of an Arc of the Meridian. 
4 8 7 
shall conclude this article with giving, in order, the subtenses 
in the heavens, of the different parts of my terrestrial arc. 
Dunnose and Clifton - - 2 0 
Dunnose and Arbury Hill - 1 
Arbury Hill and Clifton - 1 
Dunnose and Greenwich « o 
Greenwich and Clifton 1 
6. Arbury Hill and Greenwich - o 
7. Dunnose and Blenheim - 1 
8. Blenheim and Clifton - 1 
50' 23", 38 
3 6 *9,9 8 
340 
31,39 
51,59 
4 8 ,!9 
19 . 6 9 
3.69 
14 
51 
58 
44 
13 
37 
'Determination of the Lengths of the Degrees on the Meridian , in 
the middle Points of the several Arcs given in the last Article. 
On a reference to the Phil. Trans, for 1800, it will be found, 
that Blenheim Observatory is 446458 feet from the perpendicular 
to the meridian of Dunnose. But the parallel to the perpendi- 
cular at Dunnose, from that observatory, where it cuts the 
meridian of the former, is about JL of a second in latitude north 
of the latter; therefore, 446498 feet may be taken for the 
distance of Blenheim north of Dunnose. This premised, we have 
the following terrestrial arcs, in conjunction with the preceding 
celestial ones, for computing the lengths of the several degrees. 
Arcs. Feet. 
1. Dunnose and Clifton - i°3%37 
2. Dunnose and Arbury Hill - - 586320 
3. Arbury Hill and Clifton - - 450017 
4. Dunnose and Greenwich - 313696 
5. Greenwich and Clifton - 722641 
6. Arbury Hill and Greenwich - 272624 
7. Dunnose and Blenheim - - 446498 
8. Blenheim and Clifton - - 5 8 9 8 39 
3 R 2 
