The core, completed as described, and which had previously and repeatedly been under electrical examination, was at length submerged in water of a temperature of 75 deg. Fah., and so remained during twenty-four hours. This was done that the subsequent electrical tests for conductivity and insulation might be made under circumstances the most unfavourable to the manufacture, from the well-known fact, that the insulating power of gutta percha is sensibly decreased by heat. It also ensures uniformity of condition to the core under test, and, the temperature in which it was tested being higher by 20 deg. than that of the water of the North Atlantic, there was plenty of margin against any disappointment from the effects of temperature after submersion. At the expiration of the term of soaking, the coils of core submitted to that process were expected to show an insulation of not less than 5,700,000 of Varley’s standard units, or of 150,000,000 of those of Siemens’s standard. This of itself was a very severe test, but no portion of the core showed a less perfection than that of double of either of the above high standards. Having passed this ordeal, and having been tested on separate instruments and by a different electrical process by the officers of the Atlantic Telegraph Company, in order to verify the observations of the contractors, the core was tested for insulation under hydraulic pressure, after which it was carefully unwound from the reels on which it had been wound for that purpose, and every portion was carefully examined by hand as it was rewound on to the large drums on which it was sent forward to the covering works at East Greenwich, to receive its external protecting sheath. It was then again submerged in water, and required once more to pass the full electrical tests above referred to. Finally, each reel of core was very carefully secured and protected from injury, and in this state was sent to East Greenwich, where it was immediately placed in tanks provided for it. In these it was covered with water, and the lids of the tanks being fastened down and locked, it remained until demanded for completion.