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LXII. Notices respecting New Boohs. 



A Treatise on Astronomy, Spherical and Physical ; tvith Astronomi- 

 cal Problems, and Solar, Lunar, and other Astronomical Tables. 

 For the use of Colleges and Scientific Schools. By William A. 

 Norton, 31. A., Professor of Civil Engineering in Tale College. 

 Fourth Edition. Revised, remodelled, and enlarged (pp. 560). 

 New York, lb'67. 



"TXTHEN composing the work before us, the author seems to have 

 * 7 had in view the wants of the numerous class of readers who 

 bring to the study of natural phenomena a knowledge of elementary- 

 mathematics only ; this class we suppose to be more numerous in 

 America than in England, though here it must be large and increa- 

 sing. There cannot, we apprehend, be any question of the advan- 

 tage gained by treating the subject mathematically in its elementary 

 parts, and particularly in setting the student to work problems in 

 astronomy ; but if a strictly mathematical treatment is adopted 

 throughout, the work is of necessity adapted for a small number of 

 readers. It thus becomes a question to be settled by a sort of com- 

 promise, how far the strictly scientific treatment shall be carried, and 

 where the popular or semipopular treatment shall begin. To effect 

 the compromise satisfactorily, the author must know the wants and 

 acquirements of the class he addresses ; and this knowledge, as far 

 as we can judge, Professor Norton possesses, and has used admi- 

 rably. He has undoubtedly succeeded in producing a work which, 

 if studied throughout, will put the reader in possession of an exten- 

 sive acquaintance with the facts of the science, as well as with the 

 power to work a large number of astronomical problems. 



"What the author has done and what he has not attempted we shall 

 now show by briefly mentioning the contents of the volume. It con- 

 sists of three parts — viz. Spherical Astronomy, Physical Astronomy, 

 and Astronomical Problems. The contents of the first part may be 

 inferred from its title ; but we may mention that its contents illus- 

 trate the incompleteness which must attend the compromise the 

 author has tried to effect, and the inconveniences which, at all events 

 partially, it necessitates. Thus several of the questions connected 

 with the parallax of heavenly bodies are discussed on pages 60-65 ; 

 but the formulae for parallax in right ascension and declination, in 

 latitude and longitude, and the augmentation of the moon's semi- 

 diameter, are transferred to the appendix. So with regard to eclipses ; 

 a large part of the subject is contained in Chap. XVI. pp. 190-197, 

 including the process of calculating an eclipse of the moon. We 

 get more about an eclipse of the moon on page 371, and, following 

 it, an account of the calculation of an eclipse of the sun, pp. 375— 

 392. Finally, in the appendix we have another long article, headed 

 Calculation of an Eclipse of the Sun, pp. 426-431. It seems only 

 fair to question whether the arrangement in this last case might not 

 be amended. 



The second part of the work, treating of Physical Astronomy, oc- 



