Sec. 1-k. COUNTIES OF 28,625 TO 28,630. In counties having a population of not less than twenty-eight thousand, six hundred twenty-five (28,625), nor more than twenty-eight thousand, six hundred thirty (28,630), according to the last preceding Federal Census, the County Boards of Trustees may make such provisions as they deem necessary for office and traveling expenses of the County Superintendent of Public Instruction, and any assistant he may have; provided that the amount of such expenditures for office and traveling expenses shall not exceed the sum of Six Hundred Dollars ($600) per annum. The amount allowed shall be paid in the manner and in accordance with now existing laws governing the maintenance of the office of the County Superintendent.