,transcriber's ,note3 ,bold text is surrounded by equal signs and italic text is surrounded by underscores4 ,footnotes are located at the end of the text4 ,,the ,,boys' ,,book ,,of ,,submarines ,illustration3 ,courtesy of ,leslie's ,weekly ,a ,,modern ,,american ,,submarine ,,cruising ,,in ,,the ,,afloat ,,condition ,,with ,,foreward ,,diving ,,rudders ,,folded ,,back ,,against ,,the ,,hull ,,the ,,boys' ,,book ,,of ,,submarines ,,by ,a4 ,,frederick ,,collins ,,author ,,of 8,,inventing ,,for ,,boys10 8,,manual ,,of ,,wireless ,,telegraphy10 8,,keeping ,,up ,,with ,,your ,,motor ,,car10 8,,how ,,to ,,fly10 ,,etc4 ,,and ,,virgil ,d4 ,,collins ,,author ,,of 8,a ,,working ,,algebra10 ,,and ,,co-,,author ,,of 8,,shooting ,,for ,,boys0 ,,with ,,numerous ,,illustrations ,,and ,,diagrams ,illustration3 ,emblem3 ,,frederick ,a4 ,,stokes ,,company ,,new ,,york ,,established ,,eighteen ,,eighty-,,one ,,new ,,york ,,frederick ,a4 ,,stokes ,,company ,,publishers ,copyright1 #aiag1 by ,,frederick ,a4 ,,stokes ,,company ---------- ,all rights reserved ,,to ,,lester ,,burnham ,,collins ,,united ,,states ,,navy ,a ,,word ,,to ,,you ,submarine6 ,it's a word that's in everybody's mind--on every one's tongue4 ,the very sound of it conjures up thoughts of great ships that were and will be torpedoed and sent to the bottom of the old ocean to rust and to rot there4 ,of all the mighty monsters that ever sailed the seven seas this piratical craft is by long odds the most daring as well as the most dangerous to both life and property4 ,and yet while of course you know that a submarine can travel on or under the water1 dive like a porpoise and destroy an enemy ship by shooting a torpedo at her1 do you know exactly how an undersea boat works and fights and just how she does all the seemingly impossible feats for which she is notorious8 ,at the present time the greatest war in the world's history is being fought1 and you are more than a mere looker-on for your country is in it and you may be one of the boys who will be called to the colors to defend her on1 or against1 these undersea craft4 ,if for no other reason than this you ought to follow not only the battles as they are being fought on the east and west fronts of ,europe1 but the warfare that is being waged by the submarines on the high seas1 for on these boats hinges to a very large extent the outcome of the war4 ,ever since the year of #aijj when five of the first really successful submarines were built in the ,united ,states and sent to ,england the value of this kind of war-craft has gone forward by leaps and bounds as the devices for operating them were more and more improved4 ,further too the submarine has played a far larger part in the war that is now going on than the wildest fancies of her inventors of twenty years ago could have pictured1 much less believed1 and what is of even greater import she bids fair to become the champion fighter of the sea in the future4 ,indeed so wonderful is the submarine and so great are her possibilities that you should by all means know exactly how she is made and works1 as well as her torpedoes4 ,the easiest and certainly the most interesting way to find out these things is to read this book and then build a model submarine and torpedo according to the simple directions we have given4 ,to open the covers of this book and to read it is the next thing to going through the hatch in the bridge of the conning tower and examining the mechanism at first hand4 ,so do it now4 ,a4 ,,frederick ,,collins1 ,,virgil ,d4 ,,collins1 #eej ,riverside ,drive1 ,new ,york ,city4 ,,contents ,,page 8,a ,,word ,,to ,,you0 vii ,,chapter ,i4 ,,the ,,first ,,of ,,the ,,submarines #a ,how the ,submarine ,came to ,be4--,the ,development of the ,submarine4--,the ,first ,submarine ,boat4--,a ,submarine of the ,revolution4--,the ,first ,torpedo ,fired by a ,submarine4--,robert ,fulton's ,submarine4--,the ,earliest ,steam ,propelled ,submarine4--,the ,coming of the ,torpedo-,tube ,submarine4--,the ,invention of the ,electric ,submarine4--,what the ,gas ,engine ,did for the ,submarine4--,the ,two ,types of ,submarines4 ,,ii4 ,,how ,,to ,,make ,,and ,,work ,a ,,model ,,submarine #bc ,the ,ballast ,tank4--,the ,air ,control ,mechanism4--,about the ,power ,plant4--,the ,pusher ,control ,device4--,the ,propeller-,shaft4--,installing the ,motor4--,ballasting the ,boat4--,making the ,superstructure4--,and ,now the ,conning ,tower4--,setting the ,propeller4--,putting on the ,rudder4--,painting ,your ,craft4--,how to ,work ,your ,submarine4 ,,iii4 ,,how ,a ,,real ,,submarine ,,is ,,made ,,and ,,works #ea ,the ,parts of a ,submarine4--,how the ,hull ,is ,made4--,what the ,superstructure ,is4--,the ,outside of the ,conning ,tower4--,a ,look ,inside of the ,hull4--,a ,peep into the ,conning ,tower4--,now the ,navigating ,compartment4--,next1 the ,diving ,control ,compartment4--,the ,four ,states of the ,submarine4--,how a ,submarine ,dives4--,the ,ballast ,pumps and ,what ,they ,do4--,what the ,buoyancy ,tanks ,are ,for4--,compressed ,air and ,air-,compressor ,pumps4--,inside the ,torpedo ,compartment4--,why ,trimming ,tanks ,are ,used4--,in the ,mine ,compartment4--,and ,last of ,all1 the ,sea ,anchor4--,where the ,crew of a ,submarine ,lives4 ,,iv4 ,,the ,,heart ,,of ,,the ,,submarine #gc ,what a ,good ,power ,plant ,is4--,the ,faults of the ,steam ,engine4--,when the ,gasoline ,engine ,came4--,how the ,gasoline ,engine ,works4--,the ,last ,word in ,submarine ,engines4--,why an ,electric ,power ,plant ,is ,needed4--,the ,dynamo-,motor and ,storage ,battery ,system4 ,v4 ,,making ,,and ,,shooting ,,the ,,torpedo #ia ,the ,first ,submarine ,torpedoes4--,how to ,make a ,model ,submarine ,torpedo4--,the ,body of the ,torpedo4--,your ,torpedo in ,action4--,how a ,real ,torpedo ,is ,made4--,the ,detonating1 or ,firing ,mechanism4--,the ,engine that ,drives the ,torpedo4--,how a ,torpedo ,is ,shot at a ,ship4--,a ,torpedo with a ,cannon in ,it4 ,,vi4 ,,making ,,the ,,submarine ,,deadlier #aae ,arming the ,submarine with ,guns4--,the ,need of a ,quick-,action ,gun4--,the ,spring ,action ,gun4--,the ,compressed ,air ,action ,gun4--,how a ,submarine ,lays ,mines4--,kinds of ,submarine ,mines4--,how the ,mines ,are ,made4 ,,vii4 ,,the ,,wonderful ,,eye ,,of ,,the ,,submarine #abi ,how the ,eye of the ,submarine ,got ,its ,name4--,the ,first ,submarine ,eye1 or ,periscope4--,how to ,make a ,simple ,periscope4--,the ,modern ,lenticular ,periscope4--,how the ,telescope ,is ,made4--,the ,latest ,type of ,periscope4--,the ,limited ,use of the ,periscope4--,the ,new ,enemy of the ,submarine4 ,,viii4 ,,the ,,marvelous ,,tongue ,,and ,,ears ,,of ,,the ,,submarine #adc ,the ,tongue and ,ears of a ,submarine4--,kinds of ,signaling ,systems4--,the ,wigwag ,way of ,signaling4--,the ,flashlight ,system4--,the ,wireless ,telegraph ,system4--,underwater ,signaling ,systems4--,the ,electric ,current1 or ,conductivity ,system4 ,,ix4 ,,the ,,crew ,,of ,,the ,,submarine #aei ,conditions on ,early ,submarine ,craft4--,when ,crews ,were ,hard to ,sign4--,what the ,base-,ship ,is ,for4--,how ,men ,are ,trained for ,submarine ,duty4--,the ,complement of a ,submarine4--,breaking in ,raw ,recruits4--,the ,conditions in ,war ,time4 ,x4 ,,how ,,the ,,submarine ,,attacks #aga ,the ,uses of the ,submarine4--,the ,submarine as a ,scout4--,the ,submarine as a ,blockader4--,how a ,submarine ,attacks a ,merchantman4--,when ,submarines ,attack in ,pairs4 ,,xi4 ,,the ,,new ,,submarine ,,chasers #ahe ,schemes for ,outwitting the ,submarine4--,plans for ,destroying the ,u-,boats4--,kinds of ,submarine ,chasers4--,how the ,chaser ,chases a ,submarine4--,shooting the ,guns of the ,chaser4--,submarine ,air ,chasers4--,a ,way to ,lift the ,u-,boat ,blockade4 ,,xii4 ,,the ,,last ,,word ,,in ,,submarines #aii ,uncle ,sam's ,latest ,submarines4--,the ,great ,blockades of the ,warring ,nations4--,the ,first of the ,merchant ,submarines4--,some ,facts ,about the ,deutschland4--,how the ,united ,states ,can ,break the ,blockade4--,when ,submarine ,,illustrations ,a ,modern ,american ,submarine ,cruising in the ,afloat ,condition with ,foreward ,diving-,rudders ,folded ,back against the ,hull ,frontispiece ,,facing ,,page ,a 8,baby ,holland0 ,submarine1 ,one of the ,first of the ,u4 ,s4 ,n4 #ah ,your ,model ,submarine in ,action #df ,the ,conning ,tower and ,navigating ,compartment ,controls of a ,modern ,submarine #eh ,the ,engine ,room of a ,modern ,submarine ,showing the ,diesel ,engines #hb ,a ,bliss ,torpedo with ,rotary ,compressed ,air ,motor #ih ,a #c inch ,submarine ,gun in ,action ,showing the ,deck ,well and ,manner of ,operation #aah ,the ,latest ,type of ,periscope4 ,a much ,magnified ,image of the ,object ,is ,shown in the ,inner ,circle1 while in the ,outer ,circle ,is ,shown the ,object ,plus an 8all round0 ,view of the ,horizon4 ,a ,submarine ,fitted with ,this ,periscope ,may well be ,said to ,have ,eyes in the ,back of its ,head #acf ,a ,marine ,wireless ,installation #aej ,the ,crew of a ,submarine 7,note ,sailor ,going ,below through ,hatch in ,after-deck7 #aff ,a ,german ,u-,boat 8,breaking ,water0 ,preparatory to ,examining the ,cargo of an ,enemy ship #agh ,three ,eighty-,foot ,gasolene ,chasers on their ,way to ,patrol ,duty #ahh ,navigating the 8,deutschland0 by ,means of the ,deck ,control 7,note ,open ,hatch ,leading to ,conning ,tower7 #bjb ,,the ,,boys' ,,book ,,of ,,submarines ,,chapter ,i ,,the ,,first ,,of ,,the ,,submarines ,,the outcome of the great war that is now being waged in ,europe hinges largely on the ability of the ,central ,powers#a to sink the ships of the ,allies#b by means of submarines1 and of the ,allies to destroy the enemy ,u-boats1#c as the ,german submarines are commonly called4 ,now1 while a ,u-boat is a submarine1 all submarines are not ,u-boats2 for the word submarine means any and everything that lives1 is done1 or works beneath the surface of the sea4 ,thus1 a fish is a submarine1 and so is a boy while he is under water--though his clothes may be on the shore4 ,how the ,submarine ,came to ,be4--,yes1 the fish of the ,paleozoic#d era1 see ,fig4 #a1 was the earliest submarine1 in that it moved in and through the water under its own power1 and that was millions of years before the human race and the monkey tribe branched off from a common ancestor4 ,illustration3 ,,fig4 #a4 ,a ,,paleozoic ,,submarine4 ,,it ,,was ,,the ,,first ,,fish ,,to ,,swim ,,the ,,waters ,,of ,,the ,,earth4 ,not only has the shape of the fish--or ichthyoid form1 as it is called--served as a model for inventors of the submarine boat to go by1 but the air-bladder in the fish1 which aids it in keeping its place below the surface of the water1 finds its counterpart in the ballast tanks of the modern submarine4 ,when the first real boy parted from his monkey cousin--that is1 when the boy came down from his tree-top house and left the monkey up there to eat a banana all alone--,nature had fitted him with long legs and flat feet so that he might swiftly run away from his enemies on land4 ,but in those days when the earth was young there were not only gigantic1 long-necked animals with cross-cut saw tails and cunning little heads1 but terrifying winged lizards#e flew around everywhere like airplanes do now1 and monstrous and inconceivable things swam in the sea4 ,he could easily outwit and outdistance his animal foes on land1 but he could not fly away from those that sailed the air1 nor could he venture far into the water for fear of his aquatic enemies4 ,but he learned to swim in spite of them and when he could dive down here and come up over there he became the second submarine4 7,see ,fig4 #b47 ,illustration3 ,,fig4 #b4 ,,the ,,second ,,submarine4 ,,he ,,was ,,the ,,first ,,human ,,being ,,to ,,propel ,,himself ,,through ,,the ,,water4 ,from the time he learned to swim and grew to be a man he nursed the idea of making some kind of device that he could get into and swim about with1 not only so that he might be protected from the monsters that sought him as food but that he might destroy them as well4 ,and even after all the prehistoric beasts became extinct and so were no more on the face of the earth to menace his safety1 he still kept thinking over the idea of the submarine1 and it kept getting stronger within him as the convolutions of his brain grew deeper4 ,the ,development of the ,submarine4--,by hard thinking and long experimenting1 and the other way about1 and always working to the end that he might invent some kind of boat by which he could travel under and through the water 7or1 as the ,french have it1 sous marin--sous meaning under and1 of course marin means sea7 like the swiftest of fish and quite as easily4 ,his reason for wanting a submarine boat now that the animals he had so feared in the past had disappeared1 was to find treasure ships that had sunk to the bottom of the old ocean1 or1 more likely because it seemed more practical1 to attack1 unseen and without warning1 merchantmen that carried precious cargoes--in a word1 he would a submarine pirate be4 ,but like everything else that needs mechanical devices and electrical apparatus the development of the submarine from the first crude attempts to the powerful and perfectly controlled ,u-boat as we know it to our sorrow to-day took many men working through many years to make it sea-worthy and practical4 ,in each one of these inventors the thought that ruled him was to make a boat which would sink or swim1 as he wanted it to2 and though none of the earlier workers succeeded in building a really good submarine1 it was not their fault but their misfortune1 for the vital mechanical and electrical appliances they needed had yet to be invented4 ,but the efforts of each one of these pioneers served as a stepping-stone to the building of the first practical boat1 in #aija1 which could be used successfully as an undersea destroyer4 ,this was the ,holland1 which you will read more about presently2 and the ,british ,admiralty purchased five of the first ones built4 ,the ,first ,submarine ,boat4--,away back there in the very year when the ,pilgrims landed from the ,mayflower on ,plymouth ,rock--that is to say1 in #afbj--;a ,dutchman named ,van ,drebel1 who happened to be living at that time in ,england1 worked out the idea that originated in the brain of his prehistoric ancestor1 and that was to build a submarine boat4 ,of course in those days there were no such things as steel boats1 nor had engines to propel them been invented1 but men were adept builders of wooden boats and1 as much or more to their