Note 19 — Chapter II · PRACTICAL OPERATIONS AND DETAILS.
Reading edition
In the blasting at Hell Gate, 1870-76, several cases occurred, both with nitro-glycerine and compressed gun-cotton, in which a part of the charge exploded, breaking the blast-hole nearly to the bottom, and leaving the remainder of the charge unexploded in the bottom of the hole, from which it was subsequently recovered. Similar results were obtained in experiments, conducted by Capt. (now Major) Heuer, 1875-6, with long tubes filled with nitro-glycerine. See also Encyc. Brit., vol. xvi, “Mining,” for similar information.