Tom Thomson's Approach to Plein Air

This "living reference" post will be updated as more information becomes available. It is a "work-in-progress" and should be considered as a draft while I locate images and facts that for now are just memories, somewhere, not sure where...  

Sketch or Pochade Box

The French word for "sketch" is "pochade". A pochade box is used for outdoor painting (en plein air), designed to be convenient and easy to transport while containing storage for paints, brushes, palettes, and other essentials.  Painting outside allows the artist to capture the essence of the landscape, with a focus on colour and atmosphere, with nothing between the inspiration and the eye.  

A well-designed box can be used as a portable easel as well as for storing unused and completed panels. Modern pochade boxes can be mounted on tripods so they can be employed like studio easels. 

Curators at the National Gallery of Canada believe that Thomson hand-crafted his own pochade box. Tom probably copied the design from the one that his friend A. Y. Jackson used. Dr. James MacCallum, Tom's patron, had introduced him to A. Y. Jackson in October 1913.

That pochade box was made to hold three of the 8 ½ x 10 ½ inch panels in slots in the lid, the “French Size”. The lid is deeper than the box, with the lower part being used as the palette. Paints, brushes and media would have been carried in another container. The use of this hard-to-clean "lid palette" explains the thick oils used in much of Thomson’s work. Tom's greys were unique and composed of many drying oils salvaged from the palette. Half-dry paint draws the oil medium from the fresh paint squeezed out above.

 A. Y. Jackson recalled that in the fall of 1914, Thomson threw his pochade box into the woods out of frustration. Jackson retrieved and repaired the box along with Thomson's self-doubts. 

Posture

Tom Thomson apparently preferred to sit while painting en plein air. His older brother George employed a field easel and did most of his plein are painting standing. 

Tom's pochade box did not have a method to support it from a tripod. The box was positioned conveniently on his lap, thus requiring Tom to sit. 

Arthur Lismer did a painting of Tom Thomson in 1914. It shows Thomson squatting on a rock while painting. My friend Geoff Taylor, the author of "Tom Thomson's Last Bonfire"  has completed some research and feels that "it is likely from the second trip Lismer made to Algonquin in that year (the same trip it is said he so influenced TT's painting style)." 

Lismer 1914 Sketch of Tom Thomson
 sitting on the ground while plein air painting.
What painting did Tom complete?

My Thomson friend Diana McElroy notes: 

"Although I have seen Lismer's sketch of TT painting many times, I don't think I had ever noticed how intently Tom is looking at the scene before him.  Despite the lack of specific detail, one can still make out the gaze of someone who is 100% focused on the scene before him.  Anyone who has observed artists facing a real-life subject of any kind, in any situation, would recognize that look."

More to come.

Plein Air Panels 

"Boathouse" as it would have
appeared in Tom's pochade box.

Tom preferred the French size 8.5 x 10.5 inch panels, the Goldilocks dimensions for plein air painting, not too big, not too small, just right. The artist does not need to pack a lot of oils. You don’t require or have much time to capture the moment of inspiration. The idea can be laid down in minutes with bold and colourful strokes. Often, that is all that the weather, lighting, inspiration and biting bugs allow. 

Thomson's rough cut panels from the lumber mill measured 8.5 x 10.5 inches, more or less. That size was determined by the dimensions of his pochade box described above. The extra half inch in height and width allowed for the smearing along the edges that must occur when slid in and out of his pochade box. Tom's panels essentially provided a painting area of 8 x 10 inches, which is still a standard size for artwork and frames. Perhaps Tom planned to cut the smeared excess off if the painting was to be framed after the oils cured? An untrimmed 8.5 x 10.5 inch panel would require a more expensive custom frame, which is a downside of those dimensions.

To prepare Tom's panels, the long boards likely would have been first cut with the grain (Step 2 in the following graphic). Handling the long plank makes this cut more challenging to make exactly, and it defines the 8.5 inch height dimension of the panel. A fraction of an inch would not be significant to the mill workers, thus explaining the almost 9 inch height of the "Boathouse" panel.  

The width of the panels across the wood grain would be cut from the long boards. These cuts could be quite precise, especially if a blocking jig was employed (Step 3 in the graphic). The jig would be set just once at 10.5 inches between the edge of the saw blade and the blocking jig. Panels with the precise width could be quickly cut until the long board was used up. The exact width of the panel is more crucial to allow the panel to be easily slid in and out of the pochade box. 

Thomson's finished plein air panels were likely to be accurately 10.5 inches wide, oriented along the grain of the wood. The 8.5 inch height of the panel was more likely to show some variation. 

If Thomson used the panel in a landscape format, the longer dimension and the grain would be along the width as described in the Catalogue Raisonné for the  "Boathouse" panel.  The same panels were also employed in portrait formats where the height is the longer dimension. The orientation of the grain would align along the longer dimension as indicated by the double-headed arrow in the accompanying graphic. 

Tom Thomson and his artist friends, who would form the Group of Seven used panels made at the veneer mill at South River near the entrance to Algonquin Park.

