�y��vlog

Only two accidents occurred: the little boat which we carried astern was washed away by a heavy sea that broke over us, while hoisting her in-board; and the marine barometer was broken by the violent motion of the vessel.

The sympiesometer is very sensitive, and feels the alterations in the atmospheric pressure sooner than the ordinary marine barometer.

The tube of the standard is contracted similarly to that of the marine barometer, but a provision is made for adjusting the mercury in its cistern to the zero point.

When used on shore, this contraction of the tube causes the marine barometer to be sometimes a little behind an ordinary land barometer, the tube of which is not contracted.

The cistern of this marine barometer is generally made an inch and a quarter in diameter, and the scale part of the tube a quarter of an inch in bore.