The Gare Saint-Lazare

Monet pointed his easel at a train station and decided the steam — the soft moving body of weather under the iron — was the painting.

1. 1
   The dark vault of girders

   The entire upper third of the canvas, top edge inward

   Look up. The dark beams cutting diagonally across the top of the picture are the iron girders of the train shed’s roof — the structural ribs of a great cast-iron skeleton holding up panes of dirty glass. The blue-grays you see between the girders are weak daylight leaking through the smoke-streaked glass. Monet painted the roof from underneath, from inside the shed, so this whole upper band is a kind of metal cathedral ceiling — the cathedral of modern Paris is iron, not stone.
2. 2
   Two engines, left and centre

   The lower middle of the picture, on the platform floor

   Two locomotives — the engine cars of the trains — sit on parallel tracks pointing roughly toward you. The closer one is on the left, a darker, sharper black mass with the faint suggestion of a smokestack and boiler. The farther one is just to the right of it, set back, fainter through the haze, its body half-erased by the steam it’s producing. They aren’t drawn in detail — no rivets, no nameplates — they’re solid silhouettes, more like dark blocks than rendered machines.
3. 3
   The painting’s real subject

   The centre of the canvas, rising from the engines up toward the roof

   A great soft cloud of steam fills the heart of the picture, rising from the locomotives below and billowing up under the iron roof. Get close and you can see Monet has built it out of dabs of nearly white paint, pale yellow, soft blue, and feathered gray edges. Now back up two paces. The separate dabs vanish; the dabs of white and blue and gray fuse in your eye into a single moving body of vapor. That arm’s-length blending is the broken-color trick — colors laid down side by side on the canvas, mixed by the viewer’s eye at viewing distance, not by Monet on the palette.
4. 4
   The city beyond the shed

   Upper right, beyond the steam

   Look to the right side of the cloud, toward the upper right of the canvas, and you can just make out pale rectangular shapes — the Haussmannian apartment buildings of the rue de Rome, the bourgeois Paris streets right outside the open end of the shed. They are hazed almost to ghosts here, half-erased by the steam, but they’re there. They tell you the shed is open at the far end and the city is right outside — the painting is not a sealed interior, it’s a room facing out.
5. 5
   Porters and passengers in dabs

   Low in the picture, at the platform edge near the engines

   Along the platform near the engines you can find a handful of small figures — porters, passengers, railway crew — picked out in quick brushstroke-sized dabs. They have no faces; they barely have shoulders. Monet has given them just enough mark to register as human scale, so you can tell how big the engines and the shed are.
6. 6
   Where the shed ends and the daylight begins

   The contrast between the dark upper interior and the pale far-right back

   Trace your eye from the dark iron roof at the upper left across to the pale, hazed apartments at the upper right, and you can feel where the shed ends. Under the roof on the left it is dark — the vault of iron and dirty glass keeps the light low. Out at the far end, where the shed opens onto the rail yard and the city, the light brightens. That contrast — dim interior against bright opening — is the architectural logic of any cathedral-scaled hall: dark vault, light beyond the doors.