[ 2-69 ] 
whence two things may be gathered ; firft, that many in- 
fe<fts abide high in the air^ even in rain; and next, that 
the feathers of thefe birds mull be well preened to relift 
fo much wet. Windy, and particularly windy wxather 
with heavy lliowers, they dillike ; and on fuch days with- 
draw, and fcarce ever are feen.^ There is a circum- 
ftance refpedting the colour of fwifts,, which feems not to 
be unworthy our attention^ When they appear in the 
fpring they are all over of a glolTy, dark, foot-colour, ex- 
cept their chins, which are white j but by being all day 
long in the fun and air they become quite weather- 
beaten and bleached before they depart ; and yet they 
return glolfy again in the fpring. Now if they purflie 
the fun into lower latitudes, as fome fuppofe, in order to 
enjoy a perpetual fummer, why do they not return 
bleached ? Do they not rather, perhaps, retire to reft for 
a feafon, and at that jundture moult and. change, their 
feathers, lince all other birds are known to moult fooii 
after the feafon of breeding ? Swifts are very anoma- 
lous m many particulars, dilfentihg from all their con- 
geners not only in the number of their young, but iii 
breeding but once in a fummer; whereas all the other 
Britilh bir undines breed, invariably twice. It is pad all 
doubt, th?X fwifts can breed but once, 'lince they with- 
draw in a very fhort time after the flight of their young, 
and fome time before their congeners bring out. their fe- 
cond broods. We may here remark, that as fwifts, breed 
but once in a fummer,, and only two at a. time, and the: 
other hir undines twice, the, latteiy who lay from/o^r to. 
