250 Biographical Account of {ApriL, 
to which, with all his habits of study and abstraction, he was ever 
perfectly alive. 
This indisposition did not prevent him from engaging about this 
time in a very laborious undertaking. A work with the title of 
Encyclopedia Britannica, undertaken at Edinburgh several years 
before this period, was now undergoing a third edition, in which it 
was to advance from three to 18 volumes. Twelve of these had 
been already published, under the direction of the original editor, 
Mr. Colin Macfarquhar, when, on his death, the task of continuing 
the work was committed to the care of the Rev. Dr. Gleig, and 
about the same time Professor Robison became a contributor to it. 
He was the first contributor who was professedly and really a man of 
science, and from that time the Encyclopedia Britannica ceased to 
be a mere compilation, Dictionaries of Arts and Sciences in this 
island had hitherto been little else than compilations; and though 
in France the co-operation of some of the most profound and en- 
lightened men of the age had produced a work of great merit and 
celebrity, with us compositions of the same class had been com- 
mitted to the hands of very inferior artists. The accession of Pro- 
fessor Robison was an event of great importance in the history of 
the above publication. 
It was in the year 1793 that he began to write in this book, and 
it was at the article Optics, with him a very favourite science, that 
his labours commenced. From that time he continued to enrich 
the Encyclopedia with a variety of valuable treatises, till its com- 
pletion in 1801. 
The general merit of the articles thus composed makes it difficult 
to point out particulars. Those in which theoretical and practical 
knowledge are combined are of distinguished merit ; such are Sea- 
manship, Telescope, Roof, Water-works, Resistance of Fluids, 
Running of Rivers. To these I must add the articles Electricity 
and Magnetism in the Supplement, where the theories of A¢pinus 
are laid down with great clearness and precision, as well as with 
very considerable improvement. In ascertaining the law of the 
electric attraction, his experiments were ingenious, as well as 
original, and afforded an approximation to the result which the 
great skill and the excellent apparatus of Coulomb have since 
exactly ascertained. In the Supplement is also contained a very full 
account of the theory of Boscovich; a subject with which he was 
much. delighted, and which he used to explain in his lectures with 
great spirit and elegance. 
These articles, if collected, would form a quarto volume of more 
than a thousand pages. Lam persuaded that when brought together, 
and arranged by themselves, they will make an acceptable present 
to the public; and I have the satisfaction to state that such a work 
is now preparing, under the direction of an editor whose remarks or 
corrections cannot but add greatly to its value. Notwithstanding 
the merit which the separate articles possess, they are not entirely 
