210 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[June, 



derived from tlie saving in space. She thus possesses 70 tons additional 

 buoyancy for cargo, or coal, for a more extended voyage. Another consider- 

 ation, which ouglit not to he overlooked, is that in huilding a vessel to carry 

 a certain nuniher of passengers, or quantity of cargo, the first cost of the 

 vessel may be much reduced; the same space for passengers and tonnage for 

 goods, may be obtained by a vessel of 70 tons less measurement, and the saving 

 under this head cannot be estimated at less than 1400/. in a vessel of the size 

 of the Mongibello, and it would be greater as the size increased. 



These engines work with great steadiness anfl effect, making 2.') strokes 

 per minute, and performing from I li to r2 miles per hour. They are fitted 

 with expansion gear, briue pumps, &c. In short the vessel is replete with 

 every requisite for a sea-going ship. 



RENNIE'S TRAPEZIUM PADDLE WHEEL. 



In our number for March last, we enumerated some of the advantages 

 which were likely to be derived from the adoption of the above invention in 

 steam navigation ; we have noiv the satisfaction to lay before our readers 

 the results of a series of experiments which have been made on the efficacy 

 of the Trapezium Paddle M heels, in comparison with the common Rectangu- 

 lar Paddle AVIiccIs. The Lords of the Admiralty having decided that the 

 trial should be made upon a vesscd of known qualities, fixpd upon the African. 

 an old gun brig which had been converted into a steamer, by two engines of 

 45 horse power p\it into her. as best calculated to give a comparative result. 

 Accordingly the old paddles were removed, and a pair of trapezium wheels 

 fixed in on the same siiatf, whicli formerly served for the old wheels, so that 

 with the exception of a slight alteration in the paddle boxes, no further ad- 

 ditions were required. On the 14th of April last the whole being ready, the 

 engines were set to work, and the vessel proceeded down the river to the 

 measured mile in Long Reach. 



The dimensions of the African are — length, 109 ft. 10 in. midship section; 

 breadth, 24- ft. 10 in. semi-elliptical, bluflat the bows ; depth, 12 feet full at 

 the quarters. She is a good sea boat, but not calculated for high velocities, as 

 compared with steam vessels of modern times. 



The power of tlie engines is two of 45 horse power each, the number of 

 strokes 29 to 30. 



The velocity of the vessel at a load draught of 9 ft. 5 in. is nine miles per 

 hour thriiugh still water. 



According to a sezies of experiments made with the African by Mr. King- 

 ston. Admiralty engineer, the diameter of the old wheel was 14 ft. 7 in., the 

 width 7 feet, the area of the floats immersed was about 62 feet super., the 

 mean draught of the vessel was 9 ft. 4J in., and w ith the barometer at 26^ 

 inches, and the engines making from 29 to 30 strokes per minute, the maxi- 

 mum mean velocity opposite the measured mile was 9'174 miles per hour. 



miles per hour. 



On the 14th of April last, the engines making from 22 to 23J 



strokes ....... 829 to 8-75 



On the 26th April, 23 strokes . . . . . 84 to 86 



E On the 1st of May, 25 to 28i strokes . . .88 to 9032 



On the 8th of May, 25 strokes . . . . 8'6 to 88 



On the 12th of May, 26 to 27* 85 to 9-136 



5 The last results were obtained with from 2| strokes of the engines less 

 than formerly, and with a reduced diameter of wheel of 22 inches, and an 

 immersed surface of 30 square feet. The action of the float in the water was 

 entirely free from shocks or vibration ; thus establishing on a greater scale 

 than hitherto, the properties of the trapezium wheel as promulgated in the 

 prospectus, namely, that it combines all the advantages of the common pad- 

 ale wheel, and does away with all its defects, arising as before stated, from 

 the great weight, width, and indirect action of the former, and combining 

 all and even greater simphcity of the latter. 



