1902: The company became Parkinson and W. and B. Cowan.
1919: The company opens a new factory at Stretford, Manchester to manufacture gas meters.
1937: Parkinson and Cowan (Gas Meters) Ltd was a Listed Exhibitor at the British Industries Fair. They advertised 'Gas Apparatus for Measuring and Recording, including Tin and Iron Meters, Optional Coin Meters, Rotary Meters, Station and Retort House Governors, Test Meters, Gauges, Meter Parts and Accessories'.
1939: The company, like many other engineering concerns of the period, turned their attention to being an Aircraft Industry Supplier.
1971: The company is taken over by Thorn becoming part of Thorn Gas Appliances; many of the gas meters manufactured during this period are still in use today.
1989: Gas Metering operations, now under the banner of Thorn EMI Gas Metering (formerly Thorn EMI Flow Measurement), are sold to Schlumberger (later Actaris, now Itron)
The name Parkinson Cowan still exists in the UK as a brand of gas stoves, one of the company's early products.