Quote Originally Posted by Gary Stephenson View Post
is that based on the Day & Newell Parautoptic lock. and if so when did that date from? I assume from before the exhibition, as I believe that is the lock that ACH was selling/ pushing.
Were Day & Newell known for any other locks?
They sold the original Day & Newell design first, actually importing locks for a while before making them under licence in London. Then improved the design with anti pressure etc around 1860. I'm trying to compile a list of known examples.