SCREW STEAMERS. 



agency of steam, a very important advantage will be gained for 

 the public, and the almost unanimous support and countenance of 

 the commercial community will be secured. 



19. To attain the objects here developed, it will be evidently in- 

 dispensable to remove those impediments, which at once disfigure 

 the appearance and destroy the efficiency of the sailing qualities of 

 the ship, by the enormous and unsightly excrescences projecting 

 from the sides in the shape of paddle-wheels, and the wheel-houses 

 or paddle-boxes, as they are called. These appendages are attended 

 with many evils, the least of which is perh ps the impediment 

 which they present to the progress of the shi^. 



But the form, magnitude, and position of the propelling ma- 

 chinery, 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 

 furnaces, is also an unsightly excrescence, and no inconsiderable 

 obstruction. 



When long ocean- voyages are contemplated, such as those be- 

 tween New York and the ports of England, there is another serious 

 obstacle, which is especially felt in the westward trip, because of 

 the prevalence of adverse winds. When the vessel starts on its 

 long voyage, it is necessarily laden with a large stock of fuel, 

 which is calculated to meet, not merely the average exigencies of 

 the voyage, but the utmost extremity of adverse circumstances of 

 wind and weather to which it can by possibility be exposed. This 

 fuel is gradually consumed upon the voyage ; the vessel is propor- 

 tionally lightened, and its immersion diminished. If its trim be 

 so regulated that the immersion of its wheels at starting be such 

 as to give them complete efficiency, they may, before the end of 

 the voyage, be almost if not altogether raised out of the water. 

 If, on the other hand, the efficiency of propulsion in the latter 

 part of the voyage be aimed at, they must have such a depth at 

 its commencement as to impair in a serious degree their propelling 

 effect, and to rob the vessel of its proper speed. Under such cir- 

 cumstances, there is no expedient left but compromise. The vessel 

 must start with too great and arrive with too little immersion. 

 There is no alternative, save to abandon altogether the form and 

 structure of the present machinery, and to awaken the inventive 

 genius of the age to supply other mechanical expedients, which 

 shall not be obnoxious to these objections. 



In fine, then, we look to the improvement of auxiliary steam 

 power, and the extended use of submerged propellers, as the means 



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