§ 13. Expenses. All officers, clerks, inspectors, experts and
employees of the commission shall receive the compensation fixed by the
chairman of the commission within the amounts appropriated therefor by
the legislature. The commissioners and counsel to the commission may
receive, in lieu of expenses, twenty-five dollars per day, and a
proportionate amount thereof for each fraction of a day, while engaged
in the performance of official duties at a place other than the city to
which they are regularly assigned, and shall be reimbursed for the
actual and necessary cost of transportation incurred by them; this
provision, however, shall not be applicable to the chairman or a
commissioner receiving a definite sum in lieu of traveling expenses. The
officers, clerks, inspectors, experts and employees, shall have
reimbursed to them all actual and necessary traveling and other expenses
and disbursements incurred or made by them in the discharge of their
official duties.