place, at various points of the gorge, and from the N. E. side of the lateral ravine, which is crossed by the viaduct, whose steeply inclined sides are in many places, covered with loose material and large angular boulder blocks. Several of these had been dislodged, and projected into the bottom, leaving in some cases the torn traces of their headlong descent, in furrows whose direction I found to be, about N. 15° E., the stones falling to the southward.
On gaining the summit of the ridge, next above the viaduct, and looking to the S. W. across the gorge to the opposite mountain, I observed a very singular cavity in the slope of the flank, and at such a distance back from the edge of the cliff, as would render it probable it may be vertically over, the subterraneous duct in the rock, carrying the water from Polla to St. Michael's Cavern.
This is sketched in Fig. 156. It appears as if produced by the falling in of the roof, of a cavernous enlargement of the subterraneous duct at this point; and the mass standing up in the middle of the crater-like cavity, is probably part of the roof, tilted over in the fall, and sustained by other fragments beneath. The Padre said there was no water at the bottom, nor any entrance from it to a subterranean chamber, and it had received no alteration, that he was aware of, since the earthquake. The cavity is probably a quarter of a mile long, from right to left in the sketch.
Amongst the many lying wonders that were narrated about the earthquake, I afterwards heard it circumstantially affirmed that this, was a crater, had been formed at the time of the shock, and that fire had been seen to issue from it.
At nearly the highest point of the road, I found the
