In 1893, the French engineer and physicist André-Eugène Blondel (1863-1938), with the help of a Greek engineer, Spyridon Psaroudaki, invented the prismatic lens lampshade, and started the Holophane Company of France, the word Holophane coming from the Greek 'holos' for whole, and 'phane' for light. The Holophane lampshade gave an even light by using the principle of a Fresnel lighthouse lens, the invention of which is credited to Augustin-Jean Fresnel (1788-1827), a scientist and French commissioner for lighthouses, and was first used in 1823 at Cordouan in the Gironde estuary. Borosilicate glass was used, also known as Pyrex, which has a very low coefficient of thermal expansion making the lampshade very resistant to thermal shock and stress.
 
In 1896 a British company licensed Holophane's patent and started Holophane Ltd in the UK. In 1898 American businessman Otis Mygatt bought Holophane Ltd and started the Holophane Glass Company Inc, New York. At the outset, neither the USA nor UK company could manufacture the glass, so they started simply by marketing and selling the French product.
 
In 1902, Otis Mygatt arranged for Heisey Glasswork Co in Newark, Ohio, to start production of Holophane lampshades, which it continued to do until 1997. Mygatt's initiative came at a time when U.S. industry needed strong and efficient factory lighting to make night shifts possible and enable workers to fabricate precise parts requiring brightly lit conditions. In 1906 Holophane established the Illuminating Engineering Society to advance scientific lighting, a role it played into the 1990s.
 
For its English branch, Otis Mygatt teamed up with a French entrepreneur, Mr. Froget, specialising in the manufacture of moulds for the rubber industry to create a company in 1920 in Paris for the manufacture of moulds for glass which, by 1921, was producing lampshades in a glass plant in Les Andelys, between Rouen and Paris, where Holophane SA is still located.
 
Holophane comprised a U.S. entity, Holophane Glass Co Inc, with its own means of production for products in the United States, the UK Holophane Limited, with a worldwide sales territory excluding only the United States, without means of production, the Société Anonyme Holophane or Holophane SA, located on Boulevard Haussmann in Paris, which managed the production at the English-owned factory in Les Andelys.
 
In 1930, Otis Mygatt sold his shares in the three Holophane entities.
 
Holophane SA was bought by Henri Balsan and became independent of the English and American companies, specialising in art glass, decorative glass, vases, glass sculptures, glass architecture, optical glass, headlights, and lanterns with reflectors of polished glass which differentiated the company from its competitors until about 1990. Holophane SA and Mazda, were the two largest players in the French market.
 
In 1965, the U.S. company bought Holophane Ltd. In 1971, Holophane Inc was bought by the American Johns-Manville. In 1989, the company was bought by a group of American venture capitalists which created a number of subsidiaries worldwide, including Holophane Europe Ltd in England for the European market.
 
Returning to the French society, from the late 1950s, Holophane SA designed residential lanterns, refracting spherical lanterns, and road lamps. In 1979, Holophane SA became Holophane and Europhane, still both producing in Les Andelys. In 1989, the British group Thorn EMI bought the two companies, and sold Holophane SA to the French company Sediver, a subsidiary of Italian Fidenza, and Holophane SA was renamed Europhane Thorn.
 
Holophane Europe Ltd in Buckinghamshire has made a video about the history of the development of holophane lighting which it has placed on YouTube. The earliest holophane prismatic borosilicate glass luminaires were designed for gas lighting during the 1890s. It became the lampshade of choice for public electric lighting in places such as churches, factory and industrial buildings.
 
[thanks to Skin Flint Design for the tip-off about Simon Cornwell and the Holophane video