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British Thomson-Houston Company, Ltd.
Crown House,
London WC2

BTH's booth at the 1936 APLE Conference.

Exhibits included Mercra Lamps (150W, 250W and 400W) and Lighting Equipment for street lighting and flood lighting. The new Dilen and Diref lanterns were shown. - Public Lighting #3, 1936

The firm are exhibiting several installations at the APLE's Folkestone Conference of 1937. The layouts use "BTH Planned Street Lighting" principles, which ensures that the very best use is made of each individual lantern. Use of these principles allows a spacing of 150 ft., which is the maximum recommended by the interim report of the Ministry of Transport Committee on Street Lighting. The firm notes how cream coloured walls along some of the routes enhance the lighting. The County Junior is one of the lanterns being exhibited. - APLE Conference Programme Folkestone 1937

The newly designed Mercra H lantern takes centre stage, along with a representative range of Mercra (80W, 125W, 250W and 400W) and Sodra Lamps, together with BTH Auxiliary Equipment for Street Lighting. - APLE Conference Programme Folkestone 1938

They have issued a booklet, Planned Street Lighting, of over seventy pages, fully illustrated which describes the various types of lamps, lanterns and accessory equipment manufactured by the company. The booklet is much more than a mere catalogue or list of BTH street lighting products; it is a guide to correct methods, as approved by the latest practice. Prolonged laboratory work has enabled the company's engineers to establish basic principles and to ascertain the most suitable sources of light and the most effective systems of light distribution for general requirements. Then comes the application of the knowledge, thus gained by practical tests on roads and streets. The results of this wide experience is embodied admirably and lucidly in the new booklet. Details are given of the Mercra range of electric discharge lamps, and of several lanterns designed for different classes of road. The Sodra electric discharge lamps are also described; and the County Junior lantern, which is low priced and suitable for either Mercra or Mazda lamp, is exceptionally effective for side roads. A description is included of BTH photoelectric relays and their action in street lighting control; of the foot-candle meter for testing; and finally a couple of pages are given to illuminated traffic signs and guard posts; all models conforming to MOT requirements. In brief, Planned Street Lighting covers all the principle needs of authorities who may wish for information on the subject. - Public Lighting #12, January 1939

The Mercra "H" has been a huge success and the firm have designed a sodium counterpart, the Sodra "H" for the whole range of sodium lamps. The Sodra "H" also includes many engineering improvements in design, most being related to its side entry design. (The Dilen lantern has also been redesigned for side-entry to take advantage of these). The Sodra "H" is being exhibited. - APLE Conference Programme Glasgow 1939

The company describe the pre-war scene, with special reference to the Mercra "H" and Dilen lanterns. In some respects, they seem to feel that street lighting has reached a natural goal: "The methods employed, therefore, in the lighting of streets, especially main roads, are to a large extent stabilized, and it is difficutl to visualise any extensive changes unless a considerably greater amount of money per mile is going to be available in the future." The County Junior and County Cadet lanterns are the standard products for side sreets. In reality, the firm are still selling 1939 stock, and have justified this by claiming that there has been no progress made in the war and immedaite post-war years. - APLE Conference Programme Glasgow 1945

The Illuminating Engineer 1928
APLE Conference Programme Folkestone 1937
APLE Conference Programme Bournemouth 1938
APLE Conference Programme Glasgow 1939
APLE Conference Programme Glasgow 1945

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