Section 1. That the salary of the County Superintendent of Public Instruction of each County in Texas having a population of not less than twelve thousand one hundred (12,100) and not more than twelve thousand one hundred and ninety (12,190), according to the last available Federal Census, shall from and after the passage of this Act be not less than the sum of twenty-one Hundred Dollars ($2100.00) and not more than the sum of Three Thousand Dollars ($3,000.00) per annum.