Joseph Lancaster confidently claimed that "a boy who can read can teach, although he knows nothing about it". Thus came into existence Lancaster's famous monitorial system of teaching Monitors were drawn from the brightest pupils and at Hitchin they were usually no older than 12 or 13 years. Before or after the schoolday the Master would hold classes to teach the monitors. They, when school assembled would instruct the pupils, marching them to stand on the semi - circles around a teaching post from which the lesson in spelling,reading or arithmatic would be hung. The Monitor demonstrated and the pupils repeated, in turn at his commands. The lesson finished, the monitor gave the commands by which the children returned to their desks to write what they had learned and to be tested by the Master. If the teaching had been successful the monitor as well as the pupil might be rewarded with a merit sticker, badge or small prize. As well as teaching there were monitors for ruling books, organising slates for writing, mending pens, distributing and collecting books and dealing with absentees. A monitor - general looked after all the other monitors.

Monitors were paid a small amount for their work. In 1820 monitors in the Girls' School at Hitchin received a penny a week. In 1846 the chief monitor in the Boys' School received £20 a year. During the 1840s teaching monitors began to be replaced by pupil teachers. At Hitchin British Schools records show monitors being employed to good effect as late as 1891 but in less responsible tasks.