THE NATURAL HISTORY [LETT. 
LETTER LV. 
TO THE HOXOURABLE DAINES BARRIKGTON. 
In obedience to your inj auctions I sit down to give you some 
account of the liouse-niartin, or martlet;^ and, if my mono- 
graphy of tliis little domestic and familiar bird should happen 
to meet with your approbation, I may probably soon extend 
my inquiries to the rest of the British hirundines — the swallow, 
the swift, and the bank-martin. 
A few house-martins begin to appear about the IGth of 
April ; usually some few days later than the swallow. For some 
time after they appear, the Idruiiclincs in general pay no atten- 
tion to the business of nidification, but play and sport about, 
either to recruit from the fatigue of their journey, if they do 
migrate at all, or else that their blood may recover its true tone 
and texture after it has been so long benumbed by the seveiities 
of winter. About the middle of May, if the weather be fine, the 
martin begins to think in earnest of providing a mansion for its 
family. The crust or shell of this nest seems to be formed of 
such dirt or loam as comes most readily to hand, and is tem- 
pered and wrought together with little bits of broken straws to 
render it tough and tenacious. As this bird often builds against 
a perpendicular wall without any projecting ledge under, it re- 
quires its utmost efforts to get the first foundation firmly fixed, 
so that it may safely carry the superstructure. On this occa- 
sion the bird not only clings with its claws, but partly supports 
itself by strongly inclining its tail against the wall, making that 
a fulcrum ; and thus steadied, it works and plasters the materials 
into the face of the brick or stone. But then, that this work 
may not, while it is soft and green, pull itself down by its own 
weight, the provident architect has prudence and forbearance 
enough not to advance her work too fast ; but by building only 
1 Hirundo urhica, Liniiaeiis. 
