THE MECANIQUE CELESTE. 273 
of astronomical refractions ; the determination of heights by 
the barometer; the investigation of the effects produced on 
the movements of the planets and comets by a resisting me- 
dium ; and the determination of the values of the masses of the 
planets and satellites. In the six books forming the fifth 
volume of the work, the author, besides presenting his readers 
with an historical exposition of the labours of Newton and his 
successors on the theory of gravitation, gives an account of 
various researches relative to the system of the universe, 
which had occupied his attention subsequently to the publi- 
cation of the previous volumes. In the eleventh book he 
considers the subjects of the figure and rotation of the earth. 
In the twelfth book he investigates the attraction and repul- 
sion of spheres, and the laws of equilibrium and motion of 
elastic fluids. The thirteenth book is devoted to researches 
on the oscillations of the fluids which cover the surfaces of 
the planets ; the fourteenth, to the subject of the movements 
of the celestial bodies around their centres of gravity; the 
fifteenth, to the movements of the planets and comets; and 
the sixteenth, to the movements of the satellites. The author 
published a supplement to the third volume, containing the 
results of certain researches on the planetary theory, and a 
supplement to the tenth book, in which he investigates very 
fully the theory of capillary attraction. There was also pub- 
lished a posthumous supplement to the fifth volume, the 
manuscript of which was found among his papers after his 
death. 
