NORTH AMERICA. 
23 I 
be productive of any real benefit to mankind, and 
pronounce fuch attention to natural hiftory merely 
Speculative, and only fit to amufe and entertain the 
idle virtuofo ; however the ancients thought other- 
wife : for with them, the knowledge of the paffage 
of birds was the ftudy of their priefts and philoso- 
phers, and was confidered a matter of real and in- 
difpenfable ufe to the date, next to aftronomy ; as 
we find their fyflem and practice of agriculture was 
in a great degree regulated by the arrival and dis- 
appearance of birds of paffage ; and perhaps a ca- 
lendar under fuch a regulation at this time, might 
be ufeful to the hufbandman and gardener. 
But however attentive and obfervant the an- 
cients were on this branch of fcience, they feem to 
have been very ignorant or erroneous in their con- 
jectures concerning what became of birds, after 
their difappearance, until their return again. In 
the fouthern and temperate climates fome imagined 
they went to the moon : in the northern regions 
they fuppofed that they retired to caves and hollow 
trees, for (belter and fecurity, where they remained 
in a dormant ftate during the cold feafons : and. 
even at this day, very celebrated men have after ted 
that fwallows (hirundo) at the approach of winter, 
voluntarily plunge into lakes and rivers, defcend 
to the bottom, and there creep into, the mud and 
fiime, where they continue overwhelmed by ice in 
a toipid Hate, until the returning fummer warms 
them again into life ; when they rife, return to the 
furface of the water, immediately take wing, and 
again people the air. This notion, though the latefl, 
feems the mo ft difficult to reconcile to reafon and 
common fenfe, refpe&ing a bird fo fwift of flight 
that it can with eaf; and pleafure move through the 
