106 
tion.” For years this solution has occupied my attention, and 
although I have myself always been convinced that such of these 
entirely American birds as occasionally visit Europe do reach us by 
a passage across the Atlantic, this remains a mere opinion, carrying 
no weight if unsupported by facts, or by at least sufficient argument 
to make good the question at issue. 
The mere comparative review of the occasional visitors among the 
birds of Great Britain and of Germany will lead to the conclusion 
that the route of American birds to Europe must needs be a voyage 
across the Atlantic, for, almost all the additions to the birds of 
Europe, of species purely American, have been obtained in Great 
Britain—which could not have been the case if they had proceeded 
in any other than an eastern direction—whilst the additions by Ger- 
many, furnished to the European Ornis, consist nearly entirely of 
birds belonging to Asia. 
However striking the result of such a comparative review may be, 
one question will always present itself, namely :—Whether it be pos- . 
sible for a bird to sustain an uninterrupted flight sufficient to carry 
it across the wide expanse of the Atlantic. I am convinced that this 
is possible, and shall endeavour to prove such possibility. 
This purpose necessitates a measure for the rate of locomotion of 
a bird through the atmosphere. Fora long time I vainly endeavoured 
to obtain reliable data upon which to found an estimation of the rate 
of flight of birds—when at last I hit upon a passage in Yarrell’s 
‘ British Birds,’ ii. p. 295, where, speaking of the Carrier Pigeon, he 
mentions the fact of one of these birds having performed a flight of 
150 miles in an hour anda half: it was on the 24th of June 1833; 
the Pigeon flew from Rouen to Ghent ; sixteen others flew the same 
distance in two hours and a half. 
Wonderful as this instance of swiftness of the flight of a bird may 
appear, it certainly is still surpassed by birds when on their period- 
ical migrations ; for, the above feat was accomplished by an indivi- 
dual hatched and reared in at least semi-confinement, whose powers 
of flight consequently could not be nearly so well developed as in a 
bird grown up wild and free, which nearly every hour of his life ‘has 
to depend on the utility of its wings, either for the purpose of over- 
taking its prey, or for that of escaping from being caught. 
Laying down, therefore, 100 geographical miles per hour as the 
rate of flight of birds during distant migration, one keeps—after 
the above—quite within safe bounds, and, at this rate, the 1600 
geographical miles from Newfoundland to Ireland would be effected 
in sixteen hours. No orithologist will doubt for a moment the 
capability of a healthy bird to sustain a flight of that duration ; 
during the long summer days many of the Hirwndinide are on the 
wing for as long a period, and although their flight may be inter- 
rupted by occasional rests of very short duration, it is performed in 
the lower, less buoyant atmosphere, and consists of so many evolu- 
tions, that most decidedly it must on the whole be much more tiresome 
than the straight path in the pure upper regions of a bird bent on 
the performance of one long pilgrimage. 
