PREFACE. XI 



long-delayed material the changes have been mainly confined to condens- 

 ing and leaving out what has in a measure lost its value by the lapse of 

 time. Where new facts have been obtained, they have been inserted in 

 notes. The report as it now stands is therefore essentially that which was 

 prepared four years ago, and as such it should be criticised by those who have 

 occasion to read it. 



S. F. EMMONS. 

 WASHINGTON, October 1, 1885. 



