216 The Natural History of Selborne 



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 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 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. 1 



After so much labour is bestowed in erecting a mansion, as nature 

 seldom works in vain, martins will breed on for several years together 



1 In the case of some house-martins which had built under the eaves of my 

 own cottage, I removed no less than twelve successive nests of sparrows. While 

 each nest was being removed, the sparrows hopped about close by with building 

 materials in their mouths, looking exceedingly saucy, and with an obviously insolent 

 air of self-assertion. They seemed to say, " Who's afraid of you ? We mean to 

 go on building in spite of you." In the end, however, we tired them out, and the 

 house-martins returned to undisturbed possession. ED. 



