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ter, in cold climates, appears to be a fufficient 
reafon for the Swallow tribes quitting them: but 
fince it is probable that the fame caufe does not 
fubfift in warm countries, recourfe fhould be had 
to fome other plaufible reafon for their difappear- 
ing. Of the three opinions propagated by natu- 
ralifts, the firft feems to carry the greateft degree 
of probability alortg with it; namely, that they 
remove nearer the fun, where they can procure a 
continual fupply of their natural food, and a tem- 
perature of air adapted to their conftitutions. Mr. 
Adanfon has proved beyond contradiftion, that 
this is the cafe with refpeft to fome fpecies of 
American Swallows : they are often feen aflem- 
bled in flocks innumerable, on churches, rocks, 
and trees, previous to their departure thence. 
And Mr. Collinfon proves their return here in 
equal numbers, by two curious experiments of 
lindubitable credit ; the one communicated to 
him by Mr. Wright, mafter of a fhip ; the other 
by Sir Charles Wager; who both defcribed what 
happened to each during their refpeftive voyages. 
Their accounts being virtually the fame, we fhall 
only adduce that of Sir Charles Wager. ' Re- 
turning, * fays he, * in the fpring of the year, as 
I came into foundings in our channel, a great 
flock of Swallows came and fettled on all my rig- 
ging; every rope was covered; they hung on 
one another, like a fwarm of bees ; the decks and 
carvings were filled with them. They feemed 
almoft famifhed and fpent, and were only feathers 
and bones ; but being recruited with a night's 
reft, took their flight in the morning.' This vafl: 
fatigue is an abfolute proof that their journey muft 
have been very long, confidering the amazing 
fwiftnefs of thefe birds : it is therefore probable 
they had croflcd the Atlantic Ocean, and were re- 
turning from the fliores of Senegal, or fome other 
parts of Africa. 
A gentleman named White, whofe veracity 
appears unqueftionable, in the year 1768 had an 
ocular proof of what may be reafonably fuppofed 
to amount to an aftual migration of Swallows. 
Travelling very early> on the morning of Mi- 
chaelmas-day, near the fea-coaft ; at the begin- 
ning of his journey he was furrounded by a thick 
fog ; but, on a large wild heath, the mift began 
to break, and difcovered to him numberlefs cluf- 
ters of Swallows perched on the ft:anding bufhes, 
as if they had roofted there. As foon as the fun 
burft out, they were inftantly on the wing ; and, 
with an eafy and placid flight, direded their 
courfe towards the fea ; after which only a few 
fl:ragglers were to be feen. 
This rendezvous of Swallows, about the fame 
time of the year, is obferved by Pennant to be 
very common on the willows in the iflets of the 
Thames ; where, in lefs than half an hour, fifty 
dozen have been caught by torch-light. 
The fecond opinion has the fandlion of anti- 
quity for it's fupport. Arifl:otle and Pliny think 
that Swallows do not remove to any great dift:ance 
from their fummer habitations, but repofe during 
winter in the hollows of rocks, and lofe their plu- 
mage at that period. Many ingenious gentle- 
men have adopted the former part of their opi- 
nion ; and feveral teftimonies have lately been pro- 
duced that fome Ipecics at leaft have been difco- 
vered in a torpid fl:ate. The honourable Mr. 
Daines Harrington, a few years ago, comm.uni- 
cated the following faft to Mr. Pennant, on the 
authority of the late Lord Belhaven — that num- 
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bers of Swallows haVe been found in old dry vva?]?;^ 
and fand-banks, near his lordfliip's Itrat in hint 
Lothian; not once only, but from year to year; 
and that, on being expofed to the warmth of a finr, 
they revived. This circumftance is confirmed 
by fimilar obfervations in difirrent places of this 
kingdom, by perfons of whofe veracity it would 
be illiberal to doubt. 
The fubfcquent account of fome Swallows on 
the Rhine, by Mr. Achard, was communicated 
by Mr. Peter Collinfon, and read before the Royal 
Society, in 17^3. 
* In the latter end of March,' f lys Mr. Achard, 
* I took my paflage down the Rhine to Rotter- 
dam. A little below Bafil, the fouth bank of the 
river was very high and fl:eep, of a fandy fcii, 
fixty or eighty feet above the furface of the water, 
* I was furprifcd at feeing, near the top of the 
cliff, fome boys, tied to ropes, hanging down, do- 
ing fomething. The Angularity of thofe adven- 
turous boys, and the bufinefs they fo daringly at- 
tempted, made us fl:op our navigation to enquire 
into the meaning of it. The watermen told us, 
they were fearching the holes in the clifi' for Swal- 
lows or martins, which took refuge in them, and 
lodged there all the winter, till warm weather, and 
then they came abroad again. 
* The boys, being let down by their comrades 
to the holes, put in a long rammer, with a fcrew 
at the end, fuch as is u fed to unload guns; and 
twifl:ing it about, drew out the birds. For a trifie 
I procured fome of them. When I firft had them, 
they feemed fl:iff and lifelefs. I put one of tl^m 
in my bofom, between my flcin and fliirt; and 
laid another on a board, the fun fhining full and 
warm on it; and one or two of my companions 
did the like. 
' That in my bofom revived in about a quar- 
ter of an hour. Feeling it move, I took it out to 
look at it, and law it ftretch ttfelf on my handj 
but perceiving it not fufficiently come to itfelf, I 
put it in again. In about another quarter, feeling 
it flutter pretty brifl^ly, I took it out, and admired 
it. Being now perfeftly recovered, before I was 
aware, it took flight : the covering of the boat 
prevented me from feeing whither it went. The 
bird on the board, though expofed to a full fun, 
yet, I prefume, from a chillnefs of the air, did not 
revive fo as to be able to fly.' 
Such is Mr. Achard's account; on which the 
following obfervations were made by Mr. Collin- 
fon. 
' What I colled from this gentleman's rela- 
tion is, That it was the pradlice of the boys an- 
nually to take thefe birds, by their apparatus, and 
ready method of doing it ; and the frequency of it 
was no remarkable thing to the w^atermen. Next, 
it confirmed my former fentiments, that fome of 
this Swallow tribe go away, and fome flray behind 
in thefe dorm.itories all the winter. If my friend 
had been particular as to the fpecies, it would 
have fettled that point.' 
We cannot withhold our afltnt from the abeve 
circumftances, though feemingly contradiflory to 
the common courfe of nature in refped to other 
birds : and muft therefore divide our belief refDe(fl- 
ing thefe two very different opinions; and con- 
clude that fome Swallows emigrate, while others 
take up their winter-quarters at home. 
The third notion would be too chimerical and 
unnatural to merit the leaft attention, were it not 
that fome of the learned have been credulous 
enough 
