Section 61. No person shall employ a minor under sixteen or permit him to work in operating or assisting in operating any of the following machines: (1) Circular or band saws or ensilage cutters, which shall include any such saw or cutter on a farm, except with respect to a minor under sixteen who is related by blood or marriage to the owner or operator of the farm on which such minor is employed or permitted to work, (2) wood shapers, (3) wood jointers, (4) planers, (5) picker machines or machines used in picking wool, cotton, hair or other material, (6) paperlace machines, (7) leather burnishing machines, (8) job or cylinder printing presses operated by power other than foot power, (9) stamping machines used in sheet metal and tinware or in paper or leather manufacturing or in washer and nut factories, (10) metal or paper cutting machines, (11) corner staying machines in paper box factories, (12) corrugating rolls such as are used in corrugated paper or in roofing, or washboard factories, (13) steam boilers, (14) dough brakes or cracker machinery of any description, (15) wire or iron straightening or drawing machinery, (16) rolling mill machinery, (17) power punches or shears, (18) washing or grinding or mixing machinery, (19) calendar rolls in paper and rubber manufacturing or other heavy rolls driven by power, (20) laundering machinery, (21) upon or in connection with any dangerous electrical machinery or appliances, or in adjusting or assisting in adjusting any hazardous belt to any machinery, or in oiling or cleaning hazardous machinery, or in proximity to any hazardous or unguarded belts, machinery or gearing while such machinery or gearing is in motion; or in scaffolding; or in heavy work in the building trades; or in stripping, assorting, manufacturing or packing tobacco; or in any tunnel; or in a public bowling alley; or in a pool or billiard room; or in any capacity on moving motor vehicles; or in any gasoline service establishment; provided, however, that such minor may be employed solely to dispense gasoline and oil and to provide courtesy service outside of the service bay area of any such gasoline service establishment.