BRITISH BIRDS OF FASTEST FLIGHT Gl 
known that in proportion to its weight, other 
things such as shape and specific gravity being 
similar, a small body experiences much greater 
resistance than a large body. The resistance of 
the air to the fine particles of vapour which con- 
stitute a cloud is such that they only fall at the 
same rate of a few feet per hour. And in the case 
of two birds of similar shape and specific gravity, 
but one eight times the weight of the other, the 
larger bird would ultimately attain a velocity 
roughly twice as great as the other, if both fell 
for a sufficient distance to attain their limiting 
velocities, i.e. the velocity at which the resistance 
offered by the air is equal to the attraction of 
gravity. Similarly if the one bird were four times 
the weight of the other, the velocity ultimately 
attained under the conditions mentioned would 
be roughly one and a half times as great as the 
other. 
In " Notes by an Old Stalker " in the Field 
for September 9, 1922 (p. 370) there appears the 
following interesting account of a duel between a 
golden eagle and a peregrine which the writer 
himself witnessed : 
" Although by a long way our most powerful 
bird, the eagle is by no means a match for some 
