Sec. 2. The salary of the County Superintendent of Public Instruction of each county in Texas having a population of not less than forty-one thousand and fifty (41,050) and not more than forty-two thousand, one hundred (42,100), according to the last preceding Federal Census, shall from and after the passage of this Act be not less than the sum of Two Thousand, Eight Hundred Dollars ($2,800) per annum and not more than Three Thousand, Six Hundred Dollars ($3,600) per annum to be fixed by the County Board of Education of each county; and in addition thereto, the county superintendents of such counties shall receive office expenses for stamps, telephone, and stationery not exceeding Three Hundred Dollars ($300) per annum, as well as an amount not in excess of Three Hundred Dollars ($300) per annum to defray traveling expenses incurred by such county superintendents, which said sum shall be paid by said County Board of Trustees on the certificate of such superintendent that the expenses had been incurred in the discharge of his duties as such superintendent.