A species of vertigo seized him.

His brain reeled.

He fancied that the whole fabric of the bridge was cracking over head,--that the arch was tumbling upon him,--that the torrent was swelling around him, whirling him off, and about to bury him in the deafening abyss.

He shrieked with agony, and clung with desperate tenacity to the roughened stones.

But calmer thoughts quickly succeeded.
On taxing his recollection, the whole circumstance rushed to mind with painful distinctness.