vi Editor J Preface. 



acquired results, but by explaining as fully as possible 

 the nature of the methods of inquiry and reasoning 

 by which these results have been obtained. Con- 

 sequently, although the treatment of each subject 

 will be strictly elementary, the fundamental facts 

 will be stated and discussed with the fulness needed 

 to place their scientific significance in a clear light, 

 and to show the relation in which they stand to the 

 general conclusions of Science. 



In order to ensure the efficient carrying-out of the 

 general scheme indicated above, the Editors have 

 endeavoured to obtain the co-operation, as Authors 

 of the several treatises, of men who combine special 

 knowledge of the subjects on which they write with 

 practical experience in Teaching. 



The volumes of the Series will be published, if 

 possible, at a uniform price of is. 6d. It is intended 

 that eventually each of the chief branches of Science 

 shall be represented by one or more volumes. 



G. C. R, 

 R M. 



