Mr. Forster on Earthquakes — Salisbury. 18S 
which gives him exceptional opportunities for observation, it is 
not strange that Mr. Forster is able to contribute some facts of 
great importance to the theory of earthquakes. Some of these 
facts, so far as possible in the words of the author, are here re- 
produced. That the language in which they are recorded may 
be the better understood, the hypothesis which they are thought 
by the author to support, may be briefly indicated by a few 
citations. 
The irregularities of the bed of the Mediterranean are, as is 
well known, very considerable. ''In many parts a difference of 
depth equal to 2,000 feet has been found between the bow and 
stern soundings." * * ''We know of mushroom-shaped 
mountain ranges, abrupt and precipitous table-lands, immense 
marginal shelves and overhanging cliffs, many of which do not 
form part and parcel of the earth's upper crust, but are divided 
from it by beds of firm ooze or clay. Now, all these idiosyn- 
crasies of the surface must become eventually levelled down. 
We know, by soundings, that many of these tottering masses 
are hanging over precipices from 3,000 to 5,000 feet in depth, 
and that the erosion of the water at the base of the inverted 
cone-shaped rocks, eventually, causes them to slip over in this 
very natural course of levelling down." After referring to like 
irregularities of bottom in other seas, Mr. Forster further says: 
"We know that the form of these (submarine elevations) is pre- 
cisely inverse to our terrestrial mountain peaks and sharply 
pointed ranges, and we also know that both mechanical and 
chemical action erode them at their base, then loosen them, and 
finally hurl them over to the abysses below." The same idea is 
still further emphasized by the following: "From the few in- 
stances which have been obtained by soundings, we have actual 
proof afforded us that the sinuosities of this (sub-marine) sur- 
face are most remarkable and erratic, and that they receive 
vast deposits, produced by the various existing curruets, and 
that their bases (that is, the bases of the sub-marine elevations 
and ledges,) suffer erosion, or become honey-combed, as it were, 
in the lapse of geological time; that also they eventually fall 
over, are levelled down and become homogeneous masses. All 
this is exhaustively proven by the known condition of the cen- 
tral beds of our ocean." In these unstable elevations the author 
thinks we have "the true and only reason for seismic disturb- 
