1841.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



I6f) 



at the rate of eight miles pci- hour, her speed cannot he doiililefl, even though 

 the power he mnltiplied twelve times, and the entire hold of the vessel occu- 

 pied as an engine room. 



The weight" of fuel is also in direct proportion to the size of the engines; 

 so that taking, for example, two vessels of two hundred and of four hundred 

 horses power respectively — that of the higher power will have to carry nearly 

 double the weight both' of fuel and of engines, and it is still questionable 

 whether the increased force will propel the one ship more than 1} mile per 

 horn' faster than the other. 



The space occupied by the engines and fuel in the most valuable part of 

 the ship, is also an important consideration: neither the " President" nor 

 "British Queen" steamer, although of two thousand tons measurement, is 

 capable of earning more than live hundred tons of cargo when the fuel is on 

 board. 



The author then examines the question of employing too much power in a 

 steam vessel, and refers to the " Liverpool," as an instance that such may be 

 the fact. It ajipears that with the original dimensions of thirty feet ten 

 inches beam, and engine power of four hundred and fifty horses, being a pro- 

 portion of power to tonnage of about 1 to 2}, the vessel was immersed four 

 feet beyond the calculated water line, and a decided failure was the natural 

 consequence ; but when the breadth of beam was increased to thirty-seven 

 feet, augmenting the capacity four hundred tons, and giving the proportion 

 of one horse power to .3J tons burthen, the performance of the engine and 

 the speed of tlie vessel were both materially improved. 



The " Gem," Gravesend steamer, one hundred and forty-five feet long, by 

 nineteen feet beam, had two engines of fifty horses power e.ich; the speed 

 was insufficient, being only twelve and a half miles through the water ; but 

 Tvhen the same engines were placed in the " Ruby," which was one hundred 

 and fifty feet long, and nineteen feet nine inches Ijeam, the velocity of the 

 latter vessel was thirteen and a half miles per hour. A pair of engines, of 

 forty-five horses power each, were then placed in the " Gem," without alter- 

 ing the vessel, and in consequence of the diminished weight and draught of 

 water, lier speed then nearly etinalled that of the " Ruby." 



The author does not condemn the application of considerable power for 

 vessels, provided it can be employed without materially increasing the weight 

 and the area of the immersed midship section. It appears that tifie length of 

 a steam voyage, to be profitable, is at present limited to twenty days for the 

 largest class of steamers ; that we have about thirty others which can approach 

 twelve days, while the majority cunnot em|doy steam beyond eight days suc- 

 cessively, without a fresli supply of fuel. It is evident, tliercfore, that more 

 efficient means must be adopted for the general wants of commerce in our 

 extended intercourse with the East and West Indies, the Pacific, Mexico, 

 Brazil, Australia, and all the distant colonies, wliich now demand rapid com- 

 munication with England. 



Tlie author refers to a ]iamph!et, published by him in 1827, entitled, " Ob- 

 servations on the possibility of successfully employing Steam Power in navi- 

 gating Ships between this country and the East liidies by the Cape of Good 

 Hope." He therein proposed that large sq\iare-tigged ships, of fifteen hun- 

 dred to eighteen hundred tons measurement, should be fully equipped and 

 constructed, so as to sail ten or eleven miles per hour with a fair winil ; that 

 they should cariT engines of small power, to assist the sails in light winds, 

 propel them at a moderate speed during calms, work into and out of harbour, 

 &c., and thus shorten those portions of the voyage wherein so much time was 

 usually lost. 



To all well-built good-sailing vessels, of four hundred tons and upwards, 

 *' auxiliary steam" is applicable. A steani engine of the necessary power can 

 without inconvenience be placed in such vessels, either on or between decks, 

 so as propel a ship at the rate of four to five nautical miles per hour in a calm, 

 and for this speed a proportion of one horse power to twenty-five tons is am- 

 ply sufiicient. The practicability of applying this system to East Indiamen 

 and other similar vessels is then examined at length, and it is shown that the 

 ordinary speed of these ships under sail is, before the wiiul, eleven to twelve 

 miles per hour, and in a gale thirteen to fourteen miles per hour, which is 

 greater by two or three miles per hour than that of any ordinary steam vessel 

 when under sail, on account of the latter bi-ing impeded by tlie wheels trail- 

 ing in the water, and the sUghtness of their masts, spars, and rigging. The 

 auxiliary steam power might, therefore, be cfliciently applied, either by using 

 it alone, or in conjunction with the sails, so as to keep up a uniform speed, 

 by which a great saving of time could be effected in a long voyage. 



The conditions of sailing and steaming voyages to India, with the influence 

 of the trade-winds, are then examined, and the author proceeds to detail the 

 experiments made by him, on board the " Vernon" Indiaman, which was the 

 first scaling vessel that actually made a voyage out and home with " auxiliary 

 steam." 



The "Vernon," built in 1839, by the owner, Mr. Green, was one thousand 

 tons burthen ; the sailing speed was about twelve to thirteen miles per hour 

 in a fresh gale, and being from her frigate build well calculated for tlie ex- 

 perimeut, it was determined to equip her with a condensing engine of thirty 

 horses power, placed midshi)is on the main deck, between the fore and main 

 hatchways ; the space occupied being twenty-four feet long by ten w ide. The 

 weight of the machinery was twenty-five tons, and it was so an'anged that 

 the motion was communicated direct from the piston cross-head by two side 

 rods to the crank on the paddle shaft, placed immediately behind the lower 

 end of the steam cylinder, which was horizontal. The wheels were fourteen 

 feet diameter, projecting five feet, and were so constructed that e float boards 



could be raised to suit the draught of water of the ship; or they could be 

 taken entirely away, if necessary, leaving the shafts projecting only eighteen 

 inches beyond the sides. Under ordinary circumstances they were discon- 

 nected from the engine by a simple contrivance, consisting of a moveable 

 head, attached to the crank on the paddle shaft, by turning wliich, one quar- 

 ter of a circle, the crank pin was liberated, and the wheels turned freely round. 