credit1 they were past masters of the art of sailing them4 ,but the lack of steel1 of engines1 and of other recent inventions didn't daunt the dauntless ,van ,drebel in the least2 for he went right ahead and built his underwater craft of such materials as he could get hold of4 ,his submarine was nothing more nor less than a regular wooden boat which was completely decked over1 covered with leather1 and smeared with tallow to make it watertight4 ,the submarine was propelled through the water by means of a pair of oars on each side as shown in ,fig4 #c1 very much in the same fashion as were the far-famed ,grecian galleys of old2 but in this boat the oars passed through watertight flexible covers fastened over the portholes4 ,a hollow mast was stepped into the deck to supply air to the crew when the submarine was under water1 and it was also used to spread a little canvas on when the boat was running afloat and the wind was good4 ,illustration3 ,,fig #c4 ,,van ,,drebel',s ,,submarine4 ,now1 you may think this submarine of ,van ,drebel's was a mighty crude attempt1 and no one will say you nay1 but just bear in mind1 please1 that it was the granddaddy of the modern submarine and that it traveled submerged down the ,thames ,river1 carrying in it no less a personage than ,king ,james the ,first1 and covering a distance of seven miles from ,westminster to ,greenwich4 ,after this first and very successful attempt at submarine building it was not long until others began to make improvements and to build underwater boats which would outdo the spectacular performance of ,van ,drebel's submarine4 ,it ought to send a thrill of pleasure through you to know that most of these inventors were ,americans1 but in your feeling of pride don't forget that the oversea workers along submarine lines followed closely on the heels of our own in ingenuity1 building1 and operative ability4 ,a ,submarine of the ,revolution4--,the first submarine designed to destroy enemy ships was invented and built by an ,american named ,david ,bushnell1 just about the time that ,liberty ,bell was ringing out the ,independence of the ,united ,states4 ,his submarine1 had it not been for an accident1 and of which ,i will tell you later1 would now be exploited in every school history of our country4 ,but even the accident showed that the submarine had great inherent possibilities and dynamic power stored up in it which warring nations of the future must reckon with4 ,different from all past ideas and present conceptions of submarines1 and far removed from any design which is ordinarily thought of in connection with boats1 ,bushnell's submarine1 instead of going through the water with its long axis horizontal to the top1 moved through it vertically4 ,the way in which this strange craft was submerged--that is1 sunk--is fundamental1 which means that it is the simple1 natural way and the one that is used in all submarines that have been built since then4 ,a number of empty tanks were so fixed in the vessel that when the pilot wanted to submerge it he could let the water into them1 and when he wanted to rise to the surface again he could pump the water out with a hand force-pump4 ,this scheme is used in all of the submarine boats of the present time1 though of course the pumps are power-driven4 ,a heavy weight that could be detached was fixed to the bottom of the craft1 which helped it to maintain its upright position and also aided in submerging it4 ,in case an accident happened to the pumps the weight could be released1 when the craft would come to the surface4 ,another good feature of this submarine was the valves which let fresh air into the vessel when it floated on top of the water but which closed automatically--that is1 without the help of the pilot--when the submarine sank below the water line4 ,the way the first submarine of ,bushnells was driven was just as primitive as the one built by ,van ,drebel2 indeed1 it was a shade worse1 for a solitary oar sticking through the rear end of the shell provided the means for going ahead while another oar on one side helped to raise and lower it4 ,he later designed1 built1 and successfully operated another submarine1 which was far superior to his first model4 ,it had the same shape as his first one but it was propelled by two screws which were turned by hand2 one of these moved the submarine forward and backward through the water1 and the other one moved it up and down--all of which is clearly shown in ,fig4 #d4 ,hence the credit for the invention of the screw-driven submarine belongs to ,bushnell4 ,illustration3 ,,fig4 #d4 ,,bushnell',s ,,submarine4 ,the ,first ,torpedo ,fired by a ,submarine4--,bushnell1 though1 did more than to invent a workable submarine1 for he also devised and used a torpedo2 or it would be better to call it a bomb1 since it was timed to explode by clock-work1 instead of by concussion4 ,he intended to hang this submarine bomb on the bottom of an enemy ship--and thereby hangs a tale4 ,the ,british man-of-war ,eagle had anchored in ,new ,york ,harbor close to ,staten ,island sometime in the famous year of #aggf4 ,the inventor was a patriot and offered his services and the use of his submarine to the new ,united ,states ,government2 the latter accepted them and ordered him to blow up the warship4 ,as the inventor became sick he gave a sergeant1 named ,lee1 the honor of using his submarine and blowing up the ship4 ,lee worked the submarine without a hitch until he reached the man-of-war1 and then his troubles began4 ,try as he would1 he could not drive the screw into the tough ,english oak of which the hull of the ship was made1 and this he must needs do in order to fasten the bomb to the bottom of it4 ,finally1 just as the clock-work of the torpedo was about to explode it1 he set it adrift1 and the young officer made off just in time to save himself4 ,as it was1 the bomb exploded close to the stern of the boat1 but it did not do any serious damage4 ,robert ,fulton's ,submarine4--,about the year #ahjj1 ,robert ,fulton1 the ,famous ,american inventor1 who built the first successful steamboat1 designed and built a submarine that was far ahead of either of those ,i have just described4 ,it was cigar-shaped1 to begin with1 and this lessened the resistance it offered to the water1 and it was fitted with a keel1 a rudder1 a propeller1 and a conning tower1 so that the pilot could see where he was going4 ,fulton did not attempt1 though1 to use a steam engine to drive the propeller1 but turned it by hand4 ,his submarine is shown in ,fig4 #e4 ,another big improvement that ,fulton made was to cover the hull of his submarine with copper plates4 ,taken altogether it came as near being a real submarine as could have been made with the materials and inventions which were available at that time4 ,illustration3 ,,fig4 #e ,,fulton',s ,,submarine4 ,after offering his submarine to the ,french1 ,british1 and ,american ,governments in turn1 and after it was turned down by all of them because they failed to see in it a useful weapon of war1 ,fulton turned his thoughts toward home and craft of a more peaceful nature4 ,had any one of these governments been able to see the wonderful possibilities of the undersea craft that ,fulton had so greatly improved upon1 the submarine would have been perfected long before it was4 ,fulton's remarkable experiment1 with his ,nautilus1 as he called his boat1 on the ,seine ,river1 which flows through ,paris1 attracted much attention1 and a plan was set on foot to use his submarine to rescue the exiled ,napoleon from the ,island of ,st4 ,helena4 ,again ,fulton was doomed to disappointment1 for the ,great ,emperor died before the scheme could be carried out4 ,it was then that ,fulton returned to the ,united ,states and set about the more peaceful task of building a steam propelled river boat1 or steam boat as it is called1 and which won for him much money and undying fame4 ,the ,earliest ,steam ,propelled ,submarine4--,it was eighty years after ,fulton made his classic underwater experiments that ,garrett1 an ,english inventor1 designed1 built1 and operated a submarine which used steam as its source of power4 ,this later submarine had all the good features of ,fulton's craft1 besides the history-making improvement of using a steam engine to drive her--not only when she was afloat but when she was submerged as well4 ,the way it was done was like this3 a regular boiler was set in the boat and this had a telescopic funnel1 as a ship's smoke-stack is called4 ,when running on the surface the water in the boiler was changed into steam and the smoke poured out of the funnel4 ,but when the craft was submerged1 the funnel was drawn under the deck1 the fire doors1 which were made air tight1 were closed1 and the steam pressure already generated in the boiler was high enough to run the boat for several miles4 ,the ,coming of the ,torpedo-,tube ,submarine4--,clear up to the time of the ,centennial ,exposition held at ,philadelphia in #ahgf1 the only idea that inventors of submarines seem to have had was to use a bomb of some sort which could be attached to the submerged hull of an enemy ship and which would blow her up4 ,this crude scheme1 as you have seen1 was not only uncertain but it was at once a difficult piece of work and very dangerous to the operator4 ,about this time1 or perhaps a little later1 a ,swedish engineer1 named ,nordenfelt1 invented a torpedo which could be shot from a tube in the head of the submarine4 ,his early submarine had a length of #ajj feet and could make #ab knots#f on top of the water2 she could be submerged to a depth of about #ej feet1 when1 of course1 her speed was considerably reduced4 ,she was steam-driven and had two propellers4 ,but the great improvement of this submarine craft over all the others that had been built before her was her torpedo tubes through which torpedoes#g could be shot from the inside of the boat and aimed at the enemy4 ,besides the torpedoes1 she carried two rapid-fire guns1 and these made her an engine of destruction greatly to be feared4 ,she is shown in ,fig4 #f4 ,the ,invention of the ,electric ,submarine4--,what with the amazing uses to which electricity was being put1 it is small wonder that as soon as the storage battery was invented and electric motor was discovered1#h inventors became imbued with the idea of using the mighty invisible power for running their submarine boats4 ,illustration3 ,,fig4 #f4 ,,the ,,nordenfelt ,,submarine4 ,the first submarine to be propelled solely by electricity was designed and built about #ahhf by ,campbell and ,ash1 of ,england4 ,the outstanding features of this undersea craft were the storage batteries1 which were formed of #ajd cells1 and the electric motors1 of which there were two and each one developed #de horsepower4 ,the boat had a speed of #f knots1 and it had a cruising radius of #hj miles1 without recharging the batteries4 ,she is shown in ,fig4 #g4 ,the electric submarine never got out of the experimental class1 because of the imperfections of the storage battery at that early date and in virtue of the fact that its range of travel was very limited4 ,but the experiments were not without value1 though1 for they led to the use of electricity as the ideal power for undersea propulsion1 as you will presently learn4 ,illustration3 ,,fig4 #g4 ,,the ,,nautilus1 ,,an ,,electrically ,,driven ,,submarine4 ,what the ,gas ,engine ,did for the ,submarine4--,greater effort to use electricity as a motive power for submarines would doubtless have been made had not the gas-engine been invented in #ahhh4 ,this new kind of engine was the ideal motive power for propelling a submarine on the surface of the sea1 and at the same time it could drive a dynamo which would generate an electric current to charge the storage batteries with4 ,and when the boat was submerged the engine could be stopped and there was no smoke or burnt gases to escape2 the storage battery then gave up its electric current1 this energized the motors1 and these in turn drove the propellers4 ,this combination system of gas and electric power is used in all submarine boats at the present time4 ,the first engineer to combine a gas and an electric power plant in a submarine as described above was ,depuy de ,lme4 ,this ,french engineer turned out a wonderfully successful submarine2 and this was still further perfected by another ,frenchman1 named ,gustave ,zd4 ,many of the submarines used in the ,french ,navy at the present time are of the ,depuy de ,lme-,zd type4 ,the ,two ,types of ,submarines4--,two ,american inventors1 name ,lake and ,holland1 were working independently of each other--that is1 neither knew the other was working on submarines--and each developed a different type of undersea boat4 ,this was about #ahif4 ,the ,lake ,submersible4--,the first underwater boat built by ,simon ,lake was shaped very much like a ship4 ,the hull was mounted on wheels1 so that it could travel on the bottom of the sea if need be1 for it was originally intended to be used by pearl divers and oystermen4 ,in the early part of this chapter ,i told you that the word submarine means anything that lives in1 is done1 or works beneath the water-line of the sea4 ,now1 in naval engineering1 submarine has come to mean an undersea craft that can dive1 while an undersea boat that simply sinks on an even keel is called a submersible4 ,so the ,lake shown in ,fig4 #h is a submersible1 for it is not intended to dive4 ,the ,holland ,submarine4--,the ,holland undersea boat is a real submarine1 for it can dive4 ,the hull of this boat looked more like a whale with its tail twisted up than like a boat1 as you will see in ,fig4 #i4 ,illustration3 ,,fig4 #h4 ,,the ,,lake ,,submersible ,,boat4 ,illustration3 ,,fig4 #i4 ,,the ,,holland ,,submarine ,,boat4 ,illustration3 ,,fig4 #aj4 ,a ,,modern ,,submarine ,,of ,,the ,k ,,class1 ,u4 ,s4 ,,navy4 ,illustration3 ,courtesy of ,leslie's ,weekly ,a 8,,baby ,,holland0 ,,submarine1 ,,one ,,of ,,the ,,first ,,of ,,the ,u4 ,s4 ,n4 ,the ,combined ,holland and ,lake ,types4--,the shape of the ,holland submarine makes it a good undersea boat2 the ,lake submersible has a large deck and roomy quarters1 and its shape makes it good for surface going4 ,the result is that naval architects have combined the two types so that the new model submarines have the advantages of the older types and are without their disadvantages4 ,nearly all of the boats of the submarine flotilla of the ,united ,states ,navy are of the ,holland and ,lake types combined1 as shown in ,fig4 #aj4 ,you will find more about