It is more than probable, observes Lieut. Green, that the good results obtained with all these ghurrah charges were entirely due to the gun-cotton disc inside causing the gunpowder itself to detonate, so that the thinness of the envelope was of little moment in determining the force of the explosion.
The tin cases having arrived, the rest of the powder was made up into five charges of 48 lb. and three ghurrah charges of 20 lb each. About four miles farther down the river, there was an old peepul tree lying in mid-channel, with several of the branches above water. Two tins, one placed under the springing of the branches and the other under the roots, blew away the lower branches on which the tree was resting, and it sank slightly in the water. A ghurrah was next fired under the trunk with splendid results, the tree disappearing entirely except one branch, which required another small charge to remove it. The trunk of this tree was nearly 8 feet in diameter, but of soft stringy wood.
On returning to camp, a small charge of 2 lb. of gun-cotton was made up in a section of bamboo, and used against the banyan tree with very good effect, and a ghurrah charge demolished the last branch but one. The next day 1½ lb. of gun-cotton in a piece of bamboo finished the last of this enormous tree.
After clearing away several more trees, the foundations of an old factory, which had slipped into the stream, were removed by introducing two charges of 1½ lb. of gun-cotton, in the ends of two bamboos, well into the crevices of the masonry under the water.
Another obstruction consisted of a row of old piles, about 15 inches square, stretching across the river below the surface of the water. Six of the most dangerous of these were removed from the dry season channel with ghurrah charges tied to the foot of the piles.
An old well that had fallen bodily into the water was afterwards met with. The position of this well is shown in Fig. 56. A charge of 4 lb. of gun-cotton completely destroyed it.
Near Azimgunge, the trunk of a very large peepul tree was found sunk in deep water. It was so large that it was thought necessary to place a 100-lb. charge underneath it; this charge broke it up completely, but two small charges of 20 lb. each were subsequently required to remove the pieces.