Such countries are especially favoured in the preservation of structures, even when composed of comparatively perishable materials; and examples have been already cited in these pages of the existence, in a remarkable state of freshness, of buildings of very ancient date. Thus in the Arch of Constantine, some of the statuettes and sculptured portions in marble preserve the sharpness of their outline; and even the more ancient monuments of Paestum, composed of calcareous travertine, are still standing. In India, ancient temples formed of laterite—a modern deposit of gravel cemented by lime—are still in perfect preservation. Such ex amples, and many more which might be produced, all go to prove that even in regions subjected to very heavy periodical rains, provided the air be pure, and free from acids, buildings of even friable and cal careous materials are capable of withstanding atmo spheric disintegration for a lengthened period. Pains which fall at long intervals, though with tropical violence, do not act so injuriously on stone structures as those less violent, but more frequent. In such countries, therefore, the chemical composition of a building stone becomes of minor importance. The architect will now be able to select the stone amongst those to which he has access, which is most agreeable to the eye, and presents the requisite phy sical characters as regards hardness, density, and