Much experience had been gained in the meanwhile. Long cables had been submerged in the Mediterranean and the Red Sea. The Board of Trade in 1859 had appointed a committee of experts, including Professor Wheatstone, to investigate the whole subject, and the results were published in a Blue-book. Profiting by these aids, an improved type of cable was designed. The core consisted of a strand of seven very pure copper wires weighing 300 lbs. a knot, coated with Chatterton's compound, which is impervious to water, then covered with four layers of gutta-percha alternating with four thin layers of the compound cementing the whole, and bringing the weight of the insulator to 400 lbs. per knot. This core was served with hemp saturated in a preservative solution, and on the hemp as a padding were spirally wound eighteen single wires of soft steel, each covered with fine strands of Manilla yam steeped in the preservative. The weight of the new cable was 35.75 cwt. per knot, or nearly twice the weight of the old, and it was stronger in proportion. Ten years before, Mr. Marc Isambard Brunel, the architect of the Great Eastern, had taken Mr. Field to Blackwall, where the leviathan was lying, and said to him, 'There is the ship to lay the Atlantic cable.' She was now purchased to fulfil the mission. Her immense hull was fitted with three iron tanks for the reception of 2,300 miles of cable, and her decks furnished with the paying-out gear. Captain (now Sir) James Anderson, of the Cunard steamer China, a thorough seaman, was appointed to the command, with Captain Moriarty, R.N., as chief navigating officer. Mr. (afterwards Sir) Samuel Canning was engineer for the contractors, the Telegraph Construction and Maintenance Company, and Mr. de Sauty their electrician; Professor Thomson and Mr. Cromwell Fleetwood Varley were the electricians for the Atlantic Telegraph Company. The Press was ably represented by Dr. W. H. Russell, correspondent of the TIMES. The Great Eastern took on board seven or eight thousand tons of coal to feed her fires, a prodigious quantity of stores, and a multitude of live stock which turned her decks into a farmyard. Her crew all told numbered 500 men. At noon on Saturday, July 15, 1865, the Great Eastern left the Nore for Foilhommerum Bay, Valentia Island, where the shore end was laid by the Caroline.