338 
MR. AIRY’S ACCOUNT OF THE HARTON EXPERIMENT 
The elements for computing the effect of the other inequalities, and the factors of d, 
are as follows ; that for 19* being inserted by estimation : — 
No. 
Elevation in 
feet above 
high water. 
Surface. 
p- 
Attraction. 
No. 
Elevation in 
feet above 
high water. 
Surface. 
P- 
Attraction. 
+ 
- 
+ 
- 
1 
- 15 
•014174 
23 
15 
3 
2-6 
•006421 
2 
0 
9 
10-7 
•000427 
24 
60 
4 
1*7 
•005920 
3 
0 
8 
9*5 
•000541 
25 
55 
4 
1-7 
•008021 
4 
5 
7 
10-0 
•000379 
26 
80 
4 
1*7 
•002537 
5 
5 
6 
9*8 
•000346 
27 
74 
4 
1*7 
•000000 
6 
30 
6 
8-3 
•000361 
28 
90 
8 
3-0 
•003292 
7 
70 
12 
7-0 
•000108 
29 
90 
12 
5-5 
•000866 
8 
80 
7 
6-9 
•000099 
30 
90 
12 
8-5 
•000244 
9 
130 
12 
7*8 
•001102 
31 
0 
6 
16-4 
•000080 
10 
125 
10 
9*7 
•000438 
32 
0 
4 
15-3 
•000065 
11 
0 
4 
7-5 
•000543 
33 
0 
12 
11-0 
•000524 
12 
15 
4 
5-8 
•000925 
34 
— 5 
5 
7-0 
•000890 
13 
5 
2 
5-2 
•000743 
35 
30 
4 
9*7 
•000151 
14 
50 
6 
3’9 
•001739 
36 
40 
20 
6-8 
•001669 
15 
80 
6 
3-7 
•000514 
37 
20 
2 
4-0 
•001229 
16 
100 
16 
4-5 
•003381 
i 
38 
74 
25 
4-4 
•000000 
17 
120 
12 
7*0 
•001244 
39 
105 
16 
6*5 
•001387 
18 
120 
24 
10-5 
•000748 
40 
90 
21 
8-5 
•000426 
19 
— 15 
50 
18-0 
•000605 
41 
140 
16 
9*3 
•001029 
19* 
'000600 
42 
100 
24 
10-4 
•000435 
20 
15 
2 
7*9 
•000186 
43 
125 
16 
12-0 
•000372 
21 
0 
2 
6-6 
•000395 
44 
120 
10 
11-0 
•000272 
22 
- 10 
9 
4-5 
•006143 
The sum of all the factors for the effects of inequality is —•044799. 
As the attraction of the shell is 12*566368 X c?, and as the effects of inequality 
amount to — *044799 Xc?, the complete effect of the ground above the lower station 
is 12*521569 X 
60. We are now in a position to obtain a result requiring only for its complete 
numerical exhibition a knowledge of the specific gravities of the mine-rocks. The 
formula for gravity at the lower station has been found to be 
69625 X D, 
and that at the upper station 
(69625 — 8*3776) X D + 1 2*52 1 6 X c?. 
Hence ^s|^ = 1+0'00012032-0-00017984X5- 
But the experiments gave (see article 45) 
Hence 
or 
Gravity below 
Gravity above 
= 1 *00005 1 85 + *000000 1 9. 
0*00006847±*00000019=0*00017984X5; 
D 
^ = 2*6266+*0073, 
