Naturally Curious: Tom Thomson's Red Pines, Little Cauchon Lake, Algonquin Park, Spring 1916

"Red Pines" is another one of those masterpieces from the spring fishing excursion of 1916. Tom was joined by Lawren Harris, Lawren’s cousin Chester Harris, and Dr. MacCallum on the Cauchon Lakes for some creative time away from the big smoke of Toronto.

They fished and painted for a couple of weeks in late April. MacCallum and Chester Harris most likely returned to the city directly by train. There is evidence suggesting that Thomson and Harris paddled down to Brent before taking the train to their respective destinations. Thomson was due to start his summer of fire ranger duty at Achray on Grand Lake around May 1st. Harris had to report to Camp Borden, where he is recorded as receiving his commission in the militia on May 5, 1916.

Given the painting locations, the group must have access to at least one canoe. Tom and Lawren had paddled together in 1914 so they were used to each other. The pair might have headed out with their paint boxes. Chester and Dr. MacCallum would have concentrated on angling for meals as neither painted. Without a second canoe, they would have had to fish from shore.

"Red Pines" might have been completed with just Lawren as company. Of course, we will never know for certain.

Creative Scene Investigation applied to this little gem will provide some surprises. There are lots of puzzle pieces to assemble but my Thomson friends provide many of the required interlocking bits of information. Most importantly, my Thomson friends have located the exact painting spot where Tom recorded exactly what he witnessed: N46. 05311 W-78.661954.

Red Pines, Little Cauchon Lake, Algonquin Park
Alternate title: Red Rocks, Georgian Bay
Spring 1916
Oil on wood panel
10 1/2 x 8 1/2 in. (26.7 x 21.6 cm)
Tom's Paint Box Size

"Red Pines, Little Cauchon Lake" is strongly front-lit. As expected for a plein air artist, the bright sun was on Tom's back. Those last rays of sunlight would have felt delicious in late April! And there were no biting bugs! The joy of the moment shines through in his oils and brushwork.

The direct beam from the sun would have had to pass through a very long trajectory of atmospheric molecules and particulates. The Earth's atmosphere is only about 10 kilometers thick so the sun was very low on the horizon to achieve these rich colours of red. Rayleigh scattering removes the shorter wavelengths of light from the beam. Only the long wavelengths of light would be left to illuminate the scene. Everything was bathed in orange and red light. The rocks and trees were radiant in the sunset light just before twilight.

The fun and very old PowerPoint slide below was highly animated to demonstrate how Rayleigh scattering removed the blue light out of the direct beam from the sun. The photographer only sees the orange or red light from the sun. Those are the colours that illuminated Tom's pines on the April sunset.

The pines catch the light and do not reveal even a sliver of shadow on either edge of the trees. The sun had to be directly behind Tom! With the time roughly established, the azimuth to the sun and thus Tom's angle of view can be readily established. For a sunrise at 5:15 local time, the azimuth to the sun is 71 degrees. This is a vital clue to search for the best match with the terrain for a sunrise painting session. The sun sets at 7:12 pm local time at an azimuth of 289 degrees in late April. These details are explained in the following graphic.

The strong red colours suggest this was a sunset rather than a sunrise. A day of sunshine generates turbulent and convective mixing of the atmosphere which puts many more particulates into the air. The dust also scatters the shorter wavelengths from the sun's direct beam.

Suspecting a sunset and a southeasterly view, my Thomson friends have already established the likely sunset painting location for "Red Pines, Little Cauchon Lake". "A" and "B" locate terrain features that Tom included in his painting.

Although the Algonquin forest has recovered considerably in the last century, the rocks are mostly unchanged. The following graphic matches the larger shapes between "Red Pines, Little Cauchon Lake" and the 2016 photograph.

The water levels were similar between the two images. A logging dam at the outlet of Little Cauchon Lake would have kept the water levels higher in the Gilmore and Company era. That dam has long rotted away but the 2016 water levels are only slightly lower than depicted in the 1916 painting.

