On Sunday, 22 February 2015 19:31:20 UTC, Mr Pounder wrote:
There was a time when apprentices had to pay for the privilege of being an
apprentice and learning a useful skill.
When would this be and for which apprenticeship?
I was an indentured apprentice heating and ventilation engineer in 1966. I
was a slave and got paid peanuts.

Probably up until the early 20th Century.

An Apprenticeship Indenture is a legal document binding a child (usually around the age of 12 or 13 but sometimes as young as 7) to a master or mistress for seven or more years. A sum of money (premium or consideration) was usually paid to the master, and in exchange he (or more rarely, she) agreed to train the child in their trade or profession, and to supply them with appropriate food, clothing and lodging for the duration of the apprenticeship.. An indenture needed the signature of a Justice of the Peace in order to become legally enforceable.

http://www.londonlives.org/static/IA.jsp

Owain