the highest of which, In the very height of a gale, was within eight inches 

 of the memorable one which so altered the ship's position in November. The poles, 

 lateral spars, and the fagots all held on well ; and, although chafed and a good deal beat 

 about and settled down, the latter had well done their work. I set the crew upon re- 

 placing and resecuring the ftw fagots which had broke away, and loading them with the 

 best bower cable, which was unshakled from the anchor, laid out, and got on board for 

 the purpose— preparatory to the trials which may be looked for before the March equi- 

 noxes shall have passed; aud, judging by those it has already withstood, there can 

 scarcely be a doubt of the breakwaker weathering gales of even longer duration and of a 

 still more violent character, if it should be the ship's fate to experience snch while in her 

 present unhappy position. 



'* Vour whole plau would have been easily carried out if the weather between the2btli 

 of January and Unh of February, could have been substituted for that of a whole month 

 after the 3Uth December; 10, Oiit) bundles of fagots might have been secured according to 

 your plan, with much greater ease than we were enabled to build and secure 50*) bundles 

 afier the completion of the foundation, on January 7, which itself contained about 1,200 

 bundles, and which kept so well together, that no one felt a doubt as to the effect of the 

 remainder, if the tides anil the weather had permitted us to goon. It was extremely for- 

 tunate that you approved so early in January of the plan of using spars to assist in keep- 

 ing the tagotb in place, as it was not until the 28th of that month that we fairly got to 

 work upon that portion which maybe said to be about a yard above the foundation, 

 which really contains the great mas.s — about ii, 000 bundles; and as we were by success 

 encouraged to extend the system of spars, at a time a fagot could not be laid, and thus 

 not only save time and money, but form an outer protection, which was of the utmost 

 service afterwards, and before the faguts were high up. The sea now first strikes through 

 this barrier of beech trees and lateral poles, the former, in some places, three deep, the 

 entire number 70 with the ship's spars, the whole fixed in the foundation of fagots, chain- 

 ed together at the heel, aud hove tight down from their heads with tackles — about 150 

 spars are lashed laterally and diagonally outsidtf of these from the sand to the ship's gun- 

 wale — the fagots, with the exception of the foundation, ara all buiit within these, resting 

 against the ship's side, fiUicg the hollow of the port quarter, and as the sea is forced, 

 with whatever violence, through the openings of this net- work of spars, which commences 

 at the starboard quarter and extends to abreast of the mainmast on the port, or exposed 

 side, it is received by the mass of fagots, aud not only is its whole force lost as it were, 

 but, although the spray is thrown up to the height of the funnel over the attermast, there 

 is no shock whatever to the ship, 



" Yours truly, 



"C. CLAXTON." 



MISCEJLiLANEA. 



Suspension Bridge^ Lumbetk, — Sir Samuel Browu, the constructor of 



Hammersmith Bridge, Brighton Pier, &c.. has offered at his own expense to construct 

 and maintfiin a suspension bridge across the Thames from Westminster to Lambeth, if 

 he can obtain the authority ot Parliament and permission to establish a toll. An inquiry 

 into the merits of the proposal has been intrusted to Captain Vetch, of the engineers, — 

 who has entered upon the investigation, with the assistance of Captnin Washington, one 

 of the Tidal Harbour Commissioners. The estimated cost, including structure, ap- 

 proaches, and the purchi.se of property, is ^0,000^. ; but this estimate has been made ou 

 granite — and the material is now intended to be either iron or stone. Ihe width of 

 water at high tide where the bridge is intended to be built is 858 feet— at low water, 828. 

 It is intended to have two piers, each ot which will intercept 45 feet of water. The erec- 

 tion of the bridge to be finished in two years from its commencement. 



Jets of Water, — Some experimenis were lately made at Liverpool by 



the Harrington Waterworks Company, in presence of the Government Commissioners of 

 Inquiry relative to the supply of water to the town, and is thus described by the ' Liverpool 

 Alail' :—" Short lengths of hose, with pipes of 7-8ths of an inch in the nozzle, were at- 



