Section 31, The Machinery (Safe Working Citation

(1) Every boiler shall be fitted with at least two reliableapparatuses, of types approved by an Inspector, for ascertaining the true level of the water in the boiler. One of these shall be a glass water-gauge, with the proper blow-through cocks. (2) When the other apparatus referred to in sub-rule (1) of this rule consists of test-cocks, these shall each be separately connected to the boiler, and the lowest one shall be at the height of the fixed lowest water level. (3) One water-gauge shall be sufficient for boilers of less than twenty ga1lons capacity. (4) The fixed lowest water level shall be indicated by conspicuous marks on the water-gauge a§ well as on the boiler shell or masonry. ·