Posted by: Merlin PJ30 OCT 2008
Daylight is one of our most precious resources, and it is free. Merlin, who daubs paint on bits of paper and calls the resulting mess a watercolour, likes to paint in his conservatory. This is on the north side of the house and receives a wonderful, scattered light filtered through the trees.
I once had an office which had no windows, which was not pleasant as it was illuminated only by two fluorescent light tubes.
Towards the end of the 19th century, the rapid expansion of industrial and commercial property in the US produced problems of illumination. Gas lighting was potentially dangerous and electric lighting was both expensive and unreliable.
In the 1880s, James Pennycuick, a British manufacturer of glass electrical insulators, set up business in the US. He hit upon the idea of using glass prisms to direct light into the interiors of buildings. Pennycuick and a group of investors set up the Luxfer Prism Company in Chicago to manufacture windows consisting of rows of prisms that would refract light into the interior of a building and render the use of artificial light unnecessary during daylight hours.
One early employee of Luxfer, Olin H. Basquin, is credited with being the first person to record sky brightness scientifically. This Basquin did in order to aid calculations on the optimal angle for the prisms to make maximum use of the available light.
Luxfer prisms also became popular in Britain. The Luxfer British Prism Syndicate was established under licence in 1898 and began making pavement lights to bring light to the basements of buildings. Many of these can still be seen in cities and towns across Britain.
The modern company Luxcrete was started in the 1920s and has been involved with supplying optical glasses to such modern London buildings as the Lloyds Building, Canary Wharf and the “Gherkin”, to maximise the use of available daylight.
A Japanese company, Ishikawa Optics and Arts, has developed the Solbene system in which 1cm glass prisms are sandwiched between sheets of plate glass. These refract external light into dark rooms.
With concerns mounting about energy supplies, it would seem that there will be a ready market for any system that can make maximum use of daylight.