678 SCIENTIFIC PROBLEMS OF THE FUTURE. 



a straw or light floating object lying near its conrse to a far greater 

 extent than would the real fish passing throngh the water at the same 

 speed. Experiments ou this i)oint would be easy, and would be as val- 

 uable and suggestive when api)lied to different materials and surfaces 

 as the former suggested experiments on horsepower. 



Nature seems to abhor generally a really smooth or polished surface 

 for water iiropulsion. Thus, if we put a x)iece of the skin of the sole 

 under the microscope we shall see that it is composed of overlapping 

 layers of scales. On the lower or outer end of each scale we see a 

 number of small projecting horns or points. I can only presume that 

 the i^articles of water in most immediate contact with the fish are 

 passed on from scale to scale like the rain running ofl" a slated roof 

 without pausing to adhere to any individual scale, and that their 

 disengagement without adhesion or friction arising from molecular 

 attractiou is facilitated in some way l)y the projecting rows of points. 

 Further similar and collateral investigations will easily suggest them- 

 selves. But enough, and perhaps more than enough, has been said. 

 I will therefore conclude this discussion by repeating that the question 

 of the reduction of fluid friction is one of primary importance to the 

 whole future of ocean navigation, and that it is high time that the 

 attention of competent marine engineers should be directed to the 

 subject. 



So far I have conftned myself to this question of fluid friction, as a 

 thorough study of its laws constitutes, it is contended, the proper and 

 the only sound and scientific basis for the marine engineering of the 

 future. But we must not stop there. It does not require the trained 

 perception of a naval architect to see that we must go further. I hope 

 that the majority of such skilled specialists, who take a broad view of ^ 

 the present position of their profession, will agree with me that tbe 

 next step after we have eliminated as far as possible, or brought down j 

 to an irreducible minimum, the all-important element of fluid friction, 

 will be to set ourselves to reduce similarly to a minimum the other 

 important retarding element of wave action. This means probably, in 

 the case especially of cargo-carrying steamships, the adoption of a 

 vessel of the American whale-back type, or some suitable modification 

 of it, with a light commodious superstructure for the convenience and 

 comfort of passengers and crew. 



Should we be fairly successful in these two distinct objects, the 

 reduction to a minimum of fluid friction by suitable modifications in 

 the external materials and structure of our ships, and the similar 

 reduction of retarding wave action by the employment of a long, deep, 

 mainly submerged vessel, the ocean steamships of the future may 

 perhai)S run at 40 or even 50 knots an hour without any undue or 

 extraordinary increase in propulsive power. 



It is at present quite impossible to give any estimate of the magni- 

 tude and importance of the issues involved in a successful solution of 



