No doubt the fees varied according to the merits of the school, for the schools at Athens seem to have differed greatly. Demosthenes, when boasting of his career, in his speech _On the Crown_, says that he went as a boy to the _respectable_ schools;[220] the quality and quantity of the teaching must have been varied to suit the parent’s pocket. For the poor there would probably be schools where only the elements of reading and writing were taught. In the higher class of school these elements would be taught by under-masters, frequently slaves; but free citizens might also be reduced by poverty to take such a post. This may be seen from the case of the father of Aischines, the orator.[221] Impoverished and exiled like many democrats by the Thirty Tyrants, he returned with the Restoration a ruined man. To earn his living, he became an usher at the school of one Elpias, close to the Theseion, and taught letters: his son Aischines seems to have begun his life by assisting his father in this occupation. His opponent, Demosthenes, takes advantage of the contempt with which these ushers were regarded to declare that the father was a slave of Elpias,[222] “wearing big fetters and a collar,” and the son was employed in “grinding the ink and sponging the forms and sweeping out the schoolroom (παιδαγωγεῖον [paidagôgeion]), the work of a servant, not of a free boy.” No doubt letters and music were often taught at the same school, in different rooms. Such an arrangement would be natural and convenient. The vases suggest it, but their evidence is uncertain. The school buildings seem often to have been surrounded by playgrounds. A passage in Aelian[223] shows us the boys, just let out of school, playing at tug-of-war. No doubt in these places they played with their hoops and tops, and amused themselves with pick-a-back and the stone- and dice-games which corresponded to our marbles. In villages these playgrounds probably did duty as palaistrai.