SCIENTIFIC PROBLEMS OF THE FUTURE. 673 



I believe, tlieu, that a practical revolutiou iu niariue navigation is 

 possible, if we ouly will set ourselves, with the wise man of old, to 

 study the way of the fish in the sea. With all possible respect to the 

 numerous professors and students and innumerable practical men 

 engaged in marine engineering and marine locomotion generally, I 

 would venture to challenge them to consider carefully whether they 

 are not all, in the main, on the wrong tack. They are one and all, so 

 far as appears by a study of all tlie publications, as the Engineer, 

 Engineering, the Scientific American, etc., setting themselves steadily 

 to gain increased speed by a continual development of the locomotive 

 power. Successive improvements in engines, boilers, screws, economy 

 of fuel, and so on, are all very desirable in their way no doubt. But 

 these things seem to me unduly to monopolize attention to the exclusion 

 of the one vital problem which appears to contain the key to the 

 whole question — namely', the diminishing of fluid resistance. At 

 present, as w^e increase the jiropulsive power continually, we are con- 

 tinually piling up extra resistance to meet and swallow it up. I repeat, 

 that any great further progress iu ocean navigation is to be sought 

 and obtained by a careful and scientific study of the way of the fish 

 in the sea. 



The subject of fluid resistance, as the leading and governing fiictor 

 in all water iiropulsion, may probably be novel to most readers, since, 

 if the question has ever been publicly discussed at all, it has been in 

 naval or other special publications. It seems necessary, therefore, to 

 rehearse the matter briefly from the beginning. 



Years ago I was informed by Mr. Brenuan, the inventor of the well- 

 known torpedo, that he applied no less than 100 horsepower to drive 

 his torpedo at its then speed, say probably at about 24 knots an hour, 

 or 25 at the outside. Xow this torpedo is well designed to the eye and 

 was adapted, to the best of the judgment of a clever inventor, for fluid 

 propulsion. It is, or then was, no larger tlian a good-sized porpoise, or, 

 say, a very moderate-sized shark. But anyone who on an ocean voyage 

 has watched a school of porpoises playing round an Atlantic liner will 

 agree with me that they experience no difficulty whatever in swimming 

 at such a pace as this and in keeping it up apparently for an Indefinite 

 length of time. 



If now we turn to any professor of physiology and ask him what 

 power a porpoise, or a small shark of about the same size as the torpedo, 

 can reasonably be expected to develop and maintain, he will probably 

 tell us 1 horsepower, or, if he were disposed to be liberal, he might per- 

 haps say 2. Anyway, whatever be the exact expenditure of force in 

 the loropulsiou of the porpoise, for which I have no data and do not 

 stop to argue, it is clear that if it were to develop anything in the 

 remotest degree approaching to tlie power required to drive the torj^edo 

 at the same speed it would quickly be reduced to impotence. It would 

 rapidly burn wp and consume the tissues of its body in such an immense 

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