THE SCIENCE OF EASY-CHAIRS. 187 



frequently adopted by Europeans resident in hot climates, and is even 

 retained hy them after returning to England. But the function of the 

 cummerbund may, to a certain extent, be fulfilled by change of posture 

 alone. When the legs are drawn up, as in the picture of " Winter " 

 already referred to, the thighs partially cover the abdomen, and, taking 

 the place of additional clothing, aid the abdominal walls in protecting 

 the intestines and the blood they contain from the cooling influence of 

 the external air. 



Thus it is that in cold weather, when the quantity of covering in 

 bed is insufficient, persons naturally draw up their legs toward the ab- 

 domen, so as to retain as much heat as possible before going to sleep. 

 In hot weather, on the contrary, thej'^ wish to expose the abdomen as 

 much as possible to the cooling influence of the atmosphere. The post- 

 ure depicted by Alma-Tadema is the most efficient for this purpose. 

 It no doubt answers the purpose to lie down flat on one's back ; but in 

 this position the abdominal walls are more or less tight, whereas, when 

 one of the legs is drawn up as in the painting just alluded to, the walls 

 are relaxed, and, the intestines not being subject to any pressure, the 

 blood in them will circulate more rapidly, and the cooling process be 

 carried on more effectually. In this attitude also the thighs are com- 

 pletely separated, and loss of heat allowed from their whole surface. 



Varjdng conditions of fatigue also alter the postures which people 

 assume. When slightly tired one is content to sit down in an ordinary 

 chair in the position of the letter N with the middle limb horizontal. 

 As we get more and more fatigued we usually assume positions in 

 which the limbs of the N become more and more oblique, the trunk 

 leaning backward and the legs extending forward. If we lie down in 

 bed on our back the legs will probably become straight, but if we rest 

 upon our side they will be more or less bent. The straightness of the 

 legs in the supine position is simply due to their weight, which is then 

 supported at every point by the bed, but when we lie on our sides the 

 genuflection of the legs is most agreeable, because not only are the 

 muscles more perfectly relaxed, but, as the late Prof. Goodsir pointed 

 out, the bones which form the knee-joint are slightly removed one from 

 another, and thus the joint itself, as well as the muscles, passes Into a 

 state of rest. Some of the bamboo easy-chairs manufactured in India 

 allow us to obtain the advantages of both positions. These chairs are 

 made in the form of a somewhat irregular, straggling W, and in them 

 one can lie on one's back with every part of the body thoroughly sup- 

 ported, and the knees bent in the same way as they would be if one 

 lay upon one's side. 



Thus simple inaction, the relaxation of muscles, and the laxity of 

 joints, are some of the factors necessary for complete rest, and an 

 easy-chair, to be perfect, must secure them all. 



But it is possible for an easy-chair to secure all these, and yet be 

 imperfect. We have just said that usually, as the fatigue becomes 



