Tornister (German, knapsack), a pack or satchel, which allows the foot soldier to keep essential items on his person anywhere in the field. It is usually of calfskin, sometimes of badger skin, the rough side exposed; often from tanned leather, and is best carried on the back, suspended from two straps over the shoulders. It is well to give the Tornister proper side walls, 4 to 6 inches wide; a lid, which reaches at least halfway down and may be strapped down tightly, protects the things inside from the rain.
Source: Rumpf, H. F.: Allgemeine Real-Encyclopädie der gesammten Kriegskunst (Berl. 1827)
Tornister (Slovak-Czech tanistra, from Medieval Greek Tánistron, feedbag for mounted men; French sac, formerly havresac), main element of the foot soldier’s baggage, typically a rectangular wooden frame with waterproof cover of furs or waterproofed canvas, carried on the back by two straps, is used in addition to the haversack to carry the equipment of the soldier. Up until the Napoleonic Wars, the Tornister was typically worn on single strap over the right shoulder. There have been ongoing trials in all armed forces to lighten the Tornister or replace it with a Rucksack.
Source: Meyers Großes Konversations-Lexikon, 6. Auflage 1905–1909