“Rediscovering S.P. Rolt Triscott: Monhegan Island Artist and Photographer.” By Richard H. Malone and Earle G. Shettleworth Jr. Tilbury House, Gardiner, Me. 228 pages.

By the time the English artist S.P. Rolt Triscott moved to Monhegan Island in 1902, he had lived in America for 31 of his 56 years. He left Gosport, England, in his mid-20s because, as the third of five sons born into a genteel family, he had no prospects for inheriting family money. So off he went to America to seek his fortune as a trained civil engineer and, more importantly, as a painter.

Triscott, the subject of a museum exhibition on Monhegan and a new book written by Richard H. Malone and Earle G. Shettleworth Jr., was not long in getting his artwork into shows in Boston.

By the 1880s, he was ensconced in the considerable art scene there as both a superb watercolorist and masterful teacher in the classic English tradition. In “Rediscovering S.P. Rolt Triscott: Monhegan Island Artist and Photographer,” his biographers reveal that Triscott is thought to have taught watercolor techniques to Winslow Homer and Robert Henri. Additionally, as an artist, Triscott had considerable success with his own name listed during that time alongside those of John Singer Sargent and Frank Benson.

Despite Triscott’s arrival in America during a fecund time in the watercolor tradition in New England, he remained in his fluid washes and pastoral vistas a European, an Englishman and a visual lyricist respected by his peers and praised by critics.

Even when his colleagues in the field moved on to expressionism and modernism, he remained constant to his earliest training in England. Out on Monhegan, he retreated into the beauty of the eccentrically populated and pastorally ideal land – and seascapes.

His only dip into modernity was an interest in photography, which he explored as an artistic end unto itself but also as an approach to a new use for watercolors. He sometimes painted his black-and-white photos to transform them into tourist items or postcards.

Triscott’s name rarely shows up in discussions of Monhegan, the enigmatic island 10 miles off Maine’s coast that drew some of the 20th century’s most formidable American painters, including Henri, Homer, George Bellows and Georgia O’Keeffe. That’s largely due to the obscurity into which he fell after his death in 1925. His work was disseminated among collectors and family members, and the glass negatives for his photographs were sequestered in storage.

Earle Shettleworth, a preservationist and Portland native, stumbled upon Triscott’s oeuvre in the late 1990s while researching another art history book, “An Eye for the Coast,” about the maritime photographer Eric Hudson.

Good historian that he is, Shettleworth recognized paydirt when he saw it and spent a considerable number of years researching Triscott’s life and tracing the provenance of the artwork and the man.

“Rediscovering S.P. Rolt Triscott” is the culmination of his work and the first official publication of a biography written by the late Richard Malone, a Maine businessman whose wife, Dorothy, has the preeminent collection of Triscott’s work.

Malone’s tribute, which relies heavily on newspaper reports and speculation, gives a small portrait of a man who spent substantial amounts of time alone on an island. There is speculation about a spurned romance with a woman, but the details are thin.

Surely there is more to this man who served tea and toast each day and corresponded with some of the art heavies of his time. Why did this artist become a recluse clinging to island life, to its harsh winters and remote location? And why did he have only 15 minutes of fame?

The heft of this book comes from the signature smartness and organizational clarity of Shettleworth, and even more so from the reproduced black-and-white photographs, which are as painterly as any of the elegantly crafted watercolors in the first half of the book.

Shettleworth’s extended captions suggest that Triscott posed many of the shots of local fishermen, artists and townies. Even if that is true, the results are portraits that teach us something about a painter’s eye that is thoroughly entrenched in and beholden to line, composition and drama.

Though no one seems able to verify Triscott’s direct influence on Homer and Henri, both the watercolors and photos – of the cliffy, sea-smoked, rambly scenes well-known to Monhegan denizens – point directly to Triscott as the forerunner to formidable American artists of the day.

In conjunction with the publication of the book, a show of Triscott’s paintings and photographs is on display through Sept. 30 at the Monhegan Museum on Monhegan Island.

The show will be reprised Dec. 14, 2002-March 9, 2003, at the Portland Museum of Art. If the combination of book and exhibition historically reinstates Triscott among his better-known peers, his biographers undoubtedly will feel – and rightly – that justice has been served.