Naval Architeciure, &€> 389 



from, clock, which, on an average, now requires three 

 months, accompanied with an expense ot nearly 10,OOOZ. 

 per month in wages, subsistence, &c. &c. 



" This plan may be practised in all countries, and must 

 be particularly advantageous where there are no dry docks 

 or flowing of tide. 



" Ships on many foreign stations when requiring to be 

 docked are now obliged to be sent home, at a great expense 

 of money and waste of time, others beinsj sent to replace 

 them. This may be avoided in future. Docks made in 

 England may be sent out in pieces of five or six tons wiih 

 the necessary rivets and bolts, and ready to be put together 

 wherever they may be wanted. 



" A caisson capable ol-' dockinc; a first-rate ship will not 

 cost above nineteen or twenty thousand poiuuls, (for mer- 

 ciiantmen and smaller ships, the size and cost will l^e pro- 

 portionably less,) and (judging from the duration of 

 vvrought-iron salt-pans) will last 20 years without repair. 

 When worn out it may be broken up, and will sell for one- 

 third of its original cost. 



" By adapting caissons to the local circumstances, ships 

 of war and merchantmen with all their stores and cargoes 

 on board, can be carried to wliarts and store-houses up 

 rivers where the depth of water is not above one half the 

 ship's draught ; For example, in the river Clyde the ships 

 may be carried to Glasgow, instead of being obliged to un- 

 load twenty miles lower down the river." 



II. Improved System for Towing Ships, Floating Docks 

 or Caissons. 



** This subject, as connected with naval affairs, pos- 

 Besses much importance. 



" It will readilv occur that there are many instances on 

 record where objects of the first magnitude might have been 

 gained by the help of an improved system of towing ves- 

 sels, particularly wiiea entering or leaving harbour. But 

 although the system about to be explained is peruetly 

 ap|)lieable to general purposes, it was chieHy with the view 

 of rendering our floating dock complete in all its appen-' 

 dages, tfiat we were induced to direct our attention to the 

 subject, 



" With respect to the general application of the system 

 of towint', it will occur, that an apparatus of this descrip- 

 tion ought to attend every naval expeuition. It will of 

 course be u.eliil in towing shi|)s into action in light winds, 

 ia briuging olf disabled vessel, and also in propelling fire- 

 B b i ship* 



