390 
THE OBSERVATORY OF TRINITY COLLEGE, 
DUBLIN 
N 1774, Dr. F. Andrews, Provost of Trinity College, 
Dublin, died, having bequeathed to the College the 
sum of 3,000/. to build and furnish an Observatory, and a 
further annual sum of 250/. as payment of a Professor of 
Astronomy. Unfortunately, litigation arose, and it was 
not until about 1781 that it was settled. In 1783 Dr. H. 
Ussher was appointed Professor ; in 1788 the present site 
of the Observatory was purchased and the buildings 
erected. Ramsden was commissioned to build the transit 
instrument, but innumerable delays occurred, and it was 
not set up until 1808, eighteen years after Professor Ussher’s 
death, and during the professorship of Dr. Brinkley. In 
1791 a License of Mortmain, together with a statute for 
regulating the duties of the Professor, were obtained, and 
the College expended out of their private funds several 
thousand pounds, so as to carry out the intentions of their 
late Provost. The competition for the professorship is 
open to all the astronomers of Europe. Since its founda- 
tion four have been appointed: Dr. Ussher, in 1783 ; Dr. 

NATURE 
[March 16, 1871 
J. Brinkley, of Cambridge, in 1790 ; Sir William Hamilton, 
in 1827; and Dr. Francis Briinnow, in 1865. The Pro- 
fessor of Astronomy is also Astronomer Royal for Ireland. 
Since 1831 the stipend granted to the Professor is 700/. per 
annum, which includes the pay of an assistant and gardener. 
The Observatory is situated about five miles from the 
College, at Dunsink, to the north-west of Dublin, beyond 
the Phoenix Park. It lies amid extensive fields and pas- 
ture lands on the summit of a hill nearly three hundred 
feet, close to the sea level. The accompanying woodcut 
represents the principal front of the Observatory. Ry 
the Statute of 1791 it is enacted, among other things, that 
a fair copy of the observations made every year shall be 
presented to the College, and also that the observations 
shall be printed every year at the expense of the College, 
the Professor to supervise the press, and copies to be sent 
as presents to the principal observatories, academies, 
libraries, and eminently-learned persons both at home and 
abroad ; the remaining copies to be sold, and the profit 
given to the Professor for his care and trouble in super- 
vising the printing of the observations. 
We welcome with great pleasure the first part of a series 






























































































































































































































































Nie 


THE OBSERVATORY OF TRINITY COLLEGE, 
of “ Astronomical Observations and Researches made at 
Dunsink” by the present Astronomer Royal for Ireland, 
which has been printed and circulated within the last few 
weeks by the College. It consists of a quarto part of 
eighty-eight pages, and it is accompanied by three plates. 
It embraces the results of observations made with the 
“south” refractor, from June 1868 to October 1869, and 
contains—1. Description of the “South” Refractor. 2. 
New determination of the Parallax of a Lyre. 3. De- 
termination of the Parallax of 61 Draconis. 4. Micro- 
metrical measurements of double stars. 5. Observations 
ofa Lyra and companion ; and 6, Observations on 61 « 
Draconis. The plates represent the new dome erected for 
the “South” Refractor, a sketch of the wheels on which 
the dome revolves, and the interior of the dome and sketch 
of the “South” Refractor. 
The object glass of this Refractor was given in 1863 to 
Trinity College, by Sir James South. It was given with 
a valuable collection of astronomical instruments on the 
accession of the Right Hon. the Earl of Rosse as Chancel- 
lor of the University. This glass is 113 inches diameter, 
and was purchased by Sir James South forty years ago 
from Cauchoix in Paris. The good qualities of the glass 


= S 
DUBLIN 
had already been fully appreciated by Arago, who recom- 
mended the French Government to purchase it for the 
Paris Observatory. Shortly after the appointment of Pro- 
fessor Briinnow, the Board made arrangements for pro- 
curing a mounting, and for erecting a suitable dome. The 
wall of the dome is of stone, neatly panelled on the inside 
with wood ; the dome is of timber covered with copper ; 
the diameter of the building is 27 feet. The machinery 
for moving the dome is very ingenious, and was designed 
and executed by Mr. Grubb. The dome can be started 
by applying a force of six pounds, while five pounds suf- 
fice to keep it in motion ; its opening is 24 feet wide, and 
extends from the horizon to a little beyond the zenith, 
The support, or the mounting, is solid pier-built on the 
limestone rock. The equatorial mounting was made by 
Mr. Grubb. The motion of the clock is very steady, keep- 
ing a star steadily on the wire. The Filar micrometer was 
made by Pistor and Martins, of Berl.n. 
The present series of observations show what work can 
be done with this excellent instrument in the hands of the 
present Professor of Astronomy, while they also reflect 
credit on the Board of Trinity College for their large but 
wise expenditure, W. 
