PROSPECTS OP STEAM NAVIGATION. 267 



PKOSPECTS OF STEAM-IAYIGATIOK 



IN navigating the ocean a steam-vessel of side-wheel construction is exposed 

 to many inevitable disadvantages. Scarcely an hour throughout its entire 

 voyage can the impelling power work with full and unimpaired efficacy. The 

 swell of the ocean is incessant, nor does it even cease in the intervals of the 

 abatement of the winds. The principles of this reasoning appear so evident, 

 that it would be a slight upon the understanding to enlarge upon them. It 

 will be easily perceived that the conclusion is inevitable, that when steam- 

 vessels of the present form are applied to ocean-voyages, a large proportion of 

 the moving power must be lost. 



Among persons who have not devoted much time to the investigation of this 

 question, it is a favorite argument to urge the immense speed obtained by the 

 steam-vessels working with these propelling-wheels upon the extensive inland 

 waters of this great continent. But there is no analogy whatever between the 

 cases. Let it be remembered that the condition upon which this extraordinary * 

 efficiency depends can never be fulfilled in sea-going steamers. That efficien- 

 cy depends essentially on the smooth and unruffled surface of the water on 

 which the vessel moves, and the power of the vessel to maintain itself in a 

 constantly perpendicular position. 



When these observations are duly considered, it will be readily admitted that 

 the attainment of perfect efficiency in ocean-steamers with the present propel- 

 ling apparatus is hopeless. 



But the form, magnitude, and position, of the propelling machinery, is far 

 from being the only obstacle to the full success of the present steam-vessels 

 when directed to the general purposes of commerce. The engines themselves, 

 and the boilers, from which the moving power proceeds, and the fuel by which 

 they are worked, occupy the very centre of the vessel, and engross the most 

 valuable part of the tonnage. The chimney, which gives efficacy to ^the fur- 

 naces, is also an unsightly excrescence, and no inconsiderable obstruction. 



If the present form and structure of steam-vessels be obnoxious to these many 

 serious objections when considered with reference to the purposes of general 



