THE EOYAL AKTILLEKY ittSITlUTIOtt. ?1 
of the point of impact, according to the instructions already given. 
Should, however, the portion of the masonry above the horizontal cut 
be visible from the gun, it is self-evident that, as in the case of direct 
fire, the full service charge, with the elevation corresponding to the 
distance, can be employed. Should counter-forts exist they must be 
destroyed, and to effect this they must be taken as low down as possible. 
Lastly, some more shots are still required to bring down with a rush 
the earth that remains; as, till this is done, a practicable breach will not 
be produced. Reduced charges are used for this, otherwise the shells 
would penetrate too deep, and their bursting effect would be lessened. 
It has also been tried whether firing at the earth in horizontal layers 
would hasten its downfall; no advantage has, however, been gained by 
this proceeding. 
When the masonry is very strong, old, and compact, the scarp cornpA 
down in large blocks, thus rendering the formation of a practicable 
breach difficult. This was the case at Graudenz, when breaching was 
being carried on by this method. Under favourable profile conditions 
these blocks can, it is true, be fired at and smashed up ; but it is 
seldom that this can be done. It is therefore recommended that, before 
the completion of the vertical cuts, a few shots should be fired at the 
portion of the scarp which has to be brought down, so as to break it 
up before it falls. 
When the masonry is weak, and the vertical dispersion of the pro¬ 
jectiles considerable, the vertical cuts may be dispensed with. This 
was the case at Strasburg in 1870. In breaching the right face of 
Lunette No. 53 the distance was 790 metres, the charge 0‘85 k.g., and 
the angle of descent 7° 45'. Lieut.-General von Decker says on the 
subject *:—“ The further process of breaching failed to produce a 
proper horizontal cut. The vertical dispersion of the projectiles effected 
much more towards demolishing the scarp; since, along with the gradual 
breaking through of its lower portion, the upper part as well became 
destroyed, and fell down in fragments, more or less large, followed by 
the earth. This unfortunately had the drawback in many cases of 
diminishing the bursting effect of the shells on the scarp itself. There 
was nO'occasion to make a vertical cut. All that had to be done to 
completely remove the upper half of the scarp was to gradually raise 
the mean point of impact towards the end of the firing. When this 
had been effected a large number of shots with a charge of 1*2 k.g. 
were fired at the earth of the parapet, in order to bring it down. About 
half the mass of the parapet fell down, and the fragments of masonry 
were in this way completely covered with earth."” 
It is very difficult to effect a practicable breach when the revetment 
is counter-arched, as in Fig. 11. In order to destroy these arches, 
and bring down the earth above them, the uprights between the arches 
must be smashed up, and this can only be done successfully when the 
effects of the fire can be watched. 
Mittheilung liber die Anwendung des indirecten Sckusses. 
10 
