322 COSMOS. 



he says, " we only find simple fragments of pumice-stone of 

 a certain size ; but at seven leagues to the south of Cotopaxi, 

 in a point which corresponds with our tenth triangle, pum- 

 ice-stone forms entire rocks, ranged in parallel banks of five 

 to six feet in thickness in a space of more than a square 

 league. Its depth is not known. Imagine what a heat it 

 must have required to fuse this enormous mass, and in the 

 very spot where it now occurs ; for it is easily seen that it 

 has not been deranged, and that it has cooled in the place 

 where it was liquefied. The inhabitants of the neighborhood 

 have profited by this immense quarry, for the small town of 

 Lactacunga, with some very pretty buildings, has been entire- 

 ly constructed of pumice-stone since the earthquake which 

 overturned it in 1698." 



The pumice quarries are situated near the Indian village 

 of San Felipe, in the hills of Guapulo and Zumbalica, which 

 are elevated 512 feet above the plateau and 9990 feet above 

 the sea level. The uppermost layers of pumice-stone are, 

 therefore, five or six hundred feet below the level of Mulalo, 

 the once beautiful villa of the Marquis of Maenza (at the foot 

 of Cotopaxi), also constructed of blocks of pumice-stone, but 

 now completely destroyed by frequent earthquakes. The sub- 

 terranean quarries are at unequal distances from the two act- 

 ive volcanoes, Tungurahua and Cotopaxi : 32 miles from the 

 former, and about half that distance from the latter. They 

 are reached by a gallery. The workmen assert that from the 

 horizontal solid layers, of which a few. are surrounded by loamy 

 pumice fragments, quadrangular blocks of 20 feet, divided by 

 no transverse fissures, might be procured. The pumice-stone, 

 which is partly white and partly bluish-gray, consists of very 

 fine and long fibres, with a silky lustre. The parallel fibres 

 have sometimes a knotted appearance, and then exhibit a sin- 

 gular structure. The knots are formed by roundish particles 

 of finely porous pumice-stone, from 1 1^ line in breadth, 

 around which long fibres curve so as to inclose them. Brown- 

 ish-black mica in small six-sided tables, white crystals of oli- 

 goclase, and black hornblende are sparingly scattered in it ; 

 on the other hand, the glassy feldspar, which elsewhere (Ca- 

 maldoli, near Naples) occurs in pumice-stone, is entirely want- 

 ing. The pumice-stone of Cotopaxi is very different from that 

 of the quarries of Zumbalica:* its fibres are short, riot paral- 



quence of the great earthquake of Riobamba on the 4th of February. 

 1797. 



" This difference has also been recognized by the acute Abich 

 (Ueber Natur nnd Zusammenhany vulkanischer BHdunqen, 1841. s. 83). 



