EXPERIMENTS ON THE STABILITY OF FLOATING BODIES. 
615 
To determine the position of the centre of gravity of the vessel, it was to be allowed 
to rest in an inclined position under the action of the deflecting weight; and the water- 
line corresponding to this position being drawn on the board, the corresponding posi- 
tion of the deflecting weight and of the centre of gravity of the immersion were thence 
to be determined. The determination of the position of the vertical passing through 
the centre of gravity of the body would thus become an elementary question of statics; 
and the intersection of this line, with that about which the section was symmetrical, 
would mark the position of the centre of gravity. This determination might be veri- 
fied by a second similar experiment with a different deflecting weight. 
These suggestions have received a great development at the hands of Mr. Rawson, 
and he has adopted many new and ingenious expedients in carrying them out. 
Among these, that by which the position of the water-line was determined in the ex- 
treme position into which the vessel rolls, appears to me specially worthy of observa- 
tion. A strip of wood was fastened at right angles to that extremity of the yard to 
which the deflecting weight was attached, of sufficient length to dip into the water 
when the vessel rolled, on this slip of wood, and also on the side of the vessel nearest 
to it, a strip of glazed paper was fixed. The highest points at which these strips of 
paper were wetted in the rolling of the vessel, were obviously points in the water- 
line in its extreme position, and being plotted upon the board, a line di’awn through 
them determined that position with a degree of accuracy which left nothing to be 
desired. 
11. Two forms of vessels were used (see Plate XLVIl. figs. 1 and 2) ; one of them 
had a triangular and the other a semicircular section. The following Table contains 
the general results of the experiments, of which the particulars are detailed in 
the Appendix ; — 
Form of the 
model experi- 
mented on. 
No. of 
experi- 
ment. 
Weight of 
model and 
loading. 
Disturb- 
ing 
weight. 
Dynamical stability, as 
determined by experiment. 
g 
•S S II 
c-aS- 
Q 43 
a 
O 
Extreme inclination into 
which the vessel rolled, as 
determined by experiment. 
Extreme inclination into 
which the vessel should roll, 
as determined by calculation 
from the formula 
U(^)=Wa(Hi-H2)*. 
Inclination in which the 
vessel finally rested when 
subjected to the action of 
the disturbing weight. 
Ratio of the volume of the 
displaced fluid in the extreme 
position into which the ves- 
sel rolled to that in the posi- 
tion in which it originally 
rested. 
1. 
lbs. 
33-8626 
lbs. 
-5485 
•5161 
•5361 
23 30 
o / 
12 30 
•8961 
Triangular 
2. 
36-8590 
-3450 
•4887 
•4951 
15 30 
8 
0 
•98114 
model. 
3. 
37-3563 
•5377 
1-1724 
1-4503 
24 
0 
13 
0 
•88512 
4. 
38-2911 
•5739 
1-2673 
1-8460 
25 
0 
13 30 
•9330 
1. 
197-18 
2-8225 
7-3761 
7-394 
26 
0 
24 20 
13 
0 
model. 
2. 
197-18 
1-9570 
3-2486 
3-122 
17 0 
16 22 
9 0 
3. 
255-43 
1-9570 
1-7727 1-7667 
10 
0 
10 0 
4 30 
In the experiments with the smaller triangular model the differences between the 
* The inclinations are calculated by the formula (9.). 
