The brains of the torpedo are in the immersion-chamber, C, between the air flask and the engine compartment. Here is placed the mechanism by which the torpedo is governed in many ways. A gyroscopic device opposes any tendency to deviate from the initial course. A depth-regulator insures running at a pre scribed depth, usually from 15 to 20 feet. A soluble plug opens a valve after a certain time and causes the torpedo to sink if it has missed its mark. An auto matic throttle-valve keeps the air pres sure constant during the discharge of the air-flask, insuring a uniform speed throughout the run. Of these devices, only the depth-regulator, Figure 2, will be described, this being, perhaps, the most characteristic feature of the tor the torpedo down. If it dives too deep, the balance of pressure is disturbed in the opposite direction and the torpedo is steered up. And so on, until the tor pedo becomes steady at the depth for which the spring is adjusted.
The range of the most powerful tor pedoes in use in 1921 is approximately 12,000 yards (six miles) and at this range a stationary target of the length of a dreadnaught can be struck three times out of four. Naturally the condi tions are greatly modified and the ac curacy enormously reduced when both the firing ship and the target ship are moving at considerable speed. The ships sunk by German torpedoes during the war were all attacked at short range, usually less than a thousand yards.
While torpedoes may be launched from battleships, all of which are fitted with elaborate arrangements for the purpose, they are more effectively fired from small er craft—destroyers and submarines— the high speed of the destroyer and the invisibility of the submarine giving such a craft a great advantage in the use of a weapon like the torpedo, which is es sentially a weapon of surprise. One of the developments promised for the future is a torpedo airplane, which shall carry a torpedo, with arrangements for launch ing it from a height of several thousand feet while flying at full speed. There is promise also of a torpedo which can be controlled from the firing ship or from a shore station, by radio. Lastly may be mentioned a possible combination of these two plans, the torpedo being called from its having housed some stir. vivors from the Armada) ; and St. Mi chael's Chapel, on a hilltop, is thought to have been connected with the abbey. St. John's Church, by Street, is a strik ing early English edifice; and other build ings are the town hall, museum, and thea ter. Torquay is a great yachting station; its chief industries are the working up of Devonshire marbles and the manu facture of terra-cotta. Pop. about 39,000.