‘A tragedy of an insidious kind has overtaken Lamorna in the last few years,’ lamented the British artist and writer Ithell Colquhoun in her 1957 book The Living Stones: Cornwall. ‘Less obvious than through sight, it is through the sense of hearing that the age of mechanisation and profit-making has here made its chief assault.’

For Colquhoun, the mechanical intrusions of the postwar world did not just disrupt the placidity of the Cornish coast; they symbolised the triumph of rationalism and technology over the mystical, intuitive and unconscious realms that had served as a source of inspiration to her work. As a practitioner of the occult, Colquhoun feared that such forces would fracture the delicate membrane between this world and worlds unknown.

Her resistance to mechanical noise was profound. She joined the Noise Abatement Society, rejected electricity in her studio, and lived without basic amenities – a self-imposed primitivism in line with her belief that no barriers should exist between land, stone and self. The megaliths, ley lines, and stone circles of Cornwall were, to her, not just relics but conduits of ancient knowledge in need of protection. She saw herself as their sentinel.

Colquhoun’s near-contemporary Edward Burra, one of 20th-century Britain’s most distinctive artists, shared her unease about the threats to the English landscape, primarily concerned with the ecological and environmental toll of industrialisation. His landscapes are of a countryside ravaged by mechanisation. In Picking A Quarrel (1968), trucks are depicted as monstrous, carnivorous entities with fiery eyes and gaping mouths, grinding through nature with predatory force.

Both Burra and Colquhoun have recently been dovetailed in a new exhibition at Tate Britain – on display until 19 October. It is, on the surface, an incongruous match, but by making them neighbours rather than bedfellows, the curators have allowed their correspondences to emerge organically. Both artists responded not only to the violence of industrialisation, but also hovered on the edges of surrealism. Burra was considered an eccentric outlier; Colquhoun, an occultist pariah.

Born in South Kensington, London, in 1905, Burra grew up in Rye, East Sussex, where he would spend the majority of his life. He had a lifelong struggle with rheumatoid arthritis and pernicious anaemia, which meant he could not stand comfortably at an easel. Instead, he sat, working in watercolour over oil, on paper laid flat on a table. Unlike the usual transparent and fluid application of watercolour, he used it like oil paint, stacking up multiple layers to create an unusual depth of colour with sharp edges. Working with a tight handline, he progressed from bottom right to top left in an arc, sometimes joining multiple sheets to form larger compositions.

Burra employed this unusual method of painting in the late 1920s and 1930s, capturing those who skimmed the shadows of society. He began to frequent gritty urban underworlds – from Marseille to Harlem – keenly observing cafés and cabarets to see what characters lurked inside. These satirical, caricature-like works, hung at the outset of the exhibit, are a delight. From Three Sailors at a Bar (1930) to Le Bal (1928), which features voluptuous figures at a dance hall in Paris so full of life you can almost hear the cacophony of chatter, clinks and crackling jazz. These aspects of Burra’s work, featuring his collection of paintings from the Harlem Renaissance, represent the exhibition’s zenith.

Yet, as the exhibition progresses, the tone abruptly shifts from lively to lifeless. It is as if Burra’s gramophone grinds to a halt. The outbreak of the Spanish Civil War in 1936, forever changed Burra’s outlook. He had a deep affinity for Spanish culture, art and music since his first visit to the country in 1933, and was particularly enamoured by its painters, such as El Greco, Goya, and José Romano.

His works during this time are menacing – a series of Goya-esque paintings with macabre figures with obscured faces, cloaked figures, skeletons and bulbous bodies. In Beezlebub (1937), he depicts a marauding gang clashing violently amid the ruins of a church, with the devilish figure of Beezlebub – one of the seven princes of hell – gloating over the destruction. Burra’s politics were ambiguous, and although he told the Tate Gallery director in 1942 that he was pro-Franco, this may have been a deliberate provocation.

The landscapes he created towards the end of his life are an even further cry from his earlier, high-octane works. As his health began to decline, his sister Ann began to drive him through the English and Scottish countryside. His landscapes from this period such as Valley and River, Northumberland (1972), and Landscape, Cornwall, with Figures and Tin Mine (1975), depict rolling hills and tempestuous skies – a Britain caught between pastoral nostalgia and postwar reality, with collieries and motorways intruding on the rolling contours of hills and sky.

While Burra found success in his lifetime, Ithell Colquhoun was largely overlooked. Between Worlds is the first major survey of her work, spanning five decades of relentless experimentation. With over 170 works – nearly double Burra’s share – the exhibition captures her shifting techniques and esoteric vision.

