404 



SHIIT.riUHNG 



Iron Shipt. The substitution of iron for wood 

 in the construction of ships' ImllH originated in 

 barges ami light craft luiilt for canal ami inland 

 lake service, and amongst the first builders of iron 

 boat* were .lohn Wilkinson, an iron-founder at 

 Cartmel in North Lancashire, in 1787 or earlier; 

 Thomas Wiliton, on the Monkland Canal, Scotland, 

 in 1818 ; and John Laird, founder of the Birkenhead 

 firm in 1 v. M .. The first iron steamer was the Aaron 

 Manby, built at Horeely Ironworks, Tipton, in 

 mO-n, and named after her designer and builder. 

 The first iron steamer constructed on the Clyde was 

 tin- Ai/lniii, built in l*.'t_: tin- lirst on tin- Txnewas 

 the Prince Albert, built also in 1832. The distrust 



and opposition which this great change met with 

 not only from the public, but from shipowners, 

 builders, and naval authorities, hindered its de- 

 velopment for many years. The building of the 

 Great Britain for the Atlantic service during the 

 years 1838-44 was, therefore, a characteristically 

 bold step on the part of Brunei and the company 

 for whom he acted. This remarkable vessel, the 

 marvel of her day, was in herself a striking 

 exemplification not only of the natural evolution 

 of the steamship as regards dimensions, but of 

 the revolution in con-tnietion and propulsion 

 under consideration. She was over 320 feet in 

 length, 51 feet beam, 32} feet deep, her hull wa 



V \ 





\ \\x-ft \ 



i*9t"tr9TtA' 5 rr. 19 



ee ==3, ..- ~ TO 



m-ctnr r/irc- "> "iec immKJ&Blitmi&tltSlStSt 



Utt'OCtAXIc" T0 FT. LOWO 



Fig. 4. Comparative Size* of Typical Atlantic Linen. 

 (From Kitfiiurrtnj, 4th December 18M1. The Oceanic, from drawing kindly furnished by Maun HarUnd * Wolff.) 



constructed of iron, and she was litti'il with a screw- 

 propeller. The employment of the screw in place 

 of paddles was resolved upon in 1839 after the 

 engines designed for paddle-wheels had l>een par- 

 tially made, the determination having been come 

 to after painstaking study of the screw as already 

 applied to .-mailer 



N ;. ir-projKllers. The idea of employing the prin- 

 ciple of the screw for ship-propulsion is known to 

 have been entertained from a ]riod at least as early 

 as the application of steam as the motive pn\u-r. 

 Claimants for priority in this matter have been 

 nm-t numerous, and the subject is so l>eset with 

 many intri.-ate and conflicting contentions tli.it 

 it would ! futile to attempt a satisfactory state- 

 ment here. AIIIOIU.'-! the lirst, however, to score 

 decisive success and convince the ennineerinjj pro- 

 femionof t he i irart inability of screw-propulsion were 

 .lohn Ericsson (q.v., l,H().H-89)aml Sir Knincis I'ettit 

 Smith (180H 74). The former with the t'rancit B. 

 Ogden on tin' Tliames in 1830 cpl.hu ..... 1 encourag- 

 ing success, and the latter with the Arrhimedet, 

 a vessel of much larger *!/<. in IS.'t'.t clearly demon- 

 Ktrated the practicability and value of screw-pro- 

 pulsion. Tin' innovation in the case of the (if 'it 

 Britain was equally a success ; but the great mis- 

 fortune which overtook lier on her fourth voyage 

 from Liverpool to New York in stranding in t)un- 

 dnini Hay, Ireland, through a mirefkoning, inter- 

 rupteil IMM -iir.-i fiilc-areerasasteamship, altliongh 

 he was long afterwanls employed in the Australian 



service. This misfortune, however, helped incal- 

 culably to further shipbuilding in iron. The 

 vessel, after lying aground in an awkward situa- 

 tion for about eleven months, was successfully 

 floated, and was found to have sustained com- 

 paratively little damage. Many of the shipbuilders 

 and owners who haul been hesitating about the 

 judiciousness of employing iron paid visits to the 

 stranded vessel, ins]M-ctod her after docking, and 

 felt entirely convinced of the suitability of iron 

 for ship-construction. Ocean-navigation by iron 

 steamers was now placed on a thoroughly practical 

 basis, and, nl though the transatlantic ser\icc eon- 

 tinned to be conducted by wooden vessels propelled 

 by paddle -wheels for some time longer, the Mi|>erior 

 eilieiency of the screw for over-sea propulsion 

 lieeaine more and more understood and accepted. 

 The advantages of the screw propeller for ocean- 

 'niiig as compared with the eumbron* paddle- 

 wheel are mainly as follows : As an instrument of 

 propulsion purely, and as com pared by |K>rformanees 

 in smooth water, its ellirieney is not much greater 

 than the paddle-wheel, but in virtue of its ffuxition 

 relatively to the body propelled, and to the water 

 through which that liody pa es, it is vastly more 

 efficient than the paddle for sea-going purposes. 

 Placed at the stern of the vessel, and fully 

 immersed, it act-* UJMIII relatively a much larger 

 quantitv of water in a given time than the paddle. 

 The rolling motions which so grievously alleet the 

 paddle, leave the screw almost uninfluenced. If 



