Page:Popular Science Monthly Volume 3.djvu/54
THE POPULAR SCIENCE MONTHLY.
all the conditions, excepting that of extreme cheapness, but it has not been so uniformly successful as the heavy iron-clad cables. The very light cable invented by Mr. Varley (No. 21) admits of being laid by having the strain taken off the core by the two hempen strands, the core itself being the third strand of the cable. As a light cable, to be manufactured in a great hurry, and laid to meet some emergency, it has a good deal of merit, but for a deep-sea cable I am of opinion that it would be found too incomplete and unfinished, and that difficulties would be experienced in laying which are not at once foreseen, and that there would be no durability even if successfully laid.
Every day of my experience in watching over the permanence of the 10,000 miles of cable under my care, confirms me in the opinion that too great caution and vigilance cannot be exercised in the making and laying a thread which is to be removed from all human vision forever, and designed to earn dividends by continuing a perfect conductor of electricity. Upward of 30,000 miles of cable have been laid since the report of the committee was printed, eleven years ago, and much experience has been gained of the exigencies incidental to submerging, buoying, grappling, and repairing; but no fact has resulted from all that experience which has established that any one precaution recommended in the report has been superfluous, whereas much has occurred, which I will not particularize, proving that any attempt to disregard any single precaution has resulted in great pecuniary loss or utter failure.
We have many reasons to confirm the belief that a submarine cable, manufactured and laid with strict attention to all known principles, may be regarded as a substantial property, likely to last for any length of time; for there is no evidence whatever upon record which shows any decay of the insulating medium or copper conductor of a well-manufactured cable, i. e., there is no decay inherent in the nature of a cable; all deterioration is external; nor is there any experience whatever to establish that this insulated copper wire will enjoy any durability if unprotected with an external covering.
A light cable or unprotected core must therefore be regarded at best as an experiment, with the chances against the successful laying, and still more against its existing as a permanent property.
I have written enough to illustrate that the present submarine cable is not a haphazard idea, but one which has grown out of many failures and thousands of experiments; all the principles of manufacture and laying down have been established by great anxiety and reflection on the part of the able men who gave their energies to this kind of enterprise prior to 1865. We who have come upon the stage since that date have only discovered that we may not neglect one of all the known principles, but elaborate every one of them, and even then the duty of laying and maintaining this class of property has enough of risks and anxieties to make one heartily dislike any experi-