The Steam Frigate " Styx." — On the 6th of May an experimental trip was 

 made with this vessel down the river as far as Gravesend. There was present 

 a numerous party of naval and scientific gentlemen, among whom were Lord 

 Prudhoc, Admiral Sir Philip Durham, Sir W. .Symonds. Chevalier Benkhau- 

 sen, the Russian Consul General. Mr. Roulh, &c. She is what is termed a 

 second class government steam frigate, and the third vessel of that class fitted 

 within the last six months. Altogether there will be five vessels, viz.. The 

 " Driver." " Vixen." " Styx," " Growler," and " Geiser," the two latter are 

 not yet finished ; they are all built to one mould, under the direction of Sir 

 William Symonds, and to be fitted with engines by Messrs. J. & S. Seaward 

 & C'apel. The dimensions of the " Styx'" are. length 210 feet over all, or 

 185 feet^between perpendiculars. 36 feet breadth of beam, and 21 feet depth 

 of hold ; she draws 13 feet aft and 12 feet forward, and when laden with her 

 full complement of guns, stores, kc. 15 feet aft and 1 i ft. 6 in. forward. She 

 is to carry four 8 inch Runs, for 64 lb. hollow shot, and two 10 inch guns on 

 swivels and slide beds for 96 lb. hollow shot. The two engines are of the 

 collective power of 560 horse power ; the cylinders are 62 inches diameter, 

 and 5 ft. 3 in. stroke, performing 17 strokes per minute ; the paddle-wheel is 

 26 feet external diameter, breadth of float boards 8 ft 3 in, divided into two, 

 each being 11 inches wide. Ihe engines are upon Messrs. Seaward's patent 

 princiiile. the action being applied direct from the pistim rod to the crank of 

 the paddle shaft, as adopted on board the " Cyclops.' Drawings and a 

 description of these engines w ill be found in the Journal for February last. 

 Mr. Samuel Seaward has also applied his patent for disconnecting the paddle 

 wheels, which is extremely simple and efficacious ; it only required 3 minutes 



to disconnect one of the wheels, and 4 minutes to reconnect it. ami we have 

 no doubt if the men had had a little more exiwrience, they could have been 

 connected and disconnected in half that time. The engines worked very 

 beautifully, and free from the slightest vibration ; the speed through still 

 water w as at the rate of about lOt miles per hour. During the excursi n the 

 company were entertained with a sumptuous collation. 



HlacUwalt Steamers. — The Blaekwall Railway Company have had three iron 

 steamers built by Messrs. Ditchburn and Mai r, to run from the Brunswick 

 Pier to Gravesend, viz. the " Brunswick." " Railway," and '• Blaekwall," all 

 of rinc mould. Their length is 146 feet and 19 ft. beam. The mould is beau- 

 tiful, tlie bows being remarkably sharp, and throwing bit little, if any, wave 

 in front ; the cabins are tastefully finished, and do credit to the builders. 

 Each vessel is fitted with engines of 90 horse power collectively, and all have 

 tubular boilers. The Jirunswkl; has a pair of oscillating engines by Messrs. 

 J. & S. Seaward it. C'apel. and the same description of engines are on board 

 the Railway fitted by Messis. John Penn & .Son. We were present at an ex- 

 perimental trip of this boat on Saturday the 8th ult.. when her speed ex- 

 ceeded that of any other boat on the river; indeed her average is about 16 

 miles per hour. Her jjcrformance gave great satisfaction to the Directors of 

 the Railway who were on board, and to the company generally. The whole 

 of the machinery incUuling the boilers is only 45J tons in weight, very little 

 more than one half the usual weight of engines of so large a power. The 

 other vessel, the " Blaekwall," has a single steeple engine of 90 liorse power 

 fitted with tubular boilers by Messrs. Miller, Ravenhill & Co. We under- 

 stand that the speed of this vessel is nearly equal to that of the " Railwaij." 



The Elbcrfelt. — This splendid vessel built of iron by Messrs. Ditchburn and 

 Mair, for navigating the Rhine, performed an experiment trip on the Thames 

 on the 8th instant. Her dimensions are, length 176 feet, beam 21 feet, depth 

 11 ft. 6 in., and draws only 2 ft. 8 in. of water, her cabins are fitted up 

 with great taste, particularly the ladies cabin, and thcs,aloon « hich isdecorated 

 with views on the Thames,— throughout the vessel every attention has been 

 paid to the comforts of the traveller. She is propelled by a pair of oscillating 

 engines of 55 horse power each, by Messrs. Miller, Ravenhill and Co., her 

 speed in still water is calculated at 13 miles per hour ; the boilers are tubular, 

 of Mr. Spiller's patent. 



