Jan. 29, 1874J 



NA TURE 



239 



the vessel is moved," Mr. Jordan supposes that this will 

 always be so ; and that the tendency of ocean-water to 

 be left behind is the great source of tides and currents. 

 But if he will try the experiment of continued rotation, 

 especially with a vessel havng not a smooth but an irre- 

 gular interior, he will find that after a time the water 

 rotates as fast as the vessel itself, and partakes of its 

 momentum. Were it otherwise in the case of the Earth, 

 no rock could withstand the abrading power of the mass 

 of water which would be constantly impelled against its 

 eastern face — not only on the surface, as in the case of 

 the trade-wind current, but at its greatest depths. That 

 Ocean-water not changing its place northwards or south- 

 wards, does fully partake of the Earth's motion, and 

 docs not tend to lag behind, is proved by the exceptional 

 cases in which a flow of water moving towards either Pole 

 tends eastwards in virtue of its excess of easterly momen- 

 tum, and in which a flow moving towards the Equator 

 tends V->est7vards in viitue of its dcjicicncy in easterly 

 momentum. The ChaUengcr temperature-sections of the 

 Atlantic show this to be the case with the cold-stratum 

 beneath the Gulf Stream, which comes to the surface 

 along the Atlantic sea-board of the United States ; a 

 similar " cold wall " has been found by our Naval 

 Surveyor, Capt. St. John, to inteivene between the Kuro 

 Siwo (which is the counterpart of the Gulf Stream in the 

 Pacific) and the eastern coast of Japan ; and the recent 

 researches of Dr. Meyer have shown that even in the 

 North Sea alike upward movement of the colder under- 

 stratum is distinctly traceable along the eastern shores of 

 Britain, and still more on the eastern slope of the Dogger 

 Bank. 



It would be quite useless to either follow Mr. Jordan 

 through his detailed application of a theory which is so 

 completely baseless, or to examine into the validity of his 

 criticisms of the views of others. He is obviously a man 

 possessed, like the notorious upholder of the earth's flat- 

 ness, by a " dominant idea " which nothing will dispel ; and 

 all we can do is to warn our readers that his book is 

 good for nothing, except as a warning example of mis- 

 directed ingenuity. 



ANIMAL MECHANICS 



Piiiiciples of Animal lifechanics. By the Rev. .S. 



Haughton, F.R.S. (Longmans, Green and Co.) 

 "T^HIS formidable volume has four languages on the 

 very title-page, and bristles throughout with nume- 

 rical calculations, analytical formula:, and geometrical 

 constructions. When, in addition, we record that it con- 

 tains anatomical details, teleological postulates, hints on 

 the best mode of hanging, &c., it will be obvious that no 

 nnc man can be expected to be able ta pronounce upon 

 its value from more than a few of the possible points of 

 view. 



I We are told in the Preface that the object of the work 



is to show "the mutual advantages obtainable by ana- 

 tomists and geometers from a combination of the sciences 

 wliich they cultivate. Anatomists will gain by the in- 



, creased precision which numerical statements must give 



] to their observations, and geometers will find in anatomy 

 a new field of problems opened out to their investigation." 



' Surely there is nothing new in this statement ! Every 



anatomist worthy of the name strives after the greatest 

 attainable precision in those observations in which it is 

 requisite, and many able mathematicians have treated of 

 anatomical problems. But passing this over, we are 

 obliged to say that Dr. Haughton's mathematics are barely 

 such as are calculated to attract the anatomist. When 

 writing for a class of persons who, at the best, rarely 

 know more than the merest elements of mathematics — 

 surely it would be well to use the sim plest processes which 

 will suffice. This is not Dr. Haughton's method ; he 

 rather acts on the principle of making an investigation as 

 showy as possible by the introduction of an immense 

 quantity of quite superfluous analysis. This is, no doubt, 

 calculated to impress the majority of readers with an idea 

 of the author's profundity ; and, though even very ordi- 

 nary mathematicians will find no reason to share this im- 

 pression, we cannot understand the necessity for putting 

 such a threatening barrier in the way of the poor anato- 

 mist who wishes to understand the reasons here assigned 

 why muscles have the particular forms which it is part of 

 his business to examine, describe, and classify. 



Excellent instances of this peculiarity of the work may 

 be given in great numbers, but one must suffice. Take 

 the investigation in p. 239, which is given to prove that no 

 work is done by a quadrilateral muscle when one of the 

 bones acted on revolves about a certain given point. The 

 result given in the text follows instantly from the most 

 elementary geometry, if a single additional line be inserted 

 in the woodcut ; always, however, providing that the 

 reader is prepared to allow the following postulates, which 

 may, perhaps, not be very readily assented to, but which 

 are as necessary for the elementary geometry as for the 

 pompous analysis. The first is, that when muscular 

 fibres are extended, as much negative work is done by 

 them as there is done of positive work when they con- 

 tract by the same amount ! The second is, that in a plane 

 quadrilateral muscle the fibres run in lines which, if pro- 

 duced, would all meet in the intersection of the lines 

 joining the ends of their places of attachment to the 

 bones, and that they are vniformly distributed radially 

 from this point. Postulates of this kind are, indeed, very 

 common throughout the work. 



The three great features of novelty in the work, so far as 

 we can perceive — in addition to the very numerous, and 

 obviously careful, determinations of the weights, (S:c., of 

 corresponding muscles in various beasts, birds, and fishes 

 — are the Laiv of Fatigue, a grand teleological Postulate^ 

 and the Principle of Least Action. 



These are enunciated as follows, the third as applied 

 to the heart :— 



" When the same muscle (or group of muscles) is kept 

 in constant action until fatigue sets in, the total work 

 done, multiplied by the rate of work, is constant." 



" The Framer of the Universe (Aij^ionpyo's tov Knanov) 

 has constructed all musck-s upon the principle that each 

 shall perform the maximum ot Work possible for it under 

 the given external conditions." 



" The arrangement of the fibres of the heart must be 

 such as to allow each fibre to contract to the fullest extent 

 required by the law of muscular contraction." 



As a simple comment on the first of these, rendered 

 very instructive by the insight it affords us into the 

 general cogency of the author's reasoning, take the fol- 

 lowing ; — 



