Blasting gelatine........................... 142 Forcite " ........................... 133 Dynamite No. 1.............................. 100 Gun-cotton, wet............................. 87 Nitro-glycerine............................. 81 Gunpowder.............................. 20 to 50 Col. Bucknill, of the Royal Engineers, in his publication of 1888, gives the following: Blasting gelatine........................... 142 Forcite " ........................... 133 Dynamite No. 1.............................. 100 Gun-cotton, dry............................. 100 " " ............................. 80 Gunpowder................................... 25 In both tables dynamite No. 1 is assumed as the standard of comparison. Col. Bucknill states that his gun-cotton results differ from Gen. Abbot's, because he experimented with much larger quantities, viz., 500-pound charges. Gen. Abbot's experiments led him to believe that an instantaneous mean pressure of 6,500 pounds per square inch would give a fatal blow to the double bottom of a modern armorclad, and he developed a formula which gives this blow with blasting gelatine at the following distances under water, viz.: Pounds. At 5 feet.................................. 4 " 10 " .................................. 17 " 20 " .................................. 67 " 30 " .................................. 160 " 40 " .................................. 311 Col. Bucknill's experiments caused him to believe that a pressure of 12,000 pounds per square inch is required, and his formula, which is somewhat different from Abbot's, gives widely different results at close quarters, but they approach each other as the distance increases. His results are as follows: Pounds. At 5 feet................................ 231/2 " 10 " ................................ 75 " 20 " ................................ 177 " 30 " ................................ 274 " 40 " ................................ 369