Mass. Gen. Laws ch. 164, § 81: Form of books and accounts

Section 81. Gas and electric companies or persons engaged in the manufacture and sale or distribution of gas or electricity shall keep their books and accounts in a form to be prescribed by the department, and the accounts shall be closed annually, so that a balance sheet can be taken therefrom. Manufacturing companies in which the manufacture of gas or electricity is a minor portion of their business shall be required to keep accounts of the expenses and income of their gas or electric business only.