[ 125 ] 
TRANSACTIONS, 
Report on the Progress of Astronomy during the present Cen¬ 
tury. By G. B. Airy, JM.A., F.R. Ast. Soc., F.G.S., Fellow 
of the American Academy of Arts and Sciences; late Fellow 
of Trinity College , Cambridge ; and Plumian Professor of 
Astronomy and Experimental Philosophy in the University 
of Cambridge. 
The “ Committee for Mathematical and Physical Science” of 
the British Association having done me the honour to desire 
of me a Report on the progress of Astronomy, I could not hut 
cheerfully comply with their request as far as I was able, 
though conscious that my Report must in many respects be 
imperfect. And I must beg the indulgence of the Society for 
any omissions or erroneous views ; and must request them to 
attribute such, in part, to the circumstance that my own con¬ 
nexion with Astronomy is of short standing, and that since 
that connexion began I have been much occupied with the 
minute duties attached to the care of an Observatory, as well 
as with other official business of a very different kind. 
I propose to take a brief survey of the progress of Astronomy 
since the beginning of the present century. That time must 
always be regarded as one of the most important epochs in the 
history of Astronomy. The English theodolite and the French 
repeating circle had been several years invented, and the ad¬ 
vantages of circles were generally recognised; the principal 
part of the Mecanique Celeste was published, and the theory 
of perturbations, and especially of inequalities of long period, 
was beginning to be well understood. But, besides that I have 
the advantage of commencing from an almost definite point in 
the history of the science, I feel that the progress of Astronomy 
since that time has been such that a correct statement of it 
must be highly interesting. I will not say that any discoveries 
of observation within the present century can be compared in 
general importance to the discovery of aberration and nutation; 
—that any theoretical discovery of the present century is equal 
to that of the great inequality of Jupiter and Saturn, or the 
