NATURAL HISTORY. 
159 
niflies them with the oil above-mentioned. 
They feem, therefore, as if created for the 
purpofe of fupplying the inhabitants of that 
part of the globe with a commodity fo effen- 
tial to light them in thofe regions, which 
could not otherwife be cheered from the win- 
try gloom.. 
7he GULL and PETREL. 
Of thefe birds, the larger fort are moft 
Ihy, and live at the greateft diilance, while 
the fmaller fort refide wherever they can take 
their prey. T’hey are principally dj^nguilli- 
ed by an angular knob on the lower chap of 
the bill, which the petrels have not. The 
fea fwallow, which is alfo of this fpecies, has 
a ftraight, flender, (harp-pointed bill. In 
their abodes and appetites, however, they all 
agi'ee, hovering over rivers, and preying on 
the (mailer (ilh, as well as following the 
ploughman into the fallow fields, to pick up 
infefts. When they can find no other fub- 
fiftence, they will feed on carrion. They 
are to be found in the greatcfl: abundance on 
our boldeft rocky fliores, where they find a 
retreat for their young, in the cavities with 
which thofe rocks abound. Like all birds of 
the I'apacious kind, the gull lays but few 
^ggs. It builds its neft, of long grals and 
fea weeds, on the ledges of rocks. The flefii 
of 
