190 On the Stability of Vessebs. [Manew, 
1G/and 17, 17 and 18, 16 and 18. ‘Compare the experiments made 
3 i ; . yon Lope Ie102 — Leg. 1°244 Wie 
ro ey £ = . 
with models 1 and 8 at 5°, 2» = ——___—_ ina aE ese vi0 ith pa Ar ee 
9? NAO, 150 ly 2G° | 259.4. 30° 
2°977 |2°579|2°330|2°22212-243)2°380 
1 and 8, Mean of the values of m, 2°455. 
27108|22565/2°451/2'396|2:431/2-579|. land 9, SRIDC HUMOR Neetetiny > 
9°41 112¢551|2-584|2-589|2-689/2°800| 8 and 9, ——— 2-596. 
2536/2-174 1-935)1-841|1-915/2168| 16 and 17, ————— — 9-095. 
9158] 1-949) 1-811/1-757|1-799|1-945| 16 and 18, ————_.. is Ge DU ngs. 
1-739] 1-700) 12674 1:66311-671/1-698| 17 and! 18, ———»—+—-_ - 1-691. 
The vertical section of models 11,12, 13, 14, 15, is an ellipsis, 
which is not a bad.form for the midship bend of a large|ship or 
vessel of burthen; and the experiments with these bodies were 
made for the purpose of ascertaining the result of increasing: the 
breadth and diminishing ‘the draft of water. By inspecting: the 
tables, the following conclusions are drawn. By comparing: the 
-experiments with model 11 and model 13, it appears, in Expers1 
and 2, when the centre of gravity of each model is placed at the 
same distance from the bottom, that model 11 had the greater 
stability ; but by Exper. 3, it appears that when the centre of gravity 
of each model was raised to the surface of the water, model 13 had 
the advantage in stability; and as the centre of gravity rises, the 
stability of model 13 may exceed that of model 11 by more than 
any assignable quantity. With the view of deducing some practical 
advantages from these experiments, it will be necessary to fix the 
centre of gravity at some point, that in all probability may not be 
widely different in practice, and which is supposed to be at the sur- 
face of the water; previously observing, that a semicircular form is 
totally rejected from practice when the centre of gravity is near the 
water line ; for although this shape has sufficient stability when the 
centre of gravity is low down, the stability becomes insensible when 
the centre of gravity coincides with the centre of the circle. In 
these experiments, it is true the metacentre falls short of this.dis~ 
tance by =, of an inch. This deviation arises in a degree from the 
part above the water ‘being a tangent to the curve instead of a con- 
tinuation, which causes model 10 to rise out of the water as it 
inclines. Model 11 has its breadth increased precisely as much as 
model 13 has the draft of water diminished. By comparing those 
experiments together in which the centre of gravity is situated at the 
surface of the water, it is evident that model 13 has more stability 
than model 11. It had the advantage also, when the centre of 
gravity was situated at 3 inches above the bottom, or +. an inch 
below the surface of the water. Again, by comparing the experi- 
ments with models 12 and 14, the draft of water is diminished 2 
inches ; and it is remarkable the diminution of the depth has the 
advantage in. stability over the increase of width, the centre of 
