LUCIE PAGE BORDEN
THE ORDINARY READER is not so familiar with the term geodesy as the surveyor, because the latter is in the habit of making use of geodetic instruments in the pursuit of his own vocation. These instruments are designed to aid the mechanic and the civil engineer in laying out public works and surveying large tracts of land, where it is necessary to introduce the question of the earth's curvature.
It is quite enough for the ordinary reader if he be able to define the word geodesy, from its root meaning. Not so with the student of Koreshanity. He knows that the fundamental proposition of this cult calls for a more extended knowledge of the subject than is held by the casual reader. He is therefore required at the outset to acquaint himself with the application of the term. He knows that while he is studying Koreshan Science, it is one of the first requisites to understand what is meant by a geodetic survey.
The most interesting account of the authenticity of the claims made by Koreshan Science would be unintelligible to one who was not aware of the significance
of the terms used. The New Geodesy has not departed from any of the known facts of mathematics. It simply rests upon the assertion which nobody can deny, that the chord of an arc is not a tangent. It is certain to all who know them, that the Koreshan geodesists were sincere and indefatigable in their efforts to ascertain whether the direction of the earth's curvature is correctly stated by the ordinary works on surveying.
It was necessary to invent an apparatus which should be capable of determining whether a line extended horizontal to a plumb vertical would prove to be a tangent or a chord. The ordinary surveyor takes it for granted in all his measurements that the surface upon which they are drawn is convex. The Koreshan does not incline to work from an assumption. His method is to use the new apparatus, which is perfectly simple, to settle a question which the ordinary surveyor takes for granted.
It becomes necessary in every extended geodetic operation to devise some method of constructing an instrument to extend a right line. The ordinary surveyor uses the theodolite or engineer's level, and does not understand why there must be an allowance made for perspective foreshortening. He is actually obliged to allow two or three inches to the mile for this factor, but he puts it down as an example of refraction. The Koreshan does not trust to any optical instrument, but tries to make his line absolutely straight by the use of the mechanical principle of right angles.
The civil engineer knows that when he has leveled his telescope or transit instrument, and trains it on his pole a mile away, he will find that the altitude of the
cross hair is five or six inches below the height of the pole. Believing that the earth's surface is convex, he is puzzled to know why the difference should not be eight inches to agree with the calculated estimate.
He considers the discrepancy is due to refraction, and claims that he is obliged to allow two or three inches to the mile for this optical factor. The Koreshan geodesist understands the law of perspective foreshortening, and differs from the engineer in his theory of refraction; but the Koreshan prefers to eliminate optical factors and to run a mechanical line.
So much for the differences between the old geodesy and the new. The most intricate problems of surveying are hot unnoticed by the latter, but the out-look of the New Geodesy is so wholly dissimilar to that of the old, that it will be obvious why theoretical problems raised by competent surveyors would be of no interest to the student who has proved to his own satisfaction that the basis of their work is an erroneous assumption.