[Footnote 24: Ulloa, Not. Amer., ent. 21.] But the surest test of the civilization of a people - at least, as sure as any - afforded by mechanical art is to be found in their architecture, which presents so noble a field for the display of the grand and the beautiful, and which, at the same time, is so intimately connected with the essential comforts of life. There is no object on which the resources of the wealthy are more freely lavished, or which calls out more effectually the inventive talent of the artist. The painter and the sculptor may display their individual genius in creations of surpassing excellence, but it is the great monuments of architectural taste and magnificence that are stamped in a peculiar manner by the genius of the nation. The Greek, the Egyptian, the Saracen, the Gothic, - what a key do their respective styles afford to the character and condition of the people! The monuments of China, of Hindostan, and of Central America are all indicative of an immature period, in which the imagination has not been disciplined by study, and which, therefore, in its best results, betrays only the ill-regulated aspirations after the beautiful, that belong to a semi-civilized people. The Peruvian architecture, bearing also the general characteristics of an imperfect state of refinement, had still its peculiar character; and so uniform was that character, that the edifices throughout the country seem to have been all cast in the same mould. *25 They were usually built of porphyry or granite; not unfrequently of brick. This, which was formed into blocks or squares of much larger dimensions than our brick, was made of a tenacious earth mixed up with reeds or tough grass, and acquired a degree of hardness with age that made it insensible alike to the storms and the more trying sun of the tropics. *26 The walls were of great thickness, but low, seldom reaching to more than twelve or fourteen feet in height. It is rare to meet with accounts of a building that rose to a second story. *27 [Footnote 25: It is the observation of Humboldt. "Il est impossible d'examiner attentivement un seul edifice du temps des Incas, sans reconnoitre le meme type dans tous les autres qui couvrent le dos des Andes, sur une longueur de plus de quatre cent cinquante lieues, depuis mille jusqu'a quatre mille metres d'elevation au-dessus du niveau de l'Ocean. On dirait qu'un seul architecte a construit ce grand nombre de monumens." Vues des Cordilleres, p. 197.] [Footnote 26: Ulloa, who carefully examined these bricks, suggests that there must have been some secret in their composition, - so superior in many respects to our own manufacture, - now lost. Not. Amer., ent. 20.] [Footnote 27: Ibid., ubi supra.]