200 
M I N 
M I N 
M 1 M 
at half the height to which the water is to be 
raised, thereby saving half the expence. 
1 he late Mr. Costar, considering that 
sometimes from small streams, and some- 
times from little springs or collections of rain- 
water, one might have a good deal of water 
above ground, though not a sufficient quan- 
tity to turn an overshot-wheel thought, that 
il a sufficient fall might be had, this collec- 
tion ot water might be made useful in raising 
the water in a mine to the adit, where it might 
be carried off. But now the most general 
method of draining mines is by the steam- 
engine. 
A Mine (in military affairs) is also a subter- 
raneous cavity made according to the rules of 
art, iu which a certain quantity of powder 
is lodged, which by its explosion blows up 
the earth above it. 
It has been found by experiment that the 
figure produced by the explosion is a para- 
boloid ; and that the centre of the powder, 
or charge, occupies the focus. 
I he place where the powder is lodged is 
called the chamber of the mine, orforneau. 
The passage leading to the powder is called 
the gallery. 
The line drawn from the centre of the 
chamber, perpendicular to the nearest sur- 
face of the ground, is called the line of least 
resistance. 
The pit or hole, made by springing the 
mine, is called the excavation. 
The fire is communicated to the mine by 
a pipe or hose, made of coarse cloth, whose 
diameter is about one inch and a half, called 
a saucisson (for the filling of which near half a 
pound of powder is allowed to every foot), 
extending from the chamber to the entrance 
of the gallery ; to the end of which is fixed a 
match, that the miner who sets lire to it may 
have time to retire before it reaches the 
chamber. 
To prevent the powder from contracting 
any dampness, the saucisson is laid in a small 
trough, called an auget, made of boards, 
three inches and a half broad, joined toge- 
ther lengthwise, with straw in it, and round 
the saucisson, with a wooden cover nailed 
upon it. 
Galleries and chambers of mines. — naile- 
ries made within the fortification, before the 
place is attacked, and from which several 
blanches are carried to different places, are 
generally four feet or four and a half wide, 
and five feel or five and a half high. The 
earth is supported from falling in by arches 
and walls, if they are to remain for a consi- 
derable time ; but when mines are made to 
be used in a short time, then the galleries are 
but three feet or three and a half wide, and 
five feet high, and the earth is supported by 
wooden frames or props. 
The gallery being carried on to the place 
where the powder is to be lodged, the miners 
make the chamber. This is generally of a 
cubical form, large enough to hold the wooden 
box, which contains the powder necessary for 
the charge : the box is lined with straw and 
sand-bags, to prevent the powder from con- 
tracting dampness. 
The chamber is sunk something lower than 
the gallery, if the soil permits ; but where 
water is to be apprehended, it must be made 
higher than the gallery ; otherwise the be- 
sieged will let in the water, and spoil the 
Kline. 
Quantities of powder to charge mines . — 
Belore any calculation can be made of the 
proper charge for a mine, the density and 
tenacity of the soil in which it is to be made 
must be ascertained, either by experiment, 
or otherwise ; tor in soils oi the same den- 
sity, that which has the greatest tenacity will 
require the greatest force to separate its 
parts. I he density- is determined by weigh- 
ing a cubic foot (or any certain quantity) of 
the soil ; but the tenacity can only be deter- 
mined by making a mine. The following ta- 
ble contains experiments in six different soils, 
which may be of some assistance to form a 
judgment of the nature of the soil, when an 
actual experiment cannot be had : 
Nature of the Soil. 
Density. 
Tenacity. 
Weight 
of 1 cubic 
foot. 
Quantity 
of powder 
to raise 1 
cub. fath. 
1. Loose earth or sand 
95 pds. 
8 pds. 
2. Common light soil 
124 
10 
3. Loam, or strong soil j 127 
!2| 
4. Potter’s clay, or stiff soil ; 135 
5. Clay, mixed with stones ; 160 
16 
6 , Masonry - - j 205 
214 
Loading and stopping of mines.— The gal- 
lery and chamber being ready to be loaded, 
a strong box of wood is made of the size and 
figure ot the chamber, being about one-third 
or oner fourth bigger than is required for con- 
taining the necessary quantity of powder ; 
against the sides and'bottom of the box is put 
some straw ; and this straw is covered over 
with empty sand-bags, to prevent the powder 
from contracting any dampness : a hole is 
made in the side next the gallery, near the 
bottom, for the saucisson to pass through; 
which is fixed to the middle of the bottom, bv 
means of a wooden peg, to prevent its loosen- 
ing from the powder; or that, if the enemy 
should get to the entrance, he may not be 
able to tear it out. This done, the powder is 
brought in sand-bags, and thrown loose in the 
box, and covered also with straw and sand- 
bags ; upon this is put the cover of the box, 
pressed down very tight with strong props; 
and, to render them more secure, planks are 
also put above them, against the earth, and 
wedged in as fast as possible. 
