PREFACE TO THIRD EDITION xxvii 
of whom, on account of their number, it would not be 
practicable to enumerate here, but whose work has 
been freely used. 
While every effort has been made to secure accuracy, 
it is quite possible, of course, that, in attempting to 
give in brief form so many details of information, 
errors may have crept in. The authors will consider 
it a favor if their attention can be called to any 
such errors. 
Mrs. Franklin W. Edgerton, besides reading all 
the proof, has rendered especial service in comparing 
and checking up carefully all statistical material, be 
sides preparing the index and furnishing valuable sug 
gestions throughout. The authors wish to acknowledge 
to her their special indebtedness. 
J. W. J. 
W. J. L. 
November, 1913.