The teacher's opportunity to work marked and permanent physical benefit to every pupil under her charge, by daily and steadily following up most or either of the above exercises, or of some substantially equivalent, can scarcely be over-estimated. The exercises strengthen the postures, whether sitting or standing. When a teacher insists on having her children erect for six hours out of the twenty-four, and makes plain to each one the value of being straight, and the self-respect it tends directly to encourage, there need be no great fear that the remaining waking hours will make any child crooked. It is in school generally that the mischief of warping and crooking is done; and hence there, of all places, would be the most appropriate place for the undoing of it. Dumb-bells of but a pound each have been mentioned here so far. Such would be fitting for pupils under ten years of age. For all older pupils the same work with two-pound bells will prove generally vigorous enough; and whoever wishes to judge what these light weights can do in a short time should examine the results of Dr. Sargent's exercises with them and other light apparatus at Bowdoin College (see Appendix II.). Those who are already decidedly strong can of course try larger bells; but it is astonishing how soon those of only two pounds seem to grow heavy, even to those who laugh at them at first. Of course, all the work before described cannot be gone through with in ten minutes in mid-morning, or even in the twenty of the morning and afternoon sessions combined; but much of it can: and an advantage of naming too much is that it enables the teacher to vary the work from day to day, and so, while effecting the same results, prevents anything like monotony.