these craft in another chapter4 ,,chapter ,,ii ,,how ,,to ,,make ,,and ,,work ,a ,,model ,,submarine ,complete ,instructions and ,working ,drawings for ,building a ,two-,foot ,model ,submarine ,,chapter ,,ii ,,how ,,to ,,make ,,and ,,work ,a ,,model ,,submarine ,,the best way to know how a machine works is to work with it1 and the next best thing to working with an actual machine is to work with a model which you have made with your own hands4 ,in this way you not only will become acquainted with the mechanism which is used to obtain a certain result1 but if you are of an inventive turn of mind you are likely to get one or more ideas for improving it which will be of more or less value4 ,now1 this is just what you should do with the submarine if you really want to know the innermost secrets of how it is made and works--that is1 you should build a model of one and experiment with it4 ,to the end that you may do this1 ,i have given in this chapter the plans and specifications1 which mean the working drawings and a full description1 of a #b-;foot model submarine boat which you can easily make and run yourself4 ,this model submarine is not only instructive but it is 8amoosin'10 as ,artemus ,ward used to say1 for while it starts out awash--that is1 with its deck just about level with the top of the water--it will soon take a dive1 run a ways submerged1 and then bob up on the surface again1 just like a real submarine4 ,the ,parts of the ,model ,submarine4--,there are only four chief parts to this model1 and these are 7#a7 the hull2 7#b7 the ballast tank2 7#c7 the power plant2 and 7#ad7 the superstructure4 ,all of this is shown in ,fig #aa4 ,the hull is of course the body of the boat4 ,the ballast tank is a tin can in the bottom of the hull2 when it is filled with water the extra weight makes the boat sink1 and when the water is blown out of it by compressed air it makes the boat rise to the surface again4 ,the power plant includes an electric motor1 the batteries to run it1 the propeller-shaft and propeller1 the pulleys which work the valve that lets the compressed air flow into the ballast tank to blow out the water1 and finally the superstructure1 which consists of the deck and the conning tower1 though in this case the latter is made to hold the compressed air4 ,the ,hull of the ,boat4--,the first thing to do is to make the hull2 and the easiest way to build one that is light1 strong1 and watertight is to whittle out1 or have sawed out1 two tapering pieces of wood as shown at ,a and ,b in ,fig4 #ab4 ,the faces are shown by the dotted lines at ,c and ,d in ,fig #aa4 ,these are for the nose and tail blocks1 as we will call them1 and each one is #ad inches long4 ,the other dimensions1 as well as the shapes of these blocks1 are also shown in ,fig4 #ab4 ,illustration3 ,,fig4 #aa4 ,,the ,,parts ,,of ,a ,,model ,,submarine4 ,bore four -inch holes1 inch deep in the faces--that is1 the flat ends of each block--at the places shown by the little circles2 these are to take in the ends of the brace rods4 ,next bore a -inch hole lengthwise through the tail block as shown by the dotted lines at ,b4 ,bore out this hole with a #a-;inch bit to a depth of inch1 to form a stuffing box4 ,illustration3 ,,fig4 #ab4 ,,the ,,nose ,,and ,,tail ,,blocks4 ,now cut off a piece of brass tube which has an inside diameter of inch and an outside diameter of inch and force it into the hole in the tail block2 this tube forms the bearing for the propeller-shaft4 ,cut out a disk of brass #a inches in diameter and #a_/af inch thick2 drill a -inch hole through the center of it for the propeller-shaft to pass through1 and three -inch holes at equal distances apart near the edge1 as shown at ,c1 so that it can be screwed to the tail block4 ,the purpose of this disk is to keep the packing in the stuffing box4 ,see ,fig4 #ab4 ,the next thing to do is to cut off two brass rods each inch in diameter and #af inches long and fit the ends of these into the lower holes in the blocks2 and then cut off two more brass rods #ag inches long and set these into the upper holes4 ,bend these latter rods out a little until the faces of the blocks are parallel with each other1 and you will have a substantial framework on which to fasten the skin of the hull4 ,the skin1 as the sheets or plates which form the hull are called1 is made of sheet tin1 and to cut the tin you should have a pair of tinner's shears4 ,you will need seven strips of tin altogether3 one for the bottom and three for each side4 ,the sizes and shapes of these strips are shown in ,fig4 #ac4 ,the widest strip is used for the bottom of the hull2 bend up the edges along the dotted lines1 then punch eight holes in the ends--these are shown by the little crosses--and screw it to the nose and tail blocks with flat-headed wood screws4 ,next punch holes in and screw one of the lower strips to each side of the nose and tail blocks1 with the hollow curved edge down and lapped over the turned-up edge of the bottom strip2 punch and screw on each of the middle strips1 with its lower hollow curved edge over the top of each of the lower strips2 and then punch and screw on the top strips4 ,when you have the bottom and all of the side strips screwed on1 each one will lap over the next lower one inch and fit snugly up to it1 and at the same time they will all curve gracefully4 ,illustration3 ,,fig4 #ac4 ,,the ,,strips ,,which ,,form ,,the ,,skin ,,of ,,the ,,hull4 ,after you have these strips screwed on1 you must solder the lap seams to make them watertight4 ,you can easily do this by using a regular tinner's soldering copper--a soldering fluid made by dissolving zinc clippings in some dilute muriatic acid--and what is called wire solder4 ,the cover of the boat1 or deck1 to give it its nautical name1 is a part of the superstructure1 and you can cut this out later on4 ,the ,ballast ,tank4--,the sole purpose of the ballast tank is to add enough weight to the boat to sink it when you want it to sink4 ,use heavy sheet tin for the tank4 ,cut out two strips1 each of which is #b inches wide and #ae inches long4 ,make a -inch lap seam and solder the ends of this strip together1 making one strip #cj inches long4 ,bend the strip so that each side is #aa inches long and the ends are #c inches long2 this will bring the ends together1 forming another -inch lap seam1 and this1 of course1 you must also solder4 ,illustration3 ,,fig4 #ad4 ,,how ,,the ,,ballast ,,tank ,,is ,,made4 ,cut out a top and a bottom1 each #d inches wide and #aa inches long4 ,cut the corners2 bend up the edges inch all round1 and solder the corners4 ,and don't be afraid to use plenty of solder1 for this tank must be strong1 and not only watertight but airtight as well4 ,about #d inches from one end of the bottom sheet cut a -inch hole for the water inlet and outlet1 that is the hole where the water flows into and out of the tank4 ,in this hole solder a piece of -inch brass pipe an inch long and flush with the surface of the tin1 as shown at ,a in ,fig #ad2 and also at ,b in ,fig4 #aa4 ,now1 with a pair of dividers #a inches in diameter1 scribe a circle which has its center #c inches from the other end of the bottom and in the middle of it4 ,cut out three strips of tin inch wide and #b inches long--or wire will do--and bend over one end of each one inch4 ,solder these strips to the bottom at equal distances around the circle as shown by the dotted line at ,b in ,fig4 #ad1 and in the cross-sectional drawing ,fig4 #ae4 ,the upright strips serve as guides to keep the cork float in place and yet let it move freely up and down in the tank4 ,cut a hole inch in diameter1 #b inches from one end of the cover1 or top1 of the tank as shown at ,a in ,fig4 #ad4 ,this is for the pipe of the valve mechanism4 ,next cut out a hole exactly inch in diameter1 and have its center #c inches from the end4 ,take a piece of tin and make a valve seat so that its small end is #i_/af inch in diameter and solder it to the top over the hole4 ,this valve seat must be made with particular care1 so that it will be perfectly smooth and the valve plug will fit it airtight4 ,the valve plug is a piece of cork cut in the shape of a cone and must fit the valve seat exactly2 soak it in machine oil1 then run a piece of aluminum wire #a inches long through it and bend it over on the bottom as shown at ,c in ,fig4 #ad and in ,fig4 #ae4 ,illustration3 ,,fig4 #ae4 ,,the ,,air ,,control ,,mechanism ,,and ,,power ,,plant4 ,next solder the bottom to the sides of the tank4 ,drop the cork float between the upright guides as shown at ,b in ,fig4 #ad4 ,set the cork valve plug on the cork float4 ,put on the cover with the aluminum wire sticking up through the hole in the valve seat2 and finally solder on the cover4 ,the ,air ,control ,mechanism4--,since you cannot be in your model submarine when it is stealing along submerged through the water1 you must fit an automatically controlled air-valve in the pipe that connects the air chamber with the ballast tank1 in order to blow out the water when it is time for the craft to come to the surface to breathe again4 ,there are two chief parts to the air control mechanism1 and these are 7#a7 the air-valve1 and 7#b7 the pusher control4 ,we will describe the air-valve and its fittings now and tell you how the pusher control is made and works under the next caption4 ,the ,power ,plant4--,the reason we have split up the air control mechanism in this fashion is because it is easier to solder the air supply pipe to the ballast tank at this stage of the work than it is to do it after the ballast tank is fixed to the bottom of the hull2 again it is easier to do the latter job before the power plant is put in the hull2 and finally the pusher control is really a part of the power plant4 ,if you will take a good look at the cross-section drawing1 ,fig4 #ae1 you will see that the air-valve and its fittings consist of 7a7 the air-valve proper2 7b7 a small piston2 and 7c7 the connecting pipes4 ,first get four lengths of pipes#i all of which have an inside diameter of #e_/af inch2 have these pipes 1 #b1 #b and #b inches long respectively4 ,thread or have these pipes threaded as follows3 the -inch length threaded inside and all the way through2 the #b-;inch length of pipe threaded on the inside to a depth of #a inch from one end and a hole drilled in it inch from the other end1 and have this threaded2 the #b-;inch pipe threaded on both ends and one end bent over of an inch2 and1 finally1 thread one end of the #b-;inch length of pipe4 ,now screw the -inch length of pipe on the end of the #b-;inch piece of pipe which has the nut and washers on it4 ,screw a bicycle tire valve into the #b-;inch piece of pipe and far enough in so that the bent end of the #b-;inch pipe can also be screwed in1 as shown in ,fig4 #ae4 ,last of all1 screw the end of the #b-;inch pipe into the threaded hole in the wall of the #b-;inch pipe4 ,next make a piston of a piece of brass rod inch long and of such diameter that it will fit snugly and yet slide easily in the end of the #b-;inch pipe4 ,drill a #a_/af inch hole through the piston and fix a stem in it tight so that it projects inch through one end and inch through the other end4 ,file a grooved ring around the piston to hold in the oil and slip the piston in the open end of the pipe4 ,this done1 clean the lower end of the long pipe well2 set it into the hole in the top of the ballast tank2 use plenty of soldering fluid and solder it in good and tight4 ,at the time you are doing this job see to it that the long pipe sets plumb--that is1 perfectly straight up and down4 ,setting the ,ballast ,tank in the ,hull4--,you are now ready to set the ballast tank in the hull4 ,to do this you must cut a hole inch in diameter1 #d inches from the face of the nose1 as shown at ,b in ,fig4 #aa4 ,set the tank in the hull so that the pipe on the bottom of it will stick through the hole which you have just cut2 and then solder the pipe to the hull on the outside4 ,putting in the ,bulkhead4--,as you will see from the end views ,c and ,d in ,fig4 #aa1 there is considerable space between the ballast tank and the skin of the hull on both sides4 ,as melted lead is to be poured into this space to give the boat the right weight to make it sink properly a bulkhead--that is1 a partition--must be cut out of tin and soldered to the hull1 on the inside of course1 up against the rear end of the ballast tank4 ,the face of the wooden nose against which the ballast tank rests will keep the lead from running out at the front end4 ,as the lead is poured in after the motor is set in place this operation will be described later4 ,about the ,power ,plant4--,while in a real submarine the power plant--the machine that converts the fuel into power to drive the boat--is a gas engine when it is cruising on the surface1 and a storage battery and an electric motor when it is running submerged1 in your model it is electricity first1 last1 and all the time4 ,that is to say1 a battery of dry cells supplies the current to run an electric motor and this in turn drives the propeller2 besides1 it also furnishes the power needed to work the pusher which controls the air supply through the bicycle valve which ,i have just explained to you4 ,the first thing to do toward getting the power plant is to beg1 buy1 or borrow a small electric motor which will develop not less than #a_/cj horsepower and at the same time run on a battery of not more than #c dry cells4#aj ,while the motor can be run to its full capacity on two dry cells it will develop more power on a three-cell battery4 ,now1 to get three dry cells which will fit into the small space that is left in the hull of your model you will have to use rectangular cells4#aa ,you will also need a small switch to open and close the battery circuit1 and this is fixed to the top of the boat1 or deck as it is more properly called2 the way it is put on will be explained under the caption of ,the ,superstructure4 ,when you want to buy one of these switches ask for a porcelain base1 single pole1 single throw switch4 ,it will cost about a quarter4 ,the way the dry cell battery1 the motor1 and the switch are connected up is shown in ,fig4 #af4 ,illustration3 ,,fig4 #af4 ,,how ,,the ,,power ,,plant ,,is ,,connected ,,up4 ,the ,pusher ,control ,device4--,before the motor is installed in the hull the pusher control device which opens the compressed air valve must be made and mounted on top of it4 ,on top of the motor1 as you will see by looking at ,fig4 #af1 there is a metal name plate1 which is fastened to the top of the