866 EEPORT — 1893. 



on the surface and diving telow. IJis speed is therefore nearly double the short 

 and five times the long distance speed of unaided man in water. As regards le-r- 

 maining under -water, fishes properly so called have unlimited powers, and even 

 aquatic mammals, such as whales, can remain under for H hour. 



Using only his own strength, but assisting himself with mechanical devices^ 

 man has been able to increase considerably his speed as a swimming animal. Mr.. 

 John McCall, of "Walthamstow, informs me that in 18GS he constructed and re- 

 peatedly used an apparatus which acted like the tail of a fish. It consisted of a. 

 piece of whalebone, having a broad yet thin and elastic blade, tapering into a 

 shank hke the end of an oar. The blade was 15 inches wide and 4 feet long, 

 including the shank. To the end of the latter a horizontal cross-bar 13 inches 

 long was fitted, and leather pockets were provided at the ends for the feet. By 

 swimming on his back and striking out alternately with his legs, he was able, with 

 the assistance of this apparatus, to keep up with a sea-boat pulled by two men 

 at about 4 miles per hour. 



By means of boats, which he propels by oars or sculls, and notwithstanding^ 

 the increased weight, and therefore displacement, involved by them, man has been 

 able to increase his speed on the surface of the water to a maximum of about 

 12 miles per hour for about 4 miles distance, under favourable circumstances. 

 So, by supplementing his bodily powers by means of mechanical aids, such as the 

 diving-bell and the diving-helmet, dress, and air-pump, or by the portable self- 

 acting apparatus used with such good efiect in the construction of the Severn 

 Tunnel, man has been able to approach very nearly to the natural diving powers of, 

 at all events, aquatic mammals, except that he cannot move about in subaqueous 

 regions with anything approaching their ease and celerity. 



Invariably on water, as almost invariably on land, man is quite unable tO' 

 compete in power of locomotion with other specially adapted animals, whether or 

 not he avails himself of mechanical aids, so long as his own bodily strength is the- 

 only motive-power he employs. He has gradually come to recognise this fact, and 

 to see that he must use his inventive faculties and find new and powerful motors- 

 external to himself if he would really claim to dominate the great waters of the 

 earth. 



The fastest mechanism of any size, animal or man-made, which, as far as I 

 know, has ever cut its way through the waters for any considerable distance is the 

 torpedo-boat ' Ariete,' made by Messrs. Thornycroft & Son, of London, in 1887. 

 It has a displacement or total weight of about 110 tons, and machinery capable of 

 exerting 1,290 effective horse-power, or 11'7 horse-power per ton of weight or dis- 

 placement ; or, to put it in another form, an effective horse-power is by it obtained 

 from a weight of 191 lb., which includes vessel, machinery, fuel, stores, and atten- 

 dants. The speed accomplished at the trials of this little craft, being the average 

 of six one-mile tests, was 26-18 knots, or 30-16 miles per hour.^ As might be- 

 expected, it resembles a fish, in that its interior is almost exclusively devoted to the 

 machinery and accessories necessary for propulsion. During the trials the water, 

 fuel, stores, and other ponderable substances carried amounted to 17-35 tons. Tw» 

 similar boats were able to make the voyage to South America by themselves, 

 though at much slower speed and replenishing their fuel on the way. No fish or 

 swimming bird can match this performance. And inasmuch as 191 lb. of dead 

 weio-ht produced 1 horse-power, as compared with from 150 to 250 lb. in certain 

 flying birds, it would seem that with suitable adaptations the ' Ariete ' might even 

 have been made to navigate the air instead of the water.- But I will revert to 

 this subject later on. 



"Where safety in any weather, and passenger- and cargo-carrying powers are 

 aimed at, as well as, or prior to, the utmost attainable speed — and these must ever 



' Enf/ineeri/iff, July 15, 1887. 



'^ M. Normand, of Havre, is building for the French Government two torpedo- 

 boats, each having a displacement of 125 tons and 2,717 effective horse-power, or 

 21-7 horse-power per ton of displacement. This is equivalent to 1 hcrse-power per 

 103 lb., and is still within the limits of weight permissible for aerial flight (see 

 Times, June 19, 1893). 



