The colonel is a man of small stature, of slender but wiry formation, and with a countenance indicative of decision and firmness. This is the fifth time he has crossed the continent in connection with his scientific purposes. His enterprises are full of hardship, peril, and the wildest romance. To sleep under the open heaven, and depend on one’s rifle for food, is coming about as near the primitive state of the hunter as a civilized man can well get; and yet this life, in his case, is adorned with the triumphs of science. The colonel and his band are to land at San Diego, secure horses, and advance upon the position of Gen. Castro, at los Angeles.

“War’s great events lie so in Fortune’s scale,

That oft a feather’s weight may kick the beam.”

Tuesday, July 28. Com. Stockton informed me to-day that I had been appointed Alcalde of Monterey and its jurisdiction. I had dreamed in the course of my life, as most people have, of the thousand things I might become, but it never entered my visions that I should succeed to the dignity of a Spanish alcalde. I much preferred my berth on board the Congress, and that the judicial functions in question should continue to be discharged by the two intelligent gentlemen, Purser R. M. Price and Dr. Edward Gilchrist, upon whom they had been devolved. But the services of these officers were deemed indispensable to the efficiency of the ships to which they were attached. This left me no alternative; my trunks were packed, my books boxed, and in an hour I was on shore, a guest in the house of our consul, T. O. Larkin, Esq., whose munificent hospitalities reach every officer of the squadron, and every functionary in the interest of the flag. This is the more appreciated from the fact that there is not a public table or hotel in all California. High and low, rich and poor, are thrown together on the private liberality of the citizens. Though a quasi war exists, all the amenities and courtesies of life are preserved; your person, life, and liberty, are as sacred at the hearth of the Californian as they would be at your own fireside. He will never betray you; the rights of hospitality, in his generous judgment, require him to peril his own life in defence of yours. He may fight you on the field, but in his family, you may dance with his daughters, and he will himself wake the waltzing string.

Wednesday, July 29. The sloop-of-war Levant, under Commander Page, sailed to-day, with Com. Sloat on board, for the United States. We gave the commodore a parting salute. He has rendered the squadron under his command efficient, and preserved harmony among the officers. The expediency of his measures in California will be canvassed elsewhere. He acted on the light and intelligence within his reach. If war has been declared, the laurel awaits him.

The Levant takes home in her my friend, Lieut. T——: he has resigned his commission in the navy, and takes orders in the church. He is a pretty good classical scholar, and has made himself familiar with the principles of biblical exegesis. All this has been accomplished during those few leisure hours which the duties of a watch-officer leave one at sea. It is seemingly reversing the order of things for the navy to supply the church with spiritual teachers. But few, however, have left the deck for the pulpit; a much larger number have reached it from the diagrams and drills of West Point. Among them are some of our most eloquent and impressive preachers. Of this class is the present Bishop of Ohio.

We have all been busy in writing letters home, and shall make up a pretty large mail, filled with tender recollections, and overflowing with the California news. How the intelligence of our proceedings here will strike our friends and the country at large, is mere matter of conjecture. We are acting, however, not only in view of the alleged collision between the American and Mexican forces on the Rio Grande, but in reference to the anarchy and confusion into which this country has been thrown by a revolution which did not originate with us.

Thursday, July 30. To-day I entered on the duties of my office as alcalde of Monterey: my jurisdiction extends over an immense extent of territory, and over a most heterogeneous population. Almost every nation has, in some emigrant, a representative here—a representative of its peculiar habits, virtues, and vices. Here is the reckless Californian, the half-wild Indian, the roving trapper of the West, the lawless Mexican, the licentious Spaniard, the scolding Englishman, the absconding Frenchman, the luckless Irishman, the plodding German, the adventurous Russian, and the discontented Mormon. All have come here with the expectation of finding but little work and less law. Through this discordant mass I am to maintain order, punish crime, and redress injuries.

Friday, July 31. Nearly all the houses in Monterey are of one story, with a corridor. The walls are built of adobes, or sun-baked brick, with tiled roofs. The centre is occupied by a large hall, to which the dining-room and sleeping apartments seem mere appurtenances. Every thing is in subordination to the hall, and this is designed and used for dancing. It has a wood floor, and springs nightly to the step of those who are often greeted in the whirl of their amusements, by the risen sun. The dance and a dashing horse are the two objects which overpower all others in interest with the Californians. The fiddle has been silent since our flag went up, from the fact that many of the gentlemen have left to join Gen. Castro. But if they return, though covered with disaster, the fiddle will be called upon to resume its fantastic functions. You might as well attempt to extinguish a love of air in a life-preserver as the dancing propensity in this people.

Saturday, Aug. 1. The Congress has sailed to-day, with all her marines and full complement of men, for San Pedro. Com. Stockton intends to land there with a force of some three hundred, march to the Pueblo de los Angeles, capture that important place, and fall upon Gen. Castro, who, it is now understood, has posted himself, with some eight hundred soldiers, in a pass a few miles below. The general will find his southern retreat cut off by Col. Fremont’s riflemen and the sailors of the Cyane, his western route obstructed by the Colorado, while the forces of the Congress will bear down upon him from the north. He has seemingly no escape, and must fight or capitulate. But his sagacity, his thorough knowledge of the country, and his fleet horses, may extricate him. We shall know in a few days; the interest felt here in the result is most intense. Many mothers have sons and many wives husbands involved in the issue.