field magnets by four screws2 unscrew the latter and take off the plate4 ,now make a pillow block1 as the bearing for the threaded spindle is called4 ,saw out with a hack saw#ab a base plate of sheet brass inch thick1 #a inch wide1 and #a inches long2 drill four -inch holes in the corners of the plate1 so that it can be screwed down to the field magnets of the motor4 ,also drill two -inch holes lengthwise in the middle of the plate and have the first one inch from one end and the other inch from the same end and in a line with the first hole4 ,take a brass bar inch thick1 inch wide1 and #a inches high1 and drill two #c_/cb inch holes in one end of it1 to correspond to the two holes in the middle of the base plate1 and thread these to fit a couple of #f-cb machine screws4 ,next drill a -inch hole clear through the top of the bar1 or standard1 as it is now called1 #c_/af inch from the top4 ,this must be very accurately done1 in fact1 it ought to be done with a drill press1 for if it is not precisely at right angles to the base1 the spindle will not run true1 and besides there will be a great loss of power4 ,drill a hole through the top of the standard until it meets the hole through which the spindle is to pass1 and by means of this top hole keep the spindle well oiled4 ,the pillow block is shown complete in ,figs4 #ae and #ag4 ,to make the spindle1 get a piece of soft steel rod inch in diameter and #d inches long4 ,thread it from one end to within #a inches of the other end1 and screw on a nut as far as it will go4 ,push the smooth end through the hole in the pillow block2 slip a collar over the end close up to the standard1 and screw it fast4 ,to make the pusher mechanism complete put a grooved pulley #a inches in diameter on the end of the spindle up close to the collar and screw it fast4#ac ,illustration3 ,,fig4 #ag4 ,,the ,,pillow ,,block4 ,the last part of the pusher control is the pusher itself4 ,it is simply a round brass rod inch in diameter and inch long1 with a hole drilled through it lengthwise and threaded to fit the spindle4 ,solder a bit of brass near one end1 to make it heavier on one side than on the other4 ,now1 when the motor is set in place in the hull and its small pulley is belted to the large pulley on the spindle and the current is turned on1 the spindle revolves1 but the weight on the pusher will keep it from turning with the spindle4 ,instead1 the curious result is that it screws itself toward the free end of the spindle1 and when it reaches the end1 the hollow pusher goes over the stem of the piston4 ,when it strikes the piston it pushes on it until it presses the other end of the stem against the pin of the bicycle valve and this opens it4 ,if you will keep the piston1 the pusher1 and the bearings well lubricated with sewing-machine oil1 there will be little power lost through undue friction4 ,but you must be careful not to get any oil on the commutator of the motor1 for this will keep it from running properly4 ,the ,propeller-,shaft4--,before you install the motor you must put the propeller-shaft through its bearing in the tail block4 ,to make the propeller-shaft1 get a piece of soft steel rod inch in diameter and #e inches long and thread it at both ends4 ,slip it through the tube which forms the bearing4 ,soak some cotton-waste in machine oil and pack it in the stuffing box in the tail block4 ,now screw the circular plate to the face of the tail block to keep the packing in place4 ,installing the ,motor4--,while we have given you the height to make the pillow block1 it will1 of course1 depend on 7#a7 the height of the motor1 and 7#b7 the height of the center of the piston when both are measured from the floor of the hull2 this is because the pusher spindle and the piston stem must be exactly in a line with each other4 ,another thing3 ,the motor we have shown is #c inches high from its base to the center of its armature shaft2 but the motor you get may not be of this height4 ,while it can't be any higher than #c inches unless you change the design of the boat1 it can be shorter if you mount it on a block of the right thickness4 ,before installing the motor in the boat1 see that both pulleys are in a line with each other1 and put on a belt4 ,thread the end of the motor-shaft and fit a coupling to it so that the propeller-shaft can be screwed into the other end4 ,to make the coupling take a piece of brass rod inch in diameter1 #e_/af inch long2 drill a #c_/cb-;inch hole in it1 and thread it to fit the motor- and propeller-shafts4 ,screw the coupling on the motor-shaft4 ,mount the motor on a board of the right thickness1 and set it in position in the hull4 ,screw the propeller-shaft into the coupling1 and be sure to have the motor set so that the shafts are in perfect alignment--that is1 in a line with each other--as shown in ,fig4 #ae4 ,unless this is done the propeller-shaft will bind in its bearing and it will take a large part of the power of your motor to overcome it4 ,when the motor1 the pusher spindle1 and the propeller-shaft all spin freely on closing the battery circuit1 you can then secure the motor to the floor of the hull with a couple of machine screws as shown in ,fig4 #ae4 ,ballasting the ,boat4--,the next thing to do is to ballast the boat by pouring melted lead into her hull to make her sink deep enough in the water to balance her and to make her submerge entirely when water is let into her ballast tank4 ,the way to do this is to cork up the hole in the pipe in the bottom that leads to the ballast tank and then set the boat in a tub full of water4 ,now lay the battery cells in the positions they are to occupy in the boat1 as shown at ,b and ,c in ,fig4 #aa1 and see how far up the water-line comes on the hull--or1 in other words1 how deep the hull sinks into the water4 ,next pour melted lead in between the sides of the ballast tank and the hull while the boat is still in the tub of water and distribute it so that the boat floats on a perfectly even keel4 ,when you have poured enough lead into the hull to make her sink to within an inch or so of her gunwales 7the upper edge of the boat's sides7 and she is nicely balanced1 let the lead cool1 take the boat out of the tub and put her back on her stocks on your bench4 ,and now a couple of parting hints3 7#a7 ,you can melt the lead in an iron ladle over a kitchen fire1 and 7#b7 put a little water in the ballast tank so that the hot lead will not open the soldered seams4 ,making the ,superstructure4--,this consists of the top1 or deck1 and the conning tower1 which in this model serves for the compressed air tank4 ,to make the deck1 cut out a sheet of heavy tin the exact shape of and dimensions given in ,fig4 #ah4 ,cut a -inch hole half way between the ends1 and in the middle1 for the air-valve pipe to pass through and which is screwed to the conning tower as shown in ,fig4 #ae4 ,cut out a #b-;inch hole in the aft end of the deck for a hatch1 and make a cover1 or hatch1 for it #c inches in diameter2 this hatch will allow you to get your hand through the deck and into the hull to reset the pusher device when your submarine is to make another trip4 ,illustration3 ,,fig4 #ah4 ,,how ,,the ,,deck ,,is ,,made4 ,cut out a rectangular hole inch wide and #b inches long in the for'ard end of the deck1 for the screws and the wires of the switch to pass through4 ,screw the porcelain block of the switch to a board of the same size1 with the tin deck in between them2 this insulates the screws of the switch from the tin1 which would otherwise short circuit the battery and run it down4 ,run sealing-wax in and around the edges of both the porcelain and wood blocks to make a watertight joint1 for water must not get into the boat4 ,this done1 connect up the batteries and these with the motor1 with heavy rubber-covered copper wire1 and connect the battery and the motor with the switch with flexible electric-light cord4 ,set the deck on the hull2 and if you are sure everything is in first-class working order1 solder it on tight4 ,if1 though1 you are not quite certain1 you can do a temporary job by putting it on with sealing-wax4 ,supposing you are young enough to have imagination or old enough to have dim vision1 the switch mounted on the deck will look very much like a gun that is just coming through the hatch and getting ready for action4 ,and ,now the ,conning ,tower4--,the conning tower is an airtight vessel--as far as your model goes--having a conical shape4 ,to make it1 scribe two circles1 using the same center1 on a sheet of heavy tin1 making one of them #d inches in diameter and the other #e inches in diameter1 and cut it out around the larger circle4 ,cut a -inch hole in the center of the disk4 ,put the -inch length of threaded pipe we told you about under the caption of ,the ,air ,control ,mechanism in the hole1 and solder it fast4 ,cut the edge of the disk radially with your shears1 from its edge to the smaller scribed circle1 and then you can bend up the edge all the way round4 ,next cut out an arc of tin of the size marked and the shape shown in ,fig4 #ai4 ,make a lap seam and solder it4 ,scribe a #c-;inch and a #d-;inch circle on a piece of tin and cut it out4 ,cut the edge radially as before1 and bend it up all the way round4 ,cut a -inch hole near the edge of the intake air-valve pipe4 ,solder the two disks to the cone and be sure the -inch threaded pipe is inside4 ,illustration3 ,,fig4 #ai4 ,,the ,,wall ,,of ,,the ,,conning ,,tower4 ,to complete the conning tower1 get a #e- or a #g-;inch length of pipe2 bend over one end a little2 thread it and screw in a bicycle valve4 ,finally stick the other end of the pipe through the hole in the top of the conning tower and solder it there1 as shown in ,fig4 #bj1 which also shows the conning tower complete4 ,the purpose of this pipe is so that you can pump air into the tank with a bicycle1 or an auto pump4 ,screw the conning tower on the end of the pipe of the air-valve mechanism which projects through the top of the deck1 and then you are ready to do something else4 ,illustration3 ,,fig4 #bj4 ,,the ,,conning ,,tower ,,or ,,compressed ,,air ,,tank4 ,setting the ,propeller4--,a #b-;inch brass propeller with three blades can be bought for about #dj cents of ,luther ,h4 ,wightman and ,co41 #acb ,milk ,street1 ,boston1 ,mass4 ,this little propeller has a hub diameter of #e_/af-;inch1 as shown in ,fig4 #ba4 ,when you get it1 drill a #c_/cb-;inch hole through the hub and thread it2 screw it on to the end of the propeller-shaft1 and then screw on a nut to hold it on tight4 7,see ,fig4 #bb47 ,putting on the ,rudder4--,and last of all comes the rudder4 ,cut off two pieces of -inch brass rod #d inches long2 thread one end of each rod down #a inch1 and sharpen the end a bit2 thread the other end of each one down inch and screw a nut on it4 ,illustration3 ,,fig4 #ba4 ,,the ,,brass ,,propeller4 ,drill two #c_/cb-;inch holes in the tail block in a vertical line with each other #d inches apart1 and screw in the brass rods as shown in ,fig4 #bb4 ,cut the rudder out of heavy tin--or1 better1 #a_/cb-;inch-thick sheet brass--the size and shape shown also in ,fig4 #bb4 ,illustration3 ,,fig4 #bb4 ,,the ,,rudder ,,and ,,propeller4 ,illustration3 ,,your ,,model ,,submarine ,,in ,,action ,bend the end of each tongue of the rudder to make a knuckle1 and slip the knuckles over the pins4 ,screw a nut on the end of each pin1 and by tightening them up you can make the rudder stay at any angle you put it4 ,painting ,your ,craft4--,you can buy a good marine paint of almost any color you want at paint stores generally4#ad ,gray is the most appropriate color to paint your model craft with2 but whatever color you choose1 lay it on the long way of the boat so as not to streak it but make a good smooth job of it4 ,put on three coats and let each coat dry thoroughly before you apply the next one4 ,and now your submarine is done1 and if you have made a good job of it1 it will look like the half-tone cut shown here4 ,how to ,work ,your ,submarine4--,having everything in readiness1 take your terrible little ,u-boat under your arm to the nearest lake or river4 ,pump the conning tower full of compressed air and then gently put her in the water4 ,throw on the switch1 and it will do the rest4 ,by this1 ,i mean that the moment you turn on the current the motor will drive the propeller at a goodly clip and the craft will travel over the surface of the water awash--that is1 with the water washing over her deck4 ,at the same time1 the ballast tank begins to fill with water1 and the added weight makes the boat go deeper and deeper until only the bridge#ae of her conning tower can be seen2 and after a few moments more her periscope 7or air supply tube7 sinks out of sight4 ,while she is going down the weighted pusher is moving slowly but surely over the threaded spindle2 when it reaches the piston it pushes it against the pin in the air-valve and so opens it and keeps it open4 ,the instant the air-valve opens1 the compressed air from the air tank 7conning tower7 rushes into the ballast tank1 and because it is under a high pressure it forces the water out of the tank through the hole whence it came in4 ,when the water has been blown out of the ballast tank the boat is1 of course1 lighter1 and naturally she rises to the surface again4 ,this is your cue to be right there with a rowboat and get her and to pump more air into the compressed air tank before she makes another trip4 ,if you don't do this and she ever goes down with her ballast tank full of water and there is no compressed air left to blow it out with1 you can send a censored report to the daily papers that another ,u-boat has been sunk and that there was no time to save the crew4 ,but1 anyway1 you will have oceans of fun with your model1 and your head will brim over with submarine lore4 ,,chapter ,,iii ,,how ,a ,,real ,,submarine ,,is ,,made ,,and ,,works ,the ,construction and ,operation of a ,real ,submarine ,simply ,explained ,,chapter ,,iii ,,how ,a ,,real ,,submarine ,,is ,,made ,,and ,,works ,,as we told you in the first chapter1 there are two kinds of undersea boats4 ,these are 7#a7 the ,holland1 or submarine type1 and 7#b7 the ,lake1 or submersible type4 ,now1 the ,holland boat has a shape very much like a cat-fish--that is1 it has a blunt round head--and hence it can dive easily2 while the ,lake is shaped more like an ordinary boat and has a large superstructure1 as that part above the hull#af is called1 and this makes it easier for the ,lake to submerge--that is1 sink on an even keel4 ,as the art of undersea boat