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THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[April, 



lize and the most powerfal that bad been made. She was 100 feet long, 

 26i feet beam, and 200 h.p. : the vessel was built by Steele, of Greenock, 

 and the engines by Uavid Napier. As deep-sea navigation by steam ad- 

 vanced, it became an object of considerable importance to save fuel.aod to 

 obviate llie inconvenience of the incrustation of llie boilers by the deposit of 

 gait, and other sediments occasioned by the use of sea water ; David Na- 

 pier therefore introduced the system of surface condensation the condenser 

 being made of a series of small copper tubes, through which the steam, 

 after being used, passed from the cylinder to the air-pumps, the pipes being 

 surrounded by a constant supply of cold water, so that tlie steam was con- 

 densed aud the water was returned directly back into liie boiler, to be 

 again converted into steam, without the admixture of salt water according 

 to the usual plan, thus employing the same fresh water over again, where- 

 by the above-mentioned inconvenience of incrustation of the boilers was in 

 a great measure avoided. Hall afterwards tried the same system with 

 certain modifications, and it was employed in several vessels ; but like 

 Walt, Cartwrighl, and others who had tried it, he found the condensation 

 was not so complete, and the weight, and cost, and difliculty of keeping 

 the apparatus in order, has hitherto prevented it from being generally used ; 

 for although it possesses advantages in many respects, still upon the whole 

 they do not counterbalance the disadvantages, and the old system of con- 

 densation by jet, with the aid of the brine pumps, is more generally em- 

 ployed. The brine pumps and refrigerators were invented and patented by 

 Maudslay and Field in 18-.i5. and were used on board the 'Enterprise.' 

 After the ' United Kingdom,' numerous vessels of similar and even greater 

 size were constructed, to ply between London and Leith, Glasgow, and 

 Liverpool, and elsewhere. 



The next great step in advance was the crossing the Atlantic. This had 

 long been in agitation, and was freely discussed by numerous enterprising 

 minds, anxiously bent upon working out the fulfllment of such a desirable 

 and important object ; but the great practical difficulties involved in the 

 execution were not so easily overcome. 