Other Painting Surfaces

Thomson painted on whatever supports were available to him, especially when his supply of birch panels ran out. Thomson painted a lot on composite wood pulp (possibly bookbinder’s) board, which he either shellacked or varnished. Other supports include plywood, cedar, veneer, commercially prepared “Birchmore” board, artist’s canvas board, Winsor and Newton paperboard, as well as canvas or paper mounted on plywood. A few of the smallest paintings were done on pine or cedar from flour or orange crates. 

More to come as required.

Warmest regards and keep your paddle in the water,

Phil Chadwick

Tom Thomson's Boathouse, Summer 1916 TT-140

Sometimes it is best to start from scratch. Much has been guessed about Tom Thomson's "Boathouse" and a great deal of it is misleading conjecture. I refer the reader to the Tom Thomson Catalogue Raisonné for "Boathouse". It makes for interesting reading. 

As real estate agents often say, the three most important considerations are:

1. Location;
2. Location; and 
3. Location. 

Creative Scene Investigation is certainly made much simpler if the location of the inspiration can be accurately determined. My Thomson friends Diana and Bob McElroy have spent considerable time paddling in the wake of Tom's canoe and identifying the specific sites where he painted. They had already located a very good match for "View over a Lake, Autumn". That landscape reminded them of the terrain displayed in "Boathouse". 

"Boathouse" Summer 1916
Oil on birch panel mounted on plywood
8 13/16 x 10 1/2 in. (22.3 x 26.7 cm)
Tom's paint box size, 1916.85

In the spirit of true adventurers, Bob and Diana scheduled a trip to Grand Lake to confirm or deny those suspicions. Here are the results of those very recent investigations (early May 2025). The McElroys reaffirmed that Tom was painting from the slope in front of the Out-Side-Inn when he created "Boathouse"!

"Bob and I agreed that was indeed the location. The vegetation on the shore there has changed somewhat in the last 100+ years (and there is now a picnic table and supports for a volleyball net), so it’s not possible to match the foreground of the painting exactly. The skyline is altered a bit by tree growth, but it is still possible to see the hills overlapping as Tom saw them. "View over a Lake, Autumn" does not have the shore in the foreground, but the angle of the water’s edge in "Boathouse" matches what one sees from in front of the cabin. The other locations we had previously considered were not as good a match, since the near shoreline in all cases appeared parallel to the far shore. It also seems like a reasonable spot for a boathouse – i.e. right in front of a ranger cabin – though I haven’t seen any old photos that show it there. As usual, we will never know for sure."

A bit of terrain matching came up with the following comparisons. 

The clincher was the matching angle of the shoreline in both the photo and Tom's "Boathouse".

Further, Diana McElroy notes:

"There is little doubt that the date of this sketch was 1916, since, as far as is known, that is the only year Thomson was at Achray. The time of year certainly appears to be summer, due to the fresh green of the foliage and the low water level. It could be either July or early August"

It has been established from earlier Creative Scene Investigations that Tom spent the fire season of 1916 gainfully employed as a  Fire Ranger. Tom could not make a living from his art. He reported for duty at Achray on Grand Lake around May 1st and was in the area all summer.

As Tom noted in his October 4, 1916 letter sent from Basin Depot to his patron Dr. MacCallum:

"Have done very little sketching this summer as I find that the two jobs don’t fit in.  It would be great for two artists or whatever you call us but the natives can’t see what we paint for.  A photo would be great but the painted things are awuful [sic]."

In that same note, Tom tried to entice his patron to come to Achray the following week.

"Could you arrange to come up this week? You could get a train to Achray at Pembroke Sat. night at 7:30 or more likely 10 o'clock and be here somewhere about 12. The train leaves from Brent Sunday morning then the next one down is Wednesday morning but I could paddle you down to Pettawa [sic] from here any day you should want to go out."

That trip probably never happened, but no one knows for certain. Tom returned to Toronto later that October or early November. The factual bottom line is that Thomson was around Grand Lake and Achray in 1916. Knowing the location of the painting thus firmly establishes the date. 

Diana continues:

"Note the low water level also in ‘View over a Lake, Autumn’, which could also have been summer or perhaps very early autumn. In this sketch, the red colour is due to sunrise behind the viewer, not foliage.  The vegetation on the hill at the time was largely young deciduous trees (any suitable pines having been cut for lumber), and the large areas of green in the sketch show this. A comparison between these two sketches shows essentially identical patches on the large hill across the lake. Some light vertical streaks near the shore probably indicate birch or poplar trunks. The few conifers appear as dark green. This can be seen in the photograph from May 1925."

A comparison between these two sketches shows essentially identical patches on the large hill across the lake."  

 The present day vegetation (October 2014 photos below and May 2025 above) shows how the conifers have grown, particularly along the shore, but much of tree cover on the hill is deciduous, largely poplar and birch (both yellow in the fall) and patches of red oak (dark reddish brown). The hillside is a challenging environment for the growth of vegetation, being largely rock with patches of organic soil here and there. Most of the trees and other plants are species that can survive a dry environment. Bushwhacking to the top of the hill is not too difficult, since the bush is fairly sparse with some open patches.

The double-headed white arrow identifies the exposed rocky shoreline and is identical in both sketches. 

