346 Darwinism and Other Essays. 



library to the general public. At the same time, 

 the skilful classification of books presents so many 

 difficulties and requires so much scientific and 

 literary training that it adds greatly to the labour 

 of catalogue-making. For this reason great libra- 

 ries rarely attempt to make subject - catalogues. 

 At every library which I have happened to visit 

 in England, France, Germany, and Italy, I have 

 received the same answer : " We do not keep any 

 subject-catalogue, for we shrink from so formida- 

 ble an undertaking." With a boldness justified 

 by the result, however, Professor Abbot began 

 such a catalogue of the Harvard library in 1861, 

 and carried out the work with the success that 

 might have been expected from his truly stupen- 

 dous erudition and most consummate ingenuity. 



It is sometimes urged that, in deference to the 

 feebleness of human memory, an ideal library 

 should have yet a third catalogue, arranged alpha- 

 betically, not according to authors, but according 

 to titles. This is to accommodate the man who 

 knows that he wants "Lectures on the Wave- 

 Theory of Light," but has forgotten the author's 

 name. In an " ideal " library this might perhaps 

 be well. But in a real library, subject to the ordi. 

 nary laws of nature, it is to be remembered that 

 any serious addition to the amount of catalogue- 



