On our arrival here in October last, it was deemed desirable to establish a small military post at San Jose, for the double purpose of giving protection to the friendly inhabitants against a band of Mexican freebooters who had crossed the gulf from Guaynas to Mulige and Loreto, and of preventing the further introduction of men and munitions from the opposite coast. The old mission building was found well adapted to the purpose in view, and with a few repairs and improvements served as an admirable protection for the little garrison in the several attacks which it afterwards sustained from greatly superior forces. It will probably be necessary to continue this post during the war with Mexico, or at least so long as there is any danger of the enemy's sending troops from the opposite coast to again disturb the tranquillity of the peninsula; but it is not deemed advisable to establish at this place any works of permanent defence, the character of the port not being such as to warrant expenditures for this purpose. The defences of the cuartel or mission building are deemed sufficient for all purposes of temporary occupation. Should the war with Mexico continue, and the naval forces be again withdrawn from the gulf, it may be necessary to establish temporarily a small military post at Mulige; but no permanent garrison will be required either at that place or Escondido, unless, perhaps, hereafter the commercial importance of the latter port should justify such a measure. La Paz is, therefore, the only port in Lower California which it will be necessary, for the present, to occupy with a permanent military force, or to secure by means of fortifications. For temporary purposes, the site of the old cuartel is well suited for the construction of defensive barracks, inasmuch as it commands the town, and may readily be secured against an attack from the side. The buildings at present occupied as barracks are not judiciously located. A permanent work on Punta Colorada will completely close the entrance to Pichilingue cove, and its heavy guns will reach the entrance to the channel of La Paz; but to give the requisite security to the latter, a small battery will be necessary on Punta Prieta. The topographical features of both these points are favorable for the construction of small fortifications: Stone of good quality for building purposes is found in the immediate vicinity, and good lime may be procured at the distance of only a few miles. Quarries have been opened in the "Calaveras," and the stone, though soft and easily worked, is found to be in this climate of a very durable character. La Paz is not difficult to defend against a naval attack, and the proposed fortifications may be constructed in a short time and without a very large expenditure of money. The commercial character of the place, its military importance as connected with the defence of the peninsula, its great value as a naval depôt and port of refuge for our commercial