Daily Republican., 1880-01-24
speed Of Ice. Yachts scientifically
Explained.
BY J. o. JACKSON.

From the Religio- Philosophical Journal
| do not quite like the heading o
your editorial in the "Journal" jus
received December 6th) concerninl
"Speed of Ice boats-Science Contra
dicted by Facts" True science nsve
coHtradicts facts, but explains them
Thoughtless orscareless professors o
science, II would appear, often maxi
foolish blunders as they have In thii
case. 1t 10 real Jolly to get such
twist on the professors as this has Civ
en- you. Right richly have they deser
we'd II, with their high handed a prior
reasoning, aud psdantic assumption
that nothing can be true which they
can not understand and explain-that
there are no laws Of nature but those
in which they are posted.
Science is fully competent to admit
and expound the fact that wind may
communicate to- an ice. yacht velocity
superior TO the wind itself, and | am
astonished that Prot. Loomis of Yale,
and Pres. Barnard Of Columbia, should
have been so careless as to commit
themselves without examining the full
bearing Of the question. Tell them q
citizen OF Delaware, q mere amateur In
science, can readily convict them Of err
ror, and show as well popularly as sci
entiically that the fact in question is
both probable and certain.
To come at the professors and others
popularity, we will ask, did they ever
when boys, shoot melon seed, cher
ry stone, or any other slippery seed by
pressure between the thumb and fin
ger : Did they ever explain scientific
ally how the comparatively slow hard
pressure of the muscles was resolved
into the rapid motion Of the mucous
missile If so, they can readily discov.
er how the ice yacht is shot forward By
being caught between the pressure o.
the wind on the one side and the solid
keel.holt Of the yacht upon the slippery
ice on the other.
To illustrate more perfectly would
say, take a wedge of wood or any
smooth rigid material and lay 1t fiat
upon hard polished table or other
smooth surface. Let it be, say, twelve
inches long and three inches thick,
tapering to an edge. Next apply a
rigid and steady perpendicular press
ure downward near the base or thick
end of the wedge. The effect will be
(if the surfaces are sufficiently smooth
or lubricated) that the wedge will be
forced forward in the direction of its
thick end, and will travel Its whole
length (twslve irches) while the per-
pendicularly pressing body descends
three inches. That is, the pressing
body will have communicated to the
movable wedge velocity four (D
times as great as its own.
Now, in the ice-yacht the keel, OF
rudder holding it to the ice, forms ont
inclined side OF the wedge, and thu
sail (not quite -" llat aft") forms tlt
other, while the pressing body is in
wind.
Should the yacht be placed with the
wind exactly beam Chat is at right
angle TO the keeD with the sail hauled
aft, but slightly to lee-ward, (say three
feet in twelve feet length OF yard) We
will have the same proportions as above
stated in the wedge, and ten mile
wind will tend to propel the yacht for
ty miles per hour.
Proper allowances for friction and the
yielding instead of rigid nature Of the
wind and the sal, will doubtless great
ly lessen this theoretical speed.
"Quad Frat Demonstrandum."
?. s. We would incline to believe
hat a wsll constructed sailing vessel
IN a smooth sea might, under favorable
circumstances, be made to illustrate
he same seeming paradox.