Name plate on the side of the gasometer.  The patent numbers are 1723397, applied for in 1924 and granted in 1927, and 1862451, applied for in 1926 and granted in 1932.  This gasometer was manufactured by the Pittsburgh Equitable Meter Company under the brand name EMCO.  This gasometer was rescued and restored by David Cowgill, Scientific Director of ATOR Labs and when found was covered with red paint and was being used to calibrate natural gas meters, which is probably close to its original purpose.  Photo courtesy of Sieggy Bennicoff-Yundt, Quality Director of ATOR labs.