PREFACE vii 



Owing to the lamented death of Professor T. Jeffrey 

 Parker, at a time when but little progress had been made 

 with this work, his actual share in it has been but slight : 

 but as it was planned between us, and the earlier parts had 

 the advantage of his revision, and more especially as it owes 

 a great deal to his work in the Text-Book it has been 

 thought right to let it appear under our joint names as origi- 

 nally intended. 



I have to express very great indebtedness to Professor W. 

 Newton Parker for the pains he has taken in revising the 

 proof-sheets and for many valuable suggestions which he has 

 made during the progress of the work. 



William A. Haswell. 



