2We will begin by describing those engines which are chiefly used in the erection of sacred buildings, and other public works. They are made as follows: three pieces of timber are prepared suitable to the greatness of the weights to be lifted, connected at the top by a pin, but spreading extensively at their feet. These are raised by means of ropes made fast to the top, and when raised, are thereby kept steady. To the top is then made fast a block, by some called rechamus. In this block are two pulleys, turning on axles; over the upper pulley passes the leading rope, which, let fall and drawn through under the lower pulley of the bottom block is returned thence over the lower pulley of the upper block: the rope again descends to the lower block, and its end is made fast to the eye of it. We refer the other end of the rope to the description of the lower part of the machine.
2On the back faces of the pieces of timber, where they diverge, are fixed socket-pieces (chelonia), for the gudgeons of the axles to work, so that they may revolve freely. The axles at the ends near the gudgeons, are pierced with two holes, so adjusted as to fit and receive the levers. Iron shears are then made fast to the under part of the lower block, whose teeth are received in holes cut in the piece of stone, for the purpose. The loose end of the rope being now attached to the axle, and that turned round by means of the levers, the rope, in winding round the axle, raises the weight to its height and place in the work.
3A block containing three pulleys is denominated Trispastos; when the lower system has two pulleys, and the upper one three, Pentaspastos. A machine for raising heavier weights requires longer and stouter beams, and the pins for joining them at top, as well as the axle below, must be increased in proportion. Having premised this, the raising ropes lying loose, are first distributed; then to the shoulders of the machine are made fast the guys, which, if there be no place to which they can be otherwise firmly fixed, must be attached to sloping piles driven into the ground, and steadied by ramming the ground about them.
4A block is to be now slung to the head of the machine, round which ropes must be carried to another block which has been previously fastened to a stake, and, passing over its pulley, must be returned to that on the top of the machine, round which the rope passes and descends to the axle at bottom, to which it is lashed. The axle is now turned round by means of the levers, and the machine is put in motion without danger. Thus the ropes being disposed around, and the guys firmly fastened to the stakes, a machine is stationed for use. The pulleys and leading ropes are applied as described in the foregoing chapter.
5If exceedingly large weights are to be raised, they must not be trusted to a mere axle; but the axle being retained by the gudgeons, a large drum should be fixed on it, which some call a drum-wheel (tympanum): the Greeks name it ἀμφίρευσις, or περίτροχος.
6In these machines the blocks are constructed differently from those already described. Having, at top and bottom, two ranks of pulleys, the rope passes through a hole in the lower block, so that each end of the rope is equal in length when extended. It is there bound and made fast to the lower block, and both parts of the ropes so retained, that neither of them may swerve either to the right or the left. The ends of the rope are then returned to the outside of the upper block, and carried over its lower pulleys; whence they descend to the lower block, and passing round its pulleys on the inner side, are carried up right and left over the tops of the higher pulleys of the upper block;
7whence descending on the outer sides, they are secured to the axle on the right and left of the drum-wheel, about which another rope is now wound, and carried to the capstan. On the turning of the capstan, the drum-wheel and axle, and consequently the ropes fastened to it, are set in action, and raise the weights gently and without danger. But if a larger drum-wheel be affixed, either in the middle or on one of the sides, of such dimensions that men may walk therein, a more effectual power is obtained than the capstan will afford.
8There is another species of machine, ingenious in respect of its contrivance, and of ready application in practice; but it should not be used except by experienced persons. A pole or log of timber is raised, and kept in its situation by means of four guy ropes in opposite directions. Under the place where the guy ropes at top are made fast to the pole, two cheeks are fixed, above which the block is tied with ropes. Under the block, a piece of timber about two feet long, six inches wide, and four inches thick, is placed. The blocks have three ranks of pulleys latitudinally, so that it is necessary to conduct three leading ropes from the upper part of the machine; these are brought down to the lower block, and are passed through its upper pulleys from the side next the pole. They then are carried to the upper block, passing from the outer sides of the lower pulleys to the inner sides of the lower pulleys of the upper block.
