Each person in custody on any industrial farm or industrial road camp who is found to have any person or persons dependent on him for support, as provided in Section 4127, shall be credited with a sum not to exceed two dollars ($2) for each day of eight hours work done by him on such farm or camp. Every other person in custody on an industrial farm or camp shall be credited with a sum not to exceed one dollar ($1) for each day of eight hours work done by him on such farm or camp.