It was seldom that all were studious at the same time, but this was one of the rare moments.

There was no shuffling of feet, and fifty heads were bent over their desks.
It was a full half hour before Harry looked up from his Tacitus.
His first glance was at the window.

The snow was driving hard, and the forest had become a white blur.

He looked next at the Doctor and he saw that the ruddy face had turned white.

The old man was gazing intently at an open letter in his hand.