building moved on apace1 the two kinds of craft began to lose their original distinctive features and were merged into a single type4 ,this was done to get a boat that was as strong and as speedy as and could dive like the ,holland1 and to have at the same time a boat that was as fast and as seaworthy on the surface as the ,lake4 ,this is the reason that most of the undersea craft of to-day are a cross between the two kinds4 ,in the older boats1 though1 the difference is still marked2 but the machinery of both is just about the same1 and consequently what we shall tell you of one is just as true of the other1 and from now on we shall call both kinds simply submarines4 ,the ,parts of a ,submarine4--,to begin with1 a submarine is formed of3 7#a7 the hull2 7#b7 the superstructure1 which is built on the hull2 7#c7 the steering apparatus1 which includes the submerging and diving devices2 7#d7 the power plant1 which consists of the engines1 the dynamo-motors1 and the storage batteries1 all of which drive the submarine when it is on the surface and under the water-line4 ,as the power plant is a most important part of the anatomy of a submarine1 it will need a whole chapter to describe it the right way1 and this will come next4 ,now ,i'll start in and tell you about the other parts of the submarine4 ,how the ,hull ,is ,made4--,the hull is made of thin but very strong sheets of steel riveted together4 ,as the pressure of the water on it amounts to #ahg pounds to the square inch1 at a depth of #cjj feet1 it must be well braced or else there would be the unpleasant possibility that it might be crushed in4 ,as a rule1 though1 a submarine never travels at a depth much greater than #ajj feet4 ,now1 there are really two classes of submarines3 7a7 those that are built for coast patrol cruising1 and 7b7 those that are built for trans-oceanic going4 ,a submarine of the first kind seldom has rough weather to contend with1 and so she need not be built as strong as one that is designed for ocean going4 ,she also has a slightly different shape from the latter1 in that she has a round cross-section1 as shown in ,fig4 #bc4 ,illustration3 ,,fig4 #bc4 ,,cross-,,section ,,of ,,coast-,,going ,,submarine4 ,by looking at ,fig4 #bd you will see that the ocean-going submarine is more nearly half-round2 this tends to prevent her from rolling unduly4 ,she also has a double hull which is divided into watertight compartments to protect her from sinking should an enemy ship ram or fire on her4 ,the compartments are used as stowage tanks for fuel1 etc41 and so the space between the inner and outer skins1 as the hulls are called1 is not wasted4 ,a large number of fittings are fixed to the hull1 such as the diving and steering rudders 7all of which will be described later71 while the superstructure is built on top of it4 ,what the ,superstructure ,is4--,the superstructure consists of 7#a7 the deck and 7#b7 the conning tower4 ,in the ,holland submarine the deck is only about one-third as long as the boat and this allows it to dive easily4 ,illustration3 ,,fig4 #bd4 ,,cross-,,section ,,of ,,ocean-,,going ,,submarine4 ,the ,lake boat is decked over nearly the whole length of the hull4 ,in it are fitted rapid-fire guns which disappear1 and there are watertight ventilators which let in fresh air when the boat is traveling on the surface4 ,further there is a hatch--that is1 an opening in the deck with a watertight door--through which the torpedoes can be lowered into the hold of the submarine4 ,the ,outside of the ,conning ,tower4--,from out of the center of the deck rises the conning tower4 ,this is a heavily armored1 shell-proof1 circular structure1 from which the captain makes his observations and sends his orders down into the engine-room and controlling compartments4 ,on the bridge or upper deck of the conning tower is a hatch by which the crew can get into and out of the boat4 ,a steering wheel and compass are fixed to the outside of the conning tower1 and the submarine can be steered by these when it is running on the surface4 ,a stanchion for carrying the signal lights is also secured to the conning tower2 while the periscope1 or eye of the submarine1 passes through the bridge and to one side of the hatch4 ,of this wonderful instrument we shall have much to say a little further on4 ,wires1 or stays1 as they are called1 fore and aft are used to brace and hold the periscope and signal stanchion firm against the force of the water which presses on them when the craft is submerged and under way4 ,the tops of the signal stanchion and the periscope are also braced by a signal halyard1 which is simply a wire1 or cable1 stretched taut between them4 ,on all modern submarines a wireless aerial is attached to a mast which can be folded down flat on the deck when the submarine is getting ready to make a dive4 ,a ,look ,inside of the ,hull4--,now let's take a look inside of the submarine4 ,the whole hull is divided up into a number of watertight compartments1 any one of which can be shut off from the others and so lessen the danger of sinking by ramming or by shell-fire1 should the boat be afloat4 ,in these compartments are placed all the machinery and the controls for operating the submarine4 ,these various compartments are3 7#a7 the conning tower2 7#b7 the navigating compartment2 7#c7 the engine and dynamo room2 7#d7 the fore and aft storage battery rooms2 7#e7 the fuel tanks2 7#f7 the diving control compartment2 7#g7 the fore and aft ballast tanks2 7#h7 the water pumps2 7#i7 the fore and aft high pressure air flasks2 7#aj7 the high pressure air compressor2 7#aa7 the torpedo compartment2 7#ab7 the mine compartment2 7#ac7 the trimming tanks2 7#ad7 the quarters of the crew2 and 7#ae7 the quarters of the officers4 ,all of these are clearly shown in ,fig4 #be4 ,the watertight doors of these compartments are worked by worm gears1 driven by electric motors1 as shown in ,fig4 #be1 and any of the doors can be opened or shut by merely throwing a switch4 ,a ,peep into the ,conning ,tower4--,the free space inside of the conning tower is not more than #h feet in height and #aj feet in diameter4 ,sticking down through the deck for about #b feet is the periscope1 or two of them1 for all submarines now built are fitted with a pair of them so that should one of them be hit and put out of business the other will be available4 ,illustration3 ,,fig4 #be4 ,,the ,,main ,,parts ,,of ,a ,,submarine4 ,this instrument is formed of a long tube with a hood at the upper end1 which is outside of the conning tower1 and an elbow at the lower end1 inside of the tower4 ,an eye-piece is fixed to the lower end1 so that the captain can scan the horizon at all times4 ,how a periscope is made and used will be described in a later chapter4 ,just below the eye-piece of the periscope is the underwater steering wheel1 and close to and to one side of the latter is the underwater compass4 ,in the more recent submarines a gyroscopic compass#ag is used as well as the regular magnetic compass because the gyroscopic compass is not affected by stray magnetic lines of force4 ,besides1 a gyro compass1 as it is called for short1 points to the true north instead of to the magnetic north pole1 and a true compass is of the greatest importance in guiding the submarine at night or when it is submerged1 for it is then as blind as the fish in ,mammoth ,cave4 ,around the inside of the tower near the bridge are placed ports through which the captain makes and takes his observation when the boat is afloat4 ,within easy reach of his mouth are speaking tubes which lead to the engine1 diving1 and torpedo compartments4 ,the captain also has at his finger-ends an electric signal system of lights and bells1 which he operates by push buttons and switches4 ,so you see he can get into instant touch with all the vital parts of his boat4 ,he also has full control over the trimming tanks and the storage batteries1 both of which ,i shall tell you about in detail presently4 ,illustration3 ,courtesy of ,scientific ,american ,,the ,,conning ,,tower 7,,upper7 ,,and ,,navigating ,,compartment 7,,lower7 ,,controls ,,of ,a ,,modern ,,submarine ,right in the line of sight of his eyes is a depth meter by which he can see at a glance at just what depth his craft is moving1 and he can also see at what angle#ah the diving rudder1 or elevator1 as it is called1 is set4 ,a compartment tell-tale 7a numbered chart showing each compartment of the boat7 also hangs in sight1 and if a compartment should begin to leak it is instantly indicated by the tell-tale1 which in this case is a miniature electric lamp that lights up back of the number4 ,by pressing a button he can ring an electric bell in the leaking compartment and so warn the crew that he is about to close the electrically operated bulkhead door and so shut the compartment off from the rest of the boat if the damage done is so serious that it cannot be repaired4 ,now the ,navigating ,compartment4--,as you have read before1 the conning tower is not a part of the hull but of the superstructure4 ,now1 when the captain or any of his crew wants to get from the conning tower into the hull of the boat he must do so through a hatch in the lower deck which is exactly like the hatch in the top or bridge of the tower4 ,this arrangement makes it easy to shut off the conning tower into the rest of the boat if it should be seriously damaged by shell-fire or by collision4 ,should this happen1 the boat is steered from another compartment called the navigating room1 in which are all of the devices used in the conning tower4 ,so you see there are two complete navigating rooms and an outside deck control by which the submarine can be steered and operated1 no matter how badly damaged she may be4 ,next1 the ,diving ,control ,compartment4--,the compartment containing the diving control1 by means of which the submarine can be made to dive and to come to the surface1 is fitted with the following devices3 ,first1 there is the diving wheel1 which works the horizontal or diving rudders4 ,next1 there is the angle indicator1 which is simply a quadrant--that is1 a quarter of a circle--marked off into degrees and each degree into quarters4 ,it has a needle which moves over the quadrant as the pilot turns the diving wheel and this indicates the number of degrees up or down the horizontal rudders have moved4 ,another instrument is the depth indicator4 ,then there is also an indicator which is merely a modified form of a carpenter's spirit level4 ,this little device shows when the craft is running on an even keel and when it is running with its keel inclined4 ,for instance1 should the diving rudder fail to respond to the touch of the man at the wheel1 the level would indicate it1 as would also the depth indicator4 ,other fittings are the levers and the valve controls1 by means of which water can be let into the ballast tanks4 ,now1 before ,i explain how the submarine is made to dive and how the ballast tanks work1 or1 rather1 the other way about1 ,i want to tell you a little about the why and the wherefore of these very interesting operations4 ,the ,four ,states of the ,submarine4--,a submarine has four states1 or conditions1 in which it exists in the water4 ,these are 7#a7 the light1 or surface cruising condition2 7#b7 the awash1 or partly submerged condition2 7#c7 the submerged condition2 and 7#d7 the totally submerged condition--all of which is clearly shown in the diagram ,fig4 #bf4 ,illustration3 ,,fig4 #bf4 ,,how ,,the ,,submarine ,,submerges ,,or ,,the ,,four ,,states ,,of ,,the ,,submarine4 ,the ,light ,condition4--,the light1 or cruising1 condition is simply the position a submarine takes when she floats on the water1 due to her own natural buoyancy1 and it is exactly like that of any other ship4 ,while in this position the captain takes his observations from the deck1 if there is no danger of being hit by the enemy2 but if there is danger1 he then makes his observations through the ports from the inside of the conning tower4 ,the ,awash ,condition4--,this condition is not as natural as the one just described1 and it has to be done by means of the ballast tanks4 ,these are located fore and aft and they can be connected with1 or disconnected from1 each other at will4 ,now1 when the captain wants to bring his submarine to the awash condition an inlet valve1 or ,kingston valve as it is called1 is opened and the sea-water then flows into these tanks1 the amount and velocity of the inrushing water being1 of course1 under control at all times4 ,this extra weight destroys part of the buoyancy of the boat1 and as she gets heavier she sinks until nothing but her conning tower remains above the water-line1 the deck being awash4 ,while in this condition observations are taken either from the ports in the conning tower or with the periscope1 the object-glass of which has been lowered enough to become useful4 ,the ,submerged ,condition4--,in this condition the periscope alone remains above the water4 ,it is had by allowing more water to flow into the ballast tanks1 thus destroying a little more of the craft's buoyancy1 which makes her sink down until the conning tower is completely submerged4 ,it is in this condition that the captain makes his observations with the periscope4 ,the ,totally ,submerged ,condition4--,this is an exaggeration of the submerged condition1 and it is had by letting still more water flow into the ballast tanks1 thus sinking the submarine completely4 ,the only way to steer the boat when it is in this condition is1 of course1 by means of the compass1 for both the conning tower and the periscope are totally submerged4 ,but do not mistake the term totally submerged to mean that the buoyancy of the submarine is totally destroyed2 for such is not the case during any stage of its submergence4 ,you can easily see that if the buoyancy were completely destroyed the submarine would then become a dead weight and sink to the bottom of the sea1 never more to rise4 ,instead1 when the submarine is totally submerged she can1 by what is known as her reserve1 or extra buoyancy1 and about which you will read later on1 come to the awash or the light condition in a few minutes by simply pumping the water out of the ballast tanks4 ,how a ,submarine ,dives4--,now let's get back to the way a submarine dives4 ,in the first place1 let us suppose the boat is running in the light1 or cruising1 condition4 ,an enemy ship is sighted and the captain of the undersea craft gives orders to clear the deck and close the hatches4 ,then he brings the boat from the cruising to the