Zetetic Astronomy, by 'Parallax' (pseud. Samuel Birley Rowbotham), [1881], at sacred-texts.com
Zetetic Astronomy, by 'Parallax' (pseud. Samuel Birley Rowbotham), [1881], at sacred-texts.com
An argument for the earth's rotundity is thought, by many, to be found in the following facts:
"Fluid or semi-fluid substances in a state of motion invariably assume the globular form, as instanced in rain, hail, dew, mercury, and melted lead, which, poured from a great height, as in the manufacture of small shot, becomes divided into spherical masses."
"There is abundant evidence, from geology, that the earth has been a fluid or semi-fluid mass, and it could not, therefore, continue in a state of motion through space without becoming spherical."
In the first place, in reply to the above, it is denied that hail is always globular. On examination immediately after or during a hail-storm, the masses present every variety of form, and very few are found perfectly globular. Rain and dew cannot so well be examined during their fall, but when standing on hard surfaces in minute quantities, they generally appear spherical, a result simply of "attraction of cohesion." The same of mercury; and in reference to the formation of shot, by pouring melted lead from the top of a very high tower into cold water, it is a mistake to suppose that all, or even a large proportion, is converted into truly spherical masses. From twenty to fifty per cent. of the masses formed are very irregular in shape, and have to be returned to the crucible for re-melting. In addition to which it may be remarked, that the tendency in falling fluids to become globular is owing to what, in chemical works, is called "attraction of cohesion" (not "attraction of gravitation "), which is very
limited in its operation. Its action is confined to small quantities of matter. If, in the manufacture of shot, the melted metal is allowed to fall in masses of several ounces or pounds, instead of being divided (by pouring through a sieve or "cullender" with small holes) into particles weighing only a few grains, it will never take a spherical form. Shot of an inch diameter could not be made by this process; bullets of even half an inch can only be made by casting the metal into spherical moulds. In tropical countries the rain, instead of falling in drops, or small globules, often comes down in large irregular masses or gushes, which have no approximation whatever to sphericity. So that it is manifestly unjust to affirm, of large masses like the earth, that which attaches only to minute portions, or a few grains, of matter.
Without denying that the earth has been, at some former period, or was, when it first existed, in a pulpy or semi-fluid state, it is requisite to prove beyond all doubt that it has a motion through space, or the conclusion that it is therefore spherical is premature, and very illogical. It should also be proved that it has motion upon axes, or it is equally contrary to every principle of reasoning to affirm that the equatorial is greater than the polar diameter, as the inevitable result of the centrifugal force produced by its axial or diurnal rotation. The assumption of such conditions by Sir Isaac Newton, as we have seen when speaking of the measurement of arcs of the meridian, was contrary to evidence, and led to and maintains a "muddle of mathematics" such as philosophers will, sooner or later, be ashamed of. The whole matter,
taken together, entirely fails as an argument for the earth's rotundity. It has been demonstrated that axial and orbital motion do not exist, and, therefore, any argument founded upon and including them as facts is necessarily fallacious.