Rhea, When I got home I pulled my Gibbon's off the shelf and searched for an hour and a half without finding any discussion of "long range canister" in that source. I did find the following on p. 359, however:
"Shot had better be used against infantry, and shells and schrapnell against cavalry, as this latter arm presents the highest mark, and enables the pieces of the bursting shells to do more execution. Moreover, the noise of the explosions frightens the horses and demoralizes the men.....A charge, when within short range, may be received by firing from each piece a solid shot on top of which is a placed a round of canister. The firing is then as rapid as possible, sponging may be dispensed with, within 150 yards, and as the enemy approaches nearer, canister alone is used, pointing very low at very short ranges, so that the projectiles may ricochet and scatter more. Canister should not be fired at distances greater than 300 to 400 yards."
Elsewhere Gibbon states of canister: "Good results can be obtained at from 300 to 600 yards, but the maximum effect is produced at from 300 to 450 yards." p. 249. Shot, shell and spherical case are used at greater ranges. Thus, historical description of spherical case as "long range canister" seems to hold up; it describes both its use (long range) and effect: "when the schrapnell bursts just in front of an object, the effect is terrific, being in fact much the same as a discharge of canister from a piece at short range." p. 147-48.
I also got out my copy of Rowell, Yankee Artillerymen, and reread his description of Hoover's Gap. Again no reference to "long range canister" in that source either, though he does describe Lilley's battery enfilading Bate's line with double canister during its attack on the 17th Indiana and again firing double canister at Johnston's two regiments as they approached a ravine seventy-five yards in front of the battery. The battery fired more canister at them as they retreated. pp. 80-81.
Tom
Bringing the