71 Pa. Stat. § 1191
The Superintendent of State Police is authorized to appoint the State Police Force, which shall consist of--One school troop consisting of: One captain, at a salary of three thousand dollars per annum; one lieutenant, at a salary of twenty-two hundred dollars per annum; one sergeant, at a salary of seventeen hundred dollars per annum; two corporals, each at a salary of fifteen hundred dollars per annum:--five troops, each consisting of: A captain, at a salary of three thousand dollars per annum; a lieutenant, at a salary of twenty-two hundred dollars per annum; a first sergeant, at a salary of two thousand dollars per annum; five sergeants, each at a salary of seventeen hundred dollars per annum; ten corporals, each at a salary of fifteen hundred dollars per annum, one of whom shall be a saddler and one a blacksmith; forty privates first-class, each at a salary of fourteen hundred dollars per annum; and forty privates second-class, each at a salary of ten hundred and eighty dollars per annum; a detective division consisting of: One lieutenant, at a salary of twenty-two hundred dollars per annum; two sergeants, each at a salary of seventeen hundred dollars per annum; and ten detectives, each at a salary of fifteen hundred dollars per annum. No private, now a member of the State Police Force, shall be reduced to the grade of private second-class, and no private second-class shall be promoted to the grade of private first-class until there is a vacancy under the provisions of this act.
71 P.S. § 1191