Flatford Lock  1823 (top)

This is Constable’s earliest known drawing of the composition for the lock series of paintings.

• Like the horizontal paintings, the drawing shows the barge on the right in the lock chamber.

• Constable has placed the lock keeper on the far side of the lock – something he didn’t do in the finished paintings.

• Constable has recorded repairs made to the lock in 1820, when a new angle brace was fitted to the near side post. He did not include these repairs in the later paintings, choosing instead to depict the lock in its dilapidated state. Either he began working on the paintings before this drawing (and the lock repairs) or he preferred to show the lock in its rundown state.

Flatford Lock  about 1826 (bottom)

This is a finished study. The extension of the sheet reveals how Constable worked out the change from his earlier vertical compositions to the horizontal format of A boat passing a lock, 1826.

• Constable has deleted the boat in the lock chamber, shown in the earlier drawing. He has not yet added the boat with sail waiting to pass upstream, as it appears in the painting A boat passing a lock, 1826.

• Constable has depicted the lock keeper on the near side of the lock with one arm raised. The keeper’s pose differs slightly in all the paintings. He is on the far side of the lock in the earlier drawing.

• The position of the lintel on the posts at the approach to the lock differs from that in the earlier drawing.

• Constable has added more trees on the right, as they appear in the horizontal paintings.

• He has introduced a rainstorm, which also appears in the painting A boat passing a lock, 1826. He first recorded the rainstorm in an oil sketch of 1819. He used the motif on several occasions, including in Branch Hill Pond, Hampstead Heath, with a boy sitting on a bank, about 1825–28.