The HOUSES of Buenos Ayres are mostly built of brick, and white-washed. Very few of them are one story high: they are flat-roofed, with a high parapet, and have a court-yard attached. The windows are protected by iron bars placed lengthwise in the front, so that a Londoner might fancy them lock-up houses. They form a complete fortification; and the loss sustained in Whitelock's attack ceases to excite surprise, recollecting that our troops had to run the gauntlet through an enemy they could not get at. Many of the houses occupy a large extent of ground. The _sala_ is the principal room. The roofs of the houses, denominated the _azotea_, are very pleasant, especially near the river; and the party-walls are so low, that a person can traverse whole streets upon the house-tops. The inhabitants do not fear robberies, relying upon the strength of their doors, iron-barred windows, and barking dogs: of the latter, two or three are in a house. The bars in the window fronts are an excellent contrivance, and quite necessary, in a climate requiring so much air, and likewise for security, the street windows being close to the foot-path, and no areas to protect them. They report that this fashion is a remnant of Spanish jealousy; at any rate, it does their invention credit. Many of the mansions are specimens of Moorish architecture; those belonging to the richer class are splendidly furnished with carpets, handsome mirrors, &c. So little wood is used in building, there is no fear of fire. Extensive houses, formerly occupied by the first families of the country, are now tenanted by British merchants; and the salas that were once graced by beauty, music, and the dance, are now stored with dry goods, and nothing is heard but the hum of business. House rent is very high: for a moderate-sized house, from 60 to 80 dollars per month. * * * * * CHURCHES.--In Catholic countries, the attention of the Protestant traveller is ever attracted towards the churches. Their gorgeous decorations, music, dress of the priesthood, &c. form so great a contrast to the simplicity of the reformed religion, that we gaze, as if viewing the splendid scenery of some theatrical spectacle, and, for the moment, cease to be astonished at the influence which this imposing church has exercised, and still continues to exercise, over a great portion of the Christian world. If the Spaniards in Europe are supposed to surpass all other Catholic nations in their strict adherence to the rights and ceremonies of "holy church," they have not neglected to transplant to South America this formidable engine of power. The charms of its music, and its general magnificence, must have bewildered the imagination of the natives, and insured to the Spaniards complete authority.