COVERING ROCK WITH EARTH. 629 
ticable to find use for it in fences, fortresses, or dwellings, 
heaped together in high piles, and the soil, thus bared of its 
stony shell, has been employed for agricultural purposes.* If 
we remember that gunpowder was unknown at the period 
when these remarkable improvements were executed, and of 
course that the rock could have been broken only with the 
chisel and wedge, we must infer that land had at that time a 
very great pecuniary value, and, of course, that the province, 
though now exhausted, and almost entirely deserted by man, 
had once a dense population. 
Covering Lock with Earth. 
If man has, in some cases, broken up rock to reach produc- 
tive ground beneath, he has, in many other instances, covered 
bare ledges, and sometimes extensive surfaces of solid stone, 
with fruitful earth, brought from no inconsiderable distance. 
Not to speak of the Campo Santo at Pisa, filled, or at least 
coated, with earth from the Holy Land, for quite a different 
purpose, it is affirmed that the garden of the monastery of St. 
Catherine at Mount Sinai is composed of Nile mud, transport- 
ed on the backs of camels from the banks of that river. Par- 
they and older authors state that all the productive soil of the 
Island of Malta was brought over from Sicily.t The accuracy 
of the information may be questioned in both cases, but similar 
practices, on a smaller scale, are matter of daily observation in 
many parts of Southern Europe. Much of the wine of the 
Moselle is derived from grapes grown on earth carried high up 
the cliffs on the shoulders of men, and the steep terraced slopes 
of the Island of Teneriffe are covered with soil painfully 
scooped out from fissures in and between the rocks which have 
* Bartu, Wanderungen durch die Kiisten des Mittelmeeres, i., p. 353. Ina 
note on page 380, of the same volume, Barth cites Strabo as asserting that a 
similar practice prevailed in Iapygia; but the epithet rpayeta, applied by 
Strabo to the original surface, does not necessarily imply that it was covered 
with a continuous stratum of rock. 
+ Parruey, Wanderungen durch Sicilien und die Levante, i., p. 404. 
