PREFACE. 



IN translating this treatise it has been thought 

 advisable to adhere as closely as possible to the 

 original text of Turner, though in many places a more 

 modern style of phraseology would doubtless have 

 better pleased the ear of the non-scientific reader. 



Not a few difficult points of interpretation have 

 arisen in the course of the work, and the Editor 

 welcomes this opportunity of expressing his gratitude 

 to Professor Newton and to Mr R. D. Archer-Hind 

 of Trinity College for the invaluable help that he has 

 received from them in elucidating the hard passages 

 and in revising the proofs. The Editor's thanks are 

 also due to the Syndics of the University Press for 

 undertaking the present publication. 



9, Harvey Road, 

 Cambridge. 

 July, 1903. 



