The essential points in a well-made chair are comfort, lightness, and strength. Of course, as men and women are pretty much of the same proportion all over the world, chairs, of which the seat is about the height of the lower process of the human knee-joints, must be of the same height, or but slightly varied, in every country. From the habit that so many persons have of throwing their whole weight back and, as we are told, in some countries, of balancing their persons on the back legs of their chairs and inclining their legs in the direction of the chimneypiece, there is often an immense strain on the back joints of chairs. Whether we lean back or swing on them, the junction of the seats of chairs with the backs is always subject to severe trials; and on no article of furniture in common use is such good joinery required. It is worth while to look at the old wall paintings of the Egyptians, as they are given in Rossellini and the great French book of the 'Description de l'Egypte,' to see what capital workmanship those most ancient carpenters bestowed on their chairs. Those of the best and oldest periods are without connecting bars to the legs before or behind, all the strength of the construction being centred in the excellence of the joints of the seat with the back and legs; and in modern workshops, the highest skill is applied to ensure strength in these points of junction. If the wood is thoroughly dry, the mortises and tenons fitting perfectly, and the glue good, the different parts are so wedded together that the whole structure becomes one piece, as if nature had made a vegetable growth in that fashion, all the fibres of which have continuous and perfect contact with each other. If, however, there is a deficiency in any of these conditions, these joints fail. If the wood shrinks, or the tenons do not fit the mortises all through, or the glue is deficient, these various portions speedily come to pieces. Sofas, couches, and stuffed chairs are so much more massive in construction that there need be no risk of such a kind of disintegration. The members of which a chair is made up may be either turned in the lathe, or left massive enough to allow of carving on the legs, backs, or round the framework of the seat. Turned work can be lightly inlaid with ivory, as that of ancient Egypt, painted, gilt, or mounted (lightly also) with metal. The subjects of the carving may be either figures of men, horses, lions, or the heads and legs of such animals, acanthus leaves, and arabesques. Many of these ornaments have been used from ancient times, and revived at various historical periods. For modern rooms the lightest construction is most in place, and therefore carving should be compact in composition and delicate in execution, without prominences or undercutting that would interfere with comfort or be liable to breakage.