'I his done, the vacant spaces between the 
props are filled up with stones and dung, and 
rammed in the strongest manner : the least 
neglect in this work will considerably alter the 
effect of the mine. 
The auget is then laid from the- chamber to 
the entrance of the gallery, with some straw 
at the bottom ; and the saucisson laid in it, 
with straw over it: lastly, it must be shut 
with a wooden cover nailed upon it. Great 
care must be taken, in stopping up the galle- 
ry, not to press too hard upon the auget, for 
| fear of spoiling the saucisson ; which may 
hinder the powder from taking fire, and so 
i prevent the mine from springing. The gal- 
j lory is stopped up with stones, •earth, and 
{ dung, well rammed, six or seven feet further 
, from 5 the chamber than the length of the line 
of least resistance, 
MINERAL WATERS. See Waters. ' 
MINERALOGY, is that science which | 
treats of the solid and inanimate material.-) of yj 
which our globe consists; and these are | 
usually arranged under four classes : the 1 
earthy, the* saline, the inflammable, and the 1 
metallic, which are thus distinguished: 
1. The earthy minerals compose the I 
greater part of the crust ol the earth, and 1 
generally form a covering to the rest. They 
are not remarkable for being heavy, brittle, 
or light-coloured. They are little disposed 
to chrystallize, are uninflammable in a low 
temperature, insipid, and without much 
smell. 
2. The saline minerals are commonly mo- 
derately heavy, soft, sapid, and possess some : 
degree oi transparency, 
3. The mfiammable class of minerals is ; 
light, brittle, mostly opaque, of a yellow, | 
brown, or black colour, seldom chrystallize, j 
and never feel cold, 
4. Metallic minerals are characterized by 
being heavy, generally opaque, tough, malle- I 
able, cold, not easily inflamed, and by ex- I 
hibiting a great variety of colours, of a pecu- 
liar lustre. 
Under each of these classes are various 
genera, species, sub-species, and kinds, which 
will be noticed in order. Sometimes, as iu 
the vegetable kingdom, we find a strict af- 
finity between different species of minerals, 
and'in that case they are said to belong to the 
same family; but in mineralogy, one class ; 
does not always blend with another in a che- j 
mical point of view, or furnish that beautiful 
gradation and almost imperceptible union >■ 
whiefc is to be traced in the other kingdoms f 
of nature. 
As the external characters are of the first 1 
importance in facilitating our acquaintance j 
with minerals, we shall briefly explain this 1 
subject, before we proceed to the classification 
of the different substances. 
Of the external characters of Minerals. 
The external characters of minerals are 1 
either generic or specilic. The generic cha- ] 
racters are certain properties of minerals j 
without any reference to their differences, as 1 
colour, lustre, weight, &c. ; and the differ- I 
ences between these properties form the spe- 1 
cifie characters. 1 
Generic characters may be general or par- 1 
ticular. In the first division are comprehended i 
those that occur in all minerals, in the last 1 
those that are found only in particular classes ] 
of minerals. 
The particular generic external charac- j 
ters are thus advantageously arranged' 
1. Colour. * s 
2. Cohesion of particles ; distinguished into 1 
solid, friable, and fluid. 
In solid minerals are to be regarded the j 
external shape, the external surface, and the - 1 
external lustre. When broken, the lustre of j 
the fracture, the fracture itself, and the shape- j 
of the fragments, are to be noticed. In das- 1 
t i net concretions, regard must be paid to the ; 
shape of the concretions, their surface, their l 
lustre, transparency, streak, and soiling. All ■■ 
these may be ascertained by the eye.’ By 1 
the touch, we may discover the hardness of \ 
inner als their tenacity, frangibility, fl ex i- 
bnty, their unctuositv, coldness, weight, and 
their adhesion to the tongue. By the ear wo 
