Preface 



undertook the section on Heat, Dr W. Marshall Watts that on Light and 

 Miss Alice Everett that on Sound. 



The subjects are arranged under the registration numbers adopted in 

 the International Catalogue of Scientific Literature ; a copy of Schedule C 

 (Physics) of that Catalogue, as revised in 1905, is prefixed to the Index, with 

 indication of the pages on which the titles for the different sections occur. 

 It has occasionally been found convenient, in order to save repetition in 

 printing, to group entries under a sub-heading which is not contained in the 

 International Catalogue Schedule. Where this has been done the sub-heading 

 is printed in italics. In some of these cases the words of the sub-heading 

 are understood to exist before the entries following them, and consequently 

 these entries commence with small letters. These minor classifications, being 

 often made mechanically on the basis of the explicit mention of the sub- 

 heading, are not to be taken as exhaustive ; cognate entries may be found 

 elsewhere under the same main heading. The unit of classification is thus 

 the complete numbered heading. 



At the end of the volume will be found an alphabetical index to the 

 subdivisions under which the subject titles have been arranged ; this will 

 much facilitate reference. The index also contains references to important 

 subjects included within some of the subdivisions but without separate 

 headings. 



The entries in the Index are arranged so that reference can be made, 

 if necessary, to the complete titles in the Catalogue of Scientific Papers. 

 Generally the author's name together with the date will indicate the volume 

 in which the title of the paper may be found in full. But these clues are 

 insufficient when the paper is anonymous, or occurs in Volume XII or in the 

 additions to Volume VI. They are also at fault for titles marked with an 

 asterisk showing that they belong to previous volumes ; in these cases the 

 number of the volume is given in the Index entry in small Roman numerals 

 within brackets. The references have been made as short as possible ; thus 

 the number of only the initial page of each paper has been given ; but the 

 length of the paper may be found by reference to the Catalogue of Authors. 



When an error has been found in an author's name in the Catalogue, 

 it is corrected in the Index and a reference made to the error. 



The Index contains references to some papers, of dates earlier than 1884, 

 which were omitted in previous volumes of the Catalogue ; these are indicated 



vi 



