The age-herald., 1898-06-09

as yet of vital importance in mine laying. Whatever later inventors may accomplish. we have at present no mines adapted to use fin deep water where the current is strong. Under such conditions the ground or obser- Yat,on models would lie too distant from ships bottom to give effective service. And the electro-contact varieties, floating at the end of their long cables, would sink so low in the sweep of the stream that no ship would teuch them, at the same time swinging so wide that their exact position in relation to the enemy's vessel would be an insolubie problem; wherefore they could be served neither by their own automatic action nor by reliable judgment-firing.
 "The great desideratum in efficient min- ing" says a recent authority, 'is not so much perfection in construction as absolute secrecy in the plan of laying; 1T the plan of the mines position is kept se- cret they constitute a far more efficient protection to a harbor than any amount or forts and guns . An opposing fleet might easily bring itself to attack a fotilla of torpedo vessels, but 1t would hesitate very seriously before risking it's vitals over a mine field'
 Three methods of mine-destroying are in ordinary naval use-ceuntermining, sweep ing" and creeping" Of these three the first is by far the quickest, and would therefore obtain if the work must be done under fire; although heavy fire would rem der it almost or quite impossible. In coun- terminng, the mine employed Is like the 590-pound observation model deSer1bf above. At the moment of action a launch is loaded with twelve such mines connected by long electric cable. One end Of the cable Is held on board battery boat The other end, together with towing lines from the battery boat and the launch, is taken to a tug or to some vessel acting as such. The tug, having got her bearings, steers at full speed straight for the mine field, drag, ging the two small boats in her wake. On reaching the vicinity of the spot to be at- tackled the battery boat retaining her end of the electric cable, casts off and anchors; but the steamer, with the launch, Sill rushes ahead, while the mines. owing to the peculiar and highly scientific manner of their arrangement, drop one by one ana in due order over the launchs side when the last mine is down. the firing-keys or the batteries at either end of the cable are simultaneously pressed, and the explo- sion occurs, clearing about 720 feet of chan mel.
 The process of Sweeping" is slow ana rather uncertain, although 1t has It's uses' and in all probability it would never be at- tempted under fire. Without entering upon a detailed description, 1t may be said that a sweep is a rope and elecrtc capie urae some $50 feet broad, armed with iron claWs to catch mines by their moorings ana With explosive charges to destroy them under water when so caught. Each sweep IS handled from two row-boats provided with batteries.
 In relatively shallow water where the bottom is not too rocky, and when great speed is not imperative, the third-named method of -destroying-"creeplng is likely to be chosen. The object here is to break the cable not to attack the mine itself gig or light launch performs the work, using two tools of very simple pat tern The first is a primer-tin containing detonators in a charge of gun cotton and set with three large, strong, outward-turn- ing steel hooks. This "explosive creep is lowed by the working boat at the end Of stout rope carrying parallel with itself an electric cable that connects the charge in the creep with a battery on board. By another tow rope a second creep-a mere matter of iron hooks-drags twenty-five feet or so astern of the first. When the hooks of tho first creep catch in mine ca ble. the battery man turns on his current and explodes the charge. Then the boat proceeds until the second creep meets the cable. If the explosion did not sever 1t entirely it is now caught again. hauled to the surface and finally cut through, or, if there is time and the enemys fire IS not too gallng, it is followed down for bit, In the hope of arriving at a multiple junction box and the opportunity to de- stroy an entire series of mines at one blow.