In confinement nightingales may be allowed to fly freely, as I have often permitted them; but they do not then sing so well as when in a cage, where they are less subject to interruptions, and where also they live longer and more healthily, from being fed with more care and regularity. The nightingale's cage, of whatever form, must not be less than a foot and a half in length, by about one in width, and one or more in height. The top should be made of linen or soft stuff, that when jumping and struggling, especially when first caught, he may not injure his head. The drinking-cup and feeding-trough are fastened on the outside, unless it is preferred to introduce the latter within, in the form of a drawer. The following are the best form and proportions for a nightingale's cage, that I am acquainted with:--Length, one foot and a half; breadth, eight inches; height, fifteen inches in the middle; thirteen at the sides, because the roof is arched. The sides are made of osiers about a quarter of an inch thick; the bottom is made of the same material, but it is covered by a drawer an inch and a quarter in depth. In order to clean it more easily, I cover it with coarse paper, which I renew every time. The feeding-trough is introduced on one side, with edges high enough to prevent the bird's spilling too much of the food. In the middle of the front of the cage, and extending from top to bottom, is a cylindrical projection in the form of a belfry, in which is suspended a large drinking-glass. The upper stick of the cage is confined here, terminating in a fork, or fixed to a semi-circle, that the projection may not be prevented from moving. This projection is made of osiers, like the rest of the cage. The middle and lower sticks are covered with green cloth, firmly sewed on, that the nightingale may have a softer perch, and not have his feet so soon injured, which is very common with imprisoned birds. The arched roof is also covered with green stuff, which is painted that colour with oil paint, as well as the whole of the cage. But it must be well dried, and quite free from smell before the bird is put into it.
My reasons for preferring this cage are, first, because being small, it occupies less room, without disadvantage to the bird or to the apartment; second, because the size of the osiers leave small intervals for the admission of light, and it is consequently darker; third, because the bird can bathe without wetting his cage or his perches: and consequently his feet remain cleaner and more healthy.