How did rising populations contribute to industrialization?

At the beginning of the 18th century, the balance between the size of the population and food production was very fine; the vast majority of people had to work in agriculture producing food, or everybody would starve. The Agricultural Revolution, which began around 1700 in Britain, boosted food production which in turn led to an ongoing population increase throughout the century. This meant that there was a surplus population available to work in the new factories that were built as the Industrial Revolution began later in the 18th century.