Assertion: blasting powder | /r/MadeOf | low proportion of saltpetre
Facets:
value: from 62 per cent
type: OTHER
Source sentences:
text: Blasting powder contains a low proportion of saltpetre, from 60 to 62 per cent.; but, although this reduction may originally have been made in order to manufacture a cheaper article, yet it is also the most effective for the object desired in many cases, which is to remove large masses of earth or soft rock, and this can best be done by using a comparatively weak or slow-burning powder.