9Descending once more to the inferior block, they pass round the second rank of pulleys from the inner to the outer side, and are then returned to the second rank of pulleys in the higher block, over which they pass and return to the lowest, whence they are again carried upwards, and passing round the uppermost pulley, return to the lower part of the machine. A third block is fixed near the bottom of the pole, whose Greek name is ἐπάγων, but with us it is called Artemo. This block, which is made fast to the pole at a small distance from the ground, has three pulleys through which the ropes are passed, for the men to work them. Thus, three sets of men, working without the intervention of a capstan, quickly raise the weight to its required height.
10This species of machine is called Polyspaston, because the facility and dispatch in working it, is obtained by means of many pulleys. One convenience in using a single pole is, that the situation of the weight in relation to the pole, whether before it or to the right or left of it, is of no consequence. All the machines above described, are not only adapted to the purposes mentioned, but are also useful in loading and unloading ships, some upright, others horizontal, with a rotatory motion. On the ground, however, without the aid of the poles, ships are drawn on shore by the mere application of blocks and ropes.
11It will be useful to explain the ingenious contrivance of Ctesiphon. When he removed from the quarry the shafts of the columns which he had prepared for the temple of Diana at Ephesus, not thinking it prudent to trust them on carriages, lest their weight should sink the wheels in the soft roads over which they would have to pass, he devised the following scheme. He made a frame of four pieces of timber, two of which were equal in length to the shafts of the columns, and were held together by the two transverse pieces. In each end of the shaft he inserted iron pivots, whose ends were dovetailed thereinto, and run with lead. The pivots worked in gudgeons fastened to the timber frame, whereto were attached oaken shafts. The pivots having a free revolution in the gudgeons, when the oxen were attached and drew the frame, the shafts rolled round, and might have been conveyed to any distance.
12The shafts having been thus transported, the entablatures were to be removed, when Metagenes the son of Ctesiphon, applied the principle upon which the shafts had been conveyed to the removal of those also. He constructed wheels about twelve feet diameter, and fixed the ends of the blocks of stone whereof the entablature was composed into them; pivots and gudgeons were then prepared to receive them in the manner just described, so that when the oxen drew the machine, the pivots turning in the gudgeons, caused the wheels to revolve, and thus the blocks, being enclosed like axles in the wheels, were brought to the work without delay, as were the shafts of the columns. An example of this species of machine may be seen in the rolling stone used for smoothing the walks in palæstræ. But the method would not have been practicable for any considerable distance. From the quarries to the temple is a length of not more than eight thousand feet, and the interval is a plain without any declivity.
13Within our own times, when the base of the colossal statue of Apollo in the temple of that god, was decayed through age, to prevent the fall and destruction of it, a contract for a base from the same quarry was made with Pæonius. It was twelve feet long, eight feet wide, and six feet high. Pæonius, driven to an expedient, did not use the same as Metagenes did, but constructed a machine for the purpose, by a different application of the same principle.
14He made two wheels about fifteen feet diameter, and fitted the ends of the stone into these wheels. To connect the two wheels he framed into them, round their circumference, small pieces of two inches square not more than one foot apart, each extending from one wheel to the other, and thus enclosing the stone. Round these bars a rope was coiled, to which the traces of the oxen were made fast, and as it was drawn out, the stone rolled on by means of the wheels, but the machine by its constantly swerving from a direct straightforward path, stood in need of constant rectification, so that Pæonius was at last without money for the completion of his contract.
15I must digress a little, and relate how the quarries of Ephesus were discovered. A shepherd, of the name of Pixodarus, dwelt in these parts at the period in which the Ephesians had decreed a temple to Diana, to be built of marble from Paros, Proconnesus, or Thasos. Pixodarus on a certain occasion tending his flock at this place, saw two rams fighting. In their attacks, missing each other, one fell, and glancing against the rock with his horns, broke off a splinter, which appeared to him so delicately white, that he left his flock and instantly ran with it into Ephesus, where marble was then in much demand. The Ephesians forthwith decreed him honours, and changed his name to Evangelus. Even to this day the chief magistrate of the city proceeds every month to the spot, and sacrifices to him; the omission of which ceremony would, on the magistrate’s part, be attended with penal consequences to him.