192 Scientific Intelligence. 



If Professor Newcomb completes the series it will be a worthy 

 monument both to himself and to American Astronomy and will 

 leave little for other writers to do until the accumulation of new 

 material calls for a new harvest, in the same way that the present 

 work is made necessary by the advance of knowledge since the 

 writings of Bessel, Chauvunt and Oppolzer. 



The most urgent want which the present volume supplies is 

 that of improved methods for deriving and reducing the posi- 

 tions and proper motions of the fixed stars made necessary by 

 the period of 150 years through which these positions now 

 have to be reduced. In this and all parts the book is full of 

 new and most valuable material, of which may be mentioned the 

 appendix of 26 tables, most of which can be found in no other 

 text-book, and a chapter on observatories and star catalogues. 



Moulton's Introduction to Astronomy has the same justifica- 

 tion as Newcomb's volume. It is intended for the student of 

 descriptive Astronomy as a part of general culture, and gives 

 access to the stores of information which have accumulated since 

 Young's unequaled text-books were published, accumulations 

 which frequent revisions of Young's series have not been wholly 

 adequate to keep pace with. 



The amount of new material is made evident at a glance by 

 the new cuts which meet the eye wherever the book is opened, 

 such as' Chandler's diagram of the variations of the pole, Todd's 

 chart of paths of total eclipses up to 1973, Maunder's figure of 

 the dimensions and distribution of sun spots for 25 years, a 

 spectroheliograph of the sun by Hale, etc. 



Both in plan and arrangement the book differs considerably 

 from the conventional form, the design being to use something 

 of the laboratory method throughout, connecting theory as closely 

 as possible with practice and familiarizing the student with the 

 lines of thought and chains of reasoning by which the great 

 theories of the noblest of the sciences have been developed. 



It is too much to expect the felicity of statement, the perfec- 

 tion of clearness and conciseness which is found in Young's writ- 

 ings. By comparison the writer seems somewhat prolix and 

 lacking in perspicuity. 



Wilson's Laboratory Astronomy is an excellent book to use 

 with the preceding in a course where time permits. It presents 

 a large number of valuable practical exercises for the average 

 student, carefully worked out and requiring such apparatus, 

 largely of the author's own devising, as can be provided in quan- 

 tities at small cost, so that a large class can be set to work 

 together on the same exercise (e. g. mapping the sun's diurnal 

 motion), under the supervision of an instructor in an ordinary 

 recitation room and from data collected by themselves, w. b. 



2. The Publications of the Royal Society of London. — A 

 circular recently issued by the Royal Society calls attention to 

 the present method of publishing the Proceedings in two series, 

 viz., A, containing mathematical and physical papers, and B, 



