Étienne Léopold Trouvelot was born on 26 Dec 1827 in Guyencourt, France. As a young man he dabbled in politics, becoming a staunch Republican. After Louis Napoleon’s coup in 1852 he fled to America with with his wife Adelaide and settled in Medford, just outside of Boston. He listed his occupation as lithographer.
Although an artist Trouvelot had a keen interest in science and turned his attentions toward sericulture. Hoping to become rich in the American silk trade he raised giant silk moths (Antheraea polyphemus), eventually having as many as a million larvae under nets on his five acre property in what he called his “infant industry.”
In Mar 1867 he returned from France with live gypsy moth (Lymantria dispar) eggs, intending to cross the two moths to develop a disease resistant strain. It would turn out to be a bad idea; not only are gypsy moths and giant silk moths two entirely different species but sometime around 1868-69 some of the moths escaped his nets. He had – quite inadvertantly – introduced the gypsy moth to North America. He knew enough at the time to become alarmed, but after contacting other entomologists there was apparently little concern.
The gypsy moth incident was the beginning of the end of his interest in entomology. In 1870, after observing the aurora, he embarked on his next scientific obsession – astromony. He bought a 6-inch telescope and began preparing drawings that caught the attention of Joseph Winlock who invited him to use the 15-inch Great Refractor at the Harvard College Observatory. His work under the especially clear skies at Cambridge set a new standard for astronomical illustration that wouldn’t be surpassed until the perfection of the photographic dry-plate. In 1872 The New York Times wrote “a person entirely ignorant of astronomy could not fail to be much impressed with [Trouvelot’s] drawings.”
In 1875 Trouvelot was invited to the US Naval Observatory to continue his work using the 26-in Great Equatorial, then the largest telescope in the world. As part of the observatory’s exhibit at the 1876 Centennial Exhibition in Philadelphia he prepared a series of large-format pastel illustrations.
In the late 1870s Trouvelot approached Scribners, who had recent experiance with color lithography, to publish some of his illustrations. He personally supervised the conversion of his pastels into lithographic stones by Armstrong and Co. of Boston. A folio of 15 large-format (24 × 38″) chromolithographs and 167-page descriptive manual was published in 1882 as The Trouvelot Astronomical Drawings. Despite its small edition size (~300) and its rather prohibitive price of 125 USD, Scribners listed it as one of their most successful titles of the period.
In 1882, the same year that the gypsy moth had reached defoliation densities in his old Medford neighborhood, Trouvelot accepted a position at the Meudon Observatory in Paris. He continued his astronomical research using their Grande Lunette and even travelled to the Caroline Islands to observe the total eclipse of 1883. He wrote that one day he hoped to return to America but he never did. He died in Meudon on 22 Apr 1895.
Trouvelot was a classic case of the Victorian autodidact. With no formal training he left behind a legacy of several books and monographs, more than 50 scientific papers and nearly 7000 illustrations covering the entire range of natural science – everything from astromony to moths and butterflies to reptiles to geological surveys. Of course he will be remembered for his other legacy – the gypsy moth – which continues to spread across North America and causes nearly a billion USD of damage each year.