============================================================== IRON. | BRASS. -----------------------+-------------------+------------------ Sea-Coast. |Siege and Garrison.| Field. -------+-------+-------+---------+---------+---------+-------- 42 | 32 | 24 | 18 | 12 | 12 | 6 -------+-------+-------+---------+---------+---------+-------- inches.|inches.|inches.| inches. | inches. | inches. | inches. 0.16 | 0.15 | 0.14 | 0.13 | 0.10 | 0.10 | 0.09 -------+-------+-------+---------+---------+---------+-------- [Sidenote: 82]] 8. What windage is allowed to columbiads and howitzers? ============================================================= COLUMBIADS.| HOWITZERS. -----------+----------------------+--------------------------- | Iron. | Brass. Iron. +----------+-----------+-------------+------------- |Sea-Coast.| Siege and | Field. | Mountain. | | Garrison. | | -----+-----+-----+----+----+------+------+------+------+------ 10-in|8-in |10-in|8-in|8-in|24-pdr|32-pdr|24-pdr|12-pdr|12-pdr -----+-----+-----+----+----+------+------+------+------+------ in. | in. | in. | in.|in. | in. | in. | in. | in. | in. 0.12|0.12 | 0.12|0.13|0.13| 0.14 | 0.15 | 0.14 | 0.10 | 0.10 -----+-----+-----+----+----+------+------+------+------+------ 9. What amount of windage is allowed to mortars? =========================================================== IRON. | BRASS. | IRON. ---------------+---------------+-------+-------+----------- Heavy. | Light. | Stone |Coehorn|Eprouvette. | |Mortar.|24-pdr.| -------+-------+-------+-------+-------+-------+----------- inches.|inches.|inches.|inches.|inches.|inches.| inches. 0.13 | 0.13 | 0.13 | 0.12 | — | 0.14 | 0.025 -------+-------+-------+-------+-------+-------+----------- [Sidenote: 83]] PART VIII. GUNPOWDER. 1. What are the ingredients in _gunpowder_? Saltpetre, charcoal and sulphur. 2. What are the proportions? In the United States, 75 to 76 saltpetre, 14 to 15 charcoal, and 10 sulphur. England, 75 Saltpetre, 15 Charcoal, 10 Sulphur. France, 75 “ 12½ “ 12½ “ Prussia, 75 “ 13½ “ 11½ “ 3. What is the combustible ingredient? Charcoal. 4. What is the use of the saltpetre? It furnishes the oxygen necessary to support a rapid combustion, and to change the whole mass into gas. 5. What is the use of sulphur? It adds consistency to the mixture and intensity to the flame, besides rendering the powder less liable to absorb moisture. 6. On what does the quality of gunpowder depend?