WAVES, THEIR MODE OF FORMATION. 25 
(ebb and flood); and partly permanent, though of unequal 
strength and rapidity at different periods (oceanic currents).” 
Who has ever sojourned on the coast, or crossed the seas, and 
has not been delighted by the aspect of the waves, so graceful 
when a light breeze curls the surface of the waters, so sublime 
when a raging storm disturbs the depths of the ocean? 
But it is easier to admire the beauty of a wave than clearly 
to explain its nature, so as to convey an accurate or sufficiently 
general conception of its formation to the reader’s mind. Those 
who are placed for the first time on a stormy sea, discover with 
wonder that the large waves which they see rushing along with 
a velocity of many miles an hour do not carry the floating body 
along with them, but seem to pass under the bottom of the ship 
with scarcely a perceptible effect in carrying the vessel out of 
its course. 
In like manner, the observer near the shore perceives that 
floating pieces of wood are not carried towards the shore with 
the rapidity of the waves, but are left nearly in the same place 
after the wave has passed them as before. Nay, if the tide be 
ebbing, the waves may even be observed rushing with great 
velocity towards the shore, while the body of water is actually 
receding, and any object floating in it is carried in the opposite 
direction to the waves out to sea. 
What, then, is wave-motion as distinct from water-motion ? 
The force of the wind, pushing a given mass of water out of its 
place into another, dislodges the original occupant, which is 
again pushed forward on the occupant of the next place, and 
so on. As the water-particles crowd upon one another, in the 
act of going out of their old places into the new, the crowd 
forms a temporary heap visible on the surface of the fluid, and 
as each successive mass is displacing the one before it, the un- 
dulation or oscillatory movement spreads farther and farther 
over the waters. Wave-motion is, in fact, the transference of 
motion without the transference of matter: of form without the 
substance, of force without the agent. 
The strongest storm cannot suddenly raise high waves, they 
require time for their development. Fancy the wind blowing 
over an even sea, and it will set water-particles in motion 
all over the surface, and thus give the first impulse to the 