The conclusions from these observations are: 

Diana continues:

"It’s unfortunate that the image in the catalogue is cropped at the edges. I think it’s always interesting to see the messy strips at the sides where the panels slid into his sketchbox. The upper and lower edges are always of interest as well, as is the verso, but of course the latter is obscured by the extra plywood mounting.

 

The Boathouse panel is birch, 10.5 inches wide, with the grain running horizontally (as can be observed on the left and right edges of other panels from 1916). The main difference is the slightly larger vertical dimension [almost 9 inches versus the typial 8.5 inches of Tom's panels]. The original panel has been reinforced by plywood glued to the back, due to three horizontal cracks in the wood. Perhaps the cracks were due to moisture, or rough handling in transporting the panel, or maybe just weaknesses in the wood. It is not clear when the plywood was added.

With regard to the reference to the sketch of Mowat Lodge from a height (1914.46), there is no way this is a boathouse at Mowat Lodge. The hills in Boathouse don’t match the far shore of Canoe Lake.

Speculation that the panel size indicates that Thomson might have been running out of his usual size boards doesn’t seem likely. While his ‘standard’ size was "8.5 by 10.5”, many of his panels from 1916 vary slightly from these dimensions. It could be due to slight variations in the cutting of the boards by whatever mill he used to make the panels for him. However, in most cases the width of the panels would have fitted into his sketch box.

The reference to the much smaller panel [5x7 inches] used for Log Jam (1916.81) doesn’t seem relevant, as it appears to be an early spring scene rather than fall. The water flow in the log chute is high, as it would be in spring, and the tree colours – pale green or greenish white for poplars with leaves just emerging, and reddish purple for maples in flower – are also characteristic of spring."

"At the bottom of the Catalogue write-up is the following:

“Record last updated June 14, 2018. Please note that the information on this and all pages is periodically reviewed and subject to change.”

Note that I sent them an email in 2019 correcting their speculation about the date, location, season, and time of day. I have yet to receive a reply, nor has the text in the catalogue been updated."

I concur with all of the above, very thoughtful observations. Science (including Creative Scene Investigation) is the ongoing search for the truth. The facts are refined with knowledge and continued study. 

The speculative comments found in the Tom Thomson Catalogue Raisonné for "Boathouse" have been addressed, but I doubt if Tom cared if the size varied. For him, the panels were all about 8.5 x 10.5 inches, and he would not see the reason for measuring the panel size to the nearest millimetre. "Tom Thomson's Approach to Plein Air" is a background post that contains a section explaining possible reasons for the variations in his panels. 

Tom certainly could not have fathomed how valuable his sketches would become, fetching a maximum to date of $2,749,500 CAD for "Early Spring, Canoe Lake" at Heffel in Vancouver on November 26th, 2009. Recall that Tom used the sketches he was unhappy with as kindling for his evening bonfire. Oh my!

It is interesting to note that the official Catalogue Entry included above describes this painting as a square measuring 8.5 inches on each side. Errors are easily made but sometimes quite challenging to correct.

There are at least fourteen paintings in Thomson's portfolio that include "Early Spring" in their title. The Creative Scene Investigation (CSI) for "Early Spring, Canoe Lake" can be found here: https://chadwicknaturallycurious.blogspot.com/2023/07/tom-thomsons-early-spring-canoe-lake.html

The value of an original Thomson plein air painting might explain why they are now measured accurately to the nearest millimetre. Some artists, including myself, consider the size of the art when pricing. In Thomson's case, an 8.5 x 10.5 yields 89.25 square inches.  If you employ "Early Spring, Canoe Lake" as the standard, each square inch is valued at $30,807 CAD, making the measurements very important! A square millimetre of that Thomson sketch is worth $48 CAD, with more than 57 thousand of those to be found in each panel. Of course, serious art collectors are motivated by factors other than size. 

I remain amazed and gratified by the considerable amount of dedicated effort and investigation into the art of Tom Thomson. Countless individuals with broad ranges of expertise and experience contribute unique insights into the art of Thomson. It would be a pity not to share this information with the larger art community. The art of Tom Thomson still helps to define the social fabric of Canada. We are all in this together, attempting to learn each day. 

Harris and MacDonald, pictured below, did their very best to catalogue the art of their friend. Unfortunately, due to World War One, they were unable to accompany him for many of the works they documented from Thomson's Shack in the spring of 1918. Those bold panels were all very "cold cases" at least a couple of years old to Harris and MacDonald. They were assigning titles, dates, location and other information as best they could. MacDonald had never been to Algonquin, which made the effort especially challenging. Viewing Thomson's final sketches would have been emotional for his friends, who were likely still grieving from his loss. 

Thomson could have made the organization of his art much easier if he had just noted some specifics about each. The date, location and motivation behind each painting would have been enough to assign a meaningful title. Tom may have left very few words behind, but he did paint exactly what he saw, and perhaps that is enough. Tom did not make anything up and recorded the reality of what inspired him in his brush strokes. Sleuthing facts by applying science to his subjects is all we have to work with. 

