Fig. 50.
No. 1. The two pieces of mahogany, carved to represent a man and a boy, one being 10 and the other 5 inches long, attached to board by hinges at h h.
Fig. 51.
No. 2. The board pushed forward, striking against a nail, when the short piece falls first, and the long one second.
Boat-accidents frequently arise in consequence of ignorance on the subject of the centre of gravity, and when persons are alarmed whilst sitting in a boat, they generally rise suddenly, raise the centre of gravity, which falling, by the oscillation of the frail bark, outside the line of direction of the base, cannot be restored, and the boat is upset; if the boat were fixed by the keel, raising the centre of gravity would be of little consequence, but as the boat is perfectly free to move and roll to one side or the other, the elevation of the centre of gravity is fatal, and it operates just as the removal of the lead would do, if changed from the base to the head of the "tombola" toy.
A very striking experiment, exhibiting the danger of rising in a boat, maybe shown by the following model, as depicted at Nos. 1 and 2, figs. 52 and 53.
Fig. 52.