The successful laying of the French Atlantic Cable has banished the last doubt as to the practicability of successfully laying and working cables of any desired length. The first attempt at laying a cable across the bed of the Atlantic failed. This failure has been followed by two remarkable successes,and ocean cables are "ienceforth to be the means by which a large proportion of all the communication will pass to and fro between the hemispheres. So long as only one cable had been laid and worked, there remained the doubt that this success was exceptional, that it might be followed by a series of failures, which would demonstrate a great risk in investing money in such enterprises. But the recovery and putting in order the first cable, for a time almost believed to be a total failure, and the now perfect and profitable working of these cables betweenEurope and America, have doubtless convinced capitalists of the safety of this class of investments, and the raising of funds for further enterprises of this kind will be an easy matter. It must be apparent to every thinking man that the present cables cannot afford facilities equal to the growing demand. A cable from San Francisco to China is inevitable, and more Atlantic cables must be provided. With these facts in view we are not surprised to learn that many new projects are talked of. Among these is a cable from Scotland to Quebec by way of the Faroe Islands, and a West India and Panama cable, which is designed to unite South America with Europe by the way of Cuba and the United States and the cables already laid down. The rapid and astonishing increase of telegraphic communication throughout the world, has only a parallel in railroad extension.