OBELISK, a Greek word used to designate the well-known Egyptian monumeutal monolith. Obelisk (affeaferor) is a diminutive of obelus (Zfleaos), a sharp-pointed thing, a spit, or skewer ; and was no doubt applied to the Egyptian obelisk on account of its shape and pointed end. Herodotus used the word dasafoscor both for an obelisk (ii. 111), and a skewer or spit (ii. 41). The Italian name for an obelisk agualle, and the French aiguille, are derived from the Latin acne, a needle or pin : a word applied also to the pin or bodkin used for fastening up the hair, and which instead of tapering to a point like a needle, sometimes, at least, had the end sloped off abruptly ; as may be seen in Montfaucon, `Ant, aupp., plate iii.
Tho Egyptian obelisk is a tall, monolithic, four-sided shaft, which diminishes gradually from the base to near the top, when the sides are sloped off so as to form a pyramidion, or diminutive pyramid, which serves as the apex. In size, obelisks vary greatly ; the shaft of the Lateran obelisk, the largest remaining, is 105 feet high, and was once more; while one at Florence, the smallest known, is under 6 feet in height. The larger Egyptian obelisks are almost invariably made of the red granite of Syene; the small ones of green basalt. Their sides are, with few exceptions, covered with hieroglyphics.
A great deal has been written respecting the origin and purpose of the obelisk, without any very definite result. It may safely be said, however, that the Egyptian obelisk was only a refinement on the stone of memorial which it was the general primitive custom to set up on special occasions or in holy places, of which that raised by Jacob at Bethel (Gen. xxviii. 18) is an instance that will occur to every one. Monoliths are in fact found among all the most ancient races. The Egyptians, a highly cultivated people, gave to theirs an artistic forum. The peculiar tapering form and pointed termination were stated by Pliny to have been suggested by a tongue of flame; and the idea of fire, or the worship of the sun, seems to have been by some tradition generally associated among the ancients with the Egyptian obelisk. Be the original idea what it may, the Egyptians somehow succeeded in devising a form which in its way has never been equalled iu grace of outline, or, where conjoined with magnitude, in imposing effect.
The Egyptians never placed their obelisks, as the moderns almost invariably do, alone, in a broad open space. They fixed them in pairs in front of the propylrea of a temple, and the hieroglyphics inscribed on their sides told the name and titles of the monarch who erected them, and the purpose of the buildiog before which they stood. They were raised on low oblong bases or pedestals, which, however, were no part of the obelisk proper, but were formed of separate blocks of granite. Tho position of the obelisk will be understood by the cut of the very fine pair—the most perfect extant—which stood in front of the pro , pyhea of the temple of Luxor : ono of these has, since the drawing was made, been removed to Paris. The bases are hidden by the accumu lated sand.
The shaft of an Egyptian obelisk is usually about eight, but sometimes ten times ns high as the width of the base. The width at the top of the ,]raft, or base of the pymmidion; is one fourth lestalmau the base of the shaft. The height of the pyramidion is from one to one and a half the width of its base. We have described the shaft as quadrilateral, but it is not square ; two of tlie sides, the front and back, being gene rally somewhat wider than the other two. Neither are the sides per fectly flat. Under COLUMN and Onecias Ancilirecrune it has been shown that, to atone for n certain optical appearance, the Greeks made the outline of their columns, and other lines which in appearance were right lines, to bo in reality very slightly convex. In the same way, and doubtleas for a similar reason, that is, to counteract a seeming concavity of surface observable in really flat-sided obelisks, the Egyptians made the sides of their obelisks slightly convex, or, as it is technically termed, to have an entaais on the plan. And it is note worthy that Mr. John Bell, the distinguished sculptor, without being acquainted apparently with the Egyptian practice, was led to give precisely such an entasis to a monumental obelisk constructed by him, as the result of a series of tentative efforts Made to overcome a seeming concavity of surface and horizontal plan observed by him in his model, and of which experiment he gave a full account in a paper read before the Institute of Architects, in May, 1858.