But this is not the type of work which Roberts advocated in 1887, when he was called from Boston to Springfield, or for which he is remembered in Association circles today. After a few years of experience, he says, it began to dawn upon him that health did not necessarily improve as strength increased, and that the Winship plan of heavy lifting was not calculated to yield “the greatest good to the greatest number, physically speaking,” any more than the Dio Lewis exercises, which he considered too light and easy. “I noticed when I taught slow, heavy, fancy, and more advanced work in acrobatics, gymnastics, athletics, etc.,” he writes,[275] “that I would have a very large membership at the first of the year, but that they would soon drop out because they could not do the work, and ... the weak members would not renew the next season.... I give most of my attention to those who need it most, the beginners and those who cannot for various reasons do the more advanced work. By ... pushing simple work I can get more men to go into it, and find it easier to find leaders to teach it, and also can run more classes in a day.... In competitive work and the harder kind of safe exercises ... the men leave the classes and become spectators, but when I teach easier work the crowd do the work and the few look on.” He was also led to emphasize trunk exercises rather than those of the legs and arms, in order to influence respiration and circulation favorably and keep the abdominal organs in a condition of healthy activity; and special attention was given to those muscles which expand the chest, draw back the head and shoulders, and hold the body erect. According to the Roberts “platform,” as it came to be known, all exercises should be “safe, short, easy, beneficial, and pleasing.” They must be safe for the man who does them, _i.e._, well within the limits of his capacity at the time. When apparatus is employed such work must be selected that the members of the squad or class follow each other rapidly, without tedious waits. No exercise must represent more than a slight advance over others which have preceded it. Each “must serve some definite and useful end,” instead of being chosen at random and with nothing in mind beyond the mere desire to keep the class busy. It must give pleasure if it is to exert its full effect and not degenerate into a sort of monotonous and mechanical “grind.” These principles found illustration in the _Roberts Dumb-bell Drill_, the _Home Dumb-bell Drill_, and the little volume of _Classified Gymnasium Exercises, with Notes_,[276] which were very generally used in Association gymnasia thirty years ago.