but partly fupports itfelf by ftrongly inclining it’s tail againft the
wall, making that a fulcrum; and thus fteadied it works and
plafters the materials into the face of the brick or Hone. But then
that this work may not, while it is Toft and green, pull itfelf down
by it’s own weight, the provident architedl has prudence and forbearance
enough not to advance her work too fa il; but by building
only in the morning, and by dedicating the reft of the day to food
and amufement, gives it fufficient time to dry and harden. About
half an inch feems to be a fufficient layer for a day. Thus careful
workmen when they build mud-walls (informed at firft perhaps by
this little bird) raife but a moderate layer, at a time, and then defift •
left the work fhould become top-heavy, and To. be ruined by it’s
own weight. By this method in about ten or twelve days is formed
an hemilpheric neft with a fmall aperture towards the top, ftrong,
compaift, and warm; and perfedtly fitted for all the purpofes for
which it was intended. But then nothing is more common than
for the houfe-fparrow, as foon as the ffiell is finifhed, to feize on it
as it’s own, to ejedt the owner, and to line it after it’s own
manner.
After To much labour is bellowed in eredling a maniion as
Nature feldom works in vain, martins will breed on for feveral
years together in the fame neft, where it happens to be well (helter-
ed and fecure from the injuries o f weather. The (hell or cruft of
the neft is a fort of ruftic-work full of knobs and protuberances
on the outlide: nor is the iniide of thofe that I have examined
fmoothed with any exadtnefs at all; but is rendered foft and warm,
and fit for incubation, by a lining of fmall draws, graffes, and feathers
; and fometimes by a bed of mofs interwoven with wool. In
this neft they tread, or engender, frequently during the time of
huilding ; and the hen lays from three to five white eggs.
At
At-firft when the young are hatched, and are in a naked and
helplefs condition, the parent birds, with tender affiduity, carry out
what comes away from their young. Was it not for this affectionate
cleanlinefs the neftlings would foon be burnt up, and de-
ftroyed in fo deep and hollow a neft, by their own cauftic excrement.
In the quadruped creation the fame neat precaution is made ufe
of; particularly among dogs and cats, where the dams lick away
what proceeds from their young. But in birds there feems to be
a particular provifion, that the dung of neftlings is enveloped in a
tough kind of jelly, and therefore is the eafier conveyed off without
foiling or daubing. Yet, as nature is cleanly in all her ways, the
young perform this office for themfelves in a little time by thruft-
ing their tails out at the aperture of their neft. As the young of
fmall birds prefently arrive at their or full growth, they foon
become impatient of confinement, and lit all day with their heads
out at the orifice, where the dams, by clinging to the neft, fupply
them with food from morning to night. For a time the young are
fed on the wing by their parents ; but the feat is done by fo quick
and almoft imperceptible a flight, that a perfon muft have attended
very exadtly to their motions before he would be able to perceive
it. As foon as the young are able to lhift for themfelves, the
dams immediately turn their thoughts to the bufmefs of a fecond
brood: while the firft flight, fhaken off and rejected by their
nurfes, congregate in great flocks, and are the birds that are feen
cluftering and hovering on funny mornings and evenings round
towers and fteeples, and on the roofs of churches and houfes.
Thefe congregatings ufually begin to take place about the firft week
in Augujl; and therefore we may conclude that by that time the firft
flight is pretty well over. The young of this fpecies do not quit their
abodes all together; but the more forward birds get abroad fome days
before