A hawk-house should have solid walls, and a floor well raised above the ground, so as to be impervious to damp. It should have a loft or room above it, which will help to save it from extreme variations of temperature by day and by night. In such a place all hawks, except merlins and those which have come from any hot climate, may be kept through all ordinary weathers, care being taken, of course, that the ventilation is sufficient, but in winter not excessive. In times of severe frost or excessive damp a very moderate amount of artificial heat should be introduced. A very good arrangement, when it can be adopted, is for the back wall of the hawk-house to be also the back wall on the other side of a warm conservatory or well-heated room. In such cases it is unnecessary, unless in exceptional winters, to have any heating apparatus in the hawk-house itself. Merlins and the tropical hawks, such as shaheens, barbarys, and also the desert falcons, should, in cold or damp weather at least, be placed in a room which is over a very well-warmed apartment, and has the flue of one chimney at least running along one of its sides. A room immediately above a kitchen is pretty safe in all weathers for all hawks if the fire is kept up all night, but not otherwise. Where the room is unavoidably isolated, there must be a stove or some heating apparatus; but the heat thrown out must be very moderate indeed, or the hawks when taken out for weathering, or even when left stoveless by day, are nearly sure to catch cold. Changes of temperature in our islands are sudden and severe enough when due to natural causes only, but if they are produced by artificial means no hawk can be expected to endure them with impunity, and least of all gers, merlins, and the denizens of the sunny south. The hardiest hawks are peregrines and hobbies, but these, too, must be given a fair chance, even if it entail upon their owner some inconvenience and expense. Whenever the weather is very wet or damp, with penetrating fogs, opportunity should be taken, when the hawks are all out on their blocks or being carried, to warm the hawk-house thoroughly by artificial means, and purge it of all suspicion of damp.