There shall be no charge for the registration of any bond or certificate whether registered at the time of issuance thereof or subsequently registered, and no charge for the transfer of registered bonds and certificates shall be made. (1887, c. 287, ss. 4, 5; Rev., s. 5027; C.S., s. 7407; Ex. Sess. 1921, c. 66, s. 6; 1925, c. 49.)