Concordia Electric Safety Lamp Co
From Graces Guide
of Luma Works, Sanatorium Road, Cardiff, Wales. Telephone: Cardiff 2977. Telegraphic Address: "Concordia, Cardiff"
The firm had many years' experience in the use of lead acid type batteries for hand lamps
1926 Private company.
1930 Name changed. Company reconstituted to manufacture and market lamps embodying the Edison-type of alkaline battery, more especially for the use of miners and mine-officials.
1937 Listed Exhibitor - British Industries Fair. High Power Miners' Electric Safety Lamps with Alkaline Batteries. Range of Lamproom Equipment. Special types including, Cap, Officials, Torch, Paddy-Mail**, and for shaft repairs. All approved by Mines Department (Stand No. Cb.603) 
1938 Patent - Improvements in or relating to miners' electric lamps.
1946 Patent - Improvements relating to electric circuits applicable to fluorescent tubes.
1961 Manufacturers of "Concordia" electric safety lamps, transformers, miners' lamps, torches, fluorescent lighting fittings, parking meter fittings, precious metals and electro plating. 170 employees. 
- Paddy-Mails were generally considered to be workmen's trains, and were operated by, or for, many companies to transport their workers to their place of work or between their sites of work.