There are, it is to be presumed, forms of exercise which are not judicious from their very nature; but I find myself at a loss to name any one which girls desire, or in which they indulge, that would properly fall under this class, unless it be sewing and washing. Whenever our girls have been injured by physical exercise of muscle or nerve, it has been, probably, because the exercise taken has been injudicious in one of the senses above defined. Even with regard to the stair-climbing, which our modern houses make a necessity, the harm generally comes from the fact that too many flights are ascended at once, or that the lifting of the weight of the body through the twenty, or forty, or sixty feet is too rapidly performed. But long flights of stairs are a necessity where land is so dear that, though a man may buy an unlimited extension up and down, he can usually afford to purchase little on a horizontal plane, and thus, to our city-bred girls, at least, the necessity of climbing stairs exists from their earliest attempts at walking, so that stair-climbing may, by my second limitation, come under the head of judicious exercise. It were, however, well to inquire whether there are not different sets of muscles called into requisition in this universal exercise by different individuals, and whether children should not be so educated in climbing, that they may lift the unavoidable weight rather by straightening the knee than by making undue demands, as many do, on other muscles not so well placed to bear it. It seems to me that there is a great difference in this respect in different persons. It were also well that architects should remember that shallow steps may be, and, indeed, generally are, much more fatiguing than steps of the usual height, for the very reason that an _unusual_ demand is made, a greater number of volitions or impulses required, for a given height. A greater width in the step, also, makes the effort more difficult--partly for the same reason, and partly because a greater and unusual effort has to be made to throw the body forward at the same time that it is lifted up.