18. What is the length of the chamber of the different mortars?
13-in., 13 inches; 10-in. sea-coast, 10 inches; 10-in. siege, 5 inches; 8-in., 4 inches; stone mortar, 6.75 inches; coehorn, 4.25 inches; eprouvette, 1.35 inches.
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19. For what purpose is the eprouvette used?
For determining the relative strength of gunpowder.
20. To what purpose is a stone mortar applied?
To throw stones a short distance, from 150 to 250 yards; and also 6-pr. shells from 50 to 150 yards.
21. In what manner are the stones disposed in this mortar?
They are put into a basket fitted to the bore, and placed on a wooden bottom which covers the mouth of the chamber.
22. What use is made of coehorn mortars?