146 THE NATURAL HISTORY [LETT. 



LETTER LV. 



TO THE HONOURABLE DAIXEX KAllllIXGTOX. 



Ix obedience to your injunctions I sit down to give you some 

 account of the house-martin, or martlet; 1 and, if my niono- 

 grapliy 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 liirunctines 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 atten- 

 tion to the business of nidification, but play and sport about, 

 either to recruit from the fatigue of their journej', 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 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 \mder, it re- 

 quires its iitmost 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 urbica, Linna'iis. 



