M O N 
M O .'T 
22 2 
above-mentioned, and partly because we find ! 
no certain consistent account of them. 
African Money of account. From Cape 
Verd lo the Cape of Good Hope, ail ex- 
changes and valuations of merchandize are 
made on the foot ol (lie macoute and piece ; 
which, though no monies of account (for 
those barbarians have no real monies, and 
therefore need no imaginary ones to estimate 
them by) y'ejt serve in lieu thereof!. At Lo- 
ango de Boirie, and other places on the coast 
of Angola, the estimations are made by 
macoutes; and at Malimboand Cabindo, oil 
the same coast, the negroes reckon by pieces: 
among the first the macoute is equal to 10 
pieces; ten macoutes make 100, which like- 
vise gives us a kind ot imaginary money, to 
estimate any purchase, exchange, &c. they 
fix on the one side the number of macoutes 
required; e.gr. for a negro; so that there 
are several bargains made for one; suppose, 
for instance, the slave to be fixed at 3,500 
pieces, this amounts to 350 macoutes ; to 
make up this number of macoutes in mer- 
chandize, they fix the price of each in ma- 
coutes. Two Flemish knives, ex. gr. are 
accounted one macoute; a copper bason, 2 
pound w eight, three ; a barrel of gunpowder, 
three, &c. For the piece, it serves in like 
manner to estimate the value of goods, duties, 
&c. on either side : thus the natives require 
]0 pieces tor a slave ; and the Europeans put, 
for instance, a fusee at 1 piece, a piece of 
salampours at 4 pieces. See. The cities of 
Barbary and Egypt, whither the Europeans 
traffic, reckon much after the same manner 
as in the Levant and the dominions of the 
grand seignor ; for the rest, through that vast 
extent ot coast where we trade for negroes, 
gold-dust, elephant’s teeth, wax, leather, &c. 
either the miserable inhabitants do not know 
what money of account is, or, if they have 
any, it is only what strangers, settled among 
them, have introduced. 
Monies of account in America. Here 
they have no money of their own ; the 
respective monies of account of the Euro- 
peans, who have made settlements there, 
being established among them. 
MONKEY. See Simia. 
MONOCHORI), a musical instrument, 
composed of one string, used to try the va- 
riety and proportion of sounds. 
It is formed of a rule, divided and sub- 
divided into several parts, on which there is 
a moveable string stretched upon two bridges 
at each extreme. In the middle between 
these is a moveable bridge, by means of 
which, in applying it to the different divisions 
of the hne, the sounds are found to bear the 
same proportion to each other as the division 
of the inie, cut by the bridge. There are 
also monochords with forty-eight fixed 
•bridges. T he following is the account of a 
monochord invented by earl Stanhope : 
.1. Tire wire is not made either of brass 
or of iron, but of steel, which is very far 
superior. For, steel wire does not keep con- 
tinually lengthening, as brass and iron wires 
■do when they are stretched considerably. 2. 
The wire in this monochord does not, as 
usual, pull downwards on the bridges, but 
the whole wire terms one straight and hori- 
zontal line, by which means the moveable 
bridge,, which determines the exact length 
the wire, can be moved without altering 
M O K 
the tension of the wire. This is not tlm case 
when the wire pulls downwards on the 
bridges. 3. The ends of the wire are not 
twisted round the two stout steel pins which 
keep it stretched; but each end of the wire 
is soft-soldered in a long groove form- 
ed in a piece of steel which goes over its cor- 
responding pin. 1 his is a great improve- 
ment. 4. One of those two steel pins is 
strongly fastened on a brass slider, which is 
moved by means of a screw with very fine 
threads, which screw Ins a large micrometer 
head minutely divided on its edge, and a 
corresponding nonius; so that the tension of 
the wire may be adjusted with the greatest 
precision, in order to obtain its exact pitch. 
5. A slider is fixed across the top of the 
moveable bridge, and is moved by means of 
another screw with very line threads; so 
that the length ot the wire may be regulated 
w ith the greatest nicety in all cases. <>. The 
above-mentioned slider, which is on the top of 
the moveable bridge, is adjusted to the steel 
rod or scale, not by sight, or by the coinci- 
dence ot lines, but by means of mechanical 
contact against projecting pieces of steel 
firmly fixed on that steel scale, which method 
is incomparably more correct. 7. Each 
bridge carries a metallic finger, which keeps 
the wire close to the top of the bridge, whilst 
the wire is made to vibrate. 8. The vibra- 
tions of the wire are produced by touching 
it with a piece of cork, with the same elastic 
force, and on the very same spot, each time, 
namely, at the distance of one inch from the 
[inmoveable bridge. 
MONNIESIA, a genus of the class and 
order, diadelphia pentandria. The calyx is 
five-parted; corolla stringent; stamina 3, 
capsules 5, 1 -seeded. There is one species, 
an American annual. 
