The members of the county board of education shall receive from the public school funds of the county $7.50 a day and their actual traveling and hotel expenses incurred in attending meetings of the board and transacting the business of the board. The members of the county board shall not be allowed pay for more than 24 days in any one year, and their expenses shall be paid in like manner as provided for the compensation of teachers; provided, that in counties having a population of 600,000 persons or more according to the last or any succeeding federal census, members of the county board of education shall receive from the public school funds of the county $35.00 per day and their actual traveling and hotel expenses incurred in attending meetings of the board and transacting the business of the board, not to exceed 52 days in any one year, said compensation and expenses to be paid in like manner as provided for the compensation of teachers.