The names applied to both of these paintings from Achray on Grand Lake are good examples of the dilemma faced by Tom's friends. Could "View over a Lake, Autumn" be any more generically bland? Perhaps "Boathouse" is even less revealing. The assigned names merely included the obvious, leaving the real motivation of Thomson to the imagination and open for investigation. For example, someone with detailed knowledge of the inspiration behind these panels might have selected "Summer Sunrise Across Grand Lake" or "Summer Morning at the Achray Ranger Boathouse" respectively. 

I select names for my art that tell the story of the motivation behind the painting. Additionally, the goal is to assign unique titles to each. Sometimes I fail at that effort with almost 3000 works in my portfolio. As a failsafe extra precaution, each work is also chronologically numbered. Additional information, like the time, date and location, is recorded on the back of each. Finally, interesting background information about the subject and the weather completes the story and is recorded in a file identified with the number of the painting. 

As an eternal student, I use art and science to continue to learn about nature. The associated numbered Word, PDF, and PowerPoint documents facilitate that effort for every painting. All of this information is available starting with my first documented work #0000 "The Glass Goat" completed in the summer of 1967. Recipe cards were initially employed to record the details. Computers greatly facilitated those efforts starting in the 1980s. Now, everything is interlinked using HTML. All 70 gigabytes of data (so far) is further backed up on my home computer. For better or worse, there is no need for anyone to conjecture about my art. I feel that the background stories can be as interesting as the brushstrokes. 

"Boathouse" as it would have
appeared in Tom's pochade box.

Inscription verso: 

• l.l. and u.r., Thomson estate stamps; 
• u.l., on frame, blue label, Art Gallery of Toronto [on loan from Peggy Lownsbrough (née Waldie, sister of R.S. Waldie), "for examination by David Brooke," 1966; 
• l.m., label (bottom part of), Laing Galleries, Toronto

Provenance:

• Estate of the artist 
• Laing Galleries, Toronto, Ontario 
• Robert Stanley & Mary Margaret (Meta) Waldie (née Gibson), Toronto, Ontario, 1966 (by descent) 
• Robert Gordon Waldie, Toronto, Ontario (by descent) 
• Private collection.

The analysis and diagnosis of "Boathouse" would have been quite impossible without the inquisitive investigations of my Thomson friends Diana and Bob McElroy. Additionally, their expert analysis of "View over a Lake, Autumn" contributed significantly to the solution of this painting. Along with Canadian society, I remain forever indebted. I would think that Tom Thomson would also be appreciative. 

The details on what happened to the boathouse within the nine years since Tom spent time on the Grand Lake shore are unknown. Fire? Ice? Waves? The investigation continues with the assistance of my Thomson friends and the kind folks at the Algonquin Provincial Park Archives & Collections.

As with all of the posts that comprise "Tom Thomson Was A Weatherman", continuing investigations might discover new information that requires revisions to this current version of our best estimate of the truth. That is the nature of science. We are all eternal students spending our days learning...

Warmest regards and keep your paddle in the water,

Phil Chadwick, Tom Thomson Post TT-140

PS: Tom Thomson Was A Weatherman - Summary As of Now contains all of the entries to date. 

PSS: Should you wish to have Creative Scene Investigation applied to one of Thomson's works that I have not yet included in this Blog, please let me know. It may already be completed but not yet posted. In any event, I will move your request to the top of the list. If you made it this far, thanks for reading! 

Tom Thomson and the 1915 May Two-Four Weekend

Something very rare happened on the "May Two-Four Weekend" in 1915. A volcano that had been sleeping for about 27,000 years suddenly woke up at about 4:00 pm Saturday afternoon. Lassen Peak in northern California produced a violent explosion that ejected rock and pumice high into the atmosphere. This explosion was the most powerful in a series of eruptions from 1914 through 1917.

On May 22, 1915, an explosive eruption at Lassen Peak, California, the southernmost active volcano in the Cascade Range, devastated nearby areas and rained volcanic ash as far away as 300 km to the east. 

Tom Thomson was staying at Mowat Lodge on Canoe Lake, busy painting before the black flies emerged and waiting for guiding and fishing to occupy his time. Tom would have been oblivious to how a faraway volcano might influence his choice of pigments. Thankfully, Tom painted what he saw.  

World War One, the so-called first "Great War" was still raging in Europe. Tom's artist friends had dispersed to participate in that conflict in one way or another. Sadly, they were unable to accompany him on his last artistic adventures which ended prematurely with his death in July of 1917. On the positive side, Thomson was finding his own, unique artist voice and creating magnificent work.

Three years later, in the spring of 1918 Lawren Harris and J.E.H. MacDonald faced a virtually impossible task to sort through the two or three hundred panels that Tom had created in their absence. The undocumented panels were stacked high in Thomson's Shack. 

His friends attempted to sort through the paintings selecting what they felt were the best works to establish Tom's legacy. The Estate Stamp applied to the front and back of the panels would authenticate his art. Tom only signed the panels when asked to do so. He certainly never bothered to put names on his paintings. In fact, Tom rarely made any mention of the inspiration for his paintings leaving the art to speak for itself.  As a result, this was a gargantuan but essential task for his friends. Many of Tom's originals had already dispersed to the wind to anyone who took a passing appreciation for his brush strokes.  

