126 
M E 1:3 
M E C 
inclines upwards, making a small angle with 
the horizontal plane. 
A horse drawing a weight over a single pul- 
ley, can draw 200lb. for eight hours a day, 
and walking at the rate of miles in an 
hour, which is about 3f feet in a second ; and 
it the same horse be made to draw 2401b., 
he can work but six hours a day, and cannot 
go quite so fast. To this may be referred the 
working of horses in all sorts of mills and 
water-works ; where we ought to know as 
near as we can, how much we make every 
horse draw, that we may judge of w hat the 
effect will be, when proper allowance shall 
have been made for all the frictions and 
hindrances, before we cause any machine to 
be erected. 
When a horse draws in a mill, or gin of 
any kind, great care should be taken that the 
horse-walk, or circle in which he moves, be 
large enough in diameter, otherwise the horse 
-cannot exert all his strength; for, in a small 
circle, the tangent (in which the horse draws) 
deviates more from the circle in which the 
horse is obliged to go, than in a larger circle. 
The horse-walk should not be less than 40 
feet in diameter, when there is room for it. 
In a walk of 19 feet diameter, it lias been 
calculated that a horse loses two-fifths of his 
strength. 
The worst way of applying the force of a 
horse, is to make him carry or draw up hill ; 
for, if the hill is steep, three m.en will do 
more than a horse ; each man loaded with 
1001b. will move up faster than a horse that is 
loaded with 3001b. 'Tills is owing to the 
position of the parts of a man’s body, which 
are better adapted for climbing than those of 
a horse. 
As a horse, from the structure of his body, 
can exert most strength in drawing almost 
horizontally in a straight line, a man exerts the 
least strength that way ; as for example : if a 
man weighing 1 401b. , walking by a river or 
canal side, draws along a boat, or barge, by 
means of a rope coming over his shoulders, or 
otherwise fastened to his body, lie cannot 
draw above 271b., or about A. of what a horse 
can draw in that case. Five men are about 
equal in strength to one horse, and can with 
the same ease push round the horizontal beam 
in a 40-foot walk; but three of the same men 
wilt push round a beam in a 19-foot w'alk, 
which a horse (otherwise equal to live men) 
can but draw rou nd. 
A man turning a horizontal windlass by a 
handle, or winch, should not have above 
301b. weight acting against him, if he is to 
work ten hours a day, and raise the weight at 
the rate of three feet and a half in a second. 
This supposes, however, that the semidi- 
ameter of the windlass is equal to the distance 
from the centre to the elbow of the handle; 
for if there is a mechanical advantage, as 
there usually is, by having the diameter of 
the axle, on which the rope winds, four or five 
times less than the diameter of the circle 
described by the hand, then may the weight 
(taking in also the resistance, on account of 
the friction and stiffness of the rope) be four 
or live times greater than 301b. ; that is, so 
much as it rises slower than the hand moves. 
MECONIUM, in pharmacy, the extract 
of English poppies. Meconium has all the 
virtues of the foreign opium, but in a some- 
what lower degree. 
S 
H E D 
MEDAL denotes a piece of metal in the 
form of coin, such as was either current mo- 
ney among the undents, or struck on any 
particular occasion to preserve the portrait 
ot some great person, or the memory of 
some illustrious action, to posterity. ' its 
etymology is probably of little consequence, 
though the best authorities give it from “ me- 
tallum.” 
To enlarge on the utility of medals in the 
sciences, were needless. "A s historical do- 
cuments, they form the principal evidence 
we can have of the veracity of old historians. 
In some few instances they correct the names 
of sovereigns; and in a great many, illus- 
trate the chronology of reigns. By their as- 
sistance the geographer has sometimes been 
enabled to determine the situation of a town 
whose name aloue has reached us. To the 
naturalist they afford the only proofs of tlie 
knowledge which the ancients had of certain 
plants and animals ; and they sometimes pre- 
serve delineations of buildings for the archi- 
tect, ol which not even a ruin is, at this day, 
standing. The connection of medals and 
poetry lias been treated at considerable 
length by Mr. Addison. To the connoisseur 
they are absolutely necessary, as they enable 
him to appropriate the busts and portraits of 
antiquity. And the scholar need hardly be 
reminded that they have contributed in no 
small degree to the elucidation of obscure 
passages in antient authors. The alto-relievo 
ot the Greek coins is one of the best schools 
of study for the sculptor. 
