i88o.] 
On Water and Air. 
125 
imagine how the waves meet. This spray is due to the 
coalescence of two waves, both adding their force together, 
and tossing their crest into the atmosphere. It is simply a 
bundle of most beautiful spheres of water. 
Now, as we must make our footing sure as we proceed, 
we will pass on from this to the consideration of a vein of 
water issuing from an orifice in the bottom of a vessel. As 
I said, this vein is composed of two distin<5t parts. One 
part is steady and the other unsteady, but the vein appears 
continous throughout. We can by a device which was 
made by that able man to whom I referred in our last lefture 
Felix Savart — so illuminate a jet of water as to reveal the 
drops into which it resolves itself. The unsteady portion of 
the vein, though it appears continuous, is the place where 
the vein resolves itself into distinct spheres or globules of 
water. Savart made very particular observations upon this 
subject, and he found that this unsteady portion of the vein 
was composed of two different kinds of drops large drops 
and small drops. Between every two large drops he found 
one or more exceedingly small drops. Now, I want to con- 
ned! this appearance which was noticed by Savart with the 
explanation of this appearance which was given by the old 
blind philosopher, Plateau. Here is a little wire stand, and 
with the greatest ease we can put a quantity of oil upon that 
stand and cause it to assume a spherical form in this mix- 
ture of alcohol and water. Here is a wire formed into a 
circle. We will bring the wire down upon the sphere of oil 
and draw out the sphere into a cylinder. You can draw the 
cylinder up to a certain point, but infallibly at a certain 
point it cuts itself into two and forms two globes. By 
properly operating you can go on until you make the length 
of the cylinder a little more than three times its diameter. 
Beyond that point you can not go. The cylinder then 
infallibly nips asunder, as I have said, and forms globules. 
This is the limit of stability of a liquid cylinder. Now when 
a jet of water falls from an orifice in the bottom of a vessel, 
you have there a liquid cylinder ; but you have that cylinder 
at a certain point resolving itself into drops. It will nip 
itself, and the nipping begins very close to the orifice which 
is left by the liquid. But it takes a certain amount of time 
to form the drops, and in the interval the vein is transported 
over a certain distance from the orifice from which the 
water issues. Now imagine this liquid cylinder nipping 
itself. The space between the two drops becomes a thinner 
and thinner cylinder. One drop separates, as it were, from 
the other, leaving a little thin or narrow cylinder between 