The estate stamp typically in the lower right often resulted in some paint eventually flaking off. The panels salvaged from The Shack and organized in the Studio building all display the stamp.

Harris and MacDonald certainly were enthralled with Tom's art but had little or no first-hand knowledge of the story behind them. They had to rely on their own devices to create plausible titles based on the subject matter and possible locations. MacDonald had never been to Algonquin. Well-intentioned mistakes were made. These are easily forgiven. Those errors still remain in the Tom Thomson Catalogue Raisonné but there is hope!

Using science and topographical maps, we can correct those mistakes - something that I have been doing since the mid-1980s. As an example, it is interesting that more than a century later, we can trace Tom's movements on the Victoria Day weekend of 1915 using only his art and a volcanic eruption in California. Please let me explain. 

From detailed research into Tom's movements, we can be fairly certain that Tom was at Canoe Lake on the weekend of May 24th, 1915. Tom was likely staying at Mowat Lodge but occasionally ventured to his favourite haunt on Hayhurst Point less than a kilometre to the east. 

Thomson Travels 1915

• March 13 – April 10: Ontario Society of Artists Forty-third Annual Exhibition, Toronto. Thomson exhibits Northern River, Split Rock and Georgian Bay Pines. Northern River is bought by the National Gallery of Canada for $500. His address is given as Studio Building, Severn Street.
• Mid-March: Arrives in Algonquin Park, via Huntsville, where he stays at the home of Winifred Trainor for two days; he travels to Tea Lake and Big Cauchon Lake; in the Kearney area, he stays at McCann’s Halfway House.
• A.Y. Jackson had returned to Quebec, evidenced by a letter to his sister Kate, dated April 18th, 1915, which he sent from Emileville Quebec. In it, he discusses his intention to join the army. His attestation papers show that he enlisted on June 14, 1915.
• April 28 – May 19: Thomson and George Rowe guide the Johnston Brothers of Pittsburgh, Pennsylvania to Pine River; they travel to Tea Lake. On their return, Thomson and Rowe travel to Big Bear Lake.
• May 24 Weekend...
• July 17: Assists H.A. Callighen in bringing tourists from Joe Lake Station to Smoke Lake by canoe.

A case can be made that links four of the 1915 paintings using colours, the volcano, the parade of weather across Canoe Lake and science.

I propose that these four sequential paintings recorded every sunrise and sunset at Canoe Lake starting on the evening of Saturday, May 22nd, 1915 - the day that Lassen Peak erupted. The potential paintings are included in above. Brief explanations follow. Detailed analysis and diagnosis of each painting can be found in the linked blogs.  Please ignore the official names of the artwork which identify them all as sunsets - two of the four were certainly sunrises. 

Sunset, Saturday May 22nd, 1915

On the late afternoon of Saturday, May 22nd, Thomson was visiting his favourite site on Hayhurst Point. He recorded the backlit clouds looking westerly at sunset in Painting 1.  A spring weather system was approaching. The details are explained in Tom Thomson's Sunset Sky, Summer 1915. Harris and MacDonald were correct in identifying this as a sunset. I feel they missed the mark by identifying the season as summer perhaps because the name "Sunset, Spring" had already been used in  Painting 2. Tom typically spent his summer guiding and fishing. He did not paint much in the summer because of pesky biting insects. The clouds are also not overly convective as one would expect in mid-summer.  

Sunrise, Sunday May 23rd, 1915

At dawn on Sunday, May 23rd, Tom was on the shore in front of Mowat Lodge looking easterly to observe strong sunrise colours in the backlit clouds. The unusual sunrise colours would have penetrated Tom's room on the second floor of Mowat Lodge. Tom must have been compelled to grab his oils and make a weather observation. For a detailed analysis see Tom Thomson's Sunset Sky, Spring 1915. The terrain features of the eastern shore of Canoe Lake as well as those recorded in other Thomson paintings confirm the easterly view. The clouds also confirm that Tom was observing the wake of a cold front. The weather system that had been approaching at sunset on Saturday had crossed Canoe Lake overnight probably bringing precipitation overnight. 

Harris and MacDonald would have incorrectly interpreted the strong colours as a sunset sky unaware that the higher level volcanic aerosols transported by the jet stream had already arrived over Canoe Lake.

Tome would have been interested in the strong colours exhibited in the sky all day Sunday. There could be other paintings to include in this sequence. We can be certain that Tom paddled over to his Hayhurst Point haunt to observe the vivid sunset colours looking west. 

Sunset, Sunday May 23rd, 1915

The details of the analysis and diagnosis can be found in Tom Thomson's "Sunset" 1915. Harris and MacDonald called Painting 3 "Sunset" from the summer of 1915. They were certainly correct about the sunset part but the season was spring right after the volcanic eruption. Matching the terrain features confirms that Tom was looking westerly across Canoe Lake. The jet stream had already delivered the next low-pressure system in the parade of weather. This time the strong winds also brought thicker concentrations of volcanic aerosols dramatically influencing the sunset colours. Tom painted exactly what he saw!

Finally, Tom awoke on Monday, May 24th, 1915 to a brilliant sunrise streaming in his window of Mowat Lodge. Terrain matching again confirms his easterly viewing angle. 

