<< >Nichol in 1899 although the principle comes from Herschel's work in the
^^^^^
I'd make that 1889. The English Pat. No. is 5374 >>
Thanks for the correction Luis. This is a good illustration of the dangers of
relying on secondary sources - owners of Cassell's Cyclopaedia (1911) may like
to correct the entry on page 314 which gives the incorrect date!
Peter Marshall
On Fixing Shadows, Dragonfire and elsewhere:
http://faraday.clas.virginia.edu/~ds8s/
Family Pictures & Gay Pride: http://www.dragonfire.net/~gallery/
and: http://www.speltlib.demon.co.uk/