S4 
Dr MacCulloch on Peat 
In a few cases, however, the depth has been measured. A 
coin of the Emperor Gordian, is quoted as having been disco- 
vered at thirty feet in depth ; and other Roman coins are men- 
tioned as having been found in Italy even at that of fifty feet. 
From the latter, of which the dates are not given, the time re- 
quired for the production of this quantity of peat, can only be 
conjectured within very wide limits. In this country, Roman 
utensils, and traces pf Roman roads, have been found at the 
depth of eight feet ; but as other parts of the moss in the spot 
in question attain to the depth of twenty feet and upwards, the 
quantity produced within the time ascertained by this register^ 
may be considerably greater. Recently, the palings of a park 
described by Camden, have been discovered beneath Chat Moss ; 
but the depth of superincumbent peat in this place has not been 
mentioned. 
It appears unnecessary to be anxious on this subject, as, 
from a variety of circumstances, it must appear evident that no 
general conclusions can be drawn. The chief causes which in- 
fluence the growth of peat, are situation, temperature, and the 
degree of moisture, all of them being causes which affect the 
rapidity of vegetation. In those cases where mountain-peat is 
in contact with the solid rock, it is obvious, that its growth, par- 
ticularly in the first stage, must be very slow, as the time which 
the lichens and mosses require to lay the foundation of a vege- 
tating surface is considerable. In aU eases, the peat of drained 
declivities is of tedious growth, and, as was formerly mentioned, 
rarely attains a greater depth than two feet. The production 
of marsh and of lake peat, are on the contrary rapid, and that 
in proportion to the circumstances of various kinds, by which 
the luxuriance of vegetation in these situations is promoted. 
That of forest-peat must, in most cases, be even more consider- 
able, as a sudden accession of depth is produced by the fall of 
the trees which contribute to its formation. Many of the deep- 
er mosses of all countries, appear accordingly to owe a large 
portion of their bulk to this cause, and are found in places well 
known by historical record, as well as by internal evidence, to 
have been once occupied by forests. 
Where no registers of time, derived from submerged works 
of artjt or from historical record, can be discovered, the antiqiiky 
