The teachers of physical training have long felt that even the combination of gymnastics and athletic sports left much to be desired in the carriage and movements of the body, so classic and esthetic dancing, which stands between the two, more closely allied to gymnastics in its movements and to games in its spirit, was introduced as an additional gymnastic exercise, to harmonize the movements of the body, and to produce an ease of manner with a grace of beauty and of motion. _Society Dancing._—A sharp distinction must be made between the modern gymnastic dancing and society dancing. In the latter, the waltz and the two-step always require a partner. The dancing is ordinarily confined to the ball-room, with its poor ventilation and overheated air; add to these the constriction of the waist, so that the free action of the heart and lungs is interfered with, and under these conditions it may even prove a dangerous pastime to the young woman with weak heart or lungs. As a physical exercise, the waxed floor of the ball-room still further reduces its value. _Gymnasium or Classic and Esthetic Dancing._—For the gymnasium dancing there must be, first of all, the loose dress and heelless slippers, and an abundant supply of fresh air at a proper temperature, while the foot grips the floor as tenaciously as in boxing or fencing; a smooth floor renders an artistic execution impossible. The floor should be rough or covered with canvas, when dancing becomes as good a developer of the heart and lungs as running or swimming. Girls in good physical condition can keep up esthetic dancing for an hour with very few rests or pauses. The work done in one hour is about equivalent to a walk of ten miles. The first steps in the attainment of grace of motion is to avoid short, angular, jerky movements, and to learn to do everything, even the most difficult exercises, with the least expenditure of power and energy. This implies considerable muscular strength and great muscular endurance and control. As soon as the dancer loses her balance or poise, holds one arm too straight, and bends the other one at too sharp an angle, or puts too much stress on this movement and too little on that, or makes too much effort, the harmony is lost and gracefulness is not attained.