A throstle doffer was a young boy or girl who changed the bobbins of thread for the throstle spinning machines in an English textile mill. It was a delicate task and had to be done quickly. There might be hundreds of spinning frames, all at different stages of completion, and so the doffers were kept constantly on their feet.
In the 1830's, the children worked long shifts, sometimes more than 15 hours, and were paid a penny an hour.