Though it seems obvious today, it was only after the mid-1700s that artists began painting directly from nature in the plain light of day — a radical evolution at the time. Working outside the studio, painters were challenged to quickly capture the changes in light, clouds and atmosphere in the natural world around them.

Termed “plein air” by the French, this practice of working outdoors called for small, portable equipment and materials. The practice of oil sketching on paper was advantageous. Though the intention may have been to develop these small studies into larger works back in the studio, we value them today for their own merits.

“Sky Studies: Oil Sketches from the Thaw Collection” is The Morgan Library & Museum’s new exhibition of just over a dozen small paintings by French, German, and Scandinavian artists of the first half of the 19th century. Along with Johan Thomas Lundbye and other familiar names are those less familiar, including Françoise-Marius Granet, Carl Maris Nicolaus Hummel, Thomas Fearnley, Jean Charles Joseph Rémond, and Alexandre Desgoffe.

An exhibit of small works can seem large when each piece grabs your attention. The immediacy of “plein air” painting naturally allows for evidence of the artist’s hand, of where the brush began and where it ended, like a note dashed off at a moment’s notice. Within these small measurements are entire worlds, as each one acts like a memory that you want to keep hold of.

The painting by Eugene Isabey entitled “Sunset on the Normandy Coast” really shows how a loaded brush can just roll across a surface. Here the gesture of the hand and the wrist create a low burning ember of sun against a smeary, bruised horizon. The yellow ochre sky stretching across above is scrubbed on in heavy, angular zig-zags, while pier posts are energetic little jabs and dashes that descend to the surf.

In the deep, ruddy shadows of “Landscape at Sunset” by Carl Gustav Carus, thatched roofs and a low tower merge with trees as the day comes to its quiet end and the distance collapses against the sky’s low lying cloud bank. The last of the day’s light holds out just a little longer in soft bands of blue gray, yellow ochre and soft orange. The entire foreground is swallowed up in the dim and indistinguishable shapes of twilight, so strange and yet so familiar.

Jean-Michel Cels’ “Cloud Study in the Late Afternoon” is a perfect moment, a memory of cerulean blue sky and tattered clouds skipping hurriedly along, full of rain, backlit with touches of faint pink. With no indication of trees tops or distant hills, the sky in the very far distance acts as an anchor as it fades to pale yellow ochre.

These paintings are wonderful as a collection, with a wide range of individual artists’ styles and working methods, and varied locales and weather effects depicted. From the wind-blown seacoast of Eugéne Boudin’s “Sunset at Étretat” to the flattened blue hills of Christian Dahl’s “Cloud Study,” with its sense of distance and twilight hovering above a dark strip of coastline as narrow as the brushstroke indicating it, these painters caught momentary effects with great clarity and empathy.

This exhibition is the first of a series at The Morgan of the oil sketches in the Thaw Collection. These works are perfect examples of 19th century “plein air” painting capturing, in a little bit of sky, the transience of the moment, of time hurrying past us, of how fleeting life is — what the Psalmist refers to as “a wind that passeth away, and cometh not again.”

“Sky Studies: Oil Sketches from the Thaw Collection” is on view through the Fall of 2014, at The Morgan Library & Museum, 225 Madison Avenue at 36th Street, New York, NY 10016. 212-685-0008, themorgan.org

More information about Robert Edward Bullock’s work can be found at bullockonline.com