Sunrise, Monday May 24th, 1915

The weather system that arrived at sunset on Sunday had passed east of Mowat. Tom was observing the sunrise light scattered from the underside of the cirrus and altocumulus cloud found in the "hang back - comma head" of the storm. The details of the analysis are recorded in Tom Thomson's Sunset, Summer 1915. Harris and MacDonald miss-named Painting 4 as "Sunset, Summer 1915" reusing the same name as applied to Painting 3. Understandably, the unusual sunrise colours tricked them again. They were also running out of unique names to employ. 

Tom must have been aware that something very unusual was happening in the atmosphere. This lends some rationale for Tom to diligently observe the increasingly spectacular colours in a series of paintings. Paintings number 1 and 3 in the above series are the only actual sunsets looking westward. 

Painting 1 Saturday sunset left -Painting 2 Sunday sunset about 30 hours after the eruption right

Painting 1 was completed just a couple of hours after the eruption well before the arrival of the volcanic aerosols. Painting 3 was completed with the arrival of the first high concentration of volcanic aerosols. The initial concentrations of aerosols can be very high behind the deformation zone of the airflow that delivers those particulates. Tom must have been amazed at the vivid sunset colours!

Paintings 2 and 4 repeated below are truly sunrises looking eastward from Mowat. The colours increased in chroma between Sunday morning on the left and Monday morning on the right. 

The progression of cloud types and structures is consistent with two separate weather systems that crossed Canoe Lake over the May Victoria Day weekend. Rain likely fell both Saturday and Sunday nights. 

In any event, Sunday supper on the Queen Victoria Holiday weekend would have been memorable - not only because of the "fireworks" in the sky. Annie Fraser, Shannon's wife was well known for her fine meals and baking at Mowat Lodge. (Note: May 24, Queen Victoria's birthday, was declared a holiday by the Legislature of the Province of Canada in 1845. After Confederation, Queen Victoria's birthday was celebrated every year on May 24 unless that date was a Sunday, in which case a proclamation was issued providing for the celebration on May 25.) The Great War was still raging in Europe and patriotic feelings would have been high. 

           Tom Thomson circa 1905-1910                 

To really appreciate Tom Thomson, it is important to place his art within the context of the times in addition to the science and the weather. 

What motivated Tom to record these weather observations? Tom must have been shocked to see the colours of the sunrise reaching into his bedroom window. I can imagine Tom grabbing his paint box and rushing out to the shore of Canoe Lake to chase the sunrise light before it disappeared. Tom was also a morning person... let's get going with the sun. Rise and shine.

Tom would have been eagerly waiting for the display of colours that the sunsets would deliver. That is why artists paint... we all chase the light in amazement at the beauty of nature ... and the weather. 

Tom might not have understood all of the science and would certainly not have known that Lassen's Peak had just exploded - but he was truthful to what he saw. In that way, the science he recorded must also be accurate. 

Warmest regards and keep your paddle in the water,

Phil Chadwick

PS: Tom Thomson Was A Weatherman - Summary As of Now contains all of the entries to date. 

PSS: If one searches Tom Thomson's Catalogue Raisonné  for "sunrise" only one painting shows up. If one searches for "sunset" 25 works are produced. Some of those sunsets are actually sunrises as we have demonstrated. Of course, it would have been helpful if Tom had left a few hints. 

Tom Thomson's "Smoke Lake" 1912

In 1976, when I graduated from Queens in Nuclear Physics, I was not aware of the friends that I would make forty years later thanks to Tom Thomson. It turned out that several of my future Thomson friends were also involved in nuclear physics. Except for a twist of fate, I was also destined to go to Chalk River to study and work in the Nuclear Industry. Those friends would have been encountered that much sooner in Deep River, and while paddling the Petawawa and the Dumoine Rivers.  One can only ride one horse at a time, and meteorology came along first, so I saddled up. There can be no looking back, but I often wonder.. Giddyup...

Smoke Lake
Alternate title: Smoke Lake, Algonquin Lake Spring 1912
Oil on paperboard (Birchmore board)
7 x 9 15/16 in. (17.8 x 25.2 cm) 
Tom's Paint Box Size

Meanwhile, in July of 1977, Jim and Sue Waddington began a 36-year journey of discovery that culminated with "In the Footsteps of the Group of Seven" in 2013. Jim even attended the same high school in Brockville, graduating from BCIVS in 1959.  Jim became a professor of physics at McMaster University, specializing in nuclear physics. Jim even married his high school sweetheart, as did I. 

My prized, autographed copy of Jim and Sue Waddington's book

Diana and Bob McElroy began their investigations into the painting places of Tom Thomson in the 1980s. Bob McElroy also has a strong background in physics. Both Diana and Bob worked at Chalk River. They enjoy a large and significant web presence detailing the painting places of Tom Thomson. I found these sites invaluable when working on the "Tom Thomson Was A Weatherman" blogs. 

I am fortunate to count Jim and Sue Waddington, the authors of "In the Footsteps" and Diana and Bob McElroy as friends. We share a similar life stories. They have contributed to several of the posts comprising "Tom". In fact, our ongoing friendship leads to this story.

