The military forces of the country were at this time under the command of Gen. José Castro, an officer of high pretensions, but utterly deficient in strength and steadiness of purpose, and that capacity which can work out important results with slender and inapposite means. His followers had gathered to him with as little discipline, sobriety, and order, as would characterize a bear-hunt. Their prime impulse lay in the excitement which the camp presented. It was the same thing to them whether their weapon was a rifle or a guitar,—whether they were going to a skirmish or a fandango. With six or eight hundred of these waltzing warriors Gen. Castro was now on his march into the southern department, with the evident purpose of taking up his position near the Pueblo de los Angeles. Such was the posture of affairs when Com. Stockton resolved to rest in no half-way measures. The wave had been set in motion and must roll on, or its returning force might sweep him and his temporary garrisons into the Pacific. And yet aggressive measures in the present condition of the squadron seemed to border on rashness. The Portsmouth, under Commander Montgomery, must be left at San Francisco to garrison the posts occupied by the flag; the Savannah, commanded by Capt. Mervin, must remain here to hold Monterey; the Warren, under Commander Hull, was at Mazatlan; only the Congress, Lieut. Livingston commanding, and the Cyane, under Commander Du Pont, remained. With the crews of these, and a hundred and sixty men under Col. Fremont, California was to be conquered and held, and this too in the presence or defeat of a military force that had the entire resources of the country at their command. But a gallant purpose will often achieve what a questioning prudence would relinquish. The mountain torrent, with its impetuosity, sweeps away the barrier which effectually obstructs the level stream. MONDAY, JULY 27. The bustle of preparation is active in the squadron. Commander Du Pont received orders last evening to have the Cyane ready for sea in twenty-four hours. She has tripped this afternoon, and is off for San Diego, though it has been given out on shore that she is bound elsewhere, but this is a war-stratagem. She has on board Col. Fremont and a hundred and fifty of his riflemen. The wind is fresh, and they are by this time cleverly sea-sick, and lying about the deck in a spirit of resignation that would satisfy the non-resistant principles of a Quaker. Two or three resolute old women might tumble the whole of them into the sea. But they will rally before they reach their port, and see that their rifles spring true to their trust.