BRADSHAW. 
foiuf of his profession, to which he had be- 
fore no great attachment: he continued, 
however, as yet to fulfil the duties of it, 
though at tins time he had made such ob- 
servations as laid the foundation of those 
discoveries which afterward distinguished 
him as one of the greatest astronomers of 
his age. These observations gained him the 
notice and friendship of the Lord Chancel- 
lor Macclesfield, Mr. Newton, afterward 
Sir Isaac, Mr. Halley, and of many other 
members of the Royal Society, into which 
he was soon after elected a member. 
Soon after, the chair of Saviiiau professor 
of astronomy at Oxford became vacant, by 
the death of the celebrated Dr. John Keil, 
and Mr. Bradley was elected to succeed him 
on the 31st of October, 1721, at 29 years of 
age : his colleague being Mr. Halley, who 
was professor of geometry on the same foun- 
dation. Upon this appointment, Mr. Brad- 
ley resigned his church livings, and applied 
himself Wholly to the study of his favourite 
science. In the course of his observations, 
which were almost innumerable, he discover- 
ed and settled the laws of the alterations of 
the fixed stars, from tile progressive motion 
of light, combined with the earth’s annual 
motion about the sun, and the nutation of 
the earth’s axis, arising from the unequal at- 
traction of the sun and moon on the different 
parts of the earth. The former of these 
effects is called the “ aberration ” of the 
fixed stars, the theory of which he publish- 
ed in 1727 ; and the latter the “ nutation ” 
of the earth’s axis, the theory of which ap- 
peared in 1737 : so that in the space of 
about ten years he communicated to the 
world two of the finest discoveries in mo- 
dern astronomy, which will for ever .make 
a memorable epoch in the history of that 
science. See Aberration and Nuta- 
tion. 
In 1730 Mr. Bradley succeeded Mr. 
Whiteside, as lecturer in astronomy and 
experimental philosophy in the Museum at 
Oxford : which was a considerable emolu- 
ment to him, and which he held till within a 
year or two of his death, when his ill state 
of health induced him to resign it. He al- 
ways preserved the esteem and friendship of 
Dr. Halley ; who, being worn out by agq 
and infirmities, thought he could not do 
better for the service of astronomy than pro- 
cure for Mr. Bradley the place of regius 
professor of astronomy at Greenwich, which 
he himself had many years possessed with 
the greatest reputation. With this view he 
wrote many letters, desiring Mr. Bradley’s 
permission to apply for a grant of the reve?* 
sion of it to him, and even offered to resign 
it in his favour, if it should be thought ne- 
cessary; but Dr. Halley died before he 
could accomplish this kind object. Dr. 
Bradley however obtained the place in 
February, 1741-2, by the interest of Lord 
Macclesfield, who was afterward president 
of the Royal Society, and upon this appoint- 
ment the University of Oxford sent him a 
diploma of doctor of divinity. 
This appointment of astronomer royal at 
Greenwich, which was dated the 3d of 
February, 1741-2, placed Mr. Bradley in 
liis proper element, and he pursued his ob- 
servations with unwearied diligence. How- 
ever numerous the collection of astronomi- 
cal instruments at that observatory, it was 
impossible that such an observer as Dr. 
Bradley should not desire to increase them, 
as well as to answer those particular views, 
as in general to make observations with 
greater exactness. In the year 1748, there- 
fore, he took the opportunity of the visit of 
the Royal Society to the observatory, an- 
nually made to examine the instruments 
and receive the professor's observations for 
the year, to represent so strongly the neces- 
sity of repairing the old instruments, and 
providing new ones, that the Society thought 
proper to make application to the king, 
who was pleased to order one thousand 
pounds tor that purpose. This sum was 
laid out under the direction of our author, 
who, with tile assistance of the late cele- 
brated Mr. Graham and Mr. Bird, furnished 
the observatory with as complete a collec- 
tion of astronomical instruments as the most 
skilful and diligent observer could desire. 
During Dr. Bradley’s residence at the 
Royal Observatory, the living of the church 
at Greenwich became vacant, and was of- 
fered to liini : upon his refusing to accept it, 
from a conscientious scruple, “ that the 
duty of a pastor was incompatible with his 
other studies and necessary engagements,” 
the king was pleased to grant him a pension 
of 2301. over and above (he astronomer’s 
original salary from the Board of Ordnance, 
“ in consideration (as (die sign manual, dated 
the loth Feb. 1752, expresses it) of his 
great skill and knowledge in the several 
branches of astronomy and other parts of 
the mathematics, which have proved so 
useful to (he trade and navigation of this 
kingdom.” A pension which has been re- 
gularly continued to the astronomers royal 
ever since. 
About 1748 our author became entitled 
jhn 