awash condition1 which is done as we have just described4 ,next1 he gives the order to the man at the diving wheel to make the dive4 ,he does not need to do this by word of mouth but he can use an electric indicator which points out the angle at which he wants the horizontal rudders set 7see ,fig4 #bg74 ,contrary1 now1 to what you might expect1 a submarine cannot dive at any angle1 but it must make a very shallow dive4 ,illustration3 ,,fig4 #bg4 ,,fore ,,diving ,,horizontal ,,rudders ,,or ,,hydroplanes ,,of ,a ,,submarine4 ,illustration3 ,,fig4 #bh4 ,,how ,,the ,,submarine ,,dives4 ,so when the order is given1 the diving rudders are set at only a degree from the horizontal1 as shown in ,fig4 #bh4 ,the craft must move through the water at about #e knots1 which is the proper diving speed4 ,when the conning tower is one-fourth submerged the angle of the rudders is increased to #a degrees4 ,this angle is held until the conning tower is half submerged2 and then the angle is changed to #b degrees1 and it is held there until the conning tower is three-quarters submerged4 ,as soon as this takes place1 the angle is decreased to #a degrees again1 and the rudders remain at this angle until the dive is completed4 ,why a ,shallow ,dive ,is ,made4--,the reason such a shallow dive must be made is the result of having to let water into the ballast tanks to bring the craft to the awash condition before diving4 ,if the angle of the dive were to be suddenly increased to #aj or #ae degrees the tilting of the boat would throw all the water forward in the tanks and this would seriously upset her balance1 and might even make her settle nose downward to the bottom of the sea4 ,how the ,boat ,is ,kept ,submerged4--,when a dive is to be made the diving rudders are set at the angles just mentioned1 but water is not let into the ballast tanks at the same time1 for this would also tend to destroy the balance of the boat4 ,but when the captain wants to keep his submarine at a certain depth below the surface of the water after the dive is made he has water admitted to the ballast tanks and this keeps her at that level4 ,when he wants to return to the surface1 or 8break water10 the water is pumped out and then the diving rudders are set and the boat makes an upward glide4 ,the ,time ,it ,takes for a ,dive4--,the time needed for a submarine to get ready to dive is about #b minutes2 but this is often long enough for it to become a target if a submarine chaser is on the little war-dog's trail4 ,should she be hard pressed she might dive at a steeper angle--say1 #e degrees1 but never more1 and under ordinary conditions she will never dive at more than #b degrees' inclination4 ,the reason it takes time for a submarine to get ready to dive is because the wireless masts have to be folded in1 the machine guns disappeared1 and the hatches fastened down4 ,finally1 it must not be forgotten that a submarine can dive only when she is pushing ahead under power4 ,if she is at rest and the captain wants her to sink he must either start her engines or else be content to simply submerge her on an even keel4 ,the ,ballast ,pumps and ,what ,they ,do4--,the pumps which pump the water from the ballast tanks are driven by electric motors4 ,they must be powerful pumps1 for they not only have to pump the water out of the tanks quickly1 but they have to force it out against the pressure of water in which the submarine is submerged2 this pressure increases the deeper the boat sinks1 and it is often #hj pounds or more to the square inch4 ,the pumps are controlled from the conning tower1 and also from the navigating compartment4 ,what the ,buoyancy ,tanks ,are ,for4--,we said previously that a submarine never loses its buoyancy completely4 ,if she were built like an ordinary ship and simply fitted with ballast tanks1 she would sink when these are filled with water and never come up again1 for her natural buoyancy would be destroyed4 ,as it is1 a submarine has tanks filled with air which keeps her buoyant1 and these will bring her to the surface the moment the ballast tanks are empty4 ,make this experiment and you will quickly understand how these buoyancy air tanks work3 ,take an empty bottle and cork it up tight4 ,it looks empty1 but as a matter of fact it is filled with air4 ,push the bottle to the bottom of a bucket of water2 let go of it and the instant you do so it will rise to the surface4 ,a large number of steel air tanks1 or buoyancy tanks1 or high pressure air-flasks1 as they are called1 are placed both fore and aft in a submarine1 and these are filled with compressed air at a pressure of #b1jjj pounds to the square inch4 ,these air-flasks have a tremendous supporting power--which is only another way of saying that they are extremely buoyant4 ,it must be clear now that even though the submarine is resting on the floor of the ocean it can always rise to the surface by the reserve buoyancy provided by these air-flasks4 ,compressed ,air and ,air-,compressor ,pumps4--,the air-flasks are filled with compressed air by air-compressor pumps which are driven by the engines when the submarine is running light or awash4 ,the air compressor is formed of several air pumps coupled together2 each air pump is made very much like a water pump1 but it sucks the air in from the outside and then forces it into the air-flasks until it is under a pressure of #b1jjj pounds to the square inch4 ,to overcome this back pressure1 as it is called1 the pumps must be extra powerful4 ,these pumps also supply compressed air for the torpedo tubes1 the trimming tanks1 and to help blow out the water from the ballast tanks4 ,inside the ,torpedo ,compartment4--,the torpedo compartment contains the extra torpedoes in their cradles4 ,near the tubes from which the torpedoes are shot is the compressed air which furnishes the propulsive power needed to make the torpedoes leave their tubes4 ,why ,trimming ,tanks ,are ,used4--,as a torpedo weighs nearly #a1jjj pounds1 it is plain that whenever one is shot from the craft it will very greatly disturb the balance of the boat unless some means is used to add weight to it which is exactly equal to the weight of the torpedo4 ,this is done by what is called the trimming tanks4 ,these are usually placed fore and aft and in or near the torpedo and mine compartments4 ,as soon as a torpedo is shot1 or a mine is laid1 the trimming tanks are filled with water which makes up for the weight lost and keeps the craft on an even keel4 ,if1 on the other hand1 any extra weight is taken aboard the submarine1 enough water to equal it is blown out by compressed air4 ,in the ,mine ,compartment4--,the mine1 as the stationary bombs that are to be laid in a harbor or some other strategic point are called1 are kept in the mine compartment4 ,this compartment has a trap door in it through which a mine-layer1 that is a man dressed in a diving-suit1 can get out of and back into the submarine again1 or through which the mines can be lowered4 ,illustration3 ,,fig4 #bi4 ,,mushroom ,,anchor4 ,and ,last of ,all1 the ,sea ,anchor4--,a submarine must have an anchor as well as a merchantman4 ,the anchor is of the mushroom type1 so called from its appearance2 and as you will see from the accompanying picture 7,fig4 #bi71 it is very different from the two armed and fluked kind that so resembles an ,irishman's anchor i4e41 a pickax4 ,where the ,crew of a ,submarine ,lives4--,proper quarters for the officers and crew in the earlier submarines were sadly neglected2 but conditions have greatly changed since then--though of course they are not quite so good as living in a luxurious hotel ashore4 ,great improvements have been made in behalf of the undersea navigators and sailors1 until in the more recent submarines the crew have quarters that compare favorably with those on board a battleship4 ,there are oxygen tanks that supply pure air1 while electric fans set up a forced draft and keep the air cool and make it circulate freely4 ,then there are electric heaters which keep the temperature just right under all conditions4 ,it goes without saying that the modern submarine has its galley--that is1 its cook room4 ,but1 very different from the galley on the old windjammers that used to sail the seas1 the sea-cook does not use a cook-stove1 which was also called a galley1 but electricity4 ,,chapter ,,iv ,,the ,,heart ,,of ,,the ,,submarine ,how the ,submarine is ,driven on the ,surface and ,undersea4 ,an ,explanation of the ,operation of the ,gasolene ,engine1 ,storage ,battery1 ,motor and ,dynamo ,,chapter ,,iv ,,the ,,heart ,,of ,,the ,,submarine ,,since the time of the first propelled underwater boat great strides have been made in the methods of driving the submarine1 until at the present day the power plant seems to be well-nigh perfect4 ,as the steam engine was improved upon1 its value for driving submarines became better thought of by inventors1 not because it was at all suitable for the purpose1 but in virtue of the fact that it was the first and for a long time the only practical scheme to produce power on a large scale4 ,for this reason1 all the early and even some of the later submarines were powered with steam engines4 ,what a ,good ,power ,plant ,is4--,there are certain things an engine must be and do to make it useful for driving a submarine boat1 and among the chief ones are3 7#a7 ,it must be as small and as light as possible and still have great strength4 7#b7 ,it must develop a lot of power for its size and weight4 7#c7 ,it must use a small amount of fuel for the power it develops4 7#d7 ,the fuel it uses must not be bulky for the power it gives4 7#e7 ,it must not give off odors4 7#f7 ,all working parts must be easily getatable1 and 7#g7 ,it must not give off poisonous gases1 or vapors that ignite easily1 for either of these are dangerous4 ,from this you will see that it is not an easy matter to make an engine for a submarine that will have all of these good features1 but inventors have come pretty close to it1 as you will presently learn4 ,the ,faults of the ,steam ,engine4--,now while the steam engine was the only motive power that could be used in the early submarine for driving it when both afloat and under water1 it lacked nearly every one of the good features named above2 for1 7#a7 ,while a steam engine can be made light and strong1 a large heavy boiler is needed1 and this makes the boat a very hot and unhealthful place for the crew2 7#b7 it is very wasteful of fuel1 for most of the heat energy#ai that is stored up in the coal or oil is lost before it ever reaches the engine2 7#c7 if coal is used1 it is too bulky1 and if oil is used it is too liable to give off vapors which will catch on fire and explode4 ,these untoward features did not matter so much when the submarine was afloat1 but when she was cruising below the water they were all present to make life miserable for the crew4 ,but when the storage battery was put into such shape that it could be used1 all this was changed and the conditions were so improved that undersea travel became bearable and pretty safe as well4 ,we will tell you all about the storage battery and how it develops power a little further on4 ,when the ,gasoline ,engine ,came4--,the next improvement in submarine power plants came when the gasoline engine was made practical4 ,this new kind of a prime mover#bj was so much better in every way than the steam engine that nearly all submarines now built are powered with them in one form or another4 ,the usual kind of gasoline engine is known as the four cycle type and has from #ab to #af cylinders1 the pistons of each of which are connected to one crankshaft1 and together they form a power unit1 as the complete engine is sometimes called4 ,a submarine engine of this kind can develop upwards of #e1jjj horsepower and the large units weigh close to #ajj tons4 ,except that it is larger and is built especially to meet the needs of the submarine it is exactly like a motor car or an airplane engine which is shown in ,fig4 #cj4 ,how the ,gasoline ,engine ,works4--,a single cylinder gasoline engine is easier to understand than one with four or more cylinders1 so ,i'll describe it first4 ,illustration3 ,,fig4 #cj4 ,,eight ,,cylinder ,,gasoline ,,or ,,petrol ,,engine4 ,illustration3 ,,fig4 #ca4 ,,how ,a ,,four-,,cycle ,,gasoline ,,engine ,,works4 ,it consists of 7#a7 a cylinder with valves in it and in which a piston moves to and fro2 this is connected to 7#b7 a crankshaft by means of 7#c7 a piston rod as shown in ,fig4 #ca4 ,to the cylinder is fixed 7#d7 a carburetor which mixes the gasoline with the air and forms the explosive gas1 or fuel mixture as it is called1 and 7#e7 a high tension magneto which generates an electric current to make the spark that fires the fuel mixture1 etc4 ,it is easy to understand how a gas-engine works if you will just remember that for every power stroke there are three other strokes1 making four strokes altogether1 or four cycles as it is called4 ,the power stroke of the piston is the stroke made by the explosion of the fuel mixture and this forces the piston down4 ,this is the stroke that turns the crankshaft one-half of a revolution and gives it force enough to carry it around until the next power stroke takes place4 ,thus the flywheel of a single cylinder four-cycle engine makes two complete turns or revolutions to each power stroke of the piston4 ,fig4 #ca shows how the inlet and exhaust valves are worked1 each one by a little wheel with a lump on one side1 or cam1 as it is called1 which is fixed on a cam-shaft and is turned by the crankshaft4 ,the cams1 of which there are two for each cylinder1 are set directly under the ends of the valve rods1 and as the cam-shaft revolves1 the little lumps on the cam strike the valve rods at the right moments and this lets the fuel mixture into the cylinder and lets the used and burnt-up gases out of it4 ,each valve is provided with a stiff spring1 which1 as soon as the lump on the cam has turned past the valve rod1 lets the latter drop again and so closes the valve4 ,fig4 #ca also shows the complete action of a four-cycle engine4 ,the suction stroke is shown at ,a2 as the piston moves down1 the cam forces the inlet valve up and the piston sucks the fuel mixture into the cylinder4 ,the exhaust valve is closed while this stroke is taking place4 ,the compression stroke is shown at ,b2 the momentum1 that is the stored up energy of the flywheel1 carries the piston up and forces the fuel mixture into a very small space1 that is1 it compresses it4 ,by this time the cams have moved past the valve rods