334 NEW PUBLICATION. 
the low country in the Tyne province and Yorkshire. The annual 
rainfall at Dublin is stated at twenty-six inches, that of the south-west 
at from forty to sixty inches; but it is probable that we derive a clearer 
idea of the climate in respect of the humidity of the atmosphere from 
the fact that there are upwards of 2000 square miles of peat-moss at 
a low level underlaid by limestone than from these last figures. The 
area of the whole island is 32,500 square miles, rather more than that 
of Scotland, and more than half that of England, of which a quarter 
is arable land, one-eighth peat-moss, and at least 1000 miles is occu- 
pied by lakes and rivers. 
The physical geography of the island is very peculiar. The centre 
is occupied by a great plain underlaid by carboniferous limestone, a 
tract not far short of 20,000 square miles in area, three times the size 
of Wales, which stretches from Dublin to Galway, and from Armagh 
and Donegal in the north, to the borders of Cork and Waterford. The 
only material interruption to the continuity of this are two groups of 
hills, the Slieve Bloom and the Slieve Baughta, which rise from the 
two opposite sides of the Shannon near its mouth. Outside the plain 
there are four principal mountainous tracts, one in each of the four 
provinces. In Ulster nearly the whole province stretches beyond it; 
and in the mountains we have the three physico-geographical regions 
of Scotland represented in nearly equal proportions. Throughout 
Donegal, extending into Derry and Tyrone, is an outlying slice of the 
Scotch highlands, only a small part actual granite, the rest mica-slate, 
reaching an altitude of 2462 feet in Errigal. Between Lough Neagh 
and the coast through Derry and Antrim we have a prolongation of 
the trap hills of the Lothians, Fifeshire, and Clydesdale; and in the 
south a Silurian tract, representing the clay-slate region that stretches 
from the dales of the Tweed to the Mull of Galloway. The moun- 
tains of the Connaught coast are a prolongation still further west of 
the Donegal granite and mica-slate range. The highest peak in Mayo 
(Mwllrea) reaches 2682 feet, and the Connemara hills 2400 feet. In 
Leinster the range immediately adjoining the central plain is gramte, 
rising in the Wicklow hills to 3000 feet; and between this and the 
sea the Silurian formation occupies a considerable space. From Water- 
ford to the coast through the southern half of Munster stretches the 
finest mountain-chain of the island, a region of Devonian conglome- 
rate and clay-slate like Cornwall and North Wales, filling up the entire 