MONOCULOS. Monoculus, a genus of 
the order aptera : the generic character is, 
leet formed for swimming ; body covered by 
a crustaceous tegument ; eyes, in most spe- 
cies, approximated, and imbedded in the 
shell. 
Of the monoculi, by far the major part are 
very small water-insects, requiring the assist- 
ance of a microscope for the investigation of 
their particular organs : some however are so 
large as to require no very minute inspection ; 
and one species in particular, (if, indeed, it can 
be allowed to stand with propriety in the ge- 
nus) is or a size so gigantic, that it is generally 
considered as the largest of the crustaceous 
tribe. '1 his animal is the monoculus polyphe- 
mus of Linnaus, commonly distinguished 
by the title molucca or king-crab. Speci- 
mens are sometimes seen of two feet in length, 
exclusive of the tail. It is a native of the' In- 
dian ocean, and is said to be generally found 
in pairs, or male and female sw imming toge- 
ther. 1 he colour of the whole animal is a yel- 
lowish-brown : the shell is very convex, 
rounded in front, and lunated behind, where 
it joins the lower part of the body : this, which 
is of the same crustaceous nature, is marked 
on each side into several spiny incisions; the 
legs, which are seven on each side, are situated 
beneath the concavity of the large or rounded 
part ot the shell, and are each terminated by 
a double claw, those of the lowest pair having 
some additional processes : the brancliiie, or 
respiratory, organs are disposed in the form of 
several flat, rounded, imbricated lamella; on 
each side the lower part of the body : the 
tail, which is strait, triangular, and of the same 
crustaceous nature with the rest of the shell, 
is equal in length to the w hole body, and gra- 
dually tapers to a sharp point. 1 lie eyes in 
tins species, instead ot being approximated, 
a s required in the Limnean generic character, 
are extremely distant from each other, being 
situated towards the sides of the shell: they 
are of a semilunar form, and the snrfaqe is 
divided into a great number of minute co- 
nical convexities : this part however should 
be considered as only constituting the cornea 
or exterior covering of each eye ; the organs 
themselves being, according to the observations 
of Mr. Petiver, m the Philosophical Transac- 
tions, placed on a pedicle beneath each of the 
above-mentioned semilunar cornea;. Peti- 
ver’s words are these. “ The whole struc- 
ture of this animal is very remarkable, and 
particularly his eyes, viz. between the fourth 
and last pair of claws on each side, reckoning 
from his mouth, and excluding the small pair 
there placed, are inserted the rudiments of 
another pair, or a claw broken off on each 
side at the second joint or elbow ; on these 
extremities are the eyes, like those of the horns 
of snails, but under the covert of a thick and 
opaque shell. Nature in that place has wonder- 
folly contrived a transparent lantern, through 
which the light is conveyed, whose superficies 
very exactly resembles the great eyes of our 
large libellx or adderbolts, which to the naked 
eye are plainly perceived to be composed of 
oi' innumerable globuli : these, like them, are 
oblong, anil guarded bv a testaceous superci- 
lium.” 
Of the European monoculi, by far the largest 
is the monoculus apus, which, when full-grown, 
measures nearly an inch and three quarters 
from the front to the end of the body, exclu- 
sive of the forked divisions of the tail. It is 
found in muddy stagnant waters, but is a rare 
species in this country, having been only ob- 
served in a few particular situations. In its 
general shape, it is considerably allied to the 
large exotic species before described, but the 
body is ot a more lengthened form in propor- 
tion, with the hinder part naked, and divided 
into numerous joints : the branchiae, or respi- 
ratory organs, are large, and are distributed 
into numerous imbricated rows on the under 
part of the body : beneath the front is a pair 
ot jointed, tritid arms, extending on each side 
to a considerable distance ; the eyes are placed 
near each other in front of the shell : the tail 
is terminated by a pair of long forks or ceta- 
ceous processes. The colour of the w hole in- 
sect is a pale greenish-brown above, and red- 
dish beneath. We are informed in vol. 40 of 
the Philosophical Transactions that this insect 
has been found in great plenty in a pond on 
Bexley’s common, in Kent. It is also added 
that the same pond, having been perfectly 
dried, and being suddenly filled during a heavy 
thunder-storm, swarms of the same animal 
were again observed in it within the space of 
two days after. 
Monoculus pulex, called, from its peculiar 
starting or springing motion, the water-ilea, 
is an almost universal inhabitant of stagnant 
waters, appearing sometimes in such vast 
swarms as to cause an apparent discoloration 
of the water itself. It is an insect of a highly 
singular and elegant appearance, exhibiting, 
when magnified, a beautiful distribution of in- 
ternal organs. Its general length is about 
