“I think the conditions I laid down are both completely satisfied in these beautiful lines from one of Home’s tragedies. But if poetical allusions were merely employed for ornament, they would cloy the taste and encumber the sense—they must therefore help to illustrate and give force to those ideas that would otherwise be obscure, or which would be too rapidly passed over by the reader. For this reason they are generally taken from material objects with which our senses are most conversant, and are applied by the fancy to those parts of intellectual or moral subjects which require illustration, and on which the mind is invited to pause.”
Caroline concluded the conversation by repeating Warton’s lines on Fancy.
Waving in thy snowy hand
An all-commanding magic wand,
Of power to bid fresh gardens grow
’Mid cheerless Lapland’s barren snow;
Whose rapid wings thy flight convey
Through air, and over earth and sea,
While the various landscape lies
Conspicuous to thy piercing eyes.
30th.—It is curious, that it has never been ascertained what becomes of swallows when they disappear in autumn. Some naturalists have supposed that they retire to hollow trees, old buildings, or caves, where they remain in a torpid state during the winter; while others affirm that they lie at the bottom of lakes and ponds. This last, my uncle says, is a most extravagant idea, for nothing can be more certain than that they would decay there in a short time; besides it is well known that they moult or change their feathers early in the year, and no one can imagine that this can be accomplished while they are torpid and under water.
Facts, however, have not been wanting, to support both these opinions; numbers certainly have been found in old dry walls, and cliffs, and several were taken out of the shaft of an abandoned lead mine in Flintshire, clinging to the timbers, and apparently asleep. They were startled by a little sand being thrown on them, but they did not attempt to fly or change their place; this happened about Christmas.
For the watery system, Kalm, the traveller, is a decided advocate: my uncle shewed me a part of his travels in America, in which there is a good deal on this subject; but I must say it does not clear up my doubts. From Spain, Italy, and France, Kalm admits that they remove to warmer climates; but in England and Germany, he says they retire into clefts and holes of rocks, and in cold countries immerse themselves in the sea, or in lakes. He gives several instances of their having been found in this state in Prussia; but even by his own account it does not appear that they could have been to any depth in the water—for all those which he mentions were caught with a net among the reeds and rushes growing on the borders.
“Besides,” said my uncle, “as they are lighter than water, they could not sink even if they tried to do so; and as the lungs of birds differ very little in their structure from those of quadrupeds, it is quite incredible that they could live for several months or for several minutes under water. Even diving birds come up exhausted, and would be drowned like any other animal, if retained under water beyond a certain time. Swallows and martins indeed sprinkle and splash themselves as they glide along the surface, but they never dip completely into the water for a single moment. At the season when they disappear there is no want of their insect food in the air; nor have any of those cold blasts come, which at a later period would benumb them; what, then, could induce them, particularly the young birds who have just begun to enjoy the use of their wings, to take a dreary plunge into a pond? Cold and scarcity may drive some animals to hibernate, like your little dormouse, Bertha, but I am satisfied that the whole tribe of swallows fly off, like other birds of passage, to distant countries.”
“To what countries?” I asked him.
“It is probable,” he replied, “that there is some general temperature that suits them best, or that is most productive of those insects on which they prey; and as the seasons change, that temperature can only be obtained by approaching the equator, or perhaps by passing into a corresponding latitude of the southern hemisphere. A circumstance mentioned by our friend Colonel Travers, made a strong impression on me:—when he was going up the Mediterranean, I think in the latter end of April, a great number of swallows settled on the yards and rigging of the ship; they began to alight there about sun-set, and before nine o’clock some thousands had collected; but in such an exhausted state that they immediately went to sleep, and allowed themselves to be handled without making any attempt to escape. At daylight next morning they rose, as if by a single impulse, and flew away to the northward; and several prodigious flights of the same bird were observed, at a great height in the air, pursuing the same course towards Europe.
“Poor creatures,” said Frederick, “they must have come all the way from the north coast of Africa. Can you tell me, father, in what part of the Mediterranean this happened, that I may measure on the map the distance they had flown?”