Queries on Steam-Boats. 201 



furnaces, is the adoption of two boilers in place of one, still used 

 in many steam-vessels, and situated athwart the vessel ? 



V. Two steam-engines have been and still are nsed in some 

 steam-vessels. What advantage have they over one of double 

 the power ? 



VI. Steam-engines have been constructed with the beam 

 working above, to t'ne rejection of tlie beams below. Does not 

 tbis lessen the stability of tlie vessel, by removing the centre of 

 gravity higher, and how far is it an improvement ? 



VII. What is the best situation of the paddle-wheels; — at the 

 extreme breadth of beam, or where ? The proper velocity for the 

 floats or paddles ? Their area with reference to the section of 

 the immersed part of the vessel ? Their properest form ? and 

 their depth with regard to their width ? The angle l)est adapted 

 to the velocity of the wheel and vessel ; so that no impediment 

 shall arise from the improper displacement of the fluid ? and 

 lastly, the number of floats ? 



VIII. The momentum acquired by a steam-vessel in motion, 

 after a short time, is analogous to that of a fly-wheel ; — ought 

 the addition of this fly, adopted in many steam-vessels, to be 

 considered superfluous ? 



IX. One of the most insuperable objections to steam-vessels, 

 in long voyages across the ocean, must lie in the vast consump- 

 tion of fuel and bulk occupied by it. How far can this be over- 

 come, witiiout the substitution of some new power ? the at- 

 tainment of which is the grandest desideratum in mechanical 

 science. 



X. In the event of steam-vessels being employed in war ; 

 — what is the best mode of rendering the paddles shot proof? 

 Would the middle of the vessel render that protection ? as with- 

 out this a vessel disabled under such circumstances, must neces- 

 sarily be at the mercy of her enemy. 



XI Presuming the above-mentioned difficulty as got over, 

 might not thcv choose their position ? and their distance ? By 

 presenting neither masts nor yards, they might crijjple their enc- 

 mv without suffering in turn ; their movements would continue 

 all along optional; they might escape from their enemy by 

 steering against tiie wind. A calm to them is a fair wind. 



XII. Bv presenting no top weiglit of masts or yards, which 

 are merely tem|)orarv, the cnutinual tendency to destroy the 

 hull would be avoided ; and all the advantages of trussing on 

 Mr. Se))pings's principle could be included, which would at once 

 add stability and strength, rendering her free from the uncertainty 

 of leeway and heave of the sea, and render the reckoning more 

 certain. By being flat-bottomed, and of course drawing little 

 water, the advantages of crossing shallows, and entering harbou»s 



at 



