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together with little bits of broken ft raws, to render 
it tough and tenacious. As this bird often builds 
againfta perpendicular wall, without any projecting 
ledge under, it requires its utmoft efforts, to get the 
firft foundation firmly fixed, fo that it may lafely 
carry the fuperftruCture. On this occafion, the bird 
not only clings with its claws, but partly fupports 
itfelf by ftrongly inclining its tail againft the 
wall, making that a Julcrum j and thus ftea- 
died, it works and plaifters the materials into the 
face of the brick or hone. But then, that this work 
may not, while it is foft and green, pull itfelf down 
by its own weight, the provident artichitedb has 
prudence and forbearance enough, not to advance its 
works too faff; but by building only in the morn- 
ing, and by dedicating the reft of the day to food 
and amufement, gives it fuffieient time to dry and 
harden. About half an inch feems to be a fuffieient 
layer for a day. Thus careful workmen, when they 
build mud-walls, informed at fii ft perhaps by this 
little bird, raife but a moderate layer -at a time, and 
then defiftj leaft the work fhould become top-* 
heavy, and fo be ruined by its own weight. By 
this method, in about ten or twelve days, is formed 
an hemifpheric ncft, with a fmall apertuie towards 
the top j flrong, compact, and warm j and per- 
fectly fitted for all the purpofes, for which it was 
intended: but then nothing is more common than 
for the houie-fparrow, as foon as the fhell is finished, 
tofeize on ir, as its own, to ejeCt the owner, and 
line it after its own manner. 
Though fo much labour is beftowed in erecting a 
manfion, yet as Nature feldom works in vain, mar- 
tins 