To construct a vessel of sufficient size, with engines of adequate power 

 to propel her through the storms of the Atlantic, and carrying with her 

 sufficient fuel to keep the engines in motion, was considered by many (aud 

 among them were very competent authorities) to be extremely doubtful, 

 but by the world in general the task was considered to be wholly impracti- 

 cable. To Bristol is due the origin of this great undertaking, and a com- 

 pany of enterprising individuals, with Brunei, as their consulting engineer, 

 was formed for that object ; it was, however, with difliculty that they 

 found engineers to carry it into etfect, some of the first constructors of the 

 day having declined to undertake it. Messrs. Maudslay and Field, how- 

 ever, who had already taken such a prominent part in the prosecution of 

 steam navigation, saw their way, and boldly engaged to construct engines 

 of the requisite power, well adapted for the purpose. Accordingly a vessel, 

 called the ' Great Western,' was designed by Haterson, and built by him 

 at Bristol; and the engines were completed and fitted on board in March, 

 1838. The vessel was 210 feet long, and 38 feet beam, drawing 15 feet 

 when laden, being 1240 tons burthen, and capable of carrying 500 tons of 

 coals, which it was calculated would last twelve days. The engines were 

 upon the side lever principle, each of 210 h.p., with cylinders 73 inches 

 diameter and 7 feel stroke, making 1.5 strokes per minutes ; they were 

 tilted in cast irou frames, with the latest improvements. The boilers were 

 constructed with the flues over the tires; they were called double-story 

 boilers, and have been since mucii used ; they had brine pumps, and were 

 worked under a pressure of 5 lb. per square inch ; the total weight of the 

 engines and boilers, including the water and the paddle-wheels, was about 

 420 tons The vessel was completed with her engines, and made her first 

 trial on the Thames in March 1838, realizing 12 miles per hour. On Sun- 

 day, 8lh April, she started on her first voyage from Bristol, under the com- 

 mand of Captain Hosken, with seven passengers, and a cargo of 50 tons of 

 goods, besides 500 tons of coals, and reached New York on Monday, 23rd 

 April, a distance of 3000 miles, in thirteen days and ten hours. Her ar- 

 rival created Ih^^ greatest interest; the quays were crowded with specta- 

 tors, anxiously waiting to give a hearty welcome to the enterprising and 

 successful adventurers, who had thus so triumphantly solved the grand 

 problem, and had brought the New World witlun a few days' sail of the 

 Old. On her return she left New York on the 7lh May and reached Bris- 

 tol on the 23rd, with 70 passengers; performing the voyage in 15 days. 

 The success of this voyage across the Atlantic having exceeded the most 

 sanguine expectations of its promoters, and indeed of the whole world, 

 there seemed no bounds to the extension of steam navigation ; other com- 

 panies were projected and numerous larger and more powerful vessels 

 were designed, in eijiial confidence of success ; then followed the ' British 

 Queen,' by N.ipier, of 500 h p., the ' Liverpool,' of 500 h.p., and the ' Pre- 

 sident,' of 600 h.p.. whose melancholy fate served for a time to damp the 

 ardour of speculation The practicability of steam communication across 

 the Atlantic having thus been established, and its superiority over the old 

 sailing system being clearly proved, time only was necessary to render it 

 perfect. The line from Liverpool to Boston was then designed, and carried 

 into etlect by Cunard, for conveying the mails ; it consisted of four fast ves- 

 sels, the ' Acadia,' ' Caledonia,' ' Hibernia,' and ' Cambria,' of about 1000 

 tons and 450 h p. each. This was followed by the gigantic project of the 

 Royal Mail Company, for carrying the mails between Kngland and the 

 West Indies, consisting of twelve vessels, each of about 1200 to 1300 tons 

 burthen, and 420 h p. The engines of these vessels resembled very much 

 those of the ' Great Western,' wuose complete success induced their being 



taken as models for others. The great weight and space occupied by these 

 engines, being upon the average about a ton for every nur,->e-po>\er, rendered 

 it difficult for them to carry any great amount of cargo beyond llie passen- 

 gers, and ihus the profits as a mercantile speculation were materially les* 

 sened ; it becamp extremely desirable, therefore, to ascertain whether en- 

 gines, equally efficient, could not be made of less weight, and to occupy 

 considerably less space. 



