a 
i wt 
FORTIFICATION. 501 
Field most proper places for the small arms; but it be- the same as of the glacis of the covered way, if not _ Field 
Fortifica- ee eee de ctw ite tn defend edtir part of the - more than 200 yards distant from the principal work. Fortifice 
* tions. toreceive the enemy with a front fire, it will If, however, the principal work has a covered way, . 
bath Deel requisite to give the small arms a place all round this is to have a command of five feet above it; and) 
i place the most numerous consequently: the must have from eleven to 
a parapet,’ but particularly to 
of Ren et the fanks. 
TP the valiant angles, thé serrated form of the faces is 
the most advantageous ; but the faces of the small sa- 
liants should never be larger than for two men, or at 
most for three, one of which is to be placed in its sa- 
twelve feet command above the field. Should the prin- 
cipal work be an outwork, then that which covers it 
must have a command of at least twelve feet above the 
field fortifications varies therefore considerably from ie 
t fortification ; it being in the'former 521 and of 
from five to six, and in the latter only two to four feet. permanent 
The! reason’ of this is, that the enemy can attack’ the fortitca- 
of the engi- him always to be at least seven feet lower than the 
simple method is requisite for determining 
this relief. But it will frequently be found impossible: 
to give such a relief as may have been determined 
upon, and in this case a more advantageous one ‘is. 
be chosen, and preferred to a great command. By 
is means, field works can. be made much stronger 
ical; a parapet, than bya defilement artificially chosen; as in permanent 
, be higher. If the fortification, and which is still more difficult:to 
i i be executed than that given by. the above rules: 
in the » or which can- Works near- 
Works which are 
ind, must be at least 300 an emi- 
distant from any eminence which commands it, if only "°° 
small arms are to-be feared ; but if cannon are employ- 
ed, it will be » that the distance should be ati 
least 900 yards. : 
’ The defilement of a work, which is open in its gorge, 
if it ke necessary to place i 
as, for instance, an outpost. No 
i less than six 
y to any distance behind, it 
6inches. At this height, how- 
to a sound jugdment, must de-~ 
relict for any work. 
i have 
ground; 
eS, Pal ong ueonaye bigherdrige ge naphalinand yresal 
or 6 feet 6 i below the crest of the covered way. 
This command may be increased to six feet, and even 
to7 Piesbae, Mt Yo te be inedlo very large. The 
should always have five to six feet command 
covert-way, and the crest of its glacis ; there- 
covert-ways will not be of any usé¢ where 
pet cannot be at least 10 feet hi A simple 
nd a field-work should never have less than 
command below the that the enemy 
same advan 
arms in its re-entering angles, then 
e the same command as a covered-way, and 
parapet as much above it. 
is is to have at least five feet less com- 
Defilement”’ 
it nearer to a mountain than of such 
300 yards, is determined as follows :—Poles four feet “OS 
six inches in length are erected on the highest visible <1 arms. 
summits of the mountain. The points which it is re-. 
quired to cover by the intended work, are then mark-: 
ed, and poles erected at them of such a height:as that: 
their tops shall just be within the command of the pa- 
— These poles being united at top bya cord, the 
iant and re-entering angles of the work are deter-- 
mined, and poles erected at each, of such a length that: 
their tops'shall be in a line, with the cord and the poles. 
on the mountain. The height of these. last poles will, 
give the height of a work necessary. to have a given: 
command over a given place near.an eminence. After) 
determining the defilement of the in this man. 
ner, the tops of the poles along the line of fire of the 
parapet are united by a cord, and wherever the line of 
this cord is below. the plane of defilement, it: is ele-. 
vated by means of poles. 
In the same manner the defilement for works to re- Against ar- - 
sist artillery is determined, if the heights are not above “srs. 
900 yards distant from it. This will always be most 
Hi 
Pa 
3 
¢ 
i 
F 
~~ 
i 
eet 
not 
the 
Ee 
i 
g 
2 
: 
F 
F 
b 
Fe 
l 
i 
L 
Hy 
Es 
ne 
FEE 
if 
a 
E 
= 
fe 
gE 
By 
ot 
difficult.where the visible heights are situated on one 
side of the fortifications. _ In this case, after fixing the. 
plane of defilement of the parapet, it will still be neces. 
sary to determine a traverse, and its plane-of defilement,. 
that the face may not be taken in: rearor im flank by 
the eminence near it. The most »convenient situation: 
for such a traverse being chosen, the plane of defilement 
is to be determined in, a manner similar to that de- 
scribed above, so as to cover every part of the works at 
such a height as may be . » The traverses are 
at the same time to.be so.chosen as always to keep up. 
