introduction: iii 



have stated times of publication. It is more important to pro- 

 vide for the early appearance of papers than for regularity in 

 issue ; and accordingly the plan has been adopted of publishing 

 numbers as often as the requisite material is furnished. 



A partial compensation for the unavoidable delays that have 

 attended the vssue of the first number will be found in the fact 

 that it has been made much larger, and more expensive in illus- 

 tration, than was promised in the original announcement. 



C. O. WHITMAN. 



