What was in the air in Manchester 1869?
Mr A W Blacklock of Manchester re silvered telescope mirrors and he noted that when he re silvered mirrors in Blackheath which was still outside the city of London they retained their lustre being untarnished even without any protection for a period of over 12 months.
Here in Manchester however he says that when mirrors are re silvered and even when kept in a closed wooden telescope tube within just 3 months they prove to be absolutely useless with some parts showing a deep blue colour and other parts of the mirror exhibiting various shades of yellow and brown colours.
Blacklock says that between April 1868 and January 1869 he was obliged to re silver his mirrors 3 times.
|Ancoats area of Manchester around 1870|