1 lie study of medals, perhaps, is not of 
very antient date. The preservation of the 
Greek coins among their choicest treasure, is 
said to have been one of those marks of due 
respect which the Romans shewed the 
Greeks : but the knowledge of medals in se- 
ries does not seem to have formed a distinct 
branch, either of study or entertainment, till 
the revival of literature in Europe. Petrarch 
is related to have been one of the first who 
began to study the medallic science. AI- 
phonso, king of Arragon, formed another col- 
lection. And a third was placed by Cosmo 
de Medici among the curiosities in the Mu- 
seum at Florence. 
In this country, though we know of the ex- 
istence ot no cabinet before the time of Cam- 
den, it may be fair to suppose that the know- 
ledge of coins and medals was introduced 
from Italy. The “ Britannia” was the first 
work in which engravings of them were pro- 
duced : and Speed’s Chronicle, which soon 
followed it, was illustrated with coins from 
the collection of sir Robert Cotton. Henry 
prince of Wales was one of the first who had 
a rich cabinet ; and he bequeathed it at his 
death to Charles. The most considerable of 
our other early collectors were, a-rchbishop 
Laud, lord Arundel, and Mr. Selden. Oli- 
ver Cromwell, we are told, had a small collec- 
tion ; and the cabinet of Charles the Second 
is mentioned by Vaillant. 
In the article here presented to the reader’s 
notice, we shall give first a brief account of 
the coins of the most antient nations which 
are still extant; reserving only the Greek 
and Roman, which are the most interesting 
of all coins, for a more extended view ; add- 
ing, at the close, a particular though con- 
densed history of the coins and coinage of 
England. For the first pjp-t, as well as for 
* 
the Greek and Roman coins, we have relied 
principally on the authority of Mr. Pinker- 
ton. For the last, all the best writers have 
been consulted. 
In what country coinage originated is un- 
certain, though the Greeks have the fairest 
claim to the invention. Ilomer, indeed, 
makes no mention of money; and even in 
Scripture we find weight alone used in the 
estimation of metals. The Hebrew shekels, 
and the brass coins with Samaritan charar- : 
ters, are thought to be, most of them, later 
than the Christian sera, and generally the fa- 
brication of modern Jews. A sprig on one 
side, and a vase upon the other, is their ge- 
neral impression. 
The Assyrians, the Medes, and the early 
inhabitants of Egypt, appear to have been 
totally ignorant of coined money. Nor was , 
it used by the Phoenicians till after the 
Greeks had set the example. '“Upon the ; 
whole,” says Mr. Pinkerton, “ the Lydian 
coins seem the most antient of Asia: they 
are without legends, but have all the rude 
appearance of antiquity.” The next are \ 
the Persian, which are well known from the 
archer on them; and from Mithras the 
Persian deity, the dress of the princes, and 
other marks. One of the Darics, coined 
about five hundred years before the Chris- 
tian sra, is engraved in the first plate of the 
Numismata Pembrochiana. “ All the real 
Darios,” says Mr. Pinkerton, “ are gold; 
the silver coins with the archer are later, and 
never were called Darics.” Of the latter, a ' 
great many are preserved in the cabinet of 
Dr. Hunter. A second series of Persian 
coins begins with Artaxares, or Artaxerxes, i 
who overthrew the Parthian monarchy about 
the year 210, and ends with the year 636, . 
when Persia was conquered by the Saracens. 
These are large and thin, with the king’s 
bust on one side, and usually the altar of Mi- 
thras on the other; the former accompanied 
by Persian letters. Four of them are en- 
graved in tlie Numismata Pembrochiana, 
and six others on a separate plate from the i 
cabinet of the late Mr. Duane. The Phoe- 
nician and Punic, with the Palmyrene and 
the Etruscan coins, and perhaps the early 
Spanish, make up the list of the more an- 
tient. The early Gaulish coins are too rude 
and indistinct for explanation. 
The description of the Greek coins it is ; 
probable will be best prefaced by a few re- 
marks on their original value. A knowledge 
of this subject is not more necessary to the 
collector than the classical scholar. The first 
shape, says Mr. Pinkerton, in which money 
appeared, it is well known, was that of pieces 
of metal without stated form or impression, 
but merely regulated to a certain weight. 
For weight was the grand standard of antient 
coinage. In Greece large sums were referred 
to so many mns or mins; and the yet larger 
denomination of so many talents. The nfina 
is thought to have contained 100 drachms, 
and the talent 60 mins. Such at least was 
the measure of Athens. A list of the value of 
the other antient talents has been given by 
Dr. Arbuthnot : its authority, however, has® 
been questioned, and the difficulty of ap- 
plying it to antient coinage seems extremely 
great. 
The leading denomination of the Greek, 
silver mon>y was the drachma, or eighty 
