One of the most promising of the new towns is called Benicia. It is situated on the Strait of Carquinez, thirty-five miles north of San Francisco. The strait forms the entrance of Suisan into Pablo Bay. The site of Benicia is a gentle slope, which, descending to the water, becomes almost a plain. Vessels of the first class can lie at anchor at its bank, and discharge their cargoes, and the harbor is safe from violent winds. The town has been made the head-quarters of the Pacific division of the United States army, and a site for a navy-yard has been selected by Commodore Jones. The marks of governmental favor show in what estimation the position of Benicia is held. The town was laid out in 1848, by Robert Semple and Thomas O. Larkin. Early in 1850, lots were selling at very high rates, and the population numbered more than a thousand persons. Between Benicia and Sacramento city, several towns have been laid out, all in very favorable positions. The principal are--Martinez, on the southern shore of the strait of Carquinez, nearly opposite Benicia; New York of the Pacific, at the junction of the River San Joaquin with the Bay of Suisan; Suisan, on the west bank of the Sacramento, at a distance of eighty miles from San Francisco. Next to San Francisco, Sacramento is the largest city in California. It is situated on the eastern bank of the Sacramento River, one hundred miles from San Francisco, and sixty-five from Suisan Bay. It is located on a beautiful plain, which is not elevated more than ten or twelve feet above the river at low water. This being insufficient to protect it from the rise of the waters of the river, several disastrous floods have occurred during the existence of the city. Up to this point, the river is navigable for large class steamers. Ships drawing not more than twelve feet of water may go up that far at all seasons; and, besides these commercial advantages, Sacramento is the natural trading depot for the richest portion of the mining regions.