“Not at all silly,” said I, losing my temper; “here for example, I take this Square,” and, at the word, I grasped a moveable Square, which was lying at hand⁠—“and I move it, you see, not Northward but⁠—yes, I move it Upward⁠—that is to say, not Northward, but I move it somewhere⁠—not exactly like this, but somehow⁠—” Here I brought my sentence to an inane conclusion, shaking the Square about in a purposeless manner, much to the amusement of my grandson, who burst out laughing louder than ever, and declared that I was not teaching him, but joking with him; and so saying he unlocked the door and ran out of the room. Thus ended my first attempt to convert a pupil to the Gospel of Three Dimensions.

How I Then Tried to Diffuse the Theory of Three Dimensions by Other Means, and of the Result

My failure with my grandson did not encourage me to communicate my secret to others of my household; yet neither was I led by it to despair of success. Only I saw that I must not wholly rely on the catchphrase, “Upward, not Northward,” but must rather endeavour to seek a demonstration by setting before the public a clear view of the whole subject; and for this purpose it seemed necessary to resort to writing.