30 ANNUAL OP SCIENTIFIC DISCOVERY. 



Association had had a great deal to do with the establishment of that 

 principle, which consisted mainly in the particular formation of the water 

 lines of the vessel. The old ships had a round, bluff, duck's-breast bow, 

 with a sloping narrow stern. At length the idea was arrived at of making a 

 boat with a bow, the water lines of which should correspond with the wave 

 of the sea itself, which should gently and gradually divide the particles of 

 water, which would then give a quiet and easy passage to the vessel enter- 

 ing, whether propelled by steam or by sails, without resisting their progress, 

 and heaping a mound of water before the bows, as in the case of the old 

 bluff, round-built vessels. It seemed now to be universally admitted, in 

 Europe and in America, that if a ship-builder wanted to have a very easy 

 and fast-going ship, he must give her bow, not the round convex line 

 formerly adopted, but a fine, long, hollow line, such as the meeting might 

 observe for themselves in all the recently-built vessels. Practical men, 

 when they desired to build a fast ship, saw that they must now no longer 

 use the convex water line, but they must build with a hollow water line 

 at the bow, and in this consisted the great revolution which had taken 

 place during the last twenty years. Whereas formerly the broadest part 

 of the vessel was only a third part from the bow, the broadest part was 

 now nearer to the stern than to the bow in the proportion of two to three, 

 so that the shape of the ship under the water was very nearly reversed. 

 The ship out of the water might remain very nearly the same, but where 

 she cut the water, the lines were as he had described. It was on this 

 principle that American clipper ships and English ships which happened 

 to be very fast were built, and upon which he would say, without fear of 

 contradiction, every vessel, to gain any thing like sixteen miles an hour, 

 must be built. Now, there was, in addition to this, another very import- 

 ant principle which had been discovered. That was the virtue of the 

 length. It used to be a dogma in the time of his pupilage, that no steam- 

 boat could ever, by any possibility, go faster than nine statute miles an hour. 

 He was born and bred in that belief. Nine statute miles an hour was the 

 creed of his instructor in ship-building. At that time they had very short 

 vessels, and they endeavored, by putting enormous power in them, to 

 compel them to go through the water, whether they would or not. He 

 remembered being present at the trial trip of a vessel out of which had 

 been taken fifty-horse power engines, and engines of seventy-horse power 

 substituted. It was a most extraordinary fact, that she only gained some- 

 thing like a quarter of a knot an hour by that enormous addition to her 

 power and fuel, because she had not sufficient length to go by any force at 

 a high speed ; and the more she was driven through the water, the greater 

 was the resistance made by the water which she raised before her. The 

 princ'ple was ascertained, that if you wanted the particles of water to go 

 out of the way of the vessel when going very fast, you must give the 

 particles more time to do so. Now, this might appear a contradiction in 

 terms, but the faster the vessel was to go through the water, the more time 

 must be allowed to the particles of water to give way. It was found that 



