OF BIRDS. 
155 
cles, that birds are qualified for flying. In men, these 
muscles scarce constitute a seventeenth part of the mus- 
cles of the body; but in birds they considerably outweigh 
all the other muscles together. This circumstance alone, 
i. e. the want of suitable muscles, renders all human at- 
temps to fly, equally vain and fruitless: though there 
have not been wanting such attempts; and much inge- 
nuity has been displayed in constructing wings for the 
purpose — but, the power of using them was beyond the 
reach of human art to supply. A fanciful genius of this 
description, once spent much time in building a pair of 
wings, with which he proposed taking his flight from the 
top of a barn. He was well advised, to fly up to the sta- 
tion, whence he intended to take his departure; but he 
observed, that u he would take a fair start, to give a fair 
trial.” His intentions were to alight on a dunghill, 
which was situated at a small distance; but it happened, 
unfortunately, that a hog-pen lay between the two sta- 
tions, over which he designed, most eagle-like, to soar. 
At length, he most courageously took his flight, and ac- 
tually succeeded in alighting at the bottom of the hog- 
pen, though not entirely clear of bruises, and not without 
being pretty well bespattered with the mire at the bottom 
of the pen: nor did he extricate himself from his wings 
without considerable difficulty— this, with much strug- 
gling, he at length effected. And now it was, that, he 
was glad to leave his wings behind him in the pen, and 
take to flight on all-fours. 
Birds exhibit a great variety of instinct: in their va- 
rious evolutions; in the construction of their nests; in 
rearing their young; in procuring their food; in their as- 
sociations, and their migrations. The structure of their 
nests, exhibits an admirable degree of mechanism: it is 
equally admirable, to observe the perfect similitude that 
appears in all the nests of birds of the same species; and 
the constant difference between the* nests of one species 
and another! together, with the neatness and precaution 
which all of them observe. One species builds its nest 
on the top of trees; another on the ground, under a ca- 
nopy of grass; or, with a shelter either of herbs, or a 
