From Brian Russell Chadderton
Contrary to what D. V. Blaylock says in her letter
(11 September, p 57), the
dangers of looking at the Sun were perfectly well known at the time of the
Second World War. This is yet another case of a danger being known, but the
knowledge not being available to the people in danger.
Take, for example, this unnamed 1687 pamphleteer quoted in Dava Sobel’s
Longitude: “Before the Back-Quadrants were Invented, when the Forestaff was
most in use, there was not one Old Master of a Ship amongst Twenty, but what a
Blind in one Eye by daily staring in the Sun to find his Way.” The English
navigator and explorer John Davis introduced the “backstaff”, or back-quadrant,
in 1595.
When will we ever learn?
Lancashire
