EXPLANATION OF THE PLATES. 483 



packet for the Ionian Islands ; all which are built on the same mode of security as 

 the Medea, and have proved to be excellent sea boats, possessing speed, ease, and 

 comfort combined with superior strength of fabric. 



PLATES CIV. TO CVII. 



CONSTRUCTION OF THE NILE STEAM SHIP, BUILT FOR THE 

 BASHAW OF EGYPT. 



That steam vessels will become of more and more importance, as well in a 

 commercial point of view as in warfare, is a point now generally admitted ; and 

 though they may never entirely supersede the vessel impelled with sails, it is likely 

 they will ultimately be employed in all services for which sailing vessels are now 

 used except that of the service for which ships of the line are employed. In 

 carrying on experiments for the general improvement of steam navigation, there 

 must necessarily be failures ; but the advantages and particular interest the intro- 

 duction of an extensive steam navigation involves, must ultimately engage the 

 energies of every nation at all interested in maritime pursuits, and desirous of the 

 benefits that an extensive application offers. 



The use that these vessels are found to be in towing ships in and out of harbours, 

 and carrying mails, is now evident ; and the advantages proposed by them in 

 warfare are too great to suffer the neglect of any experiment that may bear any 

 evidence of improvement. With a proper rig, they may be rendered effective for 

 almost every purpose for which sailing vessels are employed ; while their dis- 

 advantages on comparison are small. The liability of their machinery to be 

 destroyed by shot, and the space and weight of machinery required for impelling 

 the vessel, are the greatest objections that can be urged against them : and may 

 be particular objects for the attention of engineers. 



In the construction of the Nile these were subjects particularly attended to, 

 without speculating beyond what was warranted by experiment : to reduce the 

 consumption of fuel by her engines, bad conductors of heat were placed over her 

 boilers, &c., such as felt and cement ; and from their construction and position, a 

 greater space than common was obtained for the coals. To ensure, as far as 

 possible, the protection of the engines in the event of her being engaged in warfare, 