The rock labelled "H" in Thomson's painting is missing in action in 2016 even though the water levels are lower. What the "H"? Perhaps that rock was precarious and shifted into deeper water by the ice. Like most things Thomson, there are unknowns but perhaps that rock is just waiting to be located.

And now for the weather... I consulted with my meteorological coworker Johnny Met:

"The sun has set, so it is twilight. The red cloud is high, probably cirrus and maybe altocumulus below, because the artist has painted the cloud rather thickly and has added dark patches indicating some altocumulus. This could have also been the Belt of Venus."

Johnny wasn't sure what was behind the screen of trees.

"A red sky at night is a sailor's delight, indicating a good day tomorrow. The trees in front of the painting obscure the sky, so as a weather observer, I would walk around the trees to obtain a better view."

A sunset Belt of Venus is tricky to diagnose. If the pinkish hue in the "Civil Twilight" sky were clouds, they would have to be a retreating band of cirrus or cirrostratus hemmed in by a deformation zone. The upper edge of the cloud would be better defined than it is in Thomson's painting. Just when an observer would be trying to distinguish what was in that twilight, the eastern horizon would be getting into Nautical if not Astronomical Twilight. An observer would not be able to discern anything and then it would be "Night"! Perhaps stars would appear in the eastern night sky thus confirming the cloudy illusion of the Belt of Venus. However, even stars might poke through thin cirrostratus.

The timing of the painting just after sunset was perfect for an observation of the Belt of Venus - within the "Civil Twilight" phase of the sky. The atmosphere had to be clear beyond the western horizon to allow the abundance of red light to illuminate the scene. The "Red Sky at Night "Sailor's Delight" poetic weather prophecy that Johnny Met mentioned is most appropriate. There was no synoptic scale weather system lurking on the western horizon.

The edges separating the pink Belt of Venus from the blue twilight sky above and the shadow of the Earth below were both diffuse. Cloud edges of advancing or retreating weather systems tend to be rather sharp.

Johnny and I are both unable to stroll behind the veil of pines in Tom's painting to get a better view of what he carefully brushed in between those tree trunks. I favour the Belt of Venus interpretation of that sunset sky but it is important to keep an open mind and present all the facts.

The sunrise Belt of Venus often resembles a deformation zone of cirrostratus and altostratus on the western horizon - see the image below left. The misinterpretation of the colours in the sky only becomes apparent when the sun continues to rise out of Civil Twilight and the apparent cloud magically vanishes.

Creative Scene Investigation has diagnosed three Belt of Venus paintings from Thomson's oeuvre. Perhaps there are more yet to discover! These are summarized in the following graphic. Few admirers of Thomson's art have likely realized Tom's intense interest in atmospheric phenomena. The hope is that these posts confirms Thomson's passion for the natural world!

Tom only had 15 minutes to lay in these colours. The brilliant red light on the rocks and the pines caught his eye from 150 metres away while he was probably sitting on the rocks. The telescopic view from across the bay required Tom to zoom in on his subjects to fill his panel and complete the composition. Any details would be obscured at that distance. Tom was still particular about including exactly what he witnessed as the backdrop to his pine tree subjects. He did not make "stuff" up but painted what he saw and the things that inspired him. Even the smaller rocks like "H" were important to him.

The summary of the Creative Scene Investigation on “Red Pines, Little Cauchon Lake” follows in the graphic.

The composition of “Red Pines, Little Cauchon Lake” also says a lot about Tom Thomson.

Like most of Tom's plein air work, this painting was in the stack of panels salvaged from Thomson's Shack. Harris or MacDonald probably felt safe with the obvious "Red Pines" title. The alternate title of "Red Rocks" also misses the probable Belt of Venus.

It is certain that at least Harris was with Thomson during this painting session. This is one brilliant panel that somehow did not catch the eye of Dr. MacCallum who may have also been with Tom. This panel surprisingly did not end up in Dr. MacCallum's personal collection of Thomson's art.