We must not, however, confine ourselves to Australia, although we might be excused for dwelling upon it as our own possession. It is a portion, indeed, and the most important one, as being the centre, and probably the seat, of the great Pacific empire which is to be; but still it is only a portion. We have a young and enterprising competitor for sway in the southern hemisphere, and one who is even now making vast efforts to assert that sway; a competitor who regards lightly the geographical formation of the globe itself, if it offers a barrier to his ambition. The acquisition, by the United States, of the territory of California, with its great mineral resources, has given their people a footing in the Pacific, and opened out for them a trade not only with the fertile countries of South America, but also with Australia itself. They outstrip us in their knowledge of the wants of those countries, and in the ample provision which they have been making for their profitable supply. Nay, they have even been enabled to bring their own gold-fields, notwithstanding geographical impediments, actually nearer to Great Britain than its own gold-yielding colony. On the first discovery of the mineral riches of California, it became an object with the United States people to bring to their Atlantic ports, as expeditiously as possible, return remittances in gold for the large shipments of provisions, merchandise, and necessaries, sent by them round Cape Horn for the increasing population of California engaged in mining operations, and by whom agricultural and other pursuits were almost entirely neglected. In the first instance this was endeavoured to be effected by the employment of a line of steamers to make the passage round Cape Horn to New Orleans, whence mails and specie were conveyed by another line of steamers to New York. But our quick-sighted and energetic brethren soon discovered that this natural route was too long for their purposes. The time occupied by the voyage round the South American continent could be saved, if the means could be found of crossing the Isthmus of Panama, which, from Panama on the Pacific side, to Chagres, or Navy Bay, on the Atlantic, was only fifty miles in width; and notwithstanding the passage over the isthmus was at first a difficult and even an unhealthy one, it was adopted; and the mails and specie, having been transported across from Panama to Chagres, were taken on to New York _via_ Jamaica, by the United States Mail Steam-ship Company. By the adoption of this route, the distance from San Francisco to New York was reduced to 5450 miles, of which 2100 miles was accomplished by steaming on the Atlantic, 3300 miles on the Pacific, and 50 miles by overland conveyance across the isthmus, and the time reduced to about three weeks. In September last, we find from an article in the _New York Merchant’s Magazine_, republished in the _Sydney Herald_ of February 23d, that the following