Section 23. The registrars, assistant registrars and absent registration officers shall, before entering upon their official duties, each take and subscribe an oath faithfully to perform the same. They shall receive such compensation as the city council or selectmen may determine; but such compensation shall not be regulated by the number of names listed or registered by them, as the case may be, and a reduction of compensation shall apply only to registrars, assistant registrars and absent registration officers appointed thereafter. The city council or selectmen shall provide them suitable rooms, necessary assistance and, when required, transportation. The city or town clerk, when a member of the board of registrars, shall act as clerk thereof, and shall keep a full and accurate record of its proceedings and shall cause such notices as the registrars may require to be properly given.