Lighthouse Foghorn Recorder

This is a most unusual and rare chart recorder. The instrument operates on the Bourdon tube principle for recording the pressure which is used to work a siren or foghorn in a lighthouse or lightship for warning shipping in fogs. You can see the sturdy brass movement is supported on a substantial brass dias and there is a damper piston arrangement both of which would be necessary when a very strong and sudden pressure emanates when the foghorn is sounded. Set in a lockable mahogany case, the instrument was made by Richard Freres of Paris with serial number 58499 it can be dated to around the time of WW1. Richard used a sequential numbering system at that time meaning that as each instrument, whatever it was, was given the next available number. Below the number 58499 on this instrument is the number 65 which could well be the current number produced for this particular instrument. The Bourdon tube has been cut below the base, the clock is not functioning and the small lock case is missing. The movement was also supplied to Casella of London and it appears in their 1952 trade catalogue - see extract. This was considered a valuable and important instrument as if there were any disputes over collisions or wrecks due to non-operation of the siren, proof of the times at which the siren was sounded a record could be produced. A great collectors item for a piece of maritime history.