The SBL calculated that London schools needed a thousand new teachers every year to replace those that left or retired. Until 1906 over half of these came through the ‘pupil teacher’ system.

At 13, pupils could stay on at school as probationers to help with the teaching of younger pupils. After two years as probationers, they would then spend another three years, learning the job before taking a final exam. If they passed, they would be paid to go to training college to become a qualified teacher.

There were usually two pupil teachers to each teacher. In 1870, the head teacher was responsible for training the pupil teachers, but the SBL thought this was a bad idea and set up special colleges. For half the week they would go to the college, the rest of the time they would work in the classroom.

Pupil teachers were paid a small wage. These were their wages in 1903:

The SBL always thought the pupil teacher system was a bad idea. When the London County Council took over the SBL schools in 1904, it opened new teacher training colleges such as Avery Hill in south east London. In 1913 the final pupil teacher in London qualified for college.