Steam Frigates. — The town of Greenock exhibits at present a scene of no 

 common interest. Six large steam frigates are now being constructed in the 

 town or its vicinity, each of these of atjout 1,500 tons capacity, and carrying 

 enginesof 500 horse power, being part of the fleet of 14 armed frigates destined 

 in time of peace to carry out and distribute the mails among our West Indian 

 colonies. Four of these are to be supplied by a single firm in Greenock, who 

 deliver the ships, engines, and equipments complete, and ready for sea. We 

 announced a short time ago the successful launch of the first of these four, 

 the Clyde, which was constructed by the late Mr. Duncan. The second of 

 these ships, the Tweed, was launched from the yard of Messrs. Thompson 

 and .Spiers on .Saturday last, and we hope soon to announce the completion 

 of the series of these four sister ships, in the launch of the Tay and tlie Te- 

 viot. which are rapidly progressing on the stocks. In general appearance 

 and construction this ship resembles closely her precursor, the Clyde, being 

 slightly fuller forward, and finer abaft. To the eye she also seems larger 

 than the Clyde, but this may arise from the latter being a foot or two deeper 

 in the water, having already her whole engines and boilers fitted upon board, 

 although it is only about two months since her launch. The dimensions of 

 the Tweed are as follow : — Length, over all, 240 feet ; keel and forerake, 215 ; 

 beam, 37 : depth, ZO.— Greenock paper. 



Thames Steamers. — The competition among the steamers has become so 

 great, and their numbers have so much increased of late, tliat 17 vessels are 

 daily engaged in conveying passengers between Gravesend and London. 

 .Some of them charge 2s. in the after cabin, and Is. 6rf. in the fore part of the 

 steamer, for each passenger ; others Is. 6rf. and Is., and a few Is. only all 

 over the vessel ; while the steamers from Blackw all to Gravesend convey pas- 

 sengers for 8rf. each. Fourteen steam vessels are engaged in carrying pas- 

 sengers between London and Greenwich, and a majority of them have lately 

 reduced their fares to 6rf. each ; but the pier dues swallow up one-third of 

 the fare, and it is doubtful whether the steam boat companies will be able to 

 continue the reduced fares for any length of time. Eight steamers are con- 

 stantly running to and from M'oolwich, and they will receive a great acces- 

 sion in a few days by the fast and elegant boats of the M'atermens' Steam- 

 packet Company. There are 16 small vessels belonging to different companies 

 steaming away from morn till night above bridge, and on Sunday last they 

 carried upwards of 55,000 passengers, at 4rf. per head, between the numerous 

 piers from London -bridge to Chelsea. — Times. 



Improvement in the Construction of Steam Ships.- — A Correspondent of the 

 Times suggests that safety bulkhead's, by which a vessel is divided into three 

 or four water-tight compartments, should be introduced into ocean steamers 

 in future. The suggestion is an excellent one, but it ought to be enforced by 

 legi-slative authority, and applied to all steamers. Many lives and much 

 valuable properly would have been saved if such a regulation had been in 

 force since steam navigation h,as been so largely extended. The loss of the 

 Pha'nix, which was struck before the paddle-box by another large steamer 

 at sea, affords one instance ; and the Albion, on her voyage from Dublin to 

 Bnstol, touched a sunken rock on the Welch coast, and immediately went 

 dow n in comparatively smooth water, and on a beautiful day, in consequence 

 of the leak produced in her bow. The distressing loss of the Killarney, on 

 the coast of^ Cork, would, no doubt, have been averteil, had not the fires in 

 the engine-room been extinguished by a leak, which it was impossible to 

 keep down. Many other cases miuht be cited ; and we shall place in juxta- 

 position with the preceding an accident which happened to the Royal William 

 a celebrated steamer belonging to the City of Dublin Company, on one of her 

 voyages from London to Dublin. This vessel, we must iiremise, like several 

 others beloniiing to the same spirited company, is divided into water-tight 

 compartments by bulkheads. One dark stormy night, when oft' the Isle of 

 Wight, she suddenly came into violent collision with a three-masted ship, 



