C I0 3 ] 
cattle with a tranfit instrument of 5J feet, placed 
exadlly in the plane of the meridian, and conse- 
quently more to be relied upon than thofe made 
with a mural inftrument. 
By a mean of five obfervations, made on the 7th, 
12th, 23d, 24th, and 31ft of May, 1741, O. S. 
the difference in right afcenfion between vj Bootis and 
Ardturus was 5 0 22 / 38", 9, the extremes differing 
only 4", 4 of a degree. The difference in the vari- 
ation of right afcenfion to the end of May, 1768, is 
20 // ,5, by which the afcenfional difference is dimi- 
nished. It Should therefore have been 5 0 22' 
but it was obferved to be 5 0 21' 43", 4. Therefore 
in 27 years Ardturus has moved weftward 35", o. 
On the 1 6th and 20th of May, 1744, the differ- 
ence in right afcenfion between q Bootis and Ardtu- 
rus was 5 0 2 2 / 30 // ,o by each of the obfervations, 
which difference Should have been, fuppofing neither 
of the Stars to have any proper motion, 5 0 22' 1 1",7 
in May, 1768. But it was found to be 28", 3 lefs 
by fo much therefore had Ardturus moved weft ward 
in 24 years. 
On the 24th of May, and 8th of June, 1746, the 
difference in right afcenfion between the fame Stars 
was 5 0 22' 26 // ,2, by taking a mean of the two 
obfervations ; that difference Should have been 
5 0 22' 09 // ,5 in 1768. But it was obferved 
= 5°2i / 43 // ,4. Ardturus therefore in 22 years has 
moved 26 // ,i to the weft. 
Laftly ; on the 1 6 th of April, and 27th and 28th 
of May, 1 747, the difference in right afcenfion be- 
tween n Bootis and Ardturus, by taking a mean of 
the three obfervations, was 5 0 22' 25", o. By com- 
putation 
