Another greater and inestimable advantage is, that all landscapes, and views of the country, which constitute the background of the picture, are real, and in the reality shew, very strikingly indeed, in such a country as Africa, abounding in picturesque scenes, how much nature is superior to the creation of the warmest genius or imagination. Momentary masses of clouds, especially the heavier ones, of stormy skies, will be fixed by two or three unstudied strokes of a pencil; and figures and dress, in the most agreeable attitudes and folds, leave traces that a very ordinary hand might speedily make his own, or, what is still better, enable him with these elements to use the assistance of the best artist he can find in every line of painting, and, by the help of these, give to each the utmost possible perfection; a practice which I have constantly preferred and followed with success. It is true, this instrument has a fundamental defect in the laws of optics; but this is obvious, and known unavoidably to exist; and he must be a very ordinary genius indeed, and very lame, both in theory and practice, that cannot apply the necessary correction, with little trouble, and in a very short time. I was so well pleased with the first trial of this instrument at Julia Cæsarea, now Shershell, about 60 miles from Algiers, that I commissioned a smaller one from Italy, which, though negligently and ignorantly made, did me this good service, that it enabled me to save my larger and more perfect one, in my unfortunate shipwreck at Bengazi[3], the ancient Berenice, on the shore of Cyrenaicum; and this was of infinite service to me in my journey to Palmyra. Thus far a great part of my wants were well supplied, at least such as could be foreseen, but I still laboured under many. Besides that single province of ruined architecture, there remained several others of equal importance to the public. The natural history of the country, the manners and languages of the inhabitants, the history of the heavens, by a constant observation of, and attention to which, a useful and intelligible map of the country could be obtained, were objects of the utmost consequence.