Wooden, paper, the Bormann and the United States sea-coast fuzes.
3. Describe the wooden fuze.
It consists of a conical plug of wood, of the proper size for the fuze-hole of the shell with which it is to be fired. The axis of this plug is bored out cylindrically, from the large down to within a short distance of the small end, which is left solid. At the large end a cup is hollowed out, and the outside of the plug is divided into inches and parts, generally tenths, commencing at the bottom of the cup. The cylindrical space is filled with composition, pounded hard, and as regularly as possible, and the cup filled with mealed powder moistened with whisky or alcohol. The rate of burning is determined by experiment, and marked on a water proof cap, which is tied over the cup. Knowing the time any shell is to occupy in its flight, the fuze is cut off with a saw at the proper division, and firmly set in the fuze-hole with a fuze-set and mallet. Say the fuze burns 5" to the inch. If a shell be 10" in reaching the mark two inches of fuze will burst it as it strikes. If it takes 8" to reach the mark, 1⁶/₁₀ in. will be cut off, &c.
110]
4. What is the disadvantage of this fuze?
Its irregularity, it being very difficult to pound the composition so that equal lengths will burn in equal times. The shell may either burst too soon, and a great part of its effect be lost; or it may burst after burying itself in the ground; or it may burst after passing the proper point. This irregularity of burning is common to all fuzes where the composition is driven in successive layers in a column which burns in the same direction.
5. What is the composition for Mortar fuzes?
| No. | Nitre. | Sulphur. | Mealed Powder. | Time of burning 1 in. | Remarks. |
|---|---|---|---|---|---|
| 1 | 2 | 1 | 3 | 3.8 sec. | For Siege Mortars. |
| 2 | 2 | 1 | 2¼ | 5. “ | “ Sea-Coast “ |
| 3 | — | — | 1 | 2.2 “ | “ 8-in. Howitzers. |
6. Is the wooden fuze used?
Yes, for Mortars.