INTRODUCTION. Ixix 



scribed species, to which he gave the name of Pinus ca- 

 nariensis ; discovered a new species ofArdisia, and col- 

 lected many other new and interesting plants. Several 

 botanical travellers have noticed the singuhir appearance 

 of the roofs of the houses of Laguna, from their being co- 

 vered with a sort of house-leek, but none had described 

 it. JNIr. Smith, on examination, found it to be a new spe- 

 cies, and named it, from its situation, Sempervivum 

 urbium. 



From Santa Cruz the travellers passed near to Palmas, 

 the capital of Grand Canaria. It was now^ the month of 

 August, and the summer heat had parched the earth and 

 dried up the plants, excepting some Euphorbias and 

 others of the succulent tribe. They, however, determined 

 by the barometer, for the first time, the height of Pico del 

 Pozo de los Nieves, the most elevated on the island, to 

 be 6224 English feet above the level of the sea. 



On returning to Santa Cruz, Smith and his friend set 

 out on a journey to the Peak of Teneriffe, along the crest 

 of the mountain which crosses the island in its greatest 

 length. Near the summit of the peak the two naturalists 

 passed several days, traversing the immense stream of 

 Obsidian, which encircles its western side, examined the 

 volcano of Chahorra, remaining in the mountains till forced 

 down from want of food, water, and shoes, the latter of 

 which were fairly cut in pieces by the glassy lava. Em- 

 barking at Oratava, they proceeded to the Isle of Palmas ; 

 examined the immense and almost inaccessible crater, 

 which occupies the centre of the island ; ascended the Pico 

 de los Muchaclios, whose height was found to be 7707 

 Enghsh feet, and which commands a view of the whole 



