Page:The New International Encyclopædia 1st ed. v. 19.djvu/408

* TORONTO. 354 TORPEDO. the arts course were assigned to the faculty of the University of Toronto., the lectures nf which are open to the students of University Col- lege and of all federating institutinns. A faculty of medicine was established in 1887 ; in 1888 the Ontario Agricultural College was affiliated, and subsequently the Royal College of Dental Sur- geons, the College of Pharmacy, the Toronto Col- lege of Music, the School of Practical Science, and the Ontario Veterinary College became parts of the University. Federated with the university are Victoria University, Knox College, Wycliffe College, Saint Michael's College, and Trinity University (1903). The attendance in 1903 was 1717, including 883 in arts, 494 in medicine, and 340 in applied science, and the whole number of instructors was 146. The librai-y contained about 70,000 volumes and 22,500 pamphlets. The endowment in 1903 was .$868,899, the income $231,160, and the total value of property under the control of the institution, .$3,.503,729. Uni- versity extension work is carried on by means of lectures delivered throughout the Province of Ontario. TORPEDO (Lat. torpedo, numbness, cramp- fish, torpedo, from torpere, to be numb, stupid). A naval torpedo is an explosive device designed to destroy or injure a ship by blowing a hole in her hull at or below the water line. It consists essentially of the explosive charge, the fuse (which ignites the charge), and the case contain- ing these. Torpedoes are of two classes, fixed and moving. Fixed torpedoes are now commonly called torpedo mines or submarine mines. Torpedo mines are (1) self-acting, and (2) controlled, according to the conditions of firing. Self-acting mines are mechanically or electrically fired. The mechanical arrangements are of nu- merous types, but the most common is a set of pins projecting from the head of the torpedo, an.y one of which if struck would be driven down upon a fulminate primer in communication with the charge. The electrically fired are (1) simple buoyant mines, anchored so as to be not less than 5 nor more than 20 feet below water, and (2) combination ground mines with a buoyant con- tact piece or lloat which is anchored so as to be about the same distance beneath the water as a contact torpedo. In botli these types the explo- sion is caused by the completion of the electric circuit 1)3' the driving in of a pin by a ship which strikes the mine or fioat. Controlled mines are (1) automatic and (2) observation. The firing wires for all controlled mines lead to mine stations. For automatic mines this is done merely to secure safety. When the circuit is closed at the mine station the tor- pedo is not fired, but merely prepared to explode if one of the contact pieces on the shell is pressed down by a passing ship. The combination con- trolled torpedo, like the combination self-acting, is a ground'mine with a contact float; it is made ready in the same way as an automatic con- trolled mine. Obserimtinn mines are fired by ob- servers who keep the circuit closed at their sta- tions when the ship is on line with torpedoes as seen from their points of view. Therefore, when a ship is directly over a torpedo, the cir- cuits at both mine stations (usually placed so as to give nearly right angle intersection of lines of sight on each torpedo) are closed and the charge is exploded. Observation mines may be of the simple or compound buoyant type or of the ground tj'pe. The simple buoyant mine can only be exploded by the observers ; the compound type has extra fittings, so that it maj' be consid- ered as belonging also to the automatic buoyant type or controlled mine. Observation ground mines are simple if fitted for explosion by the observers only, and are combination if they also have contact floats. Mines of all the types mentioned are in com- mon use, their various characteristics fitting them to different local conditions. Self-acting mines have the advantages of ( 1 ) being compara- tivel}' cheap, (2) can be kept in store ready for immediate use, (3) do not require specially trained men or observation mining stations, and (4) easfempore ones can be easily made. But self- acting mines are all ( 1 ) rather dangerous to put out or pick up, (2) the condition of the igniting apparatus cannot be tested after the mine is placed in position, (3) they are as dangerous to friend as to foe when once placed, and (4) the mechanical or electric contact pins may become so overgrown with barnacles as to prevent their operation. After being two months in the water the Spanish self-acting torpedoes (in 1898) were so overgrown with barnacles that none were in a condition in which the.y would have been exploded if struck by a ship ; indeed, two United States ships actually struck them without causing ex- plosion. The objections to this type are evidently so serious as to preclude their use in important channels. In such places, particularly if it is desired to keep open a passage for friendly ves- sels, observation mines are used. If the water is not too deep, ground mines are laid ; but in deep water buoyant mines must be employed. Where the water is very deep and the currents are strong the mining of a channel is very difficult — in some cases It is impossible to lay them so that they can always be operated effectively. Self-acting mines are usually placed singly and far enough apart to prevent the explosion of one mine from setting off the others by shock. Controlled mines, and particularly the observa- tion variety, are commonly put out in groups, all the mines in each group being exploded simul- taneously. When so arranged, each group should be far enough from the others to avoid being ex- ploded by shock. The distance at which sym- pathetic explosion takes place varies with the character of the explosive and the weight of the charge. Guncotton is commonly use. Its ex- treme destructive horizontal range, according to General Abbott, U. S. A., is 14.7 feet for a 100- pound charge, 20.5 feet for a 200pound charge, and 31.7 feet for a 500-pound charge; while the safety interval or distance between mines or groups should be at least eight times the extreme destructive horizontal range. Moving TORPEnoES are (1) controlled or (2) uncontrolled. The controlled type are (1) spar, (2) tmcing, or (3) dirigible — the last-named class being either ( 1 ) extra-mobile or locomotive or (2) automobile. The uncontrolled type in- cludes (1) automobile, (2) projectile, (3) rocket, and (4) drifting torpedoes. Authorities do not favor greatly controlled tor- pedoes. In the spar type of these weapons the charge was placed at the end of a spar rigged out from a boat or ship, and torpedoes of this sort were much used in the Civil War; the rapid-