Note F — Front matter

A deduction may be made from this time; after harpooning, if the ship were anchored in a current which ran one mile and a half an hour, that would be two feet three lines a second; hence, if the distance from the harpoon to the Torpedo were sixty feet, thirty seconds would be sufficient for the tide to push it under the keel; its clockwork might be set to explode in one minute from the time the Torpedo fell out of the boat. If a vessel were under sail, running more than two miles an hour, one minute would be sufficient time for the clockwork to act before explosion. After explosion there would, of course, be no resistance, and the probability is, that all hands would be too much occupied in attempting to save themselves, to keep them under any discipline. Thus each Torpedo boat would not be more than three minutes within the line of the enemy's fire.