This little boy had a naughty brother, who said to him, one day,--Brother, pull down your balloon, so that I can look at it and take hold of it.
Then the little boy pulled it down.

Now the naughty brother had a sharp pin in his hand, and he thrust it into the balloon, and all the gas oozed out, so that there was nothing left but a shrivelled skin.
One evening, the little boy's father called him to the window to see the moon, which pleased him very much; but presently he said,--Father, do not pull the string and bring down the moon, for my naughty brother will prick it, and then it will all shrivel up and we shall not see it any more.
Then his father laughed, and told him how the moon had been shining a good while, and would shine a good while longer, and that all we could do was to keep our windows clean, never letting the dust get too thick on them, and especially to keep our eyes open, but that we could not pull the moon down with a string, nor prick it with a pin .-- Mind you this, too, the moon is no man's private property, but is seen from a good many parlor-windows.
-- Truth is tough.

It will not break, like a bubble, at a touch; nay, you may kick it about all day, like a football, and it will be round and full at evening.

Does not Mr.Bryant say, that Truth gets well if she is run over by a locomotive, while Error dies of lockjaw if she scratches her finger?
[Would that this was so:--error, superstition, mysticism, authoritarianism, pseudo-science all have a tenacity that survives inexplicably.

D.W.] I never heard that a mathematician was alarmed for the safety of a demonstrated proposition.