The havoc of clothes need not be great if the children are dressed for their little excursions, as they should be, in plainly made garments of some loosely woven woolen material, serge or flannel. Woolen has many advantages over cotton, and more over linen, as a clothing material; chiefly, that it is a bad conductor; that is to say, it does not allow the heat of the body too free an exit, nor the heat of the sun too free an entrance. Therefore the child in woolen, who has become heated in play, does not suffer a chill from the sudden loss of this heat, as does the child in linen garments; also, he is cooler in the sunshine, and warmer in the shade.