CHAPTER LXIV.—KEEPING THE BALANCE.
By the Rev. T. S. Millington, M.A.
In Greece there lived a man—
(Old Ælian tells the tale,
Believe it if you can)—
So light and thin and frail,
He could not go about
Upon a windy day
For fear of being blown out
Or carried clean away.
Therefore, so it is said,
To keep him on the ground,
Two plates of solid lead
Under his feet were bound.
Yet still he was so light,
That when the wind did blow
He could not stand upright,
But wavered to and fro.
To sit upon a chair
Was equally in vain;
The slightest breath of air
Would lift him up again.
And when, upon his bed,
He sought a brief repose,
Down went his heels; his head
Immediately uprose.
No man was ever known
So empty and so weak
(By every zephyr blown)
As this unhappy Greek.
‘The unstable man here commemorated was a native of Cos. I have enlarged a little upon the description in order to introduce to you a figure which, in some respects, resembles him. Here it is. You may easily make one like it. Get a leaden bullet and cut it through the middle with an old knife and a hammer. Then cut out a light figure of cork or pith, and fasten its feet to the flat part of the bullet. Now if you try to make him lie down, you will not succeed. The moment you let go of him he springs up again and remains in an erect position. Why is this?’
‘His heels are heavier than his head.’
‘Yes. The man himself is so light, that nearly all the weight is in the lead; and this being round or half-spherical, when you lay the figure down you set the half-bullet on its edge. By so doing, you raise the centre of gravity; and it will not rest until it has fallen again and is supported.’
‘What is the centre of gravity?’