Dictionary of Greek and Roman antiquities. Ed. by William Smith. Illustrated by numerous engravings on wood.

722 MACHINAE. MACHINAE.
steelyard (trutina, statera), and the oars and rudderIl. oars of a ship; and alludes to the principle of
virtual velocities. The inclined plane is not spoken
MACELLUM (4oorcAtra, Athen. i. 9; dForco- of by Vitruvius as a machina., but its properties
Xeov, KpeoirwXEe'ov), a provision-market, frequent- as an aid in the elevation.of weights are often
ed by cooks, fishermen, poulterers, confectioners, referred to by him and other writers; and in early
butchers, and men of similar occupations. (Varro, times it was, doubtless, the sole means by which
de Re Rust. iii. 2. 17, de Ling. Lat. v. 32. pp. 147, the great blocks of stone in the upper parts of.
148. ed. Spengel; Plant. Aulul. ii. 8. 3; Ter. buildings could be raised to their places.
Eun. ii. 2. 24; Hor. Sat. ii. 3. 229, Fpist. i. 15. Under the head of circular motion, Vitruvius
31; Seneca, Fpist. 78.) [FoRUM.] From sme- makes a passing allusion to the various forms of
celluzn, a provision-merchant was called 7macel- wheels and screws, plaustra, rledae, tynspana, rotae,
larius (o/o7srcL7os, Icpeo7rbAis). (Sueton. Jsul. 26. cochleae, scorpiones, balistee, prela, about which see
Iespas. 19; Varro, de Re Rust. iii. 2, 4.) The the respective articles.' It is worth while, also, to
Athenians called their macellum eIs ro ToV, just as notice the methods adopted by Chersiphron and his
they called their slave-markets elss Tar alspd7ro8a, son Metagenes, the architects of the temple of
their wine-market eUs rbV oboy, and other markets Artemis at Ephesus, and by later architects, to
by the name of the commodities sold in them. convey large blocks of marble from the quarries, by
(Poll. ix. 47; x. 19; Harpocr. s.v. Ae-ytka.) [J.Y.] supporting them in a cradle between wheels, or
MA'CHINAE (,u/XavaL), and O'RGANA enclosing them in a cylindrical frame-work of
(dp'yaea). The object of this article is to give a wood (Vitruv. x. 6. s. 2); and also the account
brief general account of those contrivances for the which Vitruvius gives of the mode of measuring
concentration and application of force, which are the distance passed over by a carriage or a ship,
known by the natmes of instruements, sechlanical by an instrument attached to the wheel of the
powaers, msacblines, engines, and so forth, as they former, or to a sort of paddle-wheel projecting from
were in use among the Greeks and Itomans, espe- the side of the latter (c. 9. s. 14). What lie says
cially in the time of Vitruvius, to whose tenth of the pulley will be more conveniently stated under
book the reader is referred for the details of the the next head.
subject. 2. Cownpound MiMechlanical Powuers or Mtachines
The general, but loose, definition which Vitru- for raisisg heavy weights (nmachinae tractosriae).
vius gives of a saaclhine (x. 1. ~ 1), is a wooden Of these Vitruvius describes three principal sorts,
structure, having the virtue of moving very great all of them consisting of a proper erect frame-work
wreights. A nzachina differs from an organon, in- (either three beams, or one supported by ropes);
asmuch as the former is more complex and produces from which hang pullics, the rope of which is
greater effects of power than the latter: perhaps worked either by a number of men, or by a windthe distinction may be best expressed by tralislat- lass (sucula), or by a large drum (tymLpanum1, &t fiing the terms respectively mzachine or engine and peVOaS, repITpdO'XIo ) moved as a tread-wheel, only
instrzmmsent. Under the latter class, besides com- from within. He describes the different sort of
nmon tools and simnple instrumzents, as the plough for pullies, according to the number of sheaves (omriexample, Vitruvius appears to include the simple culi) in each block (trochlea or reclainums), whence
slechlanical powers, which, however, when used in also the machine received special names, such as
combination, as in the crane and other machines, trispastos, when there were three sheaves, one in
become snachinac. Thus Horace iuses the word for the lower block and two in the upper; and pentathe machines used to launch vessels (CarGe. i. 4. 2), spastos, when there were five sheaves, two in the
which appears to have been effected by the joint lower block, and three in the upper (x. 2-5).
force of ropes and pulleys drawing the ship, and II. Military Engines. (Vitruv. x. 15-22;
a screw pushing it forwards, aided by rollers Vegetius and the other writers de Re Militari;
((dAaTyes) beneath it. The word organosl was ARIES; HELEPOLIS; TESTUDO; TORMENTUII;
also used in its modern sense of a musical instru- TURRIS, &C.)
mlent. [See IIYDRAULA.] III. Thleatrical 2Machines. [THEATRUMl.]
The Greek writers, -whom Vitruvius followed, 1V. IJydraulic Eng#nes.
divided machines into three classes, the (genus) 1. Cohveyance and delivery of water thlrough pipes
scasnscoriume or aKcpoCarTucdv (respecting which see and chzannels. [AQUAEDUCTUS; EMISSARUI s;
Vitruvius and his commentators), the spiritale or FISTULA; FONrs.] It has been shown, under the
srvsevMpaTr'' [HYDrAULA], and the tractorizmn or articles referred to, that the ancients well knew, and
BapoOhKcov (or Bdvavo'ov according to the reading that they applied in practice, the hydrostatic law,
of the old editions) for moving heavy weights. The that water enclosed in a bent pipe rises to the
information which he gives us may perhaps, how- same level in both arms. It also appears, from
ever, be exhibited better under another classifi- the work of Frontinus, that they were acquainted
cation. with the law of hydraulics, that the quantity of
I. Mechlanical Enginzes. water delivered by an orifice in a given time deL. T/ie Sin2ple M1i]echanical Powers were known pends on the size of the orifice and on the height
to the Greek mechanicians from a period earlier of the water in the reservoir; and also, that it is
than can be assigned, and their theories were com- delivered faster through a short pipe than through
pletely demonstrated by Archimedes. Vitruvius a mere orifice of equal diameter.
(x. 3. s. 8) discourses of the two modes of raising 2. Maclaines for raising oater. The ancients
heavy weights, by rectilinear (ebeEaev) and circular did not know enough of the laws of atmospheric
(IcvtcXw)s-7v) motion. He explains the action of pressure to be acquainted with the common sucking
the lever (ferrezus vectis), and its three different pump; but they had a sort of forcing pump, whichl
sorts, according to the position of the fulcrum is described by Vitruvius (x. 12), who ascribes the
(bsroidXXto.), and Eome of its applications, as in the invention to Ctesibius. For raising water a small