A SUBMARINE VESSEL.

New Zealand Tablet, Volume XXIII, Issue 47, 27 March 1896, Page 4

A SUBMARINE VESSEL.

AN IRISHMAN THE INVENTOR;

Many of onr readers who are acquainted with the scientific stories of Jules Verne will.'remember the Nautilus of Captain Nemo in " Twenty Thousand Leagues Under the Sea," The " dreams " of Verne are turning in this progressive age into actualities In Harper's Mound Table Mr Franklin Matthews gives a most readable account of a boat '• to sail under the sea " invented by Mr John P. Holland, an Irishman :— Every boat, no matter what its object, must have a certain amouDt of buoyancy to make it float. This vessel has tbe usual amount for one of its size. In its hold are a certain number of air tanks, in which are stored thirty cubic feet of compressed air at a pressure of 2,0001 bto the square inch. Ther« are also 620 electric storage batteries for propilling the ship when steam is shut ofi under water. Let us take the little vessel under water. We have been running along under steam on the surface and have Been the enemy. Al the hatches are closed water-tight, and the captain goes into a little armoured turret. He gives the word to run awash. At once the valves inthe bottom of the boat are opened, and certain apartments a>-e allowed to fill with water. This sinks the boat at once so that only the turret is visible. The enemy is near and has seen us. It is necessary to dive, Quickly the word is given, and the smoke-stack is dropped down into the ship and a thick plate is clamped over it. The fires are banked, and the engine is disconnected from the screw, and the electric power ia attached. An indicator tells the depth we have reached, and tbe mechanism is set at the required depth, and we are soon skfmming along under the water in absolute safety. The air in the tanks is beiDg released as fast as we need a fresh supply, and we are dry and comfortable. The captain decides that he wants to look around. He steers the boat up to within four f«et of the service, and then he pokes up out of tbe water what looks like a Btovepipe. Its real name is a camera lucida. It is an arrangement whereby those iniide the turret can get a good look around by means of mirrors. The captain decides to go under again, and makes for his target. He is soon passing under a ship. The darkened water tells us so. He makes a short turn, or stops, and then backs away and gives a signal to discharge a torpedo. It leaves the boat with a rush, aud in a few seconds there ii a muffled roar. A great warship has b^en struck, It lurches and staggers. Pandemonium reigns on it, the order is given for every man to save himself, aod in less than five minuteß after the torpedo has been discharged a five-million dollar battle-Bhip, the most powerful engine of destruction man ever made, is lying at the bottom of the channel, and the enemy has received a mortal blow. We come up to look around again. David has struck Goliath with a stone in the forehead and killed him. How is the diving done ? If you will look at the boat you will see at the stern two horizontal rudders. They stick oat behind like the feet of a swan as it swims about a lake. When it is necessary to dive, tbeee flat rudders are tipped down in the rear, and the Bhip is forced under, the bow at an inclination, When the required depth is reached the ruddore are flatteced out, so to speak, or held at the inclination to keep the vessel on an even keel, the tanks having been filled to overcome all bat a very small reserve buoyancy. An autdmatic arrangement allows the water to press on a rudder diaphragm and keeps the boat at an even depth. Propelling the boats under water until recently had been an unsolved problem. Sometim-s chemicals have been used, and eome1 times the stored-up heat of the engine has been tried. Electricity

has solved this problem, and made it possible to stay under water six hours going at full speed. DuriDg this time the boat can go fully fifty miles without once coming to tbe surface. Should any accident occur, each member of the crew is supplied with a life-saving helmet, which is easy of adjustment, and by means of which he can float to tbe surface of the water in safety. A folding rubber boat may also be earned in the superstructure of the craft, co that there is very little danger of loss of life under the water. Mr Holland has explored all New York harbour, and he say 8 that ladies have often asked him to take them down in Mb experimental boats.