50 ASTRONOMY • APRIL 2019
Atmospheric Chemistry and
Physics, Christos Zerefos of the
Academy of Athens, Greece,
tells how he and his team ana-
lyzed red-green ratios in more
than 500 paintings from 181
artists, dating between 1500
and 1900. They recognized the
effects of volcanic aerosols
(namely a preponderance of
warm hues) in sunset paintings
created within a period of three
years that followed each of 54
major volcanic events during
that time period. These include
works by Turner, John Singleton
Copley, Edgar Degas, and
Gustav Klimt. The findings are
not surprising. But topping the
list is Seurat.Science on canvas
Born in Paris to a wealthy fam-
ily, Seurat studied drawing
at night school before he was
accepted into the École des
Beaux-Arts in Paris in 1877.
During his two-year stay, he
became disillusioned with the
academic style of painting —
the pedantic use of “hidden”
brushstrokes and “licked” fin-
ishes to smooth the surface ofa painting. At the same time,
he was growing enamored of
the large, separate brushstrokes
in French Romantic artist
Eugène Delacroix’s murals,
and the radical new styles of
Impressionist painters Claude
Monet, Camille Pissarro, and
others. Their use of visible
brushstrokes and experimental
application of color, tone, and
texture worked together to cre-
ate a vibrant visual impression
of a f leeting moment in life.
More than an artist, Seurat
had a keen aptitude for science.
He spent hours scouring librar-
ies for books on optics, scien-
tific theories of color, and the
principles of design. Specifically,
he was keen on the visual effects
of complementary colors and
the science behind color percep-
tion. He probably learned about
those subjects in Principles of
Harmony and Contrast of
Colours, and Their Applications
to the Arts, a book written in
1835 by French chemist Michel-
Eugène Chevreul.
Seurat left the academy in
1879 to spend a year of mili-
tary service in Normandy,where, according to biographer
Daniel Catton Rich, “he
opened his eyes to the lumi-
nous effects of sky and quiet
water.” He then returned to
Paris, where he began to apply
his evolving principles of com-
position and color.
In his quest to discover a
new approach to painting,
Seurat turned to science,
including Chevreul’s law of
simultaneous contrast — how
one color can change our per-
ception of another color right
next to it. Turning away from
mixing paint on his palette, he
ultimately began applying
thousands of small dots of pure
color in broken strokes — or
small touches set side by side
— directly to the canvas in a
precise manner, so that the eye
mixed the colors instead. His
ever-evolving works achieved
such an intensity of light that
he believed he had discovered
the science of painting.
Seurat had not perfected his
Pointillist technique when he
painted his first large-scale
composition, Bathers at
Asnières. Finished in 1884,ABOVE: American artist
Frederic Edwin Church
captured the 1862
eruption of Cotopaxi,
which is about 30 miles
(50 kilometers) south
of Quito, Ecuador.
Topping out at
19,347 feet (5,897 meters),
it’s one of the highest
volcanoes on Earth. WIKIMEDIA
COMMONS/DETROIT INSTITUTE OF THE ARTSOPPOSITE PAGE, BOTTOM:
A close look at Seurat’s
A Sunday Afternoon on
the Island of La Grande
Jatte, first displayed
in 1884, reveals the
artist’s placement of
individual complementary
colors with Pointillist
brushstrokes, giving the
work a hazy, shimmering
effect. WIKIMEDIA COMMONS/
ART INSTITUTE OF CHICAGO