Even then, the way of making several implements or weapons is not entirely clear. We got several obsidian maces or lance-heads—one about ten inches long—which were taper from base to point, and covered with taper flutings; and there are other things which present great difficulties. I have heard on good authority, that somewhere in Peru, the Indians still have a way of working obsidian by laying a bone wedge on the surface of a piece, and tapping it till the stone cracks. Such a process may have been used in Mexico. We may see in museums beautiful little articles made in this intractable material, such as the mirrors and masks I have mentioned, and even rings and cups. But, as I have said, these are mere lapidaries’ work. The situation of the mines was picturesque; grand hills of porphyritic rock, and pine-forest everywhere. Not far off is the broad track of a hurricane, which had walked through it for miles, knocking the great trees down like ninepins, and leaving them to rot there. The vegetation gave evident proof of a severe climate; and yet the heat and glare of the sun were more intolerable than we had ever felt it in the region of sugar-canes and bananas. About here, some of the trachytic porphyry which forms the substance of the hills had happened to have cooled, under suitable conditions, from the molten state into a sort of slag or volcanic glass, which is the obsidian in question; and, in places, this vitreous lava—from one layer having flowed over another which was already cool—was regularly stratified.