332 Notices respecting New Books. 



between the limits of the experiments made. For this purpose 

 the two values, 



T-0=13O°, to which y= 69-9 corresponds, 



T-0=26O°, „ 3/=253-5 „ 



were deduced from the curve and introduced into the formula 



y = &(a T -*-l). 



In this manner the values 



5 = 42-9728, log b = 1-6331939, 



a= 1-00746, loga=0-00322612, 



were obtained for a and b. The following Table shows the 

 differences between the ordinates deduced from the curve and 

 the values calculated from the formula of Dulong and Petit. 



Table III. 



Difference of 



temperature. 



T-0. 



Ordinates 



taken on the 



curve. 



Ordinates 

 calculated by 

 Dulong and 



Petit' s formula. 



Difference. 



o 



50 



100 



150 



200 

 250 



o 



172 



46-4 



901 



151-7 



234-7 



19-23 



47-35 



87-98 



146-88 



232-27 



-203 

 -0-95 

 +212 



+4-82 

 +2-43 



Therefore the parabolic formula which I have proposed is 

 more suitable than that of Dulong and Petit ; and accordingly 

 I have used it in my later experiments. 

 [To be continued.] 



XXXVIII. Notices respecting New Boohs. 



Researches on the Motion of the Moon, made at the United States Naval 

 Observatory, Washington. By Simon Newcome, Professor U.S. 

 Navy. Part I. Reduction and Discussion of Observations of the 

 Moon before 1750, forming Appendix II. of the Washington Ob- 

 servations for 1875. Washington, 1878. 

 npHE object for which this work was undertaken is fully expressed 

 -*■ in the first paragraph of the author's preface as follows : — "For 

 several years after the publication of Hansen's Tables of the Moon 

 it was very generally believed that the theory of the motion of that 

 body, after having been the subject of astronomical and mathema- 

 tical research for two thousand years, was at last complete, and that 

 in consequence the motion of the moon could now be predicted 



