The city of Oeiras, the capital of the Province of Piauhy, is situated in a large circular valley, about a league in breadth, nearly surrounded by a broken range of low hills composed of a soft whitish-coloured sandstone. Until the year 1724, when it was raised to the dignity of a city, it was known by the name of Villa da Mocha, from a little stream which passes close to it and all the year round yields an abundant supply of water, which, however, in the dry season is very much impregnated with saltpetre. It is very irregularly built, consisting principally of a large square, and a few streets which proceed from the south and west sides of it. The population does not exceed three thousand souls; the most respectable part of which, not including those in the employ of the government, are shopkeepers who retail European goods. The greater part of the merchandize comes from Maranham, being carried in large canoes up the Rio Itapicuru to Cachias, from whence they are brought to Oeiras on the backs of horses. A portion is also brought by the same means from Bahia, but the distance is much too great to render such expeditions profitable; this is brought by drovers who go there yearly with cattle for sale. Sometimes a solitary launch of twenty tons burden, laden with salt, arrives in the Rio Canindé, opposite Oeiras, from the Villa da Parnahiba, a flourishing town near the coast on the east bank of a large river of the same name, which divides the Provinces of Maranham and Piauhy, and up which the navigation takes place. One such arrived during my visit, but it took nearly three months to perform the distance, which is about one hundred leagues. It is only during the rainy season, when the river is flooded, that this voyage can be undertaken, and the current is then so strong that the vessel has to be pushed up by poles all they way. Owing to the length of time, and the number of men required, it is seldom that such a speculation terminates profitably. It has been recently proposed by Mr. Sturz, the Consul-General for Brazil, in Prussia, to navigate this stream by a small steam-boat, but there are many reasons for concluding that this will never be successfully put into execution. It is not probable that the middle and southern portions of the Province will ever be much more populous than they are at present, as from the great yearly droughts to which they are liable, the cultivation of cotton or sugar can never be carried on. The only articles of export are cattle and hides, and the latter is all that a steamer would get as cargo downwards. As regards the import of European goods, it is not likely that the traffic would soon be changed from Maranham to Parnahiba. The river, moreover, would only be navigable during the rainy season, at which period the force of the current, and the numerous shifting sandbanks which its bed is said to contain, would render the transit both slow and difficult.