But the twentieth is not quite so positive.
"Perhaps it's not altogether Billy's fault," he says.

And I must confess I am inclined to agree with this.

Of course, a great deal of his "duffingness" (I believe that's the proper word) is due to his carelessness.

If he took the trouble to think about what he was doing, he would never translate a French exercise into Latin, or learn his arithmetic by heart instead of his history; he would never mix together (under his nose) two chemicals that would assuredly explode and nearly blow his head off.

For he has a few brains in that head, which makes such blunders all the less excusable.