Jim writes: "Sue read somewhere that Tom Thomson, working as a guide, took people to Molly's Island in Smoke Lake. So that was as good an excuse as needed to go for a paddle. The wind came up, and the skies darkened. The island is small. I remember a small sandy beach on the north side. We crossed the island, took a photo, retreated to the canoe, and got soaked."

The Waddington photo was taken looking south from the south shore of Molly's Island

The very best way to start with a Thomson post is with the painting location. Using that information, the direction of view is well established from the get-go. I am only left with the earth sciences to unravel. 

Comparing the Waddington photo with Tom's "Smoke Lake" was an interesting exercise that few will ever bother to do. Tom certainly was unconcerned, being in possession of his "Artistic Licence" - as am I. He chopped 16% from the width of the horizon to make his subject fit the small plein air panel. Tom judiciously removed the uninteresting flat portion of the distant ridge line. The following graphic guides you through the steps I took to deduce that cryptic number. 

2.6 cm chopped out of the flat ridge line in the Waddington photo is 16% of the 16.5 cm wide horizon.

My long-time Thomson friend and expert Daian McElroy remarked:

"How fortunate that the Waddingtons were in the right spot when the weather was so appropriate.  And I found your examination of the details of how Tom tweaked the landscape to be very interesting.  Despite those changes, the sketch still conveys the essential landscape - that's the location all right, without a doubt."

The match to the terrain with the described adjustments is indeed almost exact. Tom also frequently exaggerates the vertical extent of the terrain. He refrained from making significant changes to the heights in "Smoke Lake". The subject of this painting was the weather and not the hills. 

As noted, the weather in the Waddington photo was a close match to what Tom painted! 

Looking south from Molly's Island across the south basin of Smoke Lake

The winds were strong southwesterly on the afternoon that Tom painted "Smoke Lake". Using the Beaufort Wind Scale and matching the waves and whitecaps to the descriptions, the winds are estimated to be 20 to 25 knots (37-46 kph) when Tom was painting. The fetch across Smoke Lake is also an important factor, and the winds could have easily been stronger in a more exposed location. 

• 17-21 knots- Fresh Breeze-  Moderate waves, taking a more pronounced long form; many white horses are formed. Small trees in leaf begin to sway; crested wavelets form on inland waters.
• 22-27 knots- Strong Breeze- Large waves begin to form; the white foam crests are more extensive everywhere. Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty.

Note that the waves were much smaller in the lee of the distant shore, so the strong wind had to be mainly from the south. Further, the shape of the cumulus elements (the white arc in the above graphic) comprising the flanking line revealed that the winds at cloud level were southwesterly. 

The convective cloud was quite likely a cumulonimbus - simply a thunderstorm. Tom included the rear edge of the flanking line. That cloud was front lit, indicating that the sun was in the western sky - it was afternoon. Thunderstorms typically require significant daytime heating before they fire up, so they are more unlikely in the morning. The cloud was tall above the very dark base, which is characteristic of cumulonimbus. 

SCUD is meteorological slang for "Scattered Cumulus Under Deck". The "deck" referred to is the base of the cumulonimbus cloud, which is the lifted condensation level (LCL) for the air mass. Daytime heating of the land warms adjacent air parcels, which rise buoyantly to saturation at the LCL. 

SCUD are twisted shreds of cloud lifted from the ground by the turbulent winds. The moist surface air parcels are turbulently stirred and lifted to saturation. These air parcels saturate to become clouds "under the deck" if the ground and turbulent air parcels are additionally moist from any preceding rain.  

I used the conceptual model for a supercellular thunderstorm as a worst-case scenario. There is no absolutely conclusive evidence in Tom's painting that the convection was even a thunderstorm. Tom did not include lightning this time on his panel. The flanking line is characteristic of the significant wind shear required to create both multi-cell type cumulonimbus and supercells.  The following photo depicts a multicell thunderstorm looking from the south while Tom was on the northwest flank of the convection. 

Jim Waddington writes:

 "Many years ago, my father had a book about instant weather forecasting. I  often use the ideas while on a trip. The only trick that I remember was that dark skies with small, low, fast-moving black clouds means 'rain within five minutes'. We were about to get wet but so was Tom."

"Instant weather forecasting" is about learning from the lines in the sky... see "Lines in the Sky and the Meaning of Life" for more details. However, meteorology is typically much more complex than what can be viewed from your immediate location. Weather is always lurking just beyond the horizon. I advise that a meteorologist accompany every canoe trip... 

The trick that Jim remembered, "small, low, fast-moving black clouds" refers to SCUD  clouds. Depending on the illumination, the optically very thick SCUD clouds can be dark (backlit) or white (frontlit) as in Tom's weather observation above. The SCUD indicate that it has rained recently nearby and that moisture has been lifted to saturation by strong and turbulent winds. The fact that the clouds can be seen to be moving quickly tells us that they are nearby and thus close to the ground. Depending on the location of the convection, more showers could be just minutes upstream. This is a good trick.

I also asked my colleague Johnny Lade to have a look at this painting as if he were making a weather observation. Known to his students as "Johnny Met", he has a lifetime of experience observing the actual weather. Johnny nailed this observation since Thomson painted exactly what he saw.