and both the inlet and exhaust valves are closed4 ,the power stroke is shown at ,c1 and this is the only one of the four strokes that actually counts4 ,when the fuel mixture is compressed it is exploded by an electric spark and the force of the explosion drives the piston down and gives the flywheel great momentum4 ,it is the momentum produced by this stroke that not only furnishes enough power to carry the flywheel round until another power stroke takes place1 but also furnishes the excess power to do useful work1 such as to drive a dynamo or a propeller4 ,of course both valves are closed when this stroke is being made4 ,the exhaust stroke is shown at ,d and is one of the up strokes of the piston4 ,the cam opens the exhaust valve and the piston forces the burnt gases of the fuel mixture out of the exhaust port1 and that clears the cylinder for the next stroke1 which will be the ,a stroke over again1 and so on through the same four cycles just described4 ,the ,carburetor and ,what ,it ,does4--,this apparatus is connected to the fuel tanks1 which usually contains gasoline1 by a supply pipe4 ,the gasoline is forced out of the tank by compressed air being pumped into the latter and thence it passes into the carburetor4 ,the carburetor changes the liquid fuel into a fine spray1 or vapor1 and mixes it with air1 and this is drawn into the cylinder when the inlet valve opens and the piston is making its suction stroke4 ,the ,magneto ,electric ,machine4--,this is an electrical device which is simply a little dynamo4 ,when it is driven by the engine it generates a high tension current of electricity which will jump between the ends of two wires inch apart1 and this makes a spark4 ,the magneto is connected to a spark-plug which is screwed into the head of the cylinder4 ,a timer connected to the magneto and the spark-plug closes the circuit each time the compression stroke is completed2 the instant the circuit is closed the current generated by the magneto makes a spark at the business end of the spark-plug and this fires the fuel mixture4 ,but as good as the gasoline engine is for motor cars1 power boats1 and airplanes1 it has been found sadly wanting as a power plant for submarines2 this is due not to any fault of the engine but to the explosive nature of the gasoline which is used4 ,gasoline is a very volatile liquid1 that is1 at ordinary temperatures and pressures it tends to change from its liquid state to a vapor which is really a gaseous state4 ,you may have noticed this if you have been near a place where gasoline is stored1 for the whole air is saturated with the vapor given off by it and this is what you smell4 ,further1 it is quite impossible to store a fuel like gasoline1 and to use it for firing an engine in such a confined space as there is on a submarine1 without the air becoming charged with the vapor1 which is injurious to those who breathe it1 and which1 should it be accidentally ignited1 would explode with such force that it would wreck and sink the submarine4 ,the ,last ,word in ,submarine ,engines4--,having tried out both steam and gasoline engines for submarine work and both having been found wanting1 further experiments were made in engine building4 ,now1 since it was known that the chief fault of the gasoline engine lay in the fuel it used and not in the engine itself1 inventors worked hard to make an engine that would burn a fuel so much heavier and less volatile than gasoline that all danger from vapor would be done away with4 ,many engines were built along this line1 but all failed until ,diesel 7pronounced ,d-sel71 a ,german inventor1 found a way to make an engine that would burn a heavy oil4 ,the ,diesel engine is now used in every submarine that is built1 nearly2 and for this reason ,i want you to understand exactly how it is made and how it works4 ,how the ,diesel ,engine ,works4--,the ,diesel engine works on the same general principle as the gasoline engine--that is1 by the explosion of a fuel mixture in the cylinders--but it is different from the gasoline engine in the way in which the fuel is admitted into the cylinder and fired4 ,in the ,diesel engine1 a rough diagram of which is shown in ,fig4 #cb1 there are two valves in the head of the cylinder1 one of which lets in the heavy fuel mixture and the other one admits compressed air to the cylinder4 ,the exhaust valve is at the bottom of the cylinder1 and the lower part of the cylinder is built to form an air compressor4 ,illustration3 ,,fig4 #cb4 ,a ,,two-,,cycle ,,diesel ,,engine4 ,the way it works is like this3 7a7 ,when the compressed air valve opens1 the compressed air is forced into the cylinder and this drives the piston down when the valve closes4 7b7 ,the power that this stroke gives to the flywheel forces the piston up again1 and this compresses the air as shown in ,a1 ,fig4 #cb4 ,now when you compress air1 it heats it1 and the amount of heat developed depends on how much the air is compressed2 you can even feel the heat that is set up by compressing the air in a toy pop-gun2 or you may have noticed that when an automobile tire is pumped up fast it gets hot4 ,of course1 while the air is being compressed in the cylinder of the engine the compressed air valve stays closed4 7c7 ,when the fuel inlet valve opens1 the heavy fuel is forced into the cylinder by means of compressed air which presses on the fuel in the supply tank4 ,the instant the fuel strikes the hot air in the cylinder it ignites and burns1 and as it burns it expands just as the gases of burning powder in a cartridge expand4 ,this forces the piston down and makes the power stroke as shown in ,b1 ,fig4 #cb4 ,here1 then1 is another great advantage of the ,diesel engine over the ordinary gasoline engine3 it does not need an electric spark or any other kind of flame to fire it4 7d7 ,as soon as the piston has reached the down end of its power stroke1 the exhaust ports are opened and more compressed air flows through the compressed air valve2 this blows what is left of the burnt gases out of the cylinder through the ports1 and as soon as this is done the piston starts to go up1 when it compresses whatever air there is in the cylinder again4 ,while this stroke is being made the air compressor piston in the bottom of the cylinder1 which is a part of the regular piston1 has been compressing the air needed to perform the above operations4 ,since there is only one waste stroke to every power stroke1 the engine is a two-cycle one1 and herein lies its third big advantage over the gasoline engine4 ,illustration3 ,courtesy of ,scientific ,american ,,the ,,engine ,,room ,,of ,a ,,modern ,,submarine ,,showing ,,the ,,diesel ,,engines ,the reason that the ,diesel engine is better adapted to burn heavier oils than the gasoline engine is because the latter uses an electric spark to ignite the fuel mixture and this must be very light and volatile1 since the spark is not hot enough to fire the heavier oils4 ,again1 in a gasoline engine the fuel mixture explodes--that is1 it burns very rapidly1 like the powder charge in a cartridge--whereas in a ,diesel engine the fuel mixture expands when it is ignited1 very much as steam expands in the cylinder of a steam engine4 ,using heavy oils very greatly reduces the cost of operating an engine1 for oils of this kind are usually the by-products obtained in the making of petroleum and gasoline4 ,these heavy oils are of little value for any other purpose than fuel2 and1 also1 since the oil is heavy1 it is more easily handled than gasoline4 ,for these very good reasons the ,diesel engine 7,fig4 #cc71 is used by nearly every government at the present time for submarine power plants4 ,moreover1 like the steam engine1 it will develop its greatest power1 nearly1 on starting2 it does not need any reducing gears to lower its speed--this is done with a throttle as it is in a steam engine2 and it can be reversed without a reversing gear1 which is better than the steam engine4 ,the ,diesel engines of present-day make range from #ijj to #e1jjj horsepower1 and eight or more cylinders are used for each engine4 ,the weight of the engine is about #cj pounds per horsepower2 or for a #e1jjj horsepower engine the weight is in the neighborhood of #gj tons4 ,as great as this weight may seem1 it is much lighter for the horsepower produced than the old-fashioned gasoline engine4 ,illustration3 ,,fig4 #cc4 ,,type ,,of ,,diesel ,,engine ,,used ,,in ,,submarine4 ,why ,an ,electric ,power ,plant ,is ,needed4--,as you know1 a submarine has two chief conditions1 and these are 7#a7 when it is afloat1 and 7#b7 when it is submerged4 ,when she is afloat the air in the craft and which the crew must breathe is being constantly sucked in from the outside1 and there is always a large enough supply to keep the compartments clear and to furnish the air compressors which fill the tanks4 ,but when the boat is submerged there is no way of getting a fresh supply unless air is taken from the tanks or the submarine goes to the surface every little while1 like a whale1 and this would hardly do4 ,the ,dynamo-,motor and ,storage ,battery ,system4--,when the storage battery came into use inventors of submarines were quick to see that the thing to do was to use two separate and distinct power plants and these are 7#a7 the steam or gas engine1 which is used when the boat is running afloat2 and 7#b7 the electric storage battery system1 which is used when the craft is running submerged4 ,three devices must be used for the undersea electric power plant1 namely1 7#a7 the dynamo1 which generates the electric current2 7#b7 the storage battery1 which is charged by the current generated by the dynamo1 and 7#c7 the motor1 which develops power when a current from the storage battery is made to flow through it4 ,the diagram shown in ,fig4 #cd will make the electric connections clear4 ,about the ,dynamo4--,the dynamo#ba 7see ,fig4 #cd7 is connected to the crankshaft of the engine and is driven by it4 ,it changes the mechanical motion of the engine into an electric current4 ,this electrical energy must then be stored up so that it can be used later when the craft is submerged and it is wanted4 ,illustration3 ,,fig4 #cd4 ,a ,,submarine ,,dynamo ,,motor4 ,and ,now the ,storage ,battery4--,to store up the electrical energy a storage battery 7see ,fig4 #ce7 is used4 ,when the current is made to flow into this kind of a battery it charges the battery1 and if then the battery is connected to a motor it will deliver an electric current1 and this runs the motor4 ,the storage battery has been almost as big a bugbear to the submarine builders as the oil engine4 ,it must be as small and as light as possible2 it must not absorb the oxygen of the air which the crew breathes1 and it must not give off any poisonous gases4 ,now1 there are two kinds of storage batteries1 and these are 7#a7 the lead-plate storage battery1 which is the oldest form1 and 7#b7 the nickel-steel storage battery1 which was invented quite recently by our own ,edison4 ,both kinds are used in submarines4 ,illustration3 ,,fig4 #ce4 ,a ,,simple ,,storage ,,battery4 ,last of ,all1 the ,motor4--,the motor is the last device by means of which the electric energy is made to drive the craft when it is undersea4 ,now1 a dynamo and a motor are made exactly alike1 in fact1 a dynamo is a motor and a motor is a dynamo4 ,that is to say1 if you turn the armature of a dynamo1 it will generate a current of electricity1 and if you make a current flow through the coils of a dynamo1 the armature will spin round and it is then a motor4 ,this being true1 however strange it may seem1 only one electric machine is needed to do the work of the dynamo and the motor2 for when it is connected to the shaft of the engine it will generate a current for charging the storage battery1 and this is done while the craft is afloat2 or it will develop power to drive the propellers when it is connected to the storage battery1 and this is done when the submarine is cruising undersea4 ,,chapter ,v ,,making ,,and ,,shooting ,,the ,,torpedo ,full ,instructions and ,working ,drawings for ,making a ,model ,torpedo4 ,how a ,real ,torpedo is ,made1 ,directed1 ,shot and ,explodes ,,chapter ,v ,,making ,,and ,,shooting ,,the ,,torpedo ,,the submarine is first1 last1 and all the time an engine of death and destruction4 ,even in the earliest underwater experiments1 you will remember1 it was fitted with a bomb the sole purpose of which was to blow the enemy ship to atoms4 ,the old bomb idea proved next to worthless1 for it was a very hard job to fix it to the ship to be sunk1 and even if the submarine operator did succeed in so doing it was at best a dangerous piece of business1 and so the odds for its failure were about as #ajj is to #a4 ,as soon1 therefore1 as the submarine had been developed to a point where it was clear that it was the coming weapon of modern naval warfare1 inventors began to rack their brains for some scheme which would do away with the danger and uncertainty of the old-fashioned bomb1 and to make the submarine safer for its crew and deadlier for the enemy4 ,many attempts were made1 but its improvement was very slow1 for the old idea of the simple bomb was firmly fixed in the minds of the inventors and it was hard for them to break away from it4 ,after a long time1 though--that is to say in #ahfj--;,captain ,lupius1 an ,austrian inventor1 hit upon a new and novel plan for a torpedo which would travel under water1 by means of a little motor in it and a pair of wires which connected it with the submarine so that it could be directed at will4 ,the ,first ,submarine ,torpedoes4--,lupius took his idea to ,whitehead1 an ,english engineer of genius and ability1 and he built the first controlled torpedo which traveled under its own power in #ahfd4 ,then ,whitehead did a little thinking on his own account and he built the automobile torpedo in #ahfh1 the cleverest and most diabolical destroyer that man has ever yet been guilty of4 ,the automobile torpedo is one that not only runs under its own power but that steers itself as well after it has left the torpedo tube of the submarine4 ,to ,whitehead1 then1 must be given the credit not only of having invented the submarine torpedo that is used with such telling effect in the present war1 but of making a success of it4 ,the ,germans1 though1 with their great dislike for everything of ,british name and make call their torpedo of this type blackheads4 ,how to ,make a ,model ,submarine ,torpedo4--,before ,i explain how a real automobile torpedo is made and works1 ,i will tell you how to make