iOO 



NA TURE 



[September 21, 1893 



I am further informed by Mr. Nelson, of Redcar, a naturalist 

 who has made the experiment, that it is impossible for an ordi- 

 nary sea-boat rowed by two men, and going at five miles per 

 hour, to overtake the aquatic bird called the Great Northern 

 Diver, when endeavouring to make his escape by alternately 

 swimming on the surface and diving below. His speed is there- 

 fore nearly double the short and five times the long distance 

 speed of unaided man in water. As regards remaining under 

 water, fishes properly so-called have unlimited powers, and 

 even aquatic mammals, such as whales, can remain under for 

 \\ hours. 



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, in- 

 forms me that in 1868 he constructed and repeatedly 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 like' 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 leg?, 

 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 displace- 

 ment, involved by iheui, man has been able to increase his speed 

 01; the surface of the water to a maximum of about 12 miles 

 per hour for about 4 miles distance, under favourable circum- 

 stances. 'So, by su[>plementing hi.- bodily powers by means of 

 mechanical aids, such as the diving-bell and Lite diving-helmet, 

 dress, and air-pump, or by the portable self-acting apparatus 

 used with such good effect in the construction of the Severn 

 tunnel, man has been able to approach very nearly to the natural 

 diving powers of, at all event--', aquatic mammals, except that he 

 cannot move about in subaqueous regions with anything 

 approaching their ease and celerily. 



Invariably on water, as almost invariably on land, man is 

 quite unable to compete in power of loconi )iion 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 this inventive faculties and 

 find new and powerful motors external 10 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, Ariele, made 

 by Messrs. Thornycroft and Son, of London, in 1887. It has a 

 displacement or total weight of about no tons, and machinery 

 capable of exerting 1290 effective horse-power, or If7 horse- 

 power per ton of weight or displacement ; or, to put it in 

 another form, an effective hor-epower is by it obtained from a 

 weight of 191 lbs., which includes vessel, machinery, fuel, 

 stores, and attendants, 'i'he speed accomplished at the trials 

 of this little craft, being the average of six one-mile tests, was 

 26'i8 knots, or 30'l6 miles per hour {Engineering, July 15, 

 18S7). As might be expected, it resembles a fish, in that its 

 inferior 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. Two similar boats were able to make 

 the voyage to South America by themselves, though at much 

 lower speed and replenishing their fuel on the way. No fish 

 or swimming bird can match this performance. And inasmuch 

 as 191 lbs. of dead weight produced I horse-power, as compared 

 with from 150 to 2Soll)s. in certain frying 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 

 attamable speed — and these must ever be the leading features of 

 ocean-transit steamers if they are to attain commercial success — 

 there I must refer you to those magnificent examples of naval 



M. Normand, of Havre, is building for tfie French Government two 

 torpedo-boats, each liaving a disptacement of 125 tons and 2717 effective 

 hor,e-power, or 21 "7 horse-power per t-jn of displacement. This is equiva- 

 lent to T horse-power per 103 lbs , and is stilt within the limits of weight 

 per.nissible for aerial flight. (See Times, June 19, 1893 ) 



architecture which are more or less familiar to you all, and off 

 which we, as a maritime nation, are so justly proud. If, for 

 example, we turn our attention for a moment to the new Cunard 

 liners, the Campania and Liicania, having each a weight or 

 displacement of lS,ooo tons and 24,000 effective horse-power, 

 or 1-33 horse-power per ton of displacement, we shall find that, 

 with the commercial advantages alluded to, they obtain a maxi- 

 mum speed of 22 '5 knots, or about 26 miles per hour. 



If, instead of 133 effeclive horse-power per ton of displace- 

 ment, they were provided with eight times that amount, or io'64 

 horse-power per ton, thereby sacrificing passenger and carga 

 accommodation and making them nearly as full of propelling 

 machinery as the Ariete torpedo-lioat, and if it were then 

 found possible to apply this enormous power effectively, then 

 there is every reason to believe they would accomplish for 

 short distances double the speed, or, say, 45 knots, or about 

 52 statute miles per hour. 



By inventing and utilising mechanical contrivances entirely 

 independent of his own bodily strength, man can now pass over 

 the surface of the waters at the rate of over 500 knots per day, 

 and at the same time retain the comforts and conveniences of 

 life as though he were on .shore. He has in this way beaten 

 the natural and specially fitted denizens of the deep in their own 

 element, as regards speed and continuity of effort. But he is 

 still behind them as to safety. We do not find that fishes or 

 aquatic mammals often perish in numbers, as man does, by col- 

 lisions in fogs, or by being cast on lee shores and rocks by stress 

 of weather. Shall we ever arrive at the point of making ocean 

 travelling absolutely safe? The Cunard Company is able to 

 boast that from its commencement, fifty-three years ago, it has 

 never lost a passenger's life or a letter, a statement which gives 

 ground for hope that almost absolute safety is attainable. But, 

 on the other hand, other owners of almost equal repute (not 

 excluding the British Admiralty) are ever and anon losing 

 magnificent vessels on rocks, in collisions, by fire, and even 

 by stress of weather, in a way which makes us doubt whether it 

 is possible for Britannia or any one else really to "rule the 

 waves." 



In one way the chances of serious disaster have been of late 

 largely diminished, and here, again, Nature has been our 

 teacher. The bodies of all animals except the very lowest are 

 symmetrically formed on either side of a central longitudinal 

 plane. Each important limb is in duplicate, and if one side is 

 wounded the other can still act. We have at last found out the 

 enormous advantage and increased safety of having the whole of 

 our ship-propelling machinery in duplicate, and our ships made 

 almost unsinkable by one longitudinal and numerous transverse 

 bulkheads. 



Locomotion in Air. — I now come to consider what is the 

 position of man as regards locomotion in and through the 

 great atmospheric envelope which surrounrls the earth, in 

 comparison with animals specially fitted by Nature for sucb 

 work. 



Nature seems never to bestow all her gifts on one individual 

 or class of animals, and she never leaves any entirely destitute. 

 For instance, the serpent, having no limbs whatever, would 

 seem at first sight to be terribly handi.apped ; yet, in the lan- 

 guage of the late Prof Owen, "it can out-climb the monkey, 

 out-swim the fish, out-leap the jerboa, and, suddenly loosing 

 the close coils of its crouching spiral, it can spring in the air 

 and seize the bird on the wing." (Pettigrew on " Animal Loce- 

 motion"). Here we have the spiral spring in nature before it 

 was devised by man. 



Flying animals seem to conform remarkably to this law. 

 Thus we have birds like the penguin, which clive and swim 

 but cannot fly; others, like the gannet, which dive, swim, ffj, 

 and walk ; others, like the ostrich, which run, but can neither 

 fly nor swim ; and numberless kinds which can fly well, but have 

 only slight pedestrian powers. 



Man, unaided by mechanism, can, as we have seen, walk, ran, 

 swim, dive, and jump, and perform many remarkable feats; 

 but for flying in the air he is absolutely unfitted. All his at- 

 tempts (and there have been many) have up to the present 

 been unsuccessful, whether or not he has availed himself of 

 mechanical aids to his own bodily powers. It is said that a 

 certain man fitted himself with apparatus in the time of James 'VL 

 of Scotland, and actually precipitated himself from the cliff 

 below Stirling Castle, in sight of tlie king and his courtiers ; bat 

 the apparatus collapsed, and he broke his leg, and that was the 

 end of the experiment. 



NO. 1247, VOL. 48] 



