r)52 MANGANESE DEPOSITS OE INDIA : MINING. [PaRT III : 
of a few feet, for a distance of some yards in all directions round the 
deposit, such as up to the circle in the figure. Further indications of 
ore will then probably be found, such as the cross-hatched areas in 
figure 28. These will probably show some signs of direction ; in the 
figure they indicate a strike AB. A trench, CD, should then be dug 
at right angles to this supposed strike, and carried down to a depth 
suflBcient to show both the full width of the ore-body, and its contact 
with the ' country ' or enclosing rocks. From the boundaries of the ore- 
band as seen in the trench, it will probably be found that this first trench 
has not been dug exactly at right angles to the strike of the ore-body, 
but askew. Another trench, such as EF in the figure, should then 
be constructed in a direction at right angles to the supposed strike of the 
ore-body, and for the purpose of testing the extension of the ore-body 
in this direction. It will probably be found necessary to dig this trench 
deeper than CD in order to reach rock in situ, for, as likely as not, the 
original outcrop corresponds to a small hill or hillock submerged in the 
alluvium. With this second trench the true strike of the ore-body 
should be ascertained ; and the width of the deposit will now be known 
at two points. The extension in both directions should now be tested 
by further trenches both to the right and left of the original ones. 
Possibly, however, there may be several small outcrops ranged along a 
low ridge some .'30 to 100 feet high, or along a higher range or hill from 
100 to 300 or even 500 feet high. In this case the length of the ridge 
probably corresponds with the strike of the ore-body, at least roughl)^ 
Figure 29 may be taken to represent a ridge about 100 feet high, showing 
Fig 29. — Prospecting an outcrop along a rid£;e 