a model torpedo which1 while it will not explode at the end of its trip through the water1 will show you how a real torpedo does its work4 ,the ,body of the ,torpedo4--,get a piece of nice soft pine #a inches in diameter and #aj inches long1 and whittle it out to the shape shown in ,fig4 #cf4 ,cut a groove down the middle of it inch deep and inch wide1 to within an inch of each end4 ,this done1 screw a small screw-eye in the warhead of the torpedo1 as the blunt nosed end of it is called1 inside the groove4 ,illustration3 ,,fig4 #cf4 ,a ,,model ,,torpedo4 ,bore a -inch hole through the propeller end1 and slip a piece of brass tube #b inches long which has a bore of inch in it to form a bearing for the propeller shaft4 ,get a brass rod #a_/af inch in diameter and #b inches long2 make an eye on one end and then push the rod through the brass tube in the tail or propeller end of the torpedo1 as shown in ,fig4 #cf1 and this is all there is to the propeller shaft4 ,now cut a propeller out of tin1 as shown at ,e1 in ,fig4 #cg1 and solder it to the end of the propeller shaft4 ,the ,steering and ,diving ,rudders4--,the torpedo1 like the submarine itself1 has two rudders1 one for diving and one for steering4 ,illustration3 ,,fig4 #cg4 ,a1 ,b1 ,c1 ,,the ,,steering ,,and ,,diving ,,rudders4 ,d1 ,e1 ,,the ,,cover ,,and ,,propeller4 ,to make the steering rudder1 which is the vertical one1 cut out a piece of heavy tin #a inches wide and #a inches long1 as shown at ,a in ,fig4 #cg2 cut out one edge inch deep as shown by the shaded part1 which will leave a tongue sticking out from each corner1 and bend these to form little tubes4 ,cut off two pieces of wire inch thick1 have each one #b inches long1 and bend them as shown at ,c4 ,next drill two holes through the tail or propeller end of the torpedo1 force the sharp ends of the wires into them and then put the other ends into the tubes of the rudder4 ,the diving rudder1 which is the horizontal one1 is made like the steering rudder except that the tongues for the hinge tubes are dropped down a little and a slot inch wide and #a inches long is cut out1 as shown by the shaded part at ,b4 ,this rudder is #a inches wide and #b inches long2 it is fastened by a pair of inch wires to the tail end of the torpedo in the same way as the steering rudder4 ,this arrangement leaves enough room for the propeller to turn inside of the wires1 as shown at ,c4 ,the ,rubber ,strand ,motor4--,the next thing to do is to fix one end of the rubber strands to the screw-eye in the warhead and the other end to the eye of the propeller-shaft4 ,this gives you a cheap and simple motor that is at once light1 powerful1 and easy to manage4 ,cut out a cover of wood to fit over the groove containing the motor1 as shown in ,d1 ,fig4 #cg1 and screw it to the body of the torpedo4 ,melt some paraffin wax and run it around the cracks to make the motor chamber watertight4 ,bore half a dozen or more holes inch in diameter and about an inch deep along the exact middle of the bottom of the torpedo2 fill each hole with shot and seal them in with sealing-wax4 ,there must be enough shot in the bottom to weight the little torpedo so that it will just sink on an even keel when you put it in the water4 ,finally1 paint the torpedo all over with black enamel 7you can buy it in drug stores for #aj cents a can71 and your model torpedo is ready for its deadly work4 ,your ,torpedo in ,action4--,to set your model torpedo scooting under the water and1 perchance1 aimed at an enemy ship1 fix the steering rudder in a line with the long axis of the hull and tilt the diving rudder at a very slight angle1 say about #b degrees1 down from the top of the torpedo4 ,hold the hull with your left hand and wind up the rubber strand motor good and tight by turning the propeller clockwise--that is1 in the direction the hands of a clock move--with your right hand4 ,when you have done this1 push the torpedo down under the water1 let go of the propeller and she will shoot forward as though shot by compressed air from a torpedo tube4 ,after it has made a run of from #be to #ajj feet--the distance depends on the skill you have shown in building it--it will sink to the bottom4 ,of course if you are playing a naval war game and you are shooting at some enemy ship1 it will give her a good hard bump1 and this counts ten points in your favor4 ,how a ,real ,torpedo ,is ,made4--,a torpedo1 as you can plainly see1 is nothing more nor less than a miniature submarine boat that moves under its own power and that is self-controlled4 ,and now that you have built and experimented with a little model it will be easy for you to understand how a real one is made and works4 ,the ,warhead of a ,torpedo4--,a real torpedo such as is shot by a submarine to sink real ships is made of three chief parts1 as far as the outside of it is concerned4 ,these are3 7#a7 the warhead1 7#b7 the body1 and 7#c7 the tail4 ,the warhead is the blunt-nosed hollow part that forms the business end of the torpedo2 it contains two things3 7a7 the charge of high powered explosive which plays such terrific havoc when it is touched off2 and 7b7 the detonating mechanism which fires it4 ,the ,high ,powered ,explosive4--,the explosive used is either guncotton1 or nitrocellulose1 to call it by its chemical name1 or tri-nitrotoluene 7pronounced ni-tro-tol-u-en7 and which is called ,,tnt for short4 ,guncotton is simply ordinary cotton which has been treated with nitric and sulphuric acids2 when this is done it becomes highly explosive4 ,,tnt is toluene1 a chemical formed of hydrogen and carbon1 which has been treated with nitric acid4 ,it is used by the ,germans in the warheads of their submarine torpedoes because it is a more powerful explosive than guncotton4 ,besides it can be melted as easily as lard and poured into the warhead1 which makes it an easy1 quick1 and safe job to fill them4 ,further1 it does not explode easily by shocks when it is transported but it instantly explodes with a detonator4 ,the reason these explosives cannot be ignited by fire but explode when struck a sharp tap is because they are very unstable compounds2 that is1 they are very easily decomposed into their original chemical parts4 ,curiously enough1 but by the very discovery of this advanced scientific principle men are now able to make the mightiest1 which means the deadliest1 explosives that the world has ever known and this makes war a thousand times as terrible now as it was in the olden days when men fought their battles at close range with their ancient lances and cross-bows4 ,the ,detonating1 or ,firing ,mechanism4--,a modern submarine torpedo has a diameter of from #ah to #ba inches through the warhead1 and this is loaded with from #bjj to #ccj pounds of guncotton or ,,tnt1 as the case may be4 ,this charge is exploded by a firing pin1 or pistol1 as it is called4 ,this firing pin goes clear through the charge and into a percussion cap1 which sets just back of the charge2 the other and front end of the firing pin goes clear through the warhead and has a threaded end on which is screwed what is known as a butterfly-nut4 ,illustration3 ,courtesy of ,e4 ,w4 ,bliss ,co4 ,a ,,bliss ,,torpedo ,,with ,,rotary ,,compressed ,,air ,,motor ,the percussion cap is simply a little copper cup and in it is placed a small charge of an explosive which is easily detonated by the percussion of the pin1 that is by the pin striking it4 ,the explosive mostly used in percussion caps is mercuric fulminate1 which is a compound formed of mercury1 carbon1 nitrogen1 and oxygen4 ,since it is the violent explosion of the percussion charge which strikes the main charge of the high explosive in the warhead1 and the fire made by the explosion of the percussion charge has nothing to do with it1 the main charge of guncotton1 where this explosive is used1 is often wet down with water before it is packed in1 for by so doing a great deal more of it can be put in the same-sized space4 ,a safety pin 7see ,fig4 #ch7 is set into the firing pin1 so that by no possible chance can the latter pin work loose and explode the charge until it strikes the ship it is intended to destroy4 ,also the butterfly-nut1 which ,i spoke of above1 is used as a further safety factor4 ,the safety pin is simply a pin which is threaded on one end and which extends down through the steel casing of the warhead and screws into the firing pin1 or pistol1 and holds it securely so that it cannot strike back against the charge until it is unscrewed and taken out or broken off1 when it strikes the ship4 ,the butterfly-nut is simply a thumb nut with a couple of wings on it4 ,when the torpedo is shot out of the torpedo tube the butterfly-nut1 which is screwed up close to the warhead on the firing pin1 begins to unscrew itself by the action of the water on the wings1 which now form little propeller blades2 by the time the nut reaches the end of the firing pin and drops off1 the torpedo is quite a distance from the submarine which shot it4 ,in this way1 all danger of the torpedo's exploding when it is in1 or leaving1 the submarine1 is done away with4 ,fig4 #ch shows a cross-section of the warhead and just how the detonating mechanism is made and works4 ,illustration3 ,,fig4 #ch4 ,,the ,,business ,,end ,,or ,,war ,,head ,,of ,a ,,real ,,torpedo ,the warheads of the latest torpedoes1 especially those used by the ,germans1 are fitted with steel cutters1 so that they can cut their way through nets which ships may spread out to protect themselves4 ,the ,body of the ,torpedo4--,the next part of the torpedo is the body1 and there are five separate and distinct parts to it4 ,these we have named in the order of their position1 and they are1 7#a7 ,the air pressure chamber2 7#b7 the balance chamber2 7#c7 the power chamber2 7#d7 the buoyancy chamber1 and 7#e7 the tail-piece which supports the propellers and the rudders4 ,the ,compressed ,air ,tanks4--,the air pressure chamber is simply a large steel tank and air is pumped into it until it is under a pressure of about #b1jjj pounds to the square inch2 this means that for every square inch of the surface of the tank there is a force pressing against it of about one ton4 ,the air is let out of the tank through what is known as a reducing valve1 which is in turn connected to the engines1 and more about it will be said a little later4 ,a reducing valve is simply a valve that regulates the amount of air which flows from the tank into the engine and keeps it at the same pressure all the time4 ,if the valve were not used1 the air in the tank1 which is at first under #b1jjj pounds pressure1 would drive the torpedo forward at a tremendous rate of speed at first1 but as the air from the tank was used up by the engine it would lose pressure and the torpedo would soon stop altogether4 ,but when a reducing valve is used the torpedo keeps up its same high speed until it has run its course and has either hit the ship or missed it4 ,what ,is in the ,balance ,chamber4--,in the balance chamber is the mechanism that controls the steering and the diving rudders1 and it is these that keep the torpedo on a straight course and at the right depth under the water4 ,the controlling mechanism is formed of four chief devices1 which are 7#a7 a gyroscope 7pronounced ji-ro-skop72 7#b7 a compressed air motor1 which drives the gyroscope2 7#c7 a water pressure control2 and 7#d7 a pendulum control4 ,the ,automatic ,gyro ,control4--,the gyroscope1 or just gyro1 as it is called for short1 is a kind of spinning top and you can buy a toy one for a quarter4#bb ,it is simply a heavy wheel fixed to a shaft1 or spindle1 and this is pivoted in a ring1 as shown at ,a in ,fig4 #ci4 ,illustration3 ,,fig4 #ci4 ,,the ,,gyroscope4 ,now hold the gyro as shown at ,b and give the wheel a good spin4 ,this done1 walk straight ahead1 and as long as you do so you will hardly know that you are carrying the gyro1 but the moment you try to change your direction you will feel the gyro twisting in your hand to counteract the movement4 ,this is the purpose of the gyro in a torpedo1 but in this case the wheel is very heavy and it is revolved at a high speed by a compressed air motor4 ,the gyro is set with its shaft at right angles with the long axis of the torpedo1 as shown at ,c4 ,now1 just as long as the torpedo moves straight ahead in its course1 the gyro has no effect on it1 but the moment the torpedo tries to swerve from one side to the other1 or shift out of its course1 the gyro pulls it back by acting on the steering rudder2 it does this by regulating the air supply of a compressed air motor1 called the servo-motor1 and this in turn works the rudder by means of a series of levers4 ,in this way the torpedo is automatically kept to its course4 ,the ,hydrostatic1 or ,water ,pressure1 ,control4--,the water pressure control is one of the devices which keeps the torpedo at the right depth in the water4 ,it consists of a steel cylinder with a piston working in it4 ,a cylinder which is open at both ends is set in the hull of the torpedo so that one end opens into the water outside4 ,a spring presses against the piston on the inside of the hull and the water presses on the piston on the outside4 ,the spring can be adjusted by a screw to just balance the pressure of the water at any depth4 ,a small valve rod is fixed to the piston1 and this opens a valve which lets compressed air into a motor when the pressure of the water is greater or lesser than the pressure of the spring and this in turn works the diving rudder as shown in ,fig4 #dj4 ,suppose1 for example1 that the captain wants the torpedo to travel at a depth of exactly #ae feet during its whole course4 ,the spring is adjusted to offset the pressure of the water at this depth1 and the torpedo is launched4 ,should it for any reason try to go deeper than #ae feet or to rise above #ae feet1 the spring or the water presses on the piston and closes or opens the air valve of the motor1 when it moves the diving rudder up or down until the torpedo is brought back to its right depth4 ,illustration3 ,,fig4 #dj4 ,,how ,,the ,,water ,,pressure ,,control ,,acts4 ,the ,automatic ,pendulum ,control4--,the water pressure control1 however1 is not enough to make the torpedo stick to an absolutely constant depth1 and so to help it a pendulum control is also used4 ,this control consists of a pendulum which swings to and fro from fore to aft as the torpedo dives and rises1 and it also starts the compressed air motor which operates the diving rudder1 and this brings the torpedo back to its proper depth4 ,it is shown in ,fig4 #da4 ,the