Newlyn Archive's historic Tidal Observatory visit.

On the first sunny day of Spring 60 Friends of the Newlyn Archive and invited guests, varying in age from eight to eighty, enjoyed a rare visit to the Tidal Observatory on the South Pier. Four visits took place on the day, with only three or four people allowed inside at any one time, since this Grade II listed building is still fulfilling a vital scientific purpose after nearly 100 years of operation.

The visit was arranged to coincide with the recent publication of a book about the observatory written by Richard Cockram and Ron Hogg.

Missed by all but the most observant...

just before the observatory itself is the second Ordnance Survey bench mark in a collection of thousands of benchmarks placed all over England and Wales - every one of them takes its height from the first bench mark set in the floor of the observatory...

an historic moment for members of the public as the doors are opened...

revealing the tidal plaque...

there were plenty of suggestions regarding the creation of a group to restore the building to allow for more visits in the future...

as co-author Ron Hogg holds up a copy of the new book in front of the Munro tidal recorder...

the wire that usually passes over the drive pulley has been temporarily removed...

as the tidal float (left) was removed from the well after it was found to be damaged...

the brass button set in the floor of the observatory is the point at which very subsequent bench mark height is then set throughout the whole of England and Wales...

Ron explains in more detail how the plunger worked - nowadays, a remote system has been installed...

which records data electronically...

using the bubbler system - whereby the tidal movements are recorded digitally and then transmitted...

from aerials atop the lighthouse using Wifi...

not much can be seen from the outside...

but inside the last few months of data recorded on the rotating paper roll are still visible.

Originally built in 1915, and equipped to establish Mean Sea Level, the Observatory now provides one of the longest continuous records of sea levels in the world, essential for studies of climate change.

For much of its existence the Observatory was run and maintained by local people, though nowadays it is automatic. For the visitors, seeing the Observatory for themselves was a perfect complement to reading about it in the book published last year. An added bonus was that the tour guides were Richard Cockram and Ron Hogg, two of the authors of the book which can be ordered online here...