“For several evenings they assembled in large numbers on a tree at a short distance from my house, and, after remaining seated for some time, one of them, who appeared to be commander-in-chief, kept flying about in all directions, and at length, with a sharp and loudly repeated call, he darted up into the air.  In an instant the whole congregation were on the wing, following their leader in a sort of spiral track.  In a little time they had risen so high that I lost sight of them, but after a short absence they again returned and took up their position on the tree which they had just left.

“This manoeuvre they continued for some time, till one day they set off in reality, and I saw no more of them for the winter.”

“I read, somewhere, Uncle Thomas, that the Chinese eat swallows’ nests.  I cannot understand this, Sir; surely the mud and clay, of which swallows’ nests are composed, would make but an indifferent repast.”

“I dare say they would, Frank, if they were made of clay and mud, as the nests of our swallows are; but such is not the case.  Various opinions are entertained as to the substance of which the nest of the esculent swallow is made.  Sir George Staunton, who accompanied Lord Macartney in his embassy to China, gives a very interesting account both of the swallow and of its nest.

“In the Cass,” says Sir George, “a small island near Sumatra, we found two caverns running horizontally into the side of the rock, and in these were a number of those birds’ nests so much prized by the Chinese epicures.  They seemed to be composed of fine filaments, cemented together by a transparent viscous matter, not unlike what is left by the foam of the sea upon stones alternately covered by the tide, or those gelatinous animal substances found floating on every coast.  The nests adhere to each other and to the sides of the cavern, mostly in horizontal rows, without any break or interruption, and at different depths from fifty to five hundred feet.  The birds that build these nests are small grey swallows, with bellies of a dirty white.  They were flying about in considerable numbers, but were so small, and their flight was so quick, that they escaped the shot fired at them.  The same sort of nests are said to be also found in deep caverns at the foot of the highest mountains in the middle of Java, at a distance from the sea; from which source it is thought that the birds derive no materials, either for their food, or the construction of their nests, as it does not appear probable they should fly in search of either over the intermediate mountains, which are very high, or against the boisterous winds prevailing thereabouts.  They feed on insects, which they find hovering over stagnated pools between the mountains, and for the catching of which their wide opening beaks are particularly adapted.  They prepare their nests from the best remnants of their food.  Their greatest enemy is the kite, who often intercepts them in their passage