472 Loss of Life at Sea. (October, 
the water, whether it owes its stability to deeply-stored 
ballast, or to a broad plane of flotation.” 
Now there are other conditions that must be complied 
with before the floating body can be swung in “any direc- 
tion whatever;” and it is not impossible to spill the water “‘so 
long, merely, as the suspending lines are kept tight by the 
operator,” for the water will inevitably be spilled if the 
motion be not communicated concurrently, slowly, and 
equably to the containing vessel and the water: moreover, 
when the model ship is placed on the mimic sea, it also must 
be so placed before motion is communicated to the dish and 
water ; for if all are not put in motion at the same time then 
the motion of the ship and water will not synchronise, for 
they will be subject to different amounts of force, and ‘‘ the 
fundamental proposition ”’ will be seen not to hold good. 
The principles contained in the experiment are the same 
as those which obtain in the milkmaid’s trick of swinging her 
pail of milk over head, and in the practice of the sailor in 
swinging his sounding lead over his head: in each case 
sufficient velocity in rotation must be given to overcome the 
gravitating force, or the milk will be spilled, or the sailor 
will be advised of his stupidity by a good thump. In the 
case before us, unhappily, it is the sailor who is punished, 
because another, the philosopher, ignores the existence of a 
well-known law. 
Mr. Froude, having stated his fundamental proposition 
that ‘“‘the surface of a fluid when dynamically inclined is 
virtually level to a body which floats on it, overlooks the 
essential difference between the conditions which obtain in 
his illustration and those which obtain in a ship in a seaway.” 
Because the floating body on his mimic sea is subject to 
the like dynamic forces with the water, and moves with it, 
he assumes that a ship in a seaway “‘is subjected to the 
same dynamic force as the wave on which she floats, and 
might be treated as a surface particle on it,” which is simply 
impossible, as a ship is subject to other forces than those 
which the sea give out; and though she is subject to the 
motions of the wave, she does not accept the wave motion, 
for if she did, her motions would always synchronise with 
those of the wave, which they never can entirely do. 
And notwithstanding that the floating body on his mimic ~ 
sea would continue to move with the water (if once set in 
motion with the water, and is not subject to any other force, — 
as a ship amongst waves is), whether the form of body 
were V- or U-shaped, whether the centre of gravity were 
