VUl 



INSTRUCTIONS. 



The present volume contains (a) Schedules and Indexes in four 

 languages; (b) An Author Catalogue ; (c) A Subject Catalogue. 



The Schedules have been revised in accordance with the decisions 

 of the International Convention of 1905. 



The Subject Catalogue is divided into sections, each of which is 

 denoted by a four-tigure number between 0000 and 9999 called 

 a Registration number. These numbers follow one anotJier in 

 numerical order. 



In each section the final arrangement of papers is in the 

 alphabetical order of authors' names. 



To find the papers dealing with a particular subject the reader 

 may consult either the Schedule or the Index to the Schedule. 

 The numbers given in the Index are Registration numbers, and can be 

 used at once for turning to the proper page of the Subject Index. This 

 is done by looking at the numbers at the right-hand top corners of 

 the pages. 



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 tiie Schedule. 



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

 to these is provided at the end of the volume. 



The literature indexed is mainly that of 1909, but includes 

 those [)ortion8 of the literature of 1901-1908 in regard to which the 

 index slips were received i»y the Central Bureau too late for inclusion in 

 the previous volumes. There are also entries dated 1910. 



Topographical Symbols. 



These symbols are letters printed in italics. They are explained in 

 the To|)ographical Classification, They are not used instead of 

 Registration nnnihfrs, but for sub-dividing the sections. 



