At 2 O’clock in the afternoon on the 1st November 1755 the sea in Mount’s Bay , Penzance rose rapidly and without warning to about 6ft above its normal level. Then it “just as quickly ebbed away”. The water continued to rise and fall in this way repeatedly for the next 5 hours. In neighbouring Newlyn however the effects were more dramatic, a deluge of sea water was said to have charged ashore at a height of 10ft engulfing everything in it’s path.
That day a large earthquake had struck the city of Lisbon in Portugal. Despite the epicentre of the quake lying over 1000 miles south west the force was great enough to send huge waves of water rolling into the Cornish coast.
An 18th century French writer, Arnold Boscowitz, wrote at the time that “a great loss of life and property occurred upon the coasts of Cornwall”. I have been unable to verify how many lives were lost but this strange and dramatic event must have been viewed as a very frightening to the folk in the area. John Davy, brother of the scientist Sir Humphrey Davy, wrote that the people of Penzance
were “very superstitious” and that a “belief in witchcraft maintained its ground there”, they must have feared what this biblical flood of water meant.
Coincidently a few months ago while looking for something entirely different in the Annual Reports of the Royal Cornwall Polytechnic Society I came across a curious entry which had been written by Mr Robert Hunt, who amongst other things, was their Secretary at the time. The article was entitled ‘Particulars of the Earthquake felt in parts of Cornwall on Feb 17th 1842’. In it Hunt summarises various historical accounts of earthquakes in the county. He refers one in Falmouth in 1757 which “was attended by a great noise” and felt as far away as Camelford. The same quake caused water to gush up through mounds of lifted sand on the beaches.
Another tremor occurred in 1759 when “a bright Aurora Borealis was seen in the evening”, this time the shock waves were felt as far as in Liskeard nearly 50 miles away and also by hundreds of miners deep underground. In 1836 there was a quake in Stithians and Hunt also tells us that Mr William Henwood, who was a geologist born at Perran Wharf, had communicated to him information concerning three other shocks felt in various areas around the county.
It seems however that it was a quake in 1842 which prompted Mr Hunt to write his article. Mr Hunt, who was eating his breakfast at his home in Berkeley Vale, Falmouth, heard “a peculiar rumbling sound” which was followed by the doors and windows of the house
shaking. Many people he spoke to thought that there had been some kind of explosion at the busy harbour. Further inland Mr J S Enys, of the Enys estate near Penryn, spoke of a sound like “a heavy weight falling” and “the shaking of articles in the rooms” Again the tide rose and fell very quickly.
But down in the valley at Perranarworthal 5 miles away the earthquake was described as a “considerable” shock, so much so that many people there thought that near-by the gunpowder works at Ponsanooth had blown up. The villagers of Perranarworthal set out for the Kennall Vale works to see what help they could give. Of course they arrived to find that all was well and that the people of Ponsanooth were as confused as they were.
There were reports of tremors that day in Mabe, Constantine, Lanner, Pool, The Lizard, St Mawes, Helston and Porthleven. The stories ranged from people being shaken in their beds to books falling from shelves and tea cups rattling in their saucers. Many had been very frightened and perhaps none more so than the miners deep underground. One of them described a rush of air which was strong enough to blow their candles out and a ‘great noise’ that could be felt as well as heard. Rather them than me!
The Falmouth Packet reported that the quake lasted for around 30 seconds and that shaking was accompanied by a noise like distant thunder. The paper also said that ‘the motion in the granite districts was so violent that many people left their homes’. The Packet draws comparisons in its article with the Lisbon quake a century before. It adds that the town of Falmouth is waiting with interest for the arrival of the Lisbon Packet Ship and any news it might bring which could shed light on what had happened.