NATURAL HISTORY OF SELBORNE. 
117 
LETTEE XYL 
' TO THE SAME. 
Selborne, Nov. 20th, 1773. 
Dear Sir, — 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 hirundines — the swallow, the swift, and the bank- 
martin. 
A few house-martins begin to appear about the 16th of April ; 
usually some few days later than the swallow. For some time after 
they appear the hirundines 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 superstructure. 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 for- 
bearance 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 it sufiicient time to dry and harden. About half an 
inch seems to be a sufficient layer for a day. Thus careful workmen, 
when they build mud- walls (informed at first perhaps by this little bird), 
raise but a moderate layer at a time, and then desist, lest the work 
should become top-heavy, and so be ruined by its own weight. By this 
method in about ten or twelve days is formed an hemispheric nest with 
a small aperture towards the top, strong, compact, and warm ; and 
perfectly fitted for all the purposes for which it was intended. But then 
nothing is more common than for the house-sparrow, as soon as the shell 
is finished, to seize on it as its own, to eject the owner, and to line it 
after its own manner. 
After so much labour is bestowed in erecting a mansion, as Nature 
seldom works in vain, martins will breed on for several years together 
in the same nest, where it happens to be well sheltered and secure from 
the injuries of weather. The shell or crust of the nest is a sort of rustic. 
