Glass was a right pain
QUESTION What was Vita glass and is it still manufactured?
In THE late 19th century, sunlight therapy (heliotherapy) became fashionable.
In 1894, niels Ryberg Finsen (1860-1904), clarified the relationship between sunlight and microbes and established the use of bactericidal ultraviolet light (UV) to treat tuberculosis of the skin.
Edward Mellanby identified rickets as a product of vitamin D deficiency with heliotherapy as treatment.
By the Twenties, the link between sunlight and health was generally accepted. The argument then moved on to the composition and quality of the transmitted light.
Physiologist Leonard Hill noted: ‘Ordinary window glass filters out the protective (UV) rays, and light entering a room through glass is robbed of these, hence rickets arise in tenement dwellings from deficient diet and want of sunlight.’
This prompted glass technologist Francis Everard Lamplough to turn to glass chemistry to enable UV-rich light to penetrate glass, with the promise of transforming buildings into heliotherapeutic devices.
Lamplough developed a glass of extremely low iron content, which enabled increased UV transparency which he called Vita glass (after ‘vitality’).
Vita glass was trialled at London Zoo’s experimental monkey house in 1925 followed by the lion, monkey and reptile houses.
Chance Brothers of Smethwick licensed production from Lamplough. Anticipating a global demand for Vita glass, Chance sub-licensed the technology to Pilkington Brothers of St Helens.
Ultimately, the product failed. Those markets it was interested in — hospitals, schools and agriculture — felt there were not enough facts to support investment.
Also, Vita glass was found to perform poorly when dusty, was time-consuming and expensive to maintain, and prone to degrade under UV light exposure in a process called solarisation.
Moreover, medical knowledge about UV radiation was changing. The therapeutic value of sunlight was being questioned by researchers and the health risks associated with UV light, including cataracts and skin cancer, identified.
It was six times more expensive than normal glass and following the Wall Street Crash of 1929, its cost could not be justified. Production of Vita glass ceased by the early Thirties.
There was one notable use in public health. Stannington Sanatorium in northumberland was opened in 1907 as the first purpose-built hospital in the UK for children with TB.
A Vita glass sun pavilion for 50 patients was built in 1927 thanks to an anonymous donor and opened by the Duchess of northumberland. This piece of medical history was demolished in the Eighties.
Dr Ian Smith, Cambridge.
QUESTION Is Sudoku a traditional Japanese number puzzle or was it, in fact, devised by a Swiss compiler?
THE forebear of Sudoku puzzles was the magic square, a grid filled with numbers in such a way that each row, column and the two diagonals add up to the same number. These were known in ancient China, perhaps as early as 650BC.
In 1783, the blind Swiss mathematician Leonhard Euler invented a Sudokulike, 81-square grid that could be filled so every column and row contained the digits one to nine.
This magic square was not presented as a puzzle, merely as an expression of Euler’s genius.
In the late 19th century, the French daily newspaper Le Siecle devised something akin to Sudoku. But rather than using the digits one to nine, the puzzle used double digit numbers.
Another French daily, La France, came up with a similar version that used the numbers one to nine. But despite the same rules, La France puzzles did not divide the 81 cells into grids of nine boxes each, though they did have the numbers one to nine in the area where the subgrids should be.
Sudoku puzzles as we know them appeared in 1979. Printed anonymously in the U.S. publication Dell Pencil Puzzles & Word Games, they were probably designed by Howard Garns, a 74-year-old retired architect and freelance puzzle constructor from Connersville, Indiana.
Garns’s name was in the list of contributors for issues of the magazine that included the feature number Place and absent from those that did not.
He died in 1989 before his creation became a worldwide phenomenon. Whether he was familiar with the French versions of the puzzle is unknown.
The puzzle was introduced in Japan in the newspaper Monthly nikolist in April 1984 as Suji wa dokushin ni kagiru, which means ‘the digits must be single’ or ‘the digits are limited to one occurrence’. The name was abbreviated to Sudoku and trademarked by the puzzlemaker Maki Kaji.
Graham Morris, Teignmouth, Devon.
QUESTION Following the arrival of the Navy’s biggest warship into Portsmouth Harbour, wasn’t there a battleship that failed to make it through the entrance?
FURTHER to the earlier answer explaining how battleship HMS Vanguard hit the harbour mouth while being towed away for scrapping in 1960, I was a young seaman on HMS Vincent, a land establishment in Gosport, opposite Portsmouth.
I was there from 1958 to 1959 when the film Sink The Bismarck! was made and Vanguard, altered by adding sheets of strong plywood painted grey to make her look like the nazi battleship, was towed around Portsmouth harbour for filming.
Fifty of us from HMS St Vincent were dressed as German seamen and told to run about pretending we were under attack. At the end of the day we would go back to St Vincent and climb the 183ft mast to watch what was going on.
I’ve seen Sink The Bismarck! several times and spotted myself in action. We were never paid, but it’s nice to be able to say I was in the film.
Eric Lander, St Helens.
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