The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1895-04-26
A REVOLUTIONARY IDEA.

Some months ago Robert Stevenson,
civil engineer of this city, born in Scot
land and graduated from the Glasgow Uni
versity, startled the California Academy of
Sciences by announcing a discovery,
which, If it is true, overtuTns the very
foundations of the science of physics. We
remember that Mr.. Stevenson was chaffed
numerically That has had the effect to
rouse his Scotch blood, and now he has
issued his lecture in pamphlet form, with
expansions and few demonstrations, and
promises to follow it with book in which
his remarkable theory is to be proved to
the smallest detail. This publication is
awaited with the liveliest interest; even
the preliminary pamphlet is sufficiently
startling and suggestive to set students
thinking.
Until Mr.. Stevenson has either proved
his case or failed in the effort adverse crit
icism makes the utterer more ridiculous
than the victim. Ptolemy's deliberately
demonstrated theory that the sun, stars
and planets revolve round the earth was
accepted implicitly until Copernicus
proved that the earth and planets revolve
round the sun; and while Mr.. Stevenson's
theory completely oyerturns Newton s the
DRY of gravitation, and therefore, if true,
is the grandest scientific discovery since
Newton's day, We may not yet say that he
will not come to bear the same relation to
Newton that Copernicus bore to Ptolemy
Mr.. Stevenson declares elasticity of mo-
ton to be the true cause of universal grav-
itation; that is, there is nothing inherent
in bodies which causes them TO gravitate
toward each other, but the persistence of
energy impaired by some extraneous cause
explains this phenomenon. Hence the New
tonian gravity is not reliable in determin-
ing the masses of bodies.
According to Mr.. Stevenson, suppose
that body moving along a straight line
in free space is acted upon by force equal
to the original force and transverse to the
! original line of motion. The author fatty
denies the old law that this body will be
detected along a straight line which shall
be the diagonal OF a rectangle, of which
the two conflicting lines of motion are
sides, and declares that instead it will pur-
sue a curviinear course, which, he says, is
an elIipse He explains this by saying that
unless the secondary impulse impaired to
the moving body is infinity Tin which
event the body will move on the straight
line of the secondary impulse) the original
impulse will constantly act on the body as
a force of restitution, striving to return it
to its original line of motion. This is
what he calls the elasticity of motion and
the persistence of energy, or "kinetic sta
bility."
| Hence Newton's theory of centripetal
| force gravity that keeps one body re-
volving about another falls to pieces. 1t
is not gravity, acting as a centripetal force
| against the centrifugal force of body, or
! its tendency to fly off into space, that
| keeps it revolving in an ellipse, for such
revolution may occur without the presence
OF central body.
Such is the body of his startling theory.
There is not space here to give it any
elaboration, as he does, but some OF his OBJ
servations may be noted.
He says that he has demonstrated the
| fallacy of Newton's theory that gravity
acts independently and constantly. He
has proven that projectile does not fall
sixteen feet in the first second after its
propulsion, and that projectile travelling
at a velocity of 1896 feet second (instead
of having to travel at d rate of $4,000 feet a
second, as we have been hitherto taught)
would travel round the earth without fall
| ing, il there were no atmospheric resist
ance.
In indicating the results which would
follow from his discovery, Mr.. Stevenson
says that we could learn how the planets
are formed and constituted, what their
heat, mass and atmospheres are, and even
the character and bodily structure of their
inhabitants. And in applying it to
molecular physics we might reduce to an
exact science the problems of matter, soul
and spirit.