NA TURE 



169 



THURSDAY, JUNE 21, 1883 



"THE NEW PRINCIPLES OF NATURAL 

 PHILOSOPHY" 

 The New Principles of Natural Philosophy. By W. L. 

 Jordan, F.R.G.S. (London : David Bogue, 1883.) 



IN the Preface to this large and handsome volume we 

 are told that " The Third Chapter, .... and more 

 especially the first nine Parts of that chapter, are the 

 justification for the title of this work." This sort of 

 intimation is unusual, but timely and useful, as it enables 

 us to go at once to the root of the m tter, and to study 

 " The New Principles " in themselves, before we com- 

 mence the perusal of the formidable array of arguments, 

 examples, and demonstrations which constitutes the bulk 

 of the volume. The chapter referred to is formally dedi- 

 cated to the memory of Descartes and Newton, "as it 

 shows the connexion between the Cartesian Vortices and 

 the Newtonian Laws (sic) of Gravitation." 



The peculiar employment of the definite article in the 

 title of the work at once arrests the attention of the 

 reader. New principles in Natural Philosophy, some of 

 them coextensive with our whole knowledge of the sub- 

 ject, have been happily introduced even in comparatively 

 recent times. The Conservation of Energy, and Carnot's 

 principle of Reversibility, are notable examples. But 

 such principles consist of generalisations of our former 

 knowledge, or additions to it, and are in no way sub- 

 versive of the fundamental Laws of Motion (or Axiomata) 

 as they were systematized by Ne,wton. 



" The New Principles" however, are not of this class. 

 They involve, essentially, somewhat extensive modifica- 

 tions of Newton's Laws, and the consequences we have 

 been accustomed to draw from them. So far as we 

 understand our author, he seems to allow that Newton 

 and his followers have correctly deduced the consequences 

 which follow from the assumption of the Laws of Motion 

 and the principle of Gravitation. But the accordance of 

 the results, so deduced, with observed facts is a remark- 

 able coincidence only : — arising from a compensation of 

 errors, where incorrect ideas as to the laws of motion are 

 rectified (so far as results go) by an omission of some of 

 the more powerful causes which are really at work. Thus 

 the true statement of the First Law of Motion is that a 

 body gradually comes to rest when the motive force 

 ceases to act ; while " Gravitation is merely the act by 

 which the material universe resists, or endeavours to 

 resist, the motive forces acting on it. And, therefore, if 

 matter were not inherently inert there would be no such 

 force as gravitation" (pp. 306-7). It follows, of course, 

 from the new principles that some cause, hitherto not 

 taken into account, is required to explain the persistence 

 of the earth's rotation and of its revolution in its orbit. 

 Of course this cause must suffice for the same results in 

 the case of each planet ; and it must also maintain the 

 rotation of the sun itself. This is found in "Astral 

 Gravitation." How so immensely effective a factor in 

 all the physics of the universe has hitherto been entirely 

 overlooked it is not for us to say. We content ourselves 

 with a humble effort to disseminate " The New Principle " 

 as widely as our circulation permits, if not as widely as 

 Vol. xxviii. — No. 71 a 



its intrinsic importance demands. We would merely 

 premise that our author distinctly points out that, after 

 all, Astrology was wrong only because its votaries recog- 

 nised "personal influences," whatever these may be, and 

 not the gigantic physical forces exerted on us and our 

 surroundings by the stars : — 



" Reason also tells us that whatever the apparent mag- 

 nitude of any given star may be, the greater its actual 

 distance from the earth, the greater is the force which it 

 exerts on the earth ; and therefore the argument that the 

 stars are too far off for their power to be felt, even if it 

 merit the designation of common sense, is absolutely 

 refuted by reason. 



" It is not possible in the present state of knowledge to 

 make a reliable (sic) estimate regarding the actual force 

 exerted by any star. 



" Sir William Herschel assures us that the star Capella 

 has an apparent diameter of 2A seconds. Its distance as 

 indicated by parallax is 4$ million times greater than that 

 of the sun. 



"Accepting these measurements as accurate, and sup- 

 posing Capella to be of the same density as the sun, the 

 force of gravitation which it exerts on the earth is equal 

 to one hundredth part of that exerted by the sun. If, 

 however, any star of equal apparent magnitude whose 

 distance is so great as not to be indicated by parallax, 

 be as many times more distant than Capella as Cape. la 

 is more distant than the sun, then the force exerted on 

 the earth by that star, according to the foregoing mea- 

 surements, would be 45,000 times greater than that 

 exerted by the sun.'' 



" It is argued that none of the stars can have so great 

 an apparent diameter as asserted by Herschel, because 

 Huygens has estimated that the sun gives us 2,000 million 

 times more light than we receive from Capella, and this, 

 supposing the two bodies to be of equal brilliancy, would 

 make Capella much smaller than estimated by Herschel. 

 For a star of the apparent size estimated in this manner 

 to exert as much force on the earth as is exerted by the 

 sun, its distance would have to be 20 million times 

 greater than the actual distance of Capella as indicated 

 by parallax. 



" Neither of these estimates can be regarded as better 

 than vague guesses at the real size of the stars ; but 

 when, on the one hand, we consider the evidence which 

 seems to necessitate the existence of some great con- 

 trolling force of gravitation far distant from our solar 

 system, and, on the other hand, the fact that the laws of 

 optics and of gravitation make it quite possible that some 

 one of the visible stars may actually be exerting a force 

 far more than sufficient for the purpose indicated, reason 

 is almost forced to the conviction that stars of the 

 requisite magnitude do exist in the heavens." 



How this, and " The " other " New Principles " account 

 for Trade Winds, Ocean Circulation, Comets, The 

 Zodiacal Light, The Secular Acceleration of the Moon's 

 Motion, &c, must be learned from an attentive perusal 

 of the work itself. The careful reader will have an ample 

 and varied treat ; for mixed with these weighty contribu- 

 tions to science, we have full details of a more strictly 

 human character, such as " Replies to Critics," " Remarks 

 on the Admiralty Current Charts," " A Public Challenge 

 to the Council of the Royal Society," &c. We quote 

 (from p. 365) a few words to show how very serious indeed 

 is the state of matters with our great scientific Society. 



" I last year publicly challenged the leaders of the 

 scientific world in London to open discussion ; and, in 

 the second of the public lectures I then gave, I made it 

 clear that the question at issue had ceased to be merely a 



1 



