Ix PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
on the great scale by the application of heat to rock accumulations 
under given conditions, observes, that ‘‘ the joint action of certain 
existing and admitted causes must necessarily produce on the earth’s 
surface a continued but usually slow change im the relative levels of 
the land and the water. Large tracts of its surface must be slowly 
subsiding through ages, whilst other portions must be rising irregu- 
larly at various rates ; some, though perhaps few, may remain sta- 
tionary.” It is important that such views should be borne in mind, 
whatever other causes of change may also present themselves to us, 
when we consider the movements which geological evidence so clearly 
proves have taken place since the accumulation of the earliest sedi- 
mentary deposits with which we are acquainted; these movements 
sometimes raising masses of rocks above the sea, at others depressing 
them, forcing the dry land into all kinds of varied positions relatively 
to the sea, modifying the life for the time existing mm the atmosphere 
or the waters, and often so entirely cutting off that mm the one or the 
other, as the case may be, that, after a long lapse of geological time, 
the organic remains subsequently entombed over the same area differ 
completely from those intermingled with the sedimentary accumula- 
tions of a previous time. 
From observations made at Puzzuoli in 1819 and in 1845, Mr. | 
Smith concludes that there had been a depression of the temple of 
Serapis at the rate of about an inch yearly. In arriving at this con- 
clusion, Mr. Smith makes every allowance for the small tidal action 
felt near Naples, and for the different altitudes at which the surface 
of the sea might stand from the pressure of different winds upon it, 
the latter a very material pomt when we estimate small changes of 
level. It appears to him probable that this depression may have 
been going on for many years, even since the last paroxysmal eleva- 
tion in 1538, one which followed a gradual movement of elevation, 
itself subsequent to the stationary time when molluscs bored the 
columns, then necessarily so far depressed beneath the sea. Mr. 
Smith afterwards notices the relative changes of level of sea and land 
shown by submarine forests, so well exposed on the coasts of Brittany, 
Normandy and the Channel Islands, and alludes to evidence indica- 
tive of a depression of land im the islands of Malta and Gozo, wheel 
tracks, not connected with existing roads, passing beneath the level 
of the sea. 
Another communication was made to the Society respecting the 
temple of Serapis by Colonel Macintosh, who visited it m May and 
June, 1847. From his observations he concludes that the land has 
been still further depressed since visited by Mr. Smith, of Jordan 
Hill. Colonel Macintosh also calls attention to the evidence of the 
sinking of the land on the Naples side of Puzzuoli; the Hospice of 
the Capuchins having so changed its level relatively to that of the 
sea, that the refectory, kitchens, &c., on the lower floor have been 
abandoned ; and an aged monk who showed the Colonel over the 
premises pointed out a spot where there had formerly been a vine- 
yard, and where he had for many years-eaten grapes, this spot now 
covered by three feet of water and traversed by boats. 
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