Section 1. That the County Board of County Trustees in co-operation with the County Superintendent in counties having a population of forty-nine thousand, one hundred (49,100) to fifty-one thousand, five hundred (51,500) according to the last Federal Census and scholastic population of twelve thousand, seven hundred and seventy-seven (12,777) as shown by the scholastic reports for the preceding school year, may employ one or two rural school supervisors to plan, outline and supervise the work of the primary and intermediate grades of the rural schools of the county. Such supervisors to have appropriate evidence of proficiency in rural supervision.