One of the children immediately replied, "Please, sir, do you know what we were laughing at ?" I replied in the negative.

"Then, sir," says the boy, "I will tell you.

Please, sir, you have made a blunder." I, thinking I had not, proceeded to defend myself, when the children replied, "Please, sir, you convict yourself." I replied, "How so ?" "Why," says the children, "you said a right-angled triangle had one right angle, and that all its angles are acute.

If it has one right angle, how can all its angles be acute ?" I soon perceived the children were right, and that I was wrong.

Here, then, the reader may perceive the fruits of teaching the children to think, inasmuch as it is shewn that children of six years of age and under were able to refute their tutor.