Sec. 2. The Superintendent of Public Instruction in each county in Texas having a population of not less than ten thousand, three hundred and sixty (10,360) and not more than ten thousand, three hundred and eighty (10,380), and in each county having a population of not less than ten thousand, three hundred and ninety-nine (10,399) and not more than ten thousand, four hundred and ninety-nine (10,499) inhabitants, according to the last preceding Federal Census, shall be allowed office and traveling expenses not exceeding Six Hundred Dollars ($600) per annum, to be paid monthly out of the Available School Fund.