The commissioner shall cause an account to be kept of the money expended by the agents for the necessary expenses of the service required by sections one hundred and fifty-eight and one hundred and fifty-nine, for correspondence and travel in procuring employment for and furnishing clothing, board and tools to discharged prisoners and for conveying them to their homes or places of employment, which, upon approval by the comptroller, shall be paid at the end of each month.
Mass. Gen. Laws ch. 127, § 161