In the Author Catalogue the numbers placed within square brackets 

 at the end of each entry are Registration numbers, and serve to 

 indicate the scope of each paper indexed. The meaning of these 

 numbers will at once be found by reference to the Schedule. 



In case the abbreviated titles of Journals are not understood, a key 

 to these is provided at the end of the volume. 



The material employed in the preparation of this volume was 

 received at the Central Bureau between March, 1904 and February, 

 1905. The literature indexed is mainly that of 190.3. 



Topographical Symbols. 



Many of the sections are sub-divided into a number of sub-sections 

 by means of topographical symbols. These symbols are letters printed, 

 in italics. They are explained in the topographical classification. The 

 topographical symbols are not intended to be used instead of registra- 

 tion numbers. 



