"Those must be masts of ships the gazer sees"

Those must be masts of ships the gazer sees
On through the little gap in the park trees
So far away that seeing almost fails.
Those must be masts, the lovely masts of ships
Stripped bare of sails.
There's nothing here to please the seeing eyes,
Four poles with crossway beams against the skies.
But beauty's not for sight. True beauty sings
Of latent movement to the unsensed soul
In love with wings.