"Yes, boys; but plain enough when you come to examine into it. And the best stuff for the hatters is such hair as has most joints ready to catch into each other: the rabbit's hair is very good, and for that reason."
"And is it possible, Uncle Philip, that any bird can do such work as this?"
"Not only possible, boys, but true. There are several birds very expert at making felt, and their nest appears like a piece of hatter's felt, or double-milled woollen cloth. I do not mean to say that it is as close and solid as the hat or cloth; it would feel in your fingers looser than either, still it is quite close; and when you examine it, you will find it put together in the same way; it is all carded into one mass, and not woven together thread by thread, or hair by hair."
"And are there many birds able to do such work, Uncle Philip?"
"I told you, boys, that there were several. The chief article which they use is wool, but with this many other things will be found mixed—sometimes, upon the outside, fine moss—sometimes pieces of a spider's web rolled up into a little bundle—sometimes, when cotton can be had, they will use small bunches of cotton-wool; but sheep's wool they must have, and by means of that, they contrive to make, with the other things I have mentioned, a felt wonderfully smooth."
"Is it smooth on the outside, Uncle Philip?"
"Sometimes quite so; but always as smooth on the inside, when it is first made, as if it had been felted together by the hat-maker. There is another thing curious enough in some of these nests. The hatter, you know, binds the rim of his hat to make it stronger; and some of these felt-making birds will make their nests stronger by a binding all around them of dry grass stems, and sometimes of slender roots, and they take care to cover these grass stems, or roots, with their felt-work of moss and wool. But there is something else not less strange, I think, than the binding. It is this: they will build their nests in the fork of a shrub or tree; and to keep them from falling, they will work bands of this felt round all the branches which touch the nest, both below and at the sides. And those parts of the nest which touch the large branches are always thinner than the other parts, which have no support; in those parts the nest is nothing but a thin wall of felt, fixed around to fit the shape of the branch, and that is enough to make that part of the nest warm and soft. Here is a picture of one of these felt-nests, fastened in the way of which I have been telling you."
Chaffinch's Nest on an Elder-tree.