PREFACE. 



Although it is intended that these Illustrations^ 

 if they be found useful to the British student, should 

 be extended not only to the whole of the Celestial 

 Mechanics of Laplace, but possibly to some other 

 works relating to astronomy and the higher mathe- 

 matics ; yet they may be considered as forming, eveui 

 in their present state, a work completely independent 

 of all others : and the separate publication of each 

 part has been considered as possessing the advantage 

 of dividing a long journey, into stages of a less for- 

 midable appearance, for the convenience both of the 

 traveller and of his conductor, so that if either party 

 should discontinue the undertaking, before the whole 

 tour is completed, the part actually travelled over 

 may be considered as making a whole within itself^ 

 and affording sufficient information and improvemeat 

 to repay the labour of the journey, even without any 

 ulterior view to the completion of the remaining part. 

 The translator having been accustomed to consider 

 the elementary doctrines of motion, and some other 

 parts of the subjects discussed, in a point of view^ 

 which, has from habit become more familiar to 



