The Giant’s Causeway is said to have been “discovered” in 1692, when William King, then Anglican Bishop of Derry and future Archbishop of Dublin, visited the area along with an unnamed Cambridge scholar. As with many “discoveries” of this era, credit tends to go to whoever first publishes their findings — the Causeway had been known to locals for a considerable time, called in old Irish Clochán na bhFomharaigh, “the stepping stones of the Fomorians,” a race said to have inhabited Ireland before the Celts.
First written accounts
The first recorded written reference is a brief mention in a 1693 letter from Sir Richard Bulkeley (d. 1710) to Dr Lister, subsequently published in the Philosophical Transactions of the Royal Society, London. Bulkeley hadn’t visited the Causeway himself — he was relying on the Bishop of Derry’s account and that of “a master of arts in Cambridge.”
Bulkeley’s questions about the nature of the Causeway’s pillars were answered in 1694 by Bishop Samuel Foley (1655–1695), again in the Philosophical Transactions, accompanied by an engraving from a drawing by Christopher Cole. Foley’s note was immediately followed in the same volume by a second article from Thomas Molyneux (1661–1733), a founding member of the Dublin Society. Molyneux hadn’t visited either — but his account led the Dublin Philosophical Society to commission artist Edwin Sandys for a more realistic drawing, published in 1697 by Thomas’s older brother William Molyneux (1656–1698), who had founded the Dublin Philosophical Society in 1683.
Susanna Drury’s paintings
In 1740, the Dublin Society offered art premiums for the best depictions of the Causeway. Dublin artist Susanna Drury submitted canvasses she’d painted during a three-month stay in Antrim, and was awarded the £25 premium. Her paintings were later engraved in London by François Vivarès and travelled across Europe.
In 1765, Volume 12 of the great French Encyclopédie used one of Drury’s engravings to illustrate an article on the “Pavé des géants.” A follow-up 1768 volume of plates paired Drury’s “East Prospect of the Giant’s Causeway” alongside similar basalt columns from the Auvergne region of France — captioned by French geologist Nicolas Desmarest, who had already concluded the Auvergne columns were volcanic in origin. Looking at Drury’s engravings, Desmarest made the same connection to the Causeway — even though he’d never actually seen it. He’s generally credited with first proposing that the Giant’s Causeway formed from erupting volcanic lava.
Neptunists versus Plutonists
Desmarest’s proposal triggered a controversy that rumbled through the fledgling science of geology for over half a century. Two camps formed: Neptunists, following Abraham Gottlob Werner (1749–1817) of Freiburg, who held that a vast primaeval ocean once covered the Earth and that all rock — including basalt — had crystallised out of it. Looking at the fossil-bearing black rocks at Portrush, containing ammonites, their case seemed reasonable — ammonites were taken as evidence of submarine deposition.
Plutonists followed Edinburgh doctor James Hutton (1726–1797), whose 1785 theory saw the planet in a state of continuous cyclicity: mountains eroded, sediments settled on ocean floors, were buried and heated at depth, then pushed back to the surface to begin again. Hutton’s ideas were radical for two reasons — he saw “no vestige of a beginning and no prospect of an end” to Earth’s geological history, and he proposed the planet had an internal heat source capable of melting rock and driving it to the surface through volcanoes. In the case of the Portrush ammonites, Plutonists argued the black rocks weren’t basalt at all, but mudstone baked by an igneous intrusion pushed up from deep within the Earth.
Portrush’s Black Rock is now a National Nature Reserve, on the shoreline by the Ramore Head car park facing East Strand Beach, and well worth a visit — with the nearby Portrush Coastal Zone holding a wealth of information on the natural and local history of the coast from Portrush to Ballycastle.
The Reverend Dr William Hamilton
In 1784, Reverend Dr William Hamilton (1755–1797) investigated the Antrim coast and wrote the first accurate account of its geology, as a series of letters to the Earl of Charlemont, published as a book in 1786 arguing clearly for the Causeway’s volcanic origin — a position taken before Hutton’s Theory of the Earth was even published, which is arguably underappreciated. Hamilton also founded the museum at Trinity College Dublin in 1777 and co-founded the Royal Irish Academy in 1785. He was killed during the local unrest leading up to the 1798 rebellion, but his book remained the standard reference on the area for decades, with a second edition published in 1822. Today, “Hamilton’s Seat,” overlooking Benbane Head, marks the spot where he’s said to have often rested while surveying the coast on horseback.
The first guidebooks
In 1788, The Complete Irish Traveller in the Kingdom of Ireland was published in two volumes — one of the first popular guidebooks, containing a detailed description of the Causeway. Guidebooks flourished through the 1830s and 1840s, by which point the Causeway featured on almost every visitor’s itinerary to Ireland, much like today. Magazines including the Dublin Penny Journal and the Illustrated London News ran images and stories of the famous stones. Naturalists, increasingly organised into club trips, arrived to see the site for themselves, and the new pastime of photography added to the interest — prints appeared from the mid-1800s, and by the century’s end photographs were a regular feature in guidebooks alongside the traditional engravings and sketches.