I once asked the doctor o' a ship that question, and says he to me, 'Tom,' says he, 'a barometer is a glass tube filled with quicksilver or mercury, which is a metal in a soft or fluid state, like water, you know, and it's meant for tellin' the state o' the weather.' "'Yes, sir,' I answers, 'I know that well enough.' "'Then why did you ask ?' says he, gettin' into a passion.
"'I asked what was the meanin' o' the _word_ barometer, sir,' said I.
"The doctor he looked grave at that, and shook his head.

'Tom,' says he, 'if I was to go for to explain that word, and all about the instrument, in a scientific sort o' way, d'ye see, I'd have to sit here an' speak to you right on end for six hours or more.' "'Oh, sir,' says I, 'don't do it, then.

_Please_, don't do it.' "'No more I will,' says he; 'but it'll serve your turn to know that a barometer is a glass for measurin' the weight o' the air, and, _somehow or other_, that lets ye know wot's a-coming.

If the mercury in the glass rises high, all's right.

If it falls uncommon low very sudden, look out for squalls; that's all.