220 GILBERT WHITE OF SELBOENE 1790 



I can remember. If these produce two broods of 5 young, 

 you see, Sir, one pair only, will in 7 years produce above 

 half a million, 559,870 birds : yet the number every Spring 

 appears the same. If both broods are destroyed, surely the 

 old birds would be lessened by accidents, so as to be per- 

 ceptible. If the early, or the latter brood is preserved, you 

 see the next Spring Birds will be as 5 to 2, if all the old 

 Birds are lost: and I never heard that Swallows are in- 

 creased in any part of the Globe. We know that all the 

 carnivorous Birds drive off their young as soon as they are 

 able to provide for themselves ; and I conclude that fish- 

 eating Birds do the same : for when I was on the charming 

 Lake of Killarney, I was told that was the case of a pair of 

 Ospreys, that yearly nested on an Island of Rock in that 

 Lake. But we cannot suppose the Swallow tribe can fear 

 the want of provision. Sir, you know the Fern Owl is one 

 of the Spring Birds, and appears here as the latest comer. 

 I used to have many in my Woods ; but since the long and 

 severe Winter of '88 I have had very few. Is not this a 

 presumptive proof of their torpidity? and that they were 

 destroyed by the severity of that Season ? — Your account of 

 the 26th and 27th of March in 1777 was felt here in Lat. 

 52.45° but no swallows appeared. The 27th was insufferably 

 hot, with a S.W. Wind ; which changed in the afternoon to 

 IST.E. with a thick Sea-hase, and my Thermometer sunk 

 above 20 degrees in 3 or 4 hours. The greatest change I 

 have ever observed. — I find in 1776, Jan. 31st, your Thermo- 

 meter sunk to 0°, mine of Farenheit was at 16°, and in 1784, 

 Deer. 10th, when your DoUands was 1° below 0°, mine was 

 but at 10°. The coldest Air I have measured was Jan. 19, 

 in 1767, when it was down to 1°. I take the liberty to tell 

 you this, as it possibly may be entertaining to you to see 

 the difference of less than 2 Degrees of Lat. 



Sir, when you print a 2^ Edition, (which the merit of your 

 Book will certainly soon demand) I hope in your description 



