PREFACE. 



The present volume is the seventh of a series com- 

 menced in 1871, and which, although entirely unconnected 

 with a work having somewhat the same object the An- 

 nual of Scientific Discovery took up the record of scien- 

 tific and industrial progress where the latter left it off, 

 after having been published since 1850. The two there- 

 fore form a continuous history of the subject for twenty- 

 seven years. 



Heretofore the "Annual Record" has for the most part 

 been composed, first, of a summary of scientific progress 

 during the year; and, second, of a series of abstracts of 

 the more important articles contained in the proceedings 

 of learned societies and in the scientific and industrial 

 journals of the day. With the rapid increase in the num- 

 ber of such papers, it has been found impossible to com- 

 press the abstracts in the limits necessarily assigned to the 

 annual volume ; and it has therefore been concluded to 

 omit them entirely, and, by an extension of the Summa- 

 ries, to furnish what will probably better answer the pur- 

 poses of the student. 



A minute alphabetical index will supply the means of 

 ready reference to the more important data. The names 

 of the several gentlemen whose assistance has been ob- 

 tained in the preparation of the series of summaries 

 will be sufficient guarantee of the completeness of their 

 work. 



