Charles Vallancey (1721-1812) was a military surveyor in the British Army eventually holding the rank of general. He was sent to Ireland where he eventually settled. He was also an antiquarian who took great interest in the history, language and mythology of his adopted country. He published a number of book on the subject which have been heavily criticised for both their content and style. He voiced the opinion that the Phoenician and Irish languages were related!(a).
Although Valancey made little reference to Atlantis, James McCulloh noted  that Vallancey was disposed to support John Whitehurst’s association of the Giants Causeway, in Northern Ireland, with Atlantis.
Marco Goti is the Italian author of The Island of Plato in which he attempts to demonstrate that Atlantis was situated in Greenland. I say attempts, because in my opinion he fails dismally. He starts by locating the Pillars of Heracles in the Atlantic, with one side being the basaltic columns at the Giants Causeway in Northern Ireland and their counterparts across the sea in Scotland’s Isle of Staffa.*This idea was touted by W. C. Beaumont over sixty years earlier(a).*
Goti then moves on to Iceland, which he identifies as Thule and spends too much time describing a variety of unpronounceable locations there. He eventually heads for Greenland, which he contends must be Atlantis as it is greater than Libya and Asia combined, ignoring that Plato was referring to might rather than size. Goti posits the huge plain apparently described by Plato to have been situated in the centre of Greenland, ignoring the fact that ice cores dated to over 100,000 years have been identified there, and apart from which the huge island is not submerged.
Goti decries other promoters of Atlantis theories for ignoring details in Plato’s account that don’t fit their particular ideas and then he moves Athens to Sweden, has Atlantis above water for hundreds of thousands of years, no elephants, no two annual crops and does not explain how Greenland Atlanteans controlled southern Italy as far as Tyrrhenia, all of which demands a thumbs down from me.
John Whitehurst (1713-1788) was a clockmaker and a scientist who developed our knowledge of geology and helped to promote it as a major scientific discipline. In a 1778 book, An Inquiry into the Original State and Formation of the Earth, republished in 1978 was perhaps the first writer to suggest that Ireland may have been part of Atlantis[p258].
Whitehurst was fascinated by the Giant’s Causeway in Northern Ireland and maintained that it had been created by a volcano to the north, which is now submerged. This volcano he linked with Atlantis.
*The 2nd edition of 1786 edition is now available to be read online(a).*
William Comyns Beaumont (1873-1956) was a British journalist and author.>He was the uncle of the novelist Daphne Du Maurier.<He is frequently referred to as an eccentric and not without reason. He published an extraordinary book, Britain – The Key to World History, in which he claimed among other things, that Edinburgh was the original Jerusalem, London was Damascus and rather worryingly that Bristol was Sodom (see map). Beaumont located the Pillars of Heracles at Northern Ireland’s Giant’s Causeway along with its counterpart on the Isle of Staffa in Scotland(h), an idea resurrected over sixty years later by Marco Goti.>This identification has now been adopted by Alberto Majrani(i).<
In addition he was convinced that 18th Dynasty Pharaohs ruled the Welsh Britons. The foreword to the ‘Key’ is available online(d) as is a 1949 newspaper review(e).
In an earlier work he had identified ancient Britain as Atlantis and claimed that Atlantis was destroyed by a cometary impact in 1322 BC. This book introduced Beaumont as possibly the first British catastrophist, who expanded on this subject of celestial collisions in a subsequent book.
It has been claimed that Beaumont’s theory of celestial impacts partly inspired Immanuel Velikovsky’s writings, but characteristically, without receiving any recognition from that quarter.
Some years ago Benny J. Peiser drew attention to how Beaumont’s work had been overlooked and probably plagiarised citing a list of 25 similarities between the theories of Beaumont and Velikovsky previously noted by Alfred De Grazia(a).
In 1975, the American psychologist, Robert Stephanos (1925-2011)(c), founded the Comyns Beaumont Society in Philadelphia. Stephanos appears to have totally accepted Beaumont’s ideas including their more bizarre elements. In 1994 Stephanos published an article in Fate magazine(f), in which he also claimed that Velikovsky had ‘borrowed’ many of Beaumont’s catastrophist ideas.
Beaumont’s books are hard to find, however, all four of them have now been made available as reprints(b) and are a must for students of the history of catastrophism and its part in the Atlantis story.
Beaumont had completed the manuscript for another book, The Great Deception, shortly before his death. This has now been edited for publication by Janice Mendez and is now available in print and online. In it, Beaumont returned to the subject of catastrophism along with some radical historical revisionism and has its objective described by his grandson, Christopher Toyne, as “to propound the ultimate subterfuge by Emperor Constantine the Great to reconstruct the story of Jesus away from the British Isles and place it in the now Middle Eastern ‘Holy Lands.’ This is THE GREAT DECEPTION.” I expect the reviews to be entertaining.
A more recent (Jan.2017) review(g) of Beaumont’s odd ideas might be worth a read.
(a) See: Archive 2315
(f) Catastrophists in Collision: Did Velikovsky borrow from Beaumont’s original works? Fate [March 1994], 66-72