1, 1; 2, 2; 3, 3, 4, 4, 5, 6, and 7, are roads for carrying off the rubbish, in correspondence with the several working levels.
b, b, b, masses of old rubbish (deblais).
c, c, ditto, from the present workings D, E, F.
d, the rocky mass called bianchetta, against which the ore extracted from a, abuts.
e, the surface of a bed of ore, near the streamlet g.
f, f, indication of beds of iron pyrites and fer oligiste.
g, a small rivulet preceding from the infiltration of rains, and which is impregnated with acidulous sulphate of iron.
h, h, ravine which separates the metalliferous hill d l, from the barren hill i.
k, masses of slags from ancient smelting operations; such are very common in this island. None of any consequence now exists; nearly the whole of the ore being exported to Tuscany, the Romagna, the Genoese territories, Piedmont, Naples, and Corsica.