I see that EX 49er beat me to it. I can add this though, when a naval commander had most of his firepower at a set distance from the target fort, the standing orders were that the fuses be cut to such a length that the shell would air-burst, just over the target. The object of this was to drive the enemy's gunners from their guns to prevent return fire. Primarily a mortar crew's responsibility, this suppression of fire was very important then so that the direct fire weapons could be carefully aimed to make holes at critical areas using solid shot to penetrate and fracture masonry and shells with fuses cut long to penetrate and then explode removing large quantities of fractured masonry and fill material. Army commander Quincy Gilmore used this technique during the investment of Fort Pulaski in 1862. He also issued orders which had a similar effect as Commodore Foote's "wetting the fuze" order. He directed that all the 13" mortar batteries "cut their fuzes long so that they strike before exploding". The purpose of this was to crush masonry arches and to produce large holes in the terraplein, disrupting ammunition delivery and to destroy gun carriages.
Land batteries had the luxury of creating true, "blind shells" which were filled with sand or dirt instead of gunpowder, naval forces just wet the fuses with much the same effect, especially with the very heavy, 220 pound 13" mortar shells fired from mortar barges.
Tracy and Mike