In order to effect this object, engines were invented, by which the power 

 was applied directly from the piston to turn the paddle-wheel -haft, with- 

 out the intervention of side levers ; these were called direct-acting engines, 

 and at first great objections were maile to them in consequence, as was 

 asserted, of the loss of power arising from the oblifiuity of the action of the 

 piston-rod upon the crank on the paddle-wheel shaft. Messrs. Seawards 

 were among the first to introduce this system inlo the ' Gorgon,' and not- 

 withstanding the tibjections above stated, it has been improved by them 

 and by other engineers, aud has materially gained ground. The obliquity 

 of action of this system, compared with that of the side lever system, can 

 only be considered in the light of a little extra friction, which is fully, if 

 not more than compensated for, by the reduction of weight and space. The 

 modifications of the system by Miller, have been very successful, and com- 

 bined with the forms of vessels adopted by him, have enabled great speed 

 to be attained both by sea going vessels, and his boats on the Kliine and 

 other rivers. Even the objection of extra friction however, if tenable, is 

 obviated by the vibrating cylinders descrilied in Trevithick and Vivian's 

 patent in 1802; patented by Witty in 1813, and by Manby in 1821, by 

 whom the tirst engines of the kind were constructed ; subsequently im- 

 proved by Maudslay and Field, ami Spiller; and now exiensively manu- 

 factured by Peun, Miller, and others ; Mauilslay and Field's double cylin- 

 der engines, so arranged that a long connecting rod is obtained by its being 

 enabled to descend between the cylinders; the Trunk engine by Hum- 

 phrey ; and the modification of the concentric cylinders by Joseph Mauds- 

 lay ; as well as other varieties of this system by dill'erent makers. The 

 substitution of wrought iron for cast in a large portion of the frame and 

 condensers; the tubular instead of the common flue boiler first proposed 

 by Blakley in 1761, and afterwards improved in the locomotive boiler, and 

 introduced into steam vessels by Maudslay, Spiller, Bramah, and others 

 about the year 1829, as well as the use of steam of higher temperature and 

 increased expansive action, have combined materially to increase the etfect 

 of the engines, and reduce the consumption of fuel; so that the space and 

 weight occupied by them is now reduced to nearly one-half what it was 

 originally, or in other words, engines of double the power now only occupy 

 the same space and tonnage in the vessel ; thus a material advantage has 

 been gained in enabling vessels to carry a larger quantity of fuel, by which 

 they can extend their voyage; and greater power is rendered disposable 

 for propelling the vessel through the water. As economy of time becomes 

 daily more important, every means which can eflect it are brought into 

 operation, and thus the power of the engines has been continually aug- 

 meuted, in order to produce greater speed and shorten the duration of the 

 voyages. Keferring to the navy, we find, that in 1822,80 h.p. was the 

 largest ; in 1827, 160 h.p. ; in 1828. 200 h.p. ; in 1830, 220 h.p. ; in 1838, 

 410 h.p.; and in 1845 we have the ' Retribution' and 'Terrible,' with 

 nearly 1000 h.p. in eai h, and it is not improbable that, ere long, greater 

 power will be employed.* Whilst the royal steam navy has been making 

 such rapid progress, the mercantile steam navy has not only kept pace 

 with it but has even led the way ; for the enterprising, commercial spirit 

 of this country is ever on the alert ; every improvement is seized upon with 

 avidity, and the greatest inducements are held out to make new discoveries, 

 in fact nothing but constant progress can satisfy the restless spirit of im- 

 provement. In the infancy of the art, we were satisfied with 5 or G miles 

 per hour, now, when we have attained above 17 miles per hour, we are 

 confidently looking to a still greater result. 



Whilst the improvements, above described, have been making in the en- 

 gines and in the mode of applying them, various attempts have been made 

 to obviate the inconvenience and loss of power occasioned by the concussion 

 of the floats of the ordinary paddle-wheel entering the water, as well as the 

 heavy drag or back action of the water when the floats leave it; numerous 

 experiments and inventions have been tried for constructing a wheel, of 

 such a form that the floats shall always enter the water in the most advan- 

 tageous manuer, and having effected the object, shall leave it again with 

 the least resistance. To describe the numerous inventions of this kind 

 would be foreign to my purpose, and would occupy too much of your time ; 

 it will suflice to mention that of Buchanan, by which the floats always en- 

 ter and depart from the water perpendicularly ; those of Cav^, Oldham, 

 Morgan, Perkins, Seaward, aud Barnes, which are modifications of it, 

 differing chiefly in the angle at which the floats enter and leave the water, 

 and the mechanism attached to the wheel by which the motion is communi- 

 cated to the float boards ; the principle of this invention is extremely good, 

 but in practice it has unfortunately been found, that the wheels of this 

 construction, after a little use, are liable to get out of order ; it is not 

 therefore generally adopt-^d, although, whilst they are in order, consider- 

 able advantage is doubtless gained. To obviate this inconvenience, as 

 well as that of the common wheel. Field invented what is technically term- 

 ed the Cycloidal Wheel; this consists in dividing each float-board inlo 

 several pans or narrower boards, and arranging them so nearly in cycloidal 

 curves that they shall all enter the water at the same place in immediate 

 succession ; as the acting force of each board is radiating, it propels whilst 



* The total ameiul of itetw power employed la ttie Itof at Navy ia atiuttl 36,000 b-ff. 



