214 
ME. C. V. WAEKEE ON MAGNETIC CALMS AND EAETH-CTJEEENTS. 
Table XVI. — Directions and Values of Earth-Currents collected at Tonbridge, 1861, 
November and December; from the Tonbridge-Dover, London-Eamsgate, and Ton- 
bridge-Ramsgate lines. 
Date. 
Time. 
Coliunn 1. 
Column 2. 
Column 3. 
Date. 
Time. 
Column 1. 
Column 2. 
Column 3. 
Dover-Tonbridge u. 
Tonbridge-Dover d. 
Bamsgate-London.... M. 
London-Ramsgate.... d. 
Ramsgate-Tonbridge, u. 
Tonbridge-Ramsgate, d. 
Dover-Tonbridge u. 
Tonbridge-Dover d. 
1 1 
^ 1 
0 
i a 
cT gT 
u 2 
s 
CS ^ 
si 
CS 0 
pH H 
1861. 
h m 
1861. 
h m 
Nov. 1 7. 
12.35 P.M. 
28 u 
10 m 
14 m 
Dec. 3. 
6.13 A.M. 
18c? 
id 
id 
Nov. 20. 
7.34 A.M. 
25 c? 
15 c? 
20 d 
Dec. 4. 
6.20 A.M. 
0 
5 d 
0 
Nov. 21. 
7.7 A.M. 
0 
0 
0 
1.25 P.M. 
40 M 
27 u 
32 M 
Nov. 22. 
7.1 A.M. 
15 m 
12 m 
0 
Dec. 6. 
6.39 A.M. 
5 M 
0 
0 
Nov. 25. 
3.25 P.M. 
14 
0 
7u 
Dec. 7- 
6.24 A.M. 
25 M 
35 M 
42 M 
Nov. 26. 
6.35 A.M. 
35 u 
20 m 
15 m 
Dec. 9- 
7. 18 A.M. 
20 M 
0 
0 
3.24 P.M. 
10 m 
15m 
15 M 
Dec. 13. 
6.49 A.M. 
10m 
20 m 
20 u 
Nov. 27. 
6.19 A.M. 
10 m 
10m 
15 m 
Dec. 14. 
6.35 A.M. 
15c? 
10(? 
20 d 
11.47 A.M. 
15c? 
11 d 
10c? 
Dec. 17. 
6.30 A.M. 
lOc? 
5 d 
bd 
12.32 P.M. 
16 c? 
0 
0 
Dec. 19- 
6.23 A.M. 
0 
15 M 
20 M 
2.18 P.M. 
28 c? 
8 c? 
20 d 
8.18 P.M. 
55 d 
55 c? 
55 c? 
2.38 P.M. 
26 
24 d 
29 c? 
Dec. 20. 
6.30 A.M. 
5 m(?) 
15c? 
10c? 
Nov. 28. 
6.20 A.M. 
0 
0 
2 u 
Dec. 21. 
6.24 A.M. 
10 m 
20 M 
30 M 
Nov. 29. 
6.33 A.M. 
5 c? 
2c? 
0 
Dec. 26. 
6.34 A.M. 
25 M 
20 m 
25 M 
1.13 P.M. 
17<? 
23 c? 
35 d 
Dec. 27. 
6.35 A.M. 
15 M 
15 M 
20 M 
Nov. 30. 
6.22 A.M. 
10c? 
0 
5 d 
Dec. 28. 
6.23 A.M. 
0 
2 u 
2m 
Dec. 2. 
2.27 P.M. 
22 u 
Id 
5 d 
Dec. 31. 
6.26 A.M. 
30 c? 
25 d 
30 c? 
Column 2 gives the Ramsgate-London results, or the survey of the north side of the 
parallelogram ; and column 1 the Do ver-Tonb ridge results, or survey of the south side 
of the parallelogram. In every instance, with a solitary exception during the two 
months of observation, the directions coincide ; the current or drift or electric plane is at 
least 20 miles wide, and the behaviour of its two limits is consistent. The proportion 
between the values of the currents on the two sides of the plane is not constant, but is 
a little better maintained than that of Table XIII. before referred to. The Ramsgate- 
London, or 67-mile line collected by 97^ miles of telegraph wire, gives in the majority 
of cases a less value than the Dover-Tonbridge, or 45-mile line, collected in 46f miles 
of wire. 
Column 3 of Table XVI., already noticed, is the Ramsgate-Tonbridge line. It makes 
a diagonal across the plane. The directions in all cases coincide with those of the 
other two lines, and so give a further evidence of consistency. 
Tonbridge is almost in a direct line between London and Hastings, and very nearly 
equidistant. Lines 21 — 22, and 23 — 24, Plate III. fig. 1, give the true readings. I have 
a switch or tum-plate in the Telegraph Office at the Tonbridge junction, by means of 
which the Tonbridge-Hastings wire can be placed at my request in connexion with the 
