Keaton's profoundly visual kind of comedy depends on his skill in directing which permits him to use space itself as an element in his gags. And thus by using different shots of a railway track describing a hairpin bend on a steep slope together with shots of a locomotive prankishly advancing and retreating, Keaton can gallop through woods, tumble down the slope and scale rocks (The General). Ultimately this turns into a sort of abstract locomotive ballet. Using an ingenious system of deceptively crossing railway tracks (one of the two, no longer in use, is suspended in the air), Keaton then superposes two trains going at top speed, one forward, the other (his, the General) backward, and after having led us to believe the two will inevitably crash, he isolates one train perched on its track in a ridiculous, grotesque position, as the other, roaring forward, disappears.

Keaton...