Hand Grenades
Hand grenades are now used solely for the defense of fortresses – either thrown at storming enemy troops or launched as a Granathagel (grenade hail) cluster or sabot charge against the heads of saps and trenches. They generally measure three inches in diameter and weigh between two and four pounds; the fuses of the former type (thrown by hand) must burn for at least 12 to 15 seconds, whereas those of the latter have a very short burn time.
Source: Rumpf, H. F.: Allgemeine Real-Encyclopädie der gesammten Kriegskunst (Berl. 1827)