The excerpt represents the core issue or deciding factor on which you must meditate, and is drawn from Memoir of Fleeming Jenkin by Robert Louis Stevenson: constituting the insulation of the Red Sea cable of 1859, are given
as the only results in the way of absolute measurements of the
electric resistance of an insulating material which had then been
made. These remarks are prefaced in the 'Encyclopaedia' article by
the following statement: 'No telegraphic testing ought in future
to be accepted in any department of telegraphic business which has
not this definite character; although it is only within the last
year that convenient instruments for working, in absolute measure,
have been introduced at all, and the whole system of absolute
measure is still almost unknown to practical electricians.'
A particular result of great importance in respect to testing is
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