His eye rests on Arthur, and he calls him up to finish construing Helen's speech.

Whereupon all the other boys draw long breaths, and begin to stare about and take it easy.

They are all safe: Arthur is the head of the form, and sure to be able to construe, and that will tide on safely till the hour strikes.
Arthur proceeds to read out the passage in Greek before construing it, as the custom is.

Tom, who isn't paying much attention, is suddenly caught by the falter in his voice as he reads the two lines-- [greek text deleted] He looks up at Arthur.

"Why, bless us," thinks he, "what can be the matter with the young un?
He's never going to get floored.