Symbolical Masonry, by H.L. Haywood, [1923], at sacred-texts.com
Having discussed the Approach to the East in its First Degree connections there is no need that we go into the matter here, though the Fellow Craft's Approach naturally falls into this place. But there is one problem associated with this rite which was not touched on in the earlier section, and as it occurs in both the First and Second Degrees, it may be fitly studied here; I refer to the Oblong Square. This has long been one of the standing puzzles of Masonry, and that because "oblong square" seems a contradiction in terms, and because no scholar has thus far traced the origin of the Masonic use of this phrase. What it really means is still a mystery, though we may make our guess as other students have done before us.
Mackey defines it as "a parallelogram, or four-sided figure, all of whose angles are equal, but two of whose sides are longer than the others" (rectangle). Following Pierson he finds in it a reference to the ground plan of the lodge room and this, in turn, he sought to trace to the shape of the world as known to the Ancients. From this point of view, we may infer, he saw in the candidate's adjusting his feet to an (not the) angle of an oblong square an indication of his willingness to stand to and abide by all the laws, rules and regulations of the Craft.
Others have seen in the oblong square a reference to the try-square, one of the working tools, when made
[paragraph continues] "gallows" shape, with one arm longer than the other. To this it may be objected, first that our working tool is properly a stone-mason's try-square with the two arms of equal length and not divided into inches; and secondly, that the "gallows" square interpretation can not explain the allusion to a "perfect square" in the Third Degree.
Others, again, find in it a suggestion that the stones of bricks used in a wall of masonry are almost never cubes, but bodies longest in their horizontal dimensions, the better to overlap; they say the candidate is to adjust himself to the Oblong Square because he is himself to be built into a wall that must stand while the ages last. But this seems a far-fetched explanation, and, also, does not explain the "perfect square" of the Master Degree.
Brother C. C. Hunt, Deputy Grand Secretary of Iowa, has given another interpretation, and one that seems to me most reasonable. "What, then, is the oblong square of Freemasonry? I believe it to be a survival in our ceremonies of a term once common but now obsolete. My reading has convinced me that at one time the word 'square' meant right-angled, and the term 'a square' referred to a four-sided figure, having four right angles, without regard to the proportionate lengths of adjacent sides. There were thus two classes of squares, those having all four sides equal, and those having two parallel sides longer than the other two. The first class were called 'perfect squares' and the second class 'oblong squares'. In time these terms were shortened to square and oblong respectively, and that is the sense in which they are used at the present time, so that when we speak of an oblong square, we are met with the objection that if it is a square it can not be oblong, and if it is oblong it
can not be square. This is true in the present sense of the term, but Freemasonry still retains the older meaning."
support of this, so far as America is concerned, at least, Brother C. F. Irwin of Ohio produced a letter written by a certain Dr. S. P. Hildreth, of Marietta, Ohio, on June 8, 1819, in regard to the fortifications near his city: "On the outside of the parapet, near the oblong square, I picked up a considerable number of fragments of ancient potter's ware." Brother Irwin contends that if this term was thus in use in Ohio in 1819 it must have been in use further east much earlier.
If Oblong Square was so used by Masons prior to the seventeenth century it may be that the Speculatives received at that time (they were accepted earlier but not in such numbers) brought with them, as an inheritance from other orders of symbolism, the Perfect Square; and it may be that the framers of our Ritual meant to signify that as the candidate in the preparatory degree is to try himself by an Oblong Square, the Master Mason, as befits the adept of perfection, must adjust himself to the Perfect Square. Thus read, the symbolism as found variously in the Three Degrees, is really a recognition of the fact that the Masonic Life is necessarily progressive, and that a Mason strives toward perfection.