I remember a story once told me by a learned friend. He had been explaining to a lady, with much care and minuteness, the reasons why the axis of the earth is slowly though constantly changing its direction in the heavens, and why, therefore, the star, which is the Pole star now, was not the Pole star 4000 years ago.

The lady had encouraged our friend to proceed with his explanation by the most marked attention, and by such appreciative interjections as “Really!” “Indeed!” “How beautiful!” In this way he was led to more than usually minute description, and with much unction proceeded to crown his argument as follows.

“Now you see, by this change of the direction of the earth's axis, if we have any permanent record of an observation of the angular distance of a star from the Pole, we can calculate how long ago that record was made.” “Of course!” “And in the Great Pyramid we have such a record.” “Indeed! how wonderful!” “The entrance passage points to the north, and its angle of inclination corresponds with the lower culmination of the Pole star of 4000 years ago.”

Here a little hand was laid on our friend's arm, and his feelings may be better imagined than described, when, in an anxious voice, the question was put, “And pray, Professor, what is an angle?”