NATURAL HISTORY OF SELBORNE. 259 



LETTER LV. 



TO THE SAME. 



October iQth, 1781. 



DEAR SIR, I think I have observed before that much of the 

 most considerable part of the house-martins withdraw from hence 

 about the first week in October ; but that some, the latter broods I 

 am now convinced, linger on till towards the middle of that month ; 

 and that at times, once perhaps in two or three years, a flight, for 

 one day only, has shown itself in the first week in November. 



Having taken notice in October, 1780, that the last flight was 

 numerous, amounting perhaps to one hundred and fifty ; and that 

 the season was soft and still ; I was resolved to pay uncommon 

 attention to these late birds ; to find, if possible, where they 

 roosted, and to determine the precise time of their retreat. The 

 mode of life of these latter Hirundines is very favourable to such a 

 design; for they spend the whole day in the sheltered district, 

 between me and the Hanger, sailing about in a placid, easy 

 manner, and feasting on those insects which love to haunt a spot 

 so secure from ruffling winds. As my principal object was to 

 discover the place of their roosting, I took care to wait on them 

 before they retired to rest, and was much pleased to find that for 

 several evenings together, just at a quarter past five in the after- 

 noon, they all scudded away in great haste towards the south-east, 

 and darted down among the low shrubs above the cottages at the 

 end of the hill. This spot in many respects seemed to be well 

 calculated for their winter residence ; for in many parts it is as 

 steep as the roof of any house, and therefore secure from the 

 annoyances of water ; and it is moreover clothed with beechen 

 shrubs, which, being stunted and bitten by sheep, make the thickest 

 covert imaginable ; and are so entangled as to be impervious to 

 the smallest spaniel ; besides it is the nature of underwood beech 

 never to cast its leaf all the winter ; so that, with the leaves on the 

 ground and those on the twigs, no shelter can be more complete. 

 I watched them on the thirteenth and fourteenth of October, and 

 found their evening retreat was exact and uniform ; but after this 



