OCR Text |
Show I Periscope Only Inch and a Half Diameter" and Very Hard to See. AN IRISH FORT, Aug. 2G. (Correspondence (Corres-pondence of the Associated Press) If the popular conception of the periscope peri-scope and tho manner in which it is brought to the surface and lowered, were accurate, chasing submarines would be a much easier task than American destroyer commanders have laid out for them. They do not see a pipe four or five inches in diameter with ldnses at the top swishing ithrough the water or disappearing during dur-ing the rather slow process of sub-merging sub-merging a U-boat. Instead they sec, if they are fortunate fortu-nate enough a slender pipe not more than one and one-half inches in diameter diam-eter shoot up above the surface and disappear within a. few seconds. It is the telescopic perlscopo that may be operated from a depth of several feel. All under-water craft now are equipped equip-ped with them rather than the old type which, through photographs and drawings, has been impressed upon many people. The operation of the periscope is controlled to a large extent by a very delicate instrument which denotes de-notes to the U-boat commander the condition of the sea at tho surface. If it Is comparatively' smooth which enhances en-hances the danger of detection he need raise the periscope only a few inches above the surface. If it is rough he must raise the "eye higher hut he really is in not as great danger dan-ger as if the water was calm because it is difficult for an observer on another an-other ship to see the small Instrument in a heavy sea. The instrument is controlled by water wa-ter pressure which varies with the height and violence of the waves and shows actual surface conditions on an indicator in the ship. In one successful fight with a U-hoat U-hoat it was estimated that the persi-scope persi-scope was vlslblo less than ten sec- I onds. It bailie up very olose to a do-I do-I stroyer, doubtless n groat deal closer I than the submarine commander had I reckoned, and When ho realized his peril he attempted to scurry away. But a depth charge was dropped and , i German submarine power decreased by one boat. I rn |