29G Scientific Intelligence. 



4. Celestial Ejectanienta ; by Henry Wilde, D.Sc, D.C.L., 

 F.R.S. Pp. 34 with 4 plates. (Tlie first Halley Lecture at the 

 University of Oxford.) — Tlie lecture consists mainly of a number 

 of novel propositions, for the most part stated without adducing 

 proofs other than references to lectures or pamphlets of the 

 author bearing on them. Most noticeable of these are the fol- 

 lowing : 



Simplification of the theory advanced by Halley that terrestrial 

 magnetism is due to rotation of the eartli's interior (presumably 

 plastic) relative to the surface, with a differential (synodic?) 

 period of 960 years (Halley, 700 years). 



That pei'iodic comets are planetary "ejectamenta " (i. e. vol- 

 canic products of the plastic period). The "Capture Theory" is 

 ignored, and the reality of hyperbolic orbits denied. 



That the "red spot" of Jupiter is a volcano, whose "ejecta- 

 menta " produce the Jovian belts in the form of fine dust like that 

 ejected by Krakatoa. 



That Bode's Law and a kindred but more accurate one, not 

 here stated, discovered by the author and based on Mercury's 

 heliocentric distance as the unit, are examples of a "law of binary 

 progression " to which the series of atomic weights also con- 

 forms. The author asserts that this " law of binary progression " 

 is one of the fundamental laws of nature, and that it admits of 

 only a teleological explanation, and is an evidence stronger than 

 any other known to science of a causal intelligence guiding the 

 universe. 



The deviation of Neptune from the place requii-ed by Bode's 

 Law is explained as due to its perturbations by the inner planets, 

 which perturbations, it is asserted, are cumulative rather than com- 

 pensating, and will, therefore, eventually precipitate the planet 

 upon Uranus. This, it is needless to point out, destroys the 

 gravitational stability of the solar system and charges Laplace 

 and Lagrange with folly. We agree with the lecturer that " it 

 is not a little remarkable that the effect . . . never presented 

 itself to writers on celestial mechanics who have elaborated the 

 doctrine of the absolute stability of the solar system." w. B. 



5. Elementary Dynamics for Students of Engineering; by 

 Ebvin S. Ferry, Professor of Physics in Purdue University. 

 Pp. 182. New York, 1910 (The Macmillan Company). — An 

 excellent text-book for all college students preparatory to Physics 

 as well as for those in Engineering, whether in connection with 

 the Calculus or not. The methods are rigid without unnecessary 

 refinement, the applications are numerous, fresh and pertinent, 

 and the underlying principles of the science are presented dis- 

 tinctly by themselves and in a manner to show that they are not, 

 as they are often made to appear to beginners, abstractions but 

 generalizations from experience. w. b. 



