“Of course,” said Prothero, “this isn’t a trotter.”

“I couldn’t get a trotter,” said Benham.

“I thought I would try this sort of thing before I tried a trotter,” he added.

And then suddenly came disaster.

There was a butcher’s cart on the right, and Benham, mistrusting the intelligence of his steed, insisted upon an excessive amplitude of clearance.  He did not reckon with the hand-barrow on his left, piled up with dirty plates from the lunch of Trinity Hall.  It had been left there; its custodian was away upon some mysterious errand.  Heaven knows why Trinity Hall exhibited the treasures of its crockery thus stained and deified in the Cambridge streets.  But it did—­for Benham’s and Prothero’s undoing.  Prothero saw the great wheel over which he was poised entangle itself with the little wheel of the barrow.  “God!” he whispered, and craned, fascinated.  The little wheel was manifestly intrigued beyond all self-control by the great wheel; it clung to it, it went before it, heedless of the barrow, of which it was an inseparable part.  The barrow came about with an appearance of unwillingness, it locked against the great wheel; it reared itself towards Prothero and began, smash, smash, smash, to shed its higher plates.  It was clear that Benham was grappling with a crisis upon a basis of inadequate experience.  A number of people shouted haphazard things.  Then, too late, the barrow had persuaded the little wheel to give up its fancy for the great wheel, and there was an enormous crash.

“Whoa!” cried Benham.  “Whoa!” but also, unfortunately, he sawed hard at the horse’s mouth.

The animal, being in some perplexity, danced a little in the narrow street, and then it had come about and it was backing, backing, on the narrow pavement and towards the plate-glass window of a book and newspaper shop.  Benham tugged at its mouth much harder than ever.  Prothero saw the window bending under the pressure of the wheel.  A sense of the profound seriousness of life and of the folly of this expedition came upon him.  With extreme nimbleness he got down just as the window burst.  It went with an explosion like a pistol shot, and then a clatter of falling glass.  People sprang, it seemed, from nowhere, and jostled about Prothero, so that he became a peripheral figure in the discussion.  He perceived that a man in a green apron was holding the horse, and that various people were engaged in simultaneous conversation with Benham, who with a pale serenity of face and an awful calm of manner, dealt with each of them in turn.

“I’m sorry,” he was saying.  “Somebody ought to have been in charge of the barrow.  Here are my cards.  I am ready to pay for any damage. . . .

“The barrow ought not to have been there. . . .

“Yes, I am going on.  Of course I’m going on.  Thank you.”

He beckoned to the man who had held the horse and handed him half-a-crown.  He glanced at Prothero as one might glance at a stranger.  “Check!” he said.  The horse went on gravely.  Benham lifted out his whip.  He appeared to have clean forgotten Prothero.  Perhaps presently he would miss him.  He went on past Trinity, past the ruddy brick of St. John’s.  The curve of the street hid him from Prothero’s eyes.