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Simplex Conduits Ltd, of Garrison Lane, Birmingham
Possibly connected with the Simplex Electric Tramway Conduit Syndicate of 1896
1898 Simplex Steel Conduits company formed.
1905 the company moved to larger premises in Garrison Lane, Birmingham, which became the Head Office for a rapidly expanding network of factories and offices in London, Manchester, Glasgow, Liverpool, Leeds, Newcastle, Swansea and Bristol.
1910 Demonstrated Prometheus kettle and Silundum heaters at the Royal Institution to illustrate a talk on electric heating.
1910 The 3rd edition of a book on Conduit Wiring was published by Simplex Conduits.
1913 Advert for wiring conduit. 
1914 Manufacturers of the Simplex conduit system for electrical installations, the Simplex heating and cooking apparatus, art fixtures and fittings and wholesale electrical suppliers. 
1917 Advert for wiring conduit. 
1919 Advert for wiring conduit. 
1919 Tube Investments was registered as a public company, combining the seamless steel tube manufacturing companies of Tubes Limited, Credenda Conduits Co, Simplex ConduitsLtd, Star Tube Co and St. Helen's Tube and Metal.
1932 Recognising the scope for improvement in the management of its electrical subsidiaries, Tube Investments formed a new organisation that would be responsible for the manufacture and sale of electrical products. Simplex Conduits merged with Credenda Conduit Co to form Simplex Electric Co which began to manufacture Creda domestic cooking appliances in addition to lighting equipment and conduits.