_Sept. 13th_.--I rode again to the botanic gardens with Mr. Hoste and Mr. Hately. Our chief object this time was the powder-mills. After walking round the garden, we proceeded along the valley of the mills; and so beautiful and sequestered a place, in the bosom of the mountains, was surely never before chosen as a manufactory for so destructive an article: I suppose the great command of water for the machinery is the chief inducement to fix it here. The powder is mixed by pounding, the mortars being of rosewood, and the pestles of the same shod with copper; yet the mortar-hoops are iron, which seems to me to be a strange oversight. I do not understand these things, however; but the machinery interested me: it is extremely simple, and the timber used in the construction very beautiful. The principal mill blew up a few months since, and is now under repair; so that we had an opportunity of seeing the watercourses, dams, wheels, &c., which we could not otherwise have enjoyed. We could not learn the relative strength of the powder. I have heard, however, that it is good. What I have seen is about as fine in grain as what we call priming powder in the navy. While we were walking about we were invited into several houses, by the overseers and other persons employed in the works, and pressed to eat and drink with great hospitality. The greatest liberality to strangers, indeed, exists in all public establishments here. For instance, at the botanic garden there is a constant nursery of the rare and the useful plants, which are given away, on application, to strangers and natives alike; so that not only the gardens of Brazil are stocked with the rarer productions of the East, but they are carried to different countries in Europe, prepared by this cooler climate for their farther transplantation.