Among the Romans , ball games were looked upon as an adjunct to the bath, and were graduated to the age and health of the bathers, and usually a place (sphaeristerium) was set apart for them in the baths (thermae). There appear to have been three types or sizes of ball, the pila , or small ball, used in catching games, the paganica , a heavy ball stuffed with feathers, and the follis , a leather ball filled with air, the largest of the three. This was struck from player to player, who wore a kind of gauntlet on the arm. There was a game known as trigon , played by three players standing in the form of a triangle, and played with the follis, and also one known as harpastum , which seems to imply a "scrimmage" among several players for the ball. These games are known to us through the Romans, though the names are Greek.