COVEKING KOCK WITH EARTH. 603 



sisted of a tliin slieet of rock covering a layer of fertile earth. 

 This rock has been broken up, and, when not practicable to find 

 use for it in fences, fortresses or dweUings, heaped together in 

 high piles, and the soil, thus bared of its stony shell, has been 

 employed for agricultural purposes.* If we remember that gun- 

 powder was unknown at the period when these remarkable im- 

 provements were executed, and of course that the rock could 

 have been broken only wdth 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 

 enthely deserted by man, had once a dense population. The 

 monks at the Abbey of Tre Fontane, near Rome, now gain 

 ground for agricultural production by blasting the thin layer of 

 tufaceous rock lying near the surface and beneath which they 

 find a fertile soil. 



Oovermg Hock with Earth. 



K man has, in some cases, broken up rock to reach productive 

 ground beneath, he has, in many other instances, covered bare 

 ledges, and sometimes extensive surfaces of soHd stone, with fruit- 

 ful earth brought from no inconsiderable distance. IS^ot 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 I^ile mud, transported on the backs of camels 

 from the banks of that river. Parthey and older authors state 

 that aU the productive soil of the Island of Malta was brought 

 over from Sicily, f 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 Eu- 

 rope. 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 



* Barth, Wanderungen durch die Kusien des Mittelmeeres, i., p. 353. In a 

 note on page 380, of the same volume, Barth cites Strabo as asserting that a 

 similar practice prevailed in lapygia ; but the epithet Tpaxela, applied by 

 Strabo to the original surface, does not necessarily imply that it was covered 

 Tvith a continuous stratum of rock. 



f Pahthey, WaTiderungen durch Sicilien und die L&tante, i., p. 404. 



