Port Torpedo.
The sea torpedo has the advantage of exploding only when in hugging contact with the vessel attacked; the levers by which it is exploded are so placed in relation to the tow-rope, that either the side or top lever is found invariably to act effectively in forcing down the exploding bolt at the instant of contact; this has been ascertained by the result of many experimental trials.
The shape is an irregular figure, which can be best understood by reference to the drawings ([p. 4]). The dimensions of exterior case are as follows:—
| ft. | in. | ||
|---|---|---|---|
| Large Torpedo | ⎧ Length | 5 | 0 |
| ⎨ Breadth | 0 | 6⅛ | |
| ⎩ Depth | 1 | 8¾ | |
| Small Torpedo | ⎧ Length | 3 | 8 |
| ⎨ Breadth | 0 | 5 | |
| ⎩ Depth | 1 | 6 |
(C)
Section (C).
The exterior case is made of well-seasoned elm 1½ in. thick, iron bound, and screwed together with water-tight packing between the joints, also cemented with pitch. The interior case is made of stout sheet copper; the case has two loading holes corresponding in size to two holes in the deck, or top of the exterior case. These holes are made sufficiently large to load with gun-cotton discs, if preferred. The loading holes are fitted with corks, which are inserted before screwing on the brass cap, to prevent any chance of accident through friction in screwing on the cap; the bushing has the thread of the screw on the outside for the same reason. If thought necessary, the cork can be cemented over before screwing on the cap, which will render the joint doubly secure from leakage. The centre of the copper case has a stout copper tube, which is soldered to the top and bottom surfaces of the copper case, the charge being all round it; into this centre tube is screwed the priming case. It should be understood that both the exterior and inner cases are thoroughly water-tight, so that in the event of the outer case being damaged, still the charge in the interior case is preserved perfectly dry, the cases being altogether independent of each other.
The capacity of the copper case of the large torpedo is such that it will contain 77 lbs. of water; the capacity of the small one, 28 lbs.; from these can be determined the quantity of any explosive agent with which it may be desired to charge either torpedo.
The charges of various powders the torpedoes will contain are as follows:—