178 NATURAL HISTORY 



that these shiftless beings in a little more than a fortnight 

 would be able to dash through the air almost with the incon- 

 ceivable swiftness of a meteor ; and perhaps, in their emigra- 

 gration must traverse vast continents and oceans as distant 

 as the equator. So soon does Nature advance small 

 birds to their ^\ucia y or state of perfection ; while the pro- 

 gressive growth of men and large quadrupeds is slow and 

 tedious ! 



I am, &c. 



LETTER XXII. 



TO THE SAME. 



Selborne, Sept. 13, 1774 



DEAR SIR, 



BY means of a straight cottage-chimney I had an opportunity 

 this summer of remarking, at my leisure, how swallows ascend 

 and descend through the shaft ; but my pleasure, in contem- 

 plating the address with which this feat was performed to a 

 considerable depth in the chimney, was somewhat interrupted 

 by apprehensions lest my eyes might undergo the same fate 

 with those of Tobitt 



Perhaps it may be some amusement to you to hear at what 

 times the different species of hirundines arrived this spring in 

 three very distant counties of this kingdom. With us the 

 swallow was seen first on April the 4th, the swift on April 

 the 24th, the bank-martin on April the 12th, and the house- 

 martin not till April the 30th. At South Zele, Devonshire, 

 swallows did not arrive till April the 25th ; swifts, in plenty, 

 on May the 1st; and house-martins not till the middle of 

 May. At Blackburn, in Lancashire, swifts were seen April 

 the 28th, swallows April the 29th, house-martins May the 1st. 

 Do these different dates, in such distant districts prove any 

 thing for or against migration ? 



1 Tobit ii. 10. 



