September 1, 1911] 



SCIENCE 



275 



considerable distance inland on the sea-breezes 

 and return with the opposite upper current 

 to the coast within a few hours. For long 

 balloon voyages, either trans-continental or 

 trans-Atlantic, the charts are invaluable, 

 showing, as they do, the level which the bal- 

 loon should seek in order to obtain the benefit 

 of the most favorable winds in respect to both 

 direction and velocity, while other tables indi- 

 cate the effects upon the passengers and upon 

 the gas and motors. 



The author does not mean to intimate that 

 it is his belief that such balloon voyages will 

 ever be of utilitarian value, but it does seem 

 to him probable that the voyages would bring 

 valuable data to the science of meteorology. 



The reviewer would bespeak for Eotch and 

 Palmer's method the most careful considera- 

 tion of those engaged in this research work. 

 There is a danger ahead. It is that in the 

 strong and justifiable desire to be original the 

 workers may follow diverse methods, making 

 comparison and coordination of results ex- 

 tremely difiicult, if not impossible, and thus 

 labor may be wasted. 



This is the day of " team-work," and only 

 by such work can the aerial ocean be charted. 



James Means 



Principles of Physics. By W. F. Magie, of 



Princeton University. New York, The 



Century Co. 1911. 



Within the past four months as many new 

 college text-books in physics have appeared 

 as in the preceding four years. New books by 

 Carhart, whose earlier texts have had such 

 wide success, by Magie of Princeton, Kim- 

 ball of Amherst, Eeed and Guthe of Michi- 

 gan, and Hurst and Lattey of Oxford, Eng., 

 added to the several good books already 

 available, give college instructors a much 

 wider range of choice for a suitable text for 

 class use than they have had for many years. 



Perhaps the most unique and original of 

 the new offerings is that by Professor Magie, 

 of Princeton University. Doubtless many 

 teachers have felt that our common texts 

 make too scant use of the historical develop- 

 m.ent of physics in their presentation of its 



principles. The connection of related topics is 

 often best brought out by showing how the em- 

 phasis of one in the scientific thought of a cer- 

 tain period, has led to discoveries in the other 

 field. After reading such a book as Mach's 

 " Mechanics " I have often longed for a text in 

 general physics enriched with more of the his- 

 toric evolution and the philosophy of the sub- 

 ject. But perhaps few of us would go as far 

 as the author of this book does when he takes 

 as a general principle " the progress of discov- 

 ery has been along the line of least intellectual 

 resistance and it is probable that what was 

 easiest to discover once will now be the easiest 

 to understand." This seems to assume that 

 the attitude of mind of the pioneer in discov- 

 ery is much like that of the student seeking 

 to grasp the principles of a new science. But 

 the one has the knowledge of what has been 

 done in his branch of science to suggest 

 further advance, the other must get his grasp 

 on the new truth rather by relating it some- 

 how to the facts of his own limited experi- 

 ence, else it will all seem unreal and bookish 

 to him. The sophomore is not a scholar; he 

 is little more than a boy and it is doubtful if 

 the line of historic development will in every 

 case give the best view-point for him. For a 

 mature student or one who is seeking- by a re- 

 view of the subject to strengthen the founda- 

 tions after a too hasty course in physics this 

 book will be most suggestive, even inspiring. 

 Professor Magie's method of treatment brings 

 one into close relationship with the master 

 minds who have given direction to the larger 

 movements in scientific thought and such re- 

 lationship is inevitably stimulating. 



This historical point of view determines 

 perhaps the unusually large proportion of the 

 book devoted to mechanics and the properties 

 of matter. This amounts to about 39 per 

 cent, of the book. (The proportion found in 

 four other recent texts by American authors 

 averages 24 per cent.) 



The use of the historical method doubtless 

 explains also the relatively small attention 

 given to the illustration of physical principles 

 from modern machinery and industrial proc- 

 esses. To devote but a haM page (p. 486) to 



