130 WHITE 



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 i6th 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 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 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 plas- 

 ters 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 it sufficient 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 mod- 

 erate layer at a time, and then desist, lest the work should be- 

 come top-heavy, and so be ruined by its own weight. By this 

 method in about ten or twelve days is formed a 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. 



