Alder and Mackay
of New Grange Works, Edinburgh, Scotland. Telephone: Edinburgh 61151. Telegraphic Address: "Alder, Edinburgh"
1850 Company established.
1914 Manufacturers of gas meters, including coin-in-the-slot meters. Employees 450. 
1922 Patent - Improvements in and relating to coin-freed prepayment and price-changing mechanism.
1929 Patent - Improvements in and relating to wet gas meters.
1937 Listed Exhibitor - British Industries Fair. Latest designs Ordinary and Prepayment Dry Gas Meters. Demonstration and Test Meters. Standard Test Holder and Meter Testing Apparatus to Board of Trade Specifications. (Stand No. Ca. 403)