10 STUDIES IN BIRD-MIGRATION 



in a pamphlet published in the year 1703 by "A Person 

 of Learning and Piety." The title of this rare and 

 curious little tract is " An Essay Towards the Probable 

 Solution of this Question — Whence Come the Crane 

 and the Swallow, when they Know and Observe the 

 Appointed Time of their Coming?" and the "probable 

 solution " is that migratory birds retreat to the moon 

 to spend the cold season ! 



The author allows sixty days for the journey, and 

 remarks that as the moon is not a stationary body in 

 the heavens, "it cannot be supposed" that the birds on 

 embarking upon their journey "direct their course to 

 the moon, but rather offended by the steams of earth 

 do tend directly from it, and that straight line 'tis 

 probable they pursue, till they come so near the moon, 

 that she is their fairest object to draw their inclination ; 

 for if the moon hath a motion in a month about the 

 earth, then at the two months' end they [the birds] find 

 it in the same line of direction where it was when they 

 began their journey ; . . . therefore if they proceed in the 

 same straight line, they will be sure to meet the moon on 

 the way." The question of food and sleep on the journey 

 is dealt with in the same nonsensical fashion. He 

 says : — " As to eating, it may possibly be [i.e., exist] 

 without in that temper of the ^ther where it passeth, 

 which may not be apt to prey upon its spirits as our 

 lower nitreous air ; and yet even here Bears are said to 

 live upon their summer fat all the winter long in 

 Greenland, without any new supply of food. Now we 

 noted before that some of those birds (and perhaps it 

 may be true of the rest) are very succulent and sanguine, 

 and so may have their provisions laid up in their very 

 bodies for the voyage. 



