156 A SAGA OF THE SEAS 
made in manufacturing and operating them. Two rocky 
ridges on the ocean bed wore out several cables. 
An interesting experiment was conducted by the British 
engineer, Latimer Clark at Valentia after the technique had 
been perfected. He requested that the Newfoundland elec- 
tricians join together their ends of the two cables, so that a 
current could pass from one to the other. This made a total 
length of continuous cable of over thirty-seven hundred miles. 
Clark then borrowed a small silver thimble from the daughter 
of the Knight of Kerry—one of the Fitzgeralds. Into the 
thimble he placed a little sulphuric acid and a tiny fragment 
of zinc. The silver, zinc, and acid constituted a miniature 
battery, and with the charge of electricity so generated, he 
sent signals back and forth across the Atlantic in little more 
than a second of time. That is, the signals went from Ireland 
to Newfoundland and back while the watch ticked twice. ‘The 
signals that came racing back from this weak charge were suf- 
ficient to deflect the ray of light from Thomson’s sensitive 
galvanometer at least twelve inches. 
This experiment shows how wrong the electricians of 1858 
were when they assumed that a large voltage of electricity 
was necessary to force signals across two thousand miles of 
ocean. As Henry Field said, “God was not in the whirlwind, 
but in the still, small voice. . . . It seemed as if the deep 
were a vast whispering gallery, and that a gentle voice, mur- 
mured in the ocean caves, like a whisper in a seashell, might 
be caught, so wonderful are the harmonies of nature, by lis- 
tening ears on remote continents.” It must be added, how- . 
ever, that this striking demonstration by Clark was only pos- 
sible when the insulation was of the superior type used in 
1866; the cable of 1858 was not so well insulated even before 
the high voltages ruined it. An ocean cable tends to leak 
electricity, because salt water is an excellent conductor and 
would dissipate the current if there were no insulation. 
Another disturbing factor in any long cable is the difference 
