5o8 



NA TV RE 



[April 22, 1922 



becomes more marked, and the author is sometimes 

 at pains to show that the doctrine he is discussing has 

 reference purely to formal logic. The subjects dealt 

 with are of the first importance. For example, the 

 relation of logic to mathematics is discussed with 

 very penetrating criticism, and Mr. Johnson finds that 

 he differs from Mr. Russell on the fundamental concept 

 of this relation. The mathematical function is for 

 Mr. Russell a description derivable from the pro- 

 positional function of logic, whereas Mr. Johnson 

 argues that the propositional function of logic is nothing 

 but a particular case of the mathematical. In dis- 

 cussing functional deduction generally Mr. Johnson says 

 " the essential purpose of symbohsm is to economise 

 the exercise of thought : and thus symbolic methods 

 are worse than useless in studying the philosophy of 

 symbohsm or of mathematics in particular." 



There are many new distinctions discovered and 

 new terms proposed. In particular we are to dis- 

 tinguish two direct principles of inference, the ap- 

 phcative and the implicative, each with a counter 

 principle ; we are to add to the distinctions of magni- 

 tudes as extensive and intensive an intermediate form 

 termed distensive ; and, more important still, we are 

 to distinguish between the question of the absolute- 

 ness or relativity of space and time and the question 

 of their substantival or adjectival nature. But perhaps 

 the most astonishing distinction of all (is it a new 

 discovery ?) is that of the syllogism and the antilogism. 

 The antilogism like the syllogism has its four modes 

 A E 1 0, and, in the illustration given, simply by 

 altering the mode we can present the argument for 

 new realism, the argument for Hume's scepticism, 

 or the argument for Kant's formalism. Verily formal 

 logic may be in the way of becoming a formidable 

 weapon in the hands of a philosophical controversialist. 



Terrestrial Magnetism in the Antarctic. 



British (" Terra Nova ") Antarctic Expedition, 1910- 

 1913 : Terrestrial Magnetism. By Dr. C. Chree. 

 Pp. xii + 5484-60 plates. (London: Harrison and 

 Sons, Ltd., 192 1.) 



BOTH of Captain Scott's Antarctic expeditions 

 included observations of the earth's magnetism 

 in their programme of scientific work, and the experi- 

 ence gained in the first was turned to good use in the 

 second. The two magnetic observers were Dr. G. C. 

 Simpson and Mr. C. S. Wright, to whom is due the 

 credit for the fine work done at the base station. A 

 noteworthy improvement was made by Dr. Simpson 

 in the method of time-marking on the magnetograph 

 sheets, which has since been adopted in some regular 

 NO. 2738, VOL. 109] 



magnetic observatories. The magnetographs were in 

 operation for nearly two years (February 191 1 to 

 November 1912) ; at the beginning of the second year 

 Dr. Simpson was recalled to his official duties in India. 

 Besides the continuous record of the three magnetic 

 elements at Cape Evans, a considerable number of 

 absolute measurements were made by the naval 

 officers of the expedition, both in the " field " (prin- 

 cipally at Cape Adare) and at sea. 



The important task of preparing a report describing 

 and discussing all these observations was entrusted, 

 as in the case of the former expedition, to Dr. Chree. 

 This report has just been issued, in the form of a large 

 quarto volume, prepared and published at the cost 

 of the fund raised by public subscription in memory 

 of Captain Scott and his companions. Apart from 

 the observations taken by the naval officers, which 

 were mainly reduced by themselves, not only the 

 discussion but also the reduction of the observations 

 has been executed by or under the supervision of 

 Dr. Chree ; the measurement of the magnetograph 

 curves, the reduction of the measurements, and the 

 discussion of the important but somewhat tedious 

 instrumental questions which arise, involve an amount 

 of labour which can be but little appreciated by those 

 unfamiliar with the subject. Of the 548 pages of 

 letterpress, about one hundred are devoted to the 

 tables, giving hourly values of the three magnetic 

 elements, while about one-quarter of the volume is 

 occupied by a valuable set of plates, mainly reproducing 

 actual magnetograph records, from the Antarctic or 

 elsewhere. 



Following out his characteristic plan. Dr. Chree 

 has kept strictly to the comparison and discussion 

 of facts as facts ; the echoes of theoretical controversy 

 can be at most remotely perceived, and speculations 

 as to the cause of the phenomena reviewed with such 

 painstaking care are expressly deprecated by the 

 author. Whether or not it is best at all times to 

 restrict the discussion within these severe limits of 

 certainty, few can disagree with the adoption of the 

 course in preparing a report of this kind. In the 

 spirit with which he has approached the task Dr. 

 Chree has shown, not only his devotion to his chosen 

 science, but also his personal appreciation of the work 

 done by those who obtained the observations, or made 

 the observations possible, in the inhospitable regions 

 of the Antarctic. 



The general plan of the volume is similar to that 

 of the one dealing with the earlier expedition. The 

 first six chapters describe the reductions which lead 

 to the monthly mean values, non-cyclic changes, 

 diurnal inequalities (with Fourier coefficients), daily 

 range, and daily maxima and minima of the magnetic 