From her early Slade drawings seen in exhibited works like Judith Showing the Head of Holofernes (1929) to her visionary tarot designs, the exhibition showcases her technical skill as well as her longstanding commitment to alchemy, animism and surrealist methods – especially through techniques such as fumage (painting with candle smoke), parsemage (scattering dust), and decalomania (blotting pigment).

Born in Shillong, Assam, India, on 9 October 1906, into a family of British administrators, Colquhoun was deeply affected by the complexities of colonial identity after moving to Cheltenham, England, at a young age. She felt as if she belonged neither here nor there, which significantly shaped her artistic vision, for she would constantly chop and change new techniques, methods and beliefs.

After studying at the Slade, a turning point in her development came in 1939 when she met Gordon Onslow and Roberto Matto, who were using surrealist automatist techniques to create imagery through chance rather than conscious control.

This is particularly seen in her use of decalomania, where she would randomly apply paint to a surface and then press it with another sheet, creating spontaneous blots and textures. The blots were seen as accidental forms, often used within a landscape, as seen in her work Gorgon (1948) where the technique is used to create an ambiguous silhouette with a yellow-orange landscape beneath curved, feathered wings.

It was also during this period that she was inspired by Dalí’s paranoiac-critical method of double imagery, a method used to convey multiple meanings within a single work.

This is best seen in her much-celebrated painting Scylla (1936). The painting used to promote the exhibition features two towering vertical rocks rising from the transparent water, but they also resemble a woman’s thighs knocked together in the bath with a tangle of seaweed for hair. It creates a complex visual metaphor that is both erotic and mythic; the title is a reference to the Greek mythological creature Scylla, a legendary man-eating sea monster that preyed on seafarers.

In 1939, Colquhoun was inaugurated into the British Surrealist Group by the Belgian artist and writer E.L.T. Mesens. In a few months, her paintings and writings were published in the surrealist journal The London Bulletin, and her works were shown at the Mayor Gallery, the foremost forum for surrealist art in Britain.

However, Colquhoun’s growing fascination with alchemy, animism, and mysticism eventually led to her expulsion by Mesens in 1940 after she refused to renounce her associations with occult organisations such as the Fellowship of Isis, a group that aims to increase awareness of the goddess Isis and the Divine Feminine as a counterbalance to patriarchy.

From then on, the fusion of her art with mysticism accelerated. Her Diagrams of Love series (1940-42) explored kabbalistic, tantric and alchemical themes, portraying the merging of male and female forms into an androgynous whole. Her occultist proclivities began to overshadow her undeniable artistic skill and range. It was during these war years that Colquhoun withdrew from modernist circles and began travelling to Cornwall, identifying closely with the ancient landscapes and windswept moorland of West Penwith.

She approached these landscapes as living, sentient entities, as seen in Sunset Birth (1942), a drawing of the megalithic monument Men an Tol. In Dance of the Nine Opals (1942), inspired by another stone circle near her Cornish home, she visualises a stream of energy linking stones and landscapes with thread, creating a spiritual connection that reflects her belief in the interconnectedness of all things. It is reminiscent of another Cornish-based artist, Barbara Hepworth, who used string in her sculptures to exaggerate the tension between herself, the sea, the wind, and the hills.

Colquhoun’s later years saw a slow departure from figuration altogether as she grew ever more the recluse. She began to publish esoteric travelogues on Ireland (The Crying of the Wind, 1955) and Cornwall (The Living Stones, 1957), a surrealist novel and volumes of poetry. She joined even more occult societies, adopting the name ‘Splendidor Vitro’, meaning ‘more sparkling than crystal’.

Right till the end of her life, Colquhoun experimented with new enamel techniques and designed a complete tarot deck, intended as aids to spiritual transcendence. The tarot deck can be purchased in the gift shop, should you feel a gravitational pull to do so. In 1988, Colquhoun died from heart failure at her care home in Cornwall. Her ashes were scattered across the rocks in Lamorna Cove – united with the forces of nature once more.

For all their differences, Colquhoun and Burra were deeply attuned to the tensions and transformations of postwar Britain. Whether through trucks or standing stones, they drew landscapes as backdrops and battlegrounds, sites charged with unease, transformation and resistance. Edward Burra – Ithell Colquhoun  serves as an overdue homage to both artists, but it is also timely. As the ties that bind us to the countryside fray further, their work is a sage warning in this time of rapid technological change. Mechanisation may no longer come with the roar of trucks alone, but its assault continues all the same.