Can anyone point me to a site or book where I can learn more about the power and safety of dynamite and black powder in the 1870s. i am writing a novel set in the iron mining communities of the North West and have a scene where my hero is threatened underground. How big an explosion would a single blast hole of blackpowder cause, compared to a single dynamite blast?
R Hunt, 1884, British Mining, Crosby, Lockwood and Co.
Should be available on Google books. The section you need is Book III, Chapter II (it's all in the same single volume).
The term Black powder is an American term common in the USA from the 1890s onwards and so not really appropriate in your context.