1822.} Memoirs of the Astronomical Society, Vol. I. 149 
circle is very much superior. The whole of its fabric is regular 
and self-balanced ; the upper circle being supported like a transit 
upon two columns is thus rendered firm and steady. Respect- 
ing sightliness, I think the man of taste would, in the different 
forms it has appeared under, pronounce it agreeable, I dare not 
say beautiful; and here I may be allowed to remark, that the art 
of instrument making, as a matter of taste, is far behind many 
others. In this country indeed at the beginning of the art, 
instruments were adorned with the flourish of the engraver, 
chaser, and carver (now long out of fashion) ; but these are not 
the beauties which 1 mean; those of uniformity of figure and 
just proportions are alone what I have in view ; and I cannot for 
a moment think that these are at all inconsistent either with 
strength or accuracy. Through the whole of this paper, every 
reader will have seen that I am an advocate for the altitude and 
azimuth instrument, and } have made no endeavour to conceal 
it; yet if 1 have said more for it than it deserves, or given to the 
repeating circle less than its due, it is a thing I am quite uncon- 
scious of.” How different is the opinion of the celebrated Biot 
respecting this degraded instrument, the following quotation 
from the Traité Elementaire d’Astronomie Physique will show : 
«< Lerreur des divisions est donc comme nulle dans les observa- 
tions faites au cercle. Il est impossible qu’elle soit aussi rgou- 
rousement detruite dans les plus grands instrumens s’ils ne sont 
pas répétiteurs. Jamais l'addresse de Uurtiste ne peut égaler un 
procédé mathematique.” (Tome 1, chap. xx. p. 278, Edit. 
Seconde.) Should Mr. Troughton candidly and attentively 
eruse the elaborate disquisition, entitled, ‘ Description et 
sages du Cercle repetiteur,” he may be induced to discard the 
predictions which he has advanced in the concluding paragraphs 
of his essay. “‘ As it was the rudeness and inaccuracy of divid- 
ing which brought this instrument into existence, we should 
think that as the art becomes cultivated, it will fall into disuse. 
The art in this country is sufficiently advanced to set repeating 
instruments aside ; and if I am rightly informed, several foreign 
artists are at this time pursuing the course of its improvement, 
in which they had for many years been impeded by circum- 
stances which science could not controul. It is, therefore, my 
opinion, that as the division of instruments becomes generally 
improved, so will the repeating circle hasten to its dissolution ; 
and, perhaps, on accuunt of the great services which in its time 
it has rendered to astronomy and geodesy, some future age may 
be induced to chaunt its requiem.” 
The repeating instrument, of which the construction is described 
in the second memoir, was finished in Jan. 1819, and is stated 
by Mr. Dollond to be applicable to all the uses where vertical 
and horizontal angies are required to be taken. It may be sufli- 
cient for our present purpose to point out the novelties by which 
itis distinguished. ‘The first novelty is the transverse or transit 
