Let us now see how the birds set about building. Here are several nests in our picture; and turning to the pages of Macgillivray’s “British Birds,” I shall find exactly the information we need. I will, therefore, extract freely from this interesting writer, that my young readers may be as grateful to him as I am myself. [Sidenote: _The Domestic Life of a Pair._] Again turning to our picture, we find four nests. “A party of eight martins arrived here on the 1st of May. As this was quite a new location, they spent the whole day in examining the eaves of the house, the corners of the windows, and the out-buildings. By the following morning the question was settled, and they had, as you see, fixed upon a high wall with a slate coping, and an eastern aspect, and at once commenced making a general foundation for their nests. Suitable materials are procured from the banks of an adjoining pond, or a puddle in the lane. Let us go down and see them. Here they come, sailing placidly over the tree-tops; now they descend so as almost to sweep the surface of the pond; some of them alight at once, others skim round, as if borne away by a brisk wind. Those that have alighted walk about with short steps, looking round for materials. Some seem not to find the mud suitable, but seize on a piece of straw, or grass, which, tempering in the mud, they then fly off with. Returning now to the building, we see one using its tail planted against the wall, or against the nest, if sufficiently advanced, as a support, deposit the material it has brought by giving its head a wriggling motion, so that the mud slides gently into the crevices of yesterday’s work; then he retouches the whole. See, one has now arrived with his supply before the other has finished: he is impatient to disburden himself, and wants to drive off the worker, who rather snappishly retorts, and he, poor fellow, goes off for a while with the mud sticking to his bill. Now she has finished; there is room for him, and he goes back again and works hard in his turn. They never alight on the nest without twittering. At noon, if the weather be hot, they betake themselves to the fields, or, after a dip in the pond, sun themselves on the house-top for half-an-hour or so. Then they will hawk about for food, and after awhile one of them may, perhaps, return and give another touch or two to the work, or seat herself in the nest to consolidate the materials. But if cold, wet, or windy, they keep away. What they do with themselves I know not; but as soon as it clears up, they are at work again. At the beginning of their building, they seem to have no objection to leave it for a whole day; but as it advances, they become more interested or anxious, and one or both will sit in it all night, even though the weather be bad.”