1004 ME. E. JENKIN’S EXPBEIMENTAL EESEAECHES OX THE TEAXSMISSIOX 
for 1802 knots, give by the curve an amplitude of 0'3 per cent, only, and there is no 
reason to doubt this estimate. 
In conclusion, the experiments, so far as they went, were successful. They have 
shown the relative etfects of signals transmitted at various speeds through various 
lengths ; they have shown how little the results are affected by changing the power or 
arrangement of the batteries ; they have sho^vn the nature of the ultimate limit set to 
the rate of signalling by the gradual diminution and disappearance of the signals, pre- 
ceded by their mutual interference. 
The coincidence between theory and observation on these points gives good proof of 
the soundness of the theory, and permits the extension of the conclusions to the case of 
a submerged and extended cable. The experiments have also given well-defined curves 
fully expressing the retardation experienced through the cable as it lay in coils ; but 
owing to this arrangement, the observations cannot be said to fix either the retardation 
or the absolute effect of signals through a straight cable. A few observations made in 
the same manner on a sound cable in actual use would be sufficient for this purpose. 
Finally, the research has proved that the rate of signalling through a given cable can 
be very materially increased by removing the confusion or interference of successive 
signals, and has led to the discovery of one method of effecting this object. 
In the present paper, the phenomena depending on the length of the cable, together 
with the rate and manner of signalling, have alone been considered. The absolute 
measurement of the effects depending on the materials and dimensions of the insulated 
conductor will probably form the subject of another research, completing the practical 
examination of the mathematical theory. 
Table I. — Arrival-curve for 2168 knots, in 10 coils, with 72 p.p. July 26, 1859. 
Maximum deflection caused by permanent current from 72 p.p. . . . 130^ 
Seconds after making contact with, battery 
4 
5 
5 
6 
6 
7 
8 
11 
15 
21 
51 
130 
Division of scale passed by spot as the current rises at far end of line 
50 
6(» 
70 
80 
80 
90 
100 
110 
120 
125 
Eeduced distance traversed by spot after contact has been made 1 
with battery for each number of seconds J 
38-5 
46-2 
53-9 
61-6 
61 6 
69-3 
77-0 
84-7 
! 
92-4 96-2 
1 
100 
Table II. — Arrival-curve for 2168 knots, in 10 coils, with 36 p.p. July 26, 1859. 
Maximum deflection caused by permanent current from 36 p.p. . . . 63-|^^. 
Seconds after making contact with battery 
74 
8 
m 
16i 
18 
19 
Division of scale passed by the spot as the current rises at far end of line 
50 
50 
55 
60 
60 
60 
Eeduced distance traversed by spot after contact has been made with battery for each number 1 
of seconds J 
78-5 
78-5 
86-4 
94-2 
94'2 
94-9 