"At first glance, I knew Tom had stopped a summer thunderstorm.

He painted, fast-moving Scud clouds, white caps on the lake, probably a wind shift in the down draft, bringing cooler temperatures, thunder and lightning, and heavy showers. Tops of the cloud would be into the tropopause, moving the cumulonimbus cloud at a fast speed, so quickly that in ten or fifteen minutes, the sun would return. A fresh and cooler air from thirty thousand feet and the smell of ozone.

I worked many thunderstorms in my weather career from daytime heating afternoon summer thunderstorms to the fast moving line ahead of a crashing cold front and the sneaky warm front thunderstorms causing lots of noise in the middle of the night. 

Most of my career were postings at airports so passing thunderstorms put a crimp in arrivals and departures with sudden wind shifts: with a head wind suddenly becoming a tail wind needing a longer runway on landing, and small aircraft not tied down on the ramp."

Many thanks to my friend Johnny Lade. His observation rings true, breathes life into Tom's painting, and adds another dimension to the story. Thomson loved painting thunderstorms!

Tom typically reserved his summers for fishing. The biting bugs discouraged staying still in one place for too long, which rules out painting. The potential to fish and be reimbursed while doing so is called "guiding". Tom was all in for that lucrative enterprise, as art did not really pay. 

Molly's Island on Smoke Lake would have been a perfect fishing and camping destination. An interesting 6-kilometre paddle from Mowat Lodge was all it took. The numerous shoals around and just south of the island are still readily apparent on Google Earth and probably attracted great schools of fish in Tom's day, well before the pressure on the fishery increased to current levels. 

"Smoke Lake" is certainly one of Tom's early works and likely correctly dated as 1912. Tom did not even sign his later plein air works. If so, this painting of a thunderstorm was completed on Thomson's first trip to Algonquin in May of that year. Tom was 34 years old and accompanied by his Grip coworker Harry B. Jackson.

Algonquin Park Ranger Mark Robinson met the Thomson and Jackson at the Joe Lake Train Station on the Saturday evening after a day of patrolling the Burnt Island Lake area. 

Later, Ranger Bud Callighen, met two individuals camped near Tea Lake Dam. Callighen did not identify the men, but the descriptions in his diary matched Thomson and Jackson. It was widely known that they had camped at the easily accessible Tea Lake Dam south-west of Canoe Lake. Callighen noted "two men camped at (Tea Lake Dam)" because most park visitors hired a local guide to show them around in 1912. 

H. B. Jackson's  wrote a Letter to Blodwen Davies dated May 5, 1931 describing Thomson's Algonquin trip.

"I am quite sure it was Tom's first visit to Algonquin Park. Tom MacLean a Toronto artist who was located with us at the Grip, gave us a letter of introduction to the elder Mr. Bartlett, who was supt. of the Park at that time:

MacLean (sic) told us of the beauty & fine fishing in that region & Tom & I thought we would try it. […]

Tom did get his painting outfit in the spring of 1912 & used it on our trip & afterwards with Broadhead; While we were together he did very little serious sketching, making a few notes, sky lines & color effects." 

H.B. Jackson completed the accompanying portrait of Thomson during that first visit to Algonquin.

A few months later, Jackson would write about the camping experience without a guide in the Editorial Section of The Toronto Sunday World on August 11, 1912 (see the accompanying article).

The above text is not clearly legible, but the hunt is on to find a transcribed version. 

Supercellular thunderstorms are fairly common in Algonquin in May due to geographical and terrain influences. I watched for such situations as a severe weather meteorologist! The brown hues Thomson selected to depict his thunderstorm from Molly's Island are characteristic of severe convection. Such a storm would have certainly caught Tom's attention, even though H.B. Jackson remarks that "he did very little serious sketching". All of the puzzle pieces fit together quite nicely. 

Inscription recto: 

• l.r., Tom Thomson 

Inscription verso: 

• t., in graphite, Smoke Lake / Algonquin Park; 
• c., in graphite, ca. 1912; 
• b.r., 5 (circled) National Gallery of Canada, Ottawa (4676) 

  

  The edges of Tom's panel show how it was
  slid into and out of his paint box.
  
  

Provenance:

• Dr. J.M. MacCallum, Toronto, c. 1913 
• James MacCallum, Toronto, before 1940 
• National Gallery of Canada, Ottawa (4676). Purchased from James MacCallum, Toronto, 1946

That's the complete story behind Tom Thomson's "Smoke Lake". His painting was really another skyscape that focused on the characteristic shapes of clouds and the weather. It was not about the lake at all. 

I wish to thank my fellow physicists for their investigative diligence and for tracking the painting places of Tom Thomson and the Group of Seven. They have filled in a large number of blank pages in the art history of Canada. Kudos to the Waddingtons and the McElroys! Thank you... We are all in this together!

Now on to more of Tom's art and meteorology in the next Blog. 

Warmest regards and keep your paddle in the water,

Phil Chadwick, Tom Thomson Post TT-199

PS: Tom Thomson Was A Weatherman - Summary As of Now contains all of the entries to date.