EDIBLE SWALLOW NESTS. 
57 
and confine themselves so closely to their holes, that 
none of them are seen any more flying, either out or 
in, but those which are hatching. They feed upon 
all sorts of insects which hover over stagnant waters, 
and these they easily catch, as they can extend their 
bills to a great width. They prepare their nests 
from the strongest remains of the food which they 
use, and not of the scum of the sea, or of sea-plants, 
as some persons have supposed. They employ two 
months in preparing their nests ; they then lay their 
eggs, on which they sit for fifteen or sixteen days. 
As soon as the young are fledged, people begin to 
collect their nests, which is done regularly every 
four months; and this forms the harvest of the 
proprietors of these rocks. 
The business of taking them down from the rocky 
ledges on which they are placed, is performed by 
men who have been accustomed, from their youth, 
to climb amongst these dangerous places. They 
construct ladders "of reeds and bamboos, by which 
they are enabled to ascend to the holes ; but, if the 
caverns are too deep, they employ ship-ropes. When 
they have got to the bottom of a cavern, they place 
bamboos, with notches in them, against the wall, if 
these be sufficiently long to reach the nests, but, if 
not, they stand on the ladders, and pull the nests 
down with poles of bamboo made for that purpose. 
This employment, which is very dangerous, sacrifices 
the lives of a great many men, and particularly of 
thieves, while attempting to rob the caverns at im- 
proper seasons. For this reason, small watch-houses 
are everywhere built in the neighbourhood. 
The mountaineers, who are the persons chiefly ac- 
