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MINUTES OF PROCEEDINGS OF 
than the longitudinal, and in itself not very great, it will be of advan¬ 
tage to shift the point of impact laterally during the course of the 
bombardment as circumstances may require. 
Should there be traverses on the terreplein, and should there be a 
deficiency of information as to their height and distance apart, we must 
take an angle of descent of 10° to 15°, place the mean point of impact at 
half the length of the space between the traverses, and after this get the 
charge corresponding to the distance from the practice tables. If the 
length of the line to be bombarded amounts to more than the whole 
longitudinal spread—that is, to more than four times the 50 per cent, 
spread—we must, in the course of the bombardment, so alter the 
laying, both as to elevation and direction, that every part of the terre- 
plein may be struck in its turn. 
If circumstances allow accurate information to be obtained as to the 
situation, height, and length of the traverses, it seems advantageous to 
take the nearest (or lowest) point of impact at the foot of a traverse—as 
is shewn in Fig. 5—and to calculate the angle of descent accordingly. 
Fig. 6. 
It is evident that, with this arrangement, all the shots of the lower half 
of the set of trajectories will strike the traverse A, and all those of the 
upper half the traverse B. If, therefore, we wish to strike the terreplein, 
we must take the nearest point of impact, not at 1\ but at 1\. If now 
we were to make TT X equal to the half of the 50 per cent, longitudinal 
spread, we could make about 25 per cent, strike the terreplein by 
placing the mean point of impact at T v and elevating the trajectory by 
a correspondingmmount; but this position of the nearest point of impact 
will, in general, give too steep an angle of descent, which would only 
allow of the employment of very small charges, and would consequently 
entail a very large vertical spread. Under such circumstances it is 
judicious, at the commencement of the bombardment, not to attempt 
to touch the guns of the defence with the lower half of the trajectory 
pencil. In proportion as the protecting traverse gets cut away by 
the shots that fall short will a greater number strike the terreplein. 
Moreover, those shells which graze the top of a traverse and explode 
will exercise a very considerable effect against the troops on duty that 
happen to be behind the traverse. With regard to the latter, it would 
appear allowable in the case of very high traverses placed near each 
other to take the nearest or lowest point of impact about a metre 
above the foot of the traverse, so as to fix the charge for the smaller 
angles of descent that will consequently result. 
A raising of the trajectory by a corresponding increase of the eleva- 
