i 38 THE NATURAL HISTORY OF SELBORNE. 
LETTER. XV I: 
SELBORNE, Vow. 20th, 1773. 
In obedience to your injunctions I sit down to give you 
some account of the house-martin, or martlet; and if my 
monography of this 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 /zrundines—the 
swallow, the swift, and the bank-martin. 
A few house-martins begin to appear about the 16th April ; 
usually some few days later than the swallow. For some time 
after they appear the H/7rundines in general pay no attention 
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 severities 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 
tempered 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 requires its utmost efforts to get the first 
foundation firmly fixed, so that it may safely carry the su- 
perstructure. On this occasion 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 in the morning, and 
by dedicating the rest of the day to food and amusement, gives 