 The " Vernon," thus equipped, having on board nine hundred tons of cargo, 

 and sixty tons of coal, drew seventeen feet of water. In the first trial the 

 speed of the vessel, under steam alone, was five and three-quarters nautical 

 miles per hour, demonstrating how small a power is necessary for a moderate 

 speed. She then started for Calcutta, and though the piston rod broke three 

 times during the voyage, owing to a defect in one of the paddle shaft beai-- 

 iugs, the passage was satisfactoiy. Tlie details are given minutely, as are 

 also those of those homeward voyage, which was performed from Calcutta to 

 London in eighty-eight days, to which must be added seven days for neces- 

 sary delay at the Cape, making a total of ninety-five days, which is the shortest 

 passage on record. Great credit is given to Captain Denny for the judgment 

 with which he used the auxiliary steam pow-er, aiid the course taken by him, 

 by which he was enabled to overcome the difficulties incidental to a first trial 

 of so important a system. The success of the " Vernon," induced the imme- 

 diate application of engine power to the " Earl Ilardwicke" Indiaman, and 

 both these vessels arc uow on their voyage out to Calcutta. 



This communication was accompanied by drawings of the " Vernoa" and 

 the " Earl Ilardwicke," and by a chart, on which was laid down the proposed 

 daily course of a steam ship, on a voyage to and from Calcutta, showing where 

 sails only are necessary, then where steam alone, and also when the joint 

 agency of steam and wind would be required. Also, the daily progress of the 

 " Jlarquis of Huutly " Indiaman, of fourteen hundred tons burthen, on a voy- 

 age to India and China, and home, from tlie author's own observation, in the 

 year 1816. 



For the purpose of demonstrating the ratio of power to velocity, a Table 

 was also given showing the velocities of ships of different tmniage, having 

 steam power of various ratios, deduced from upwards of one hundred experi- 

 ments on large steam vessels. The mode of disengaging the cranks was illns- 

 trated by models showing the gradation, from the complication of the first 

 idea, to the beautiful sim]jlicity of the present plan, which is now employed 

 on board of the Government war steamers. 



ROY.iL INSTITUTE OF BRITISH .ARCHITECTS. 

 April 19. 



The Institute met for the first time after the Easter recess. Jos. Kay 

 Esq., V. P., in the Chair. 



Beriah Botfield, Esq., M. P., was unanimously elected au Honorary Fellow. 



The Secretary anuounced the subjects for the prizes for the ensuing Ses- 

 sion, viz. a restoration of Crosby Place, Bishopsgate Street, with the addition 

 to the medal of ten guineas liberally oftered by Miss Hacket, to whom the 

 puldic are so sreatly indebted for the ])reservatioii of what remains of that 

 fine specimen of the Palatial .irchitecture of the IJth century; an essay on 

 the properties of light, shade and reflection in architecture, and another on 

 the eiTects which may resiUt to architectural desiga, fi-om the general use of 

 cast iron in construction. 



A paper was read by Mr. Poynter, Fellow, on the state of M'indsor Castle, 

 previously to the erection of the existing domm rcgk by Edward HI, in the 

 nth century. It is unnecessary to enter into any analysis of this paper, as 

 the materials were drawn from a prefatory essay to Sir Jeft'ry Wyatville's 

 iliustralions of Windsor Castle, which will immediately lie in the hands of 

 the public ; but that portion of it which was laid before the Institute, was 

 made illustrative of a ground plan, in which the condition of the Castle, as 

 it was left after the extensive alterations of Henry IH. v\as laid down upon 

 the authority of original documents, the greater part of which have now been 

 brought to light for the first time. 



A communication was it ad from John AMiitc, Esq., in pursuance of the 

 subject brought before the Institute at a former meeting, the remains of 

 ecclesiastical architecture in the pointed style, at Wisby, in Gothland. Mr. 

 AVhite's supplementary paper went to support, by the authority of Torfceus, 

 and other historians, his theory on the date of those buildings, by adducing 

 evidence on the advanced state of the arts in Seajidinavia, as early as tlie 

 tenth centuiT, 



The meeting adjourned to the refreshment of tea and coffee in the Library. 



On Monday evening of the 2Gtb ult., the President Earl de Grey, opened 

 bis house for the reception of the Members of the Society. The Council 

 had the honour of dining with his Lordship, and the conversazione which 

 followed was attended by a numerous party of noblemen and gentlemen emi- 

 nent in art, science and literature. The Marquis of Lansdowne, Lord Prud- 

 hoe, Mr. Baron Parke, Mr. Rogers, Sir Edward Cust, Sir Henry Ilalford, 

 Sir Henrv Ellis, Sir Richard Westmacott, Sir Francis Chantrey, Sir Frede- 

 rick Madden, Sir Gardner Wilkinson, Sir John Rennie, Sir Isambard Brunei. 

 Professor WiUis, the President of the Institute of Civil Engineers. Mr. Allan 

 gnnningham, Mr. Copley Fielding, Mr. Ross, Mr. Harding, Mr. Haghe, 

 and Mrl Joseph Nash were among the guests. A small party of ladies were 

 also present, including the Dudiess of Northumberland, the Marchioness o£ 

 Lansdowne, &c. The tables were covered with works of art, among wliioli 

 Mr. Nash's splendid drawings of old English mansions were conspicuous. 



2 A 



