52 Proceedings of Royal Society of Edinburgh. [sess. 
(2) First, then, let us see what has been done during the last 
fifty years to supply mathematicians with bibliographical aids. 
In 1855 Dr Joseph Henry made his appeal to the British Associa- 
tion at Glasgow for the formation of a catalogue of philosophical 
memoirs referring to mathematics and physics, and the appeal did 
not fall unheeded. Before anything tangible, however, could 
result from it, the publication of Poggendorff’s Biograpliisch- 
literarisches Handworterbuch was begun (1858) in Germany, and 
partly filled the vacant place. The two volumes of it, alphabetically 
arranged according to authors’ names, were completed in 1863, 
and dealt with scientific papers published up to 1858. 
By the time of the appearance of the first part of “Poggendorff,” 
the seed sown by Henry had germinated, the Royal Society of 
London having taken it over from the British Association, and 
having formally resolved to prepare a catalogue of scientific 
memoirs beginning with the year 1800. The first volumes of 
this great undertaking, namely, those dealing with the period 
1800-1863, were published at the rate of one volume a year, the 
last appearing in 1872. From the latter date, therefore, there 
were two books of reference available for the mathematician, the 
Handworterbuch and the Catalogue of Scientific Papers. The 
fact that they covered in the main the same period was not 
altogether a drawback, as even within that period they were often 
mutually supplementary. A more serious objection lay in the 
fact that neither of them had a subject-index, and that the more 
up-to-date of the two was almost ten years in arrears when its 
sixth volume appeared. 
About this time a very important fresh venture was made ; but, 
before speaking of it, it may be well to follow out the history of 
the other two. By 1879 two additional volumes of the Catalogue 
of Scientific Papers had been published dealing with the period 
1864-1873, and by 1896 the next decade had been covered by 
three futher volumes : so that at the latter date there were avail- 
able eleven handsome quarto volumes devoted to cataloguing the 
scientific literature from 1800 to 1883. For a long time, on 
the other hand, no addition to the Handiobrterbuch had been 
made, and it seemed as if the Royal Society were to be left in 
possession of the field. Ultimately, however, fresh counsels must 
