vessel must of necessity describe a circle on being moved from right to left or left to right. Referring again to the diagram, Figure 19, the vessel may sail from the north towards the south, upon the meridian Figure 1, and there turning due west, may pass Cape Horn, represented by D, and continue its westerly course until it passes the point C, or the Cape of Good Hope, and again reaches the meridian, Figure 1, upon which it may return to the north. Those, then, who hold that the earth is a globe because it can be circumnavigated, have an argument which is logically incomplete and fallacious. This will be seen at once by putting it in the syllogistic form:-- A globe _only_ can be circumnavigated: The Earth has been circumnavigated: Therefore the Earth is a globe. It has been shown that a _plane_ can be circumnavigated, and therefore the first or major proposition is false; and, being so, the conclusion is false. This portion of the subject furnishes a striking instance of the necessity of, at all times, proving a proposition by direct and immediate evidence, instead of quoting a natural phenomenon as a proof of what has previously been assumed. But a theory will not admit of this method, and therefore the zetetic process, or inquiry before conclusion, entirely eschewing assumption, is the only course which can lead to simple and unalterable truth. Whoever creates or upholds a theory, adopts a monster which will sooner or later betray and enslave him, or make him ridiculous in the eyes of practical observers.