He sat silent for a while gazing ahead, where the great Norman tower and the mill chimneys of Tewkesbury now began to lift themselves from the plain.  And coming to the Mythe Bridge, he called a halt, bade the children alight, and sent the car on to await him at an hotel in the High Street, recommended by the chauffeur.

“This,” said he, examining the bridge, “appears to be of considerable antiquity.  If you’ll allow me, I’ll repose myself for twenty minutes in the hoary past.”  Unfolding a camp stool, he sat down to sketch.

The children and ’Dolph, left to themselves, wandered across the bridge.  The road beyond it stretched out through the last skirts of the town, and across the head of a wide green level dotted with groups of pasturing kine; and again beyond this enormous pasture were glimpses of small white sails gliding in and out, in the oddest fashion, behind clumps of trees and—­for aught they could see—­on dry land.

The sight of these sails drew them on until, lo! on a sudden they looked upon a bridge, far newer and wider than the one behind them, spanning a river far more majestic than Avon.  Of the white sails some were tacking against its current, others speeding down stream with a brisk breeze; and while the children stood there at gaze, a small puffing tug emerged from under the great arch of the bridge with a dozen barges astern of her in a long line—­boats with masts, and bulkier than any known to Tilda.  They seemed to her strong enough to hoist sail and put out to sea on their own account, instead of crawling thus in the wake of a tug.

There was an old road-mender busy by the bridge end, shovelling together the road scrapings in small heaps.  He looked up and nodded.  His face was kindly, albeit a trifle foolish, and he seemed disposed to talk.

“Good day!” said Tilda.  “Can you tell us where the boats are goin’?”

The old road mender glanced over the parapet.

“Eh?  The trows, d’ee mean?”

“Trows?  Is that what they are?”

“Aye; and they be goin’ down to Glo’ster first, an’ thence away to
Sharpness Dock.  They go through the Glo’ster an’ Berkeley, and at
Sharpness they finish.”

“Is that anywhere in the Bristol Channel?” The old man ruminated for a moment.

“You may call it so.  Gettin’ on for that, anyway.  Fine boats they be; mons’rously improved in my time.  But where d’ee come from, you two?—­ here in Tewkesbury, an’ not to know about Severn trows?”

“We’ve—­er—­jus’ run over here for the afternoon, in a motor,” said Tilda—­and truthfully; but it left the old man gasping.

The children strolled on, idling by the bridge’s parapet, watching the strong current, the small boats as they tacked to and fro.  Up stream another tug hove in sight, also with a line of trows behind her.  This became exciting, and Tilda suggested waiting and dropping a stone—­a very small one—­upon the tug’s deck as she passed under the archway.