VOL. XXXI.] PHILOSOPHICAL TRANSACTIONS. 547 



able to resist the force of the sea. Besides, the vessel must be low- built, and 

 uncovered, and so more exposed to the beating in of the waves, by reason 

 they are obliged to proportion the length of the oar to the strength and size of 

 the men. And though the crew should be under some cover, as they are in a 

 galeass ; an opening must be left for the oars to play, by which the waves may 

 beat in. 



Both these inconveniencies are avoided by the perpendicular oars ; because the 

 addition of force may be obtained, by only applying more hands to the machine; 

 so that with two or three machines on a side, there will be more or less force, 

 in proportion to the number of men employed, and the length of the vessel 

 may be lessened at discretion. And to guard against the sea, another deck 

 may be made, shut close on all sides, even where the axis of the machine 

 passes through. 



The chief objections against this invention, seem to me sufficiently obviated 

 by M. Du Quet's Memoir : but though the whole of what is objected should 

 indeed prove, that a vessel made for sailing, as the common galley, would be 

 so incumbered with the machines, as to make the use of sails impracticable ; 

 yet if it still holds true, that she will move faster, as appears both by reason 

 and fact, it must be allowed, that a vessel might be so commodiously con- 

 structed to carry these machines, as to go as fast as a galley in a calm, and 

 better endure the weather when under sail. 



Such a vessel would have several advantages above a galley, both in sailing, 

 and in fight; not to mention the conveniencies of lodging the crew. She may 

 put off to sea any where, and so avoid the dangers attending the coast-winds, 

 which galleys find to be a-head as soon as they have doubled certain capes. 

 With respect to fight, she may mount cannon fore and aft, and on each side; 

 and even mortar-pieces. In time of battle, she would take and maintain her 

 post without assistance, either at the head, or the rear of the enemy's line, and 

 there make use of her bombs : besides the advantages of towing off other 

 vessels from their danger in a calm, and of boarding, or making off from the 

 enemy. And this holds in ships of any rate ; provided the length of the oars, 

 the breadth of the pallets, and the strength of the handspikes be proportion- 

 able. And the moving force will always be in proportion to the strength and 

 number of the men employed, and not to the number of machines, as in the 

 common oars, which too are impracticable in ships above the fourth rate, by 

 reason of their great length, which will be disproportionate to the ordinary 

 bulk of a man. 



By this means the crew will be free from the fatigue of towing, and the 

 vessel will move incomparably faster than if it was towed; because the chaloups 



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