PREFACE ix 



and Mr. A. T. Simmons have generously given to me 

 through the whole period occupied by the compilation of 

 the book. The proof-sheets have been read by Mr. W. A. 

 Davis, by Dr. Merriman, by Lieut. Victor Steele and by 

 Mr. H. S. Patterson, to whom I am grateful for much 

 valuable help and criticism. 



T. M. LOWRY. 

 LONDON : 

 August, 1915. 



