ADLER] CATALOGUE OF SCIENTIFIC LITERATURE 220 
a whole improved. Let me emphasize the fact that in order to be 
useful the criticisms and suggestions must be definite. 
That the work is one of magnitude may be gathered from the fact 
that while now only in its third year of publication over half a 
million reference cards have been received at the London Central 
Bureau of which over fifty thousand are references sent for the 
United States from the Smithsonian Institution. The limited funds 
at our disposal delay and embarrass the work in this country ; how- 
ever the system as at present organized is capable of expansion at 
any time either into fields not at present embraced within the 
scope of the work, such as the so called applied sciences, or in 
adding to the manner of presenting the index. For instance, cards 
or proof sheets might be furnished immediately after the appearance 
of the publications indexed. Such methods would of course only 
_ be adjuncts to the yearly volumes which would always be the per- 
manent records. 
Recently a plan has been organized whereby authors of papers 
are in special cases communicated with in order that through the 
cooperation of author and indexer the subject matter may be com- 
pletely treated from the point of view of the author and systemat- 
ically treated from the point of view of the bibliographer. 
This method entails considerable clerical work but the results 
seem to justify the effort. Another plan which is being gradually 
worked out as time permits is to send to each author from time 
to time a list of his papers which have been indexed at the insti- 
tution for the catalogue with the request that attention be called 
to any omissions or errors which may exist. These two plans, were 
it possible to devote a sufficient time to them, would. render the 
work as exact as it is possible to make a complex index. 
The entire work of preparing cards for the United States is done 
at the Smithsonian Institution by five persons though we have the 
advantage of the advice of members of the staff of the Smithsonian 
Institution and the National Museum and in some cases also of 
persons connected with other government scientific bureaus. 
I wish to specially acknowledge the services of Mr. Leonard C. 
Gunnell who is in immediate charge of the force to which I have 
referred. 
The cost of the work in the United States thus far has been borne 
out of an allotment made by the Secretary of the Smithsonian Insti- 
tion and the actual work is carried on in connection with the library 
of the institution. 
