Young Factory Worker Children composed a substantial element of the workforce in early factories, where they toiled long hours in dangerous and unsanitary conditions. Until a mechanized process was invented at the end of the nineteenth century, boys working in glass-bottle factories, like the youth pictured here, stoked blazing furnaces with coal and learned to blow glass. (Detail, Interior of a Furnace, 1865, oil on canvas by Charles Housez [1822–1888]/© Boume Gallery, Reigate, Surrey, UK/The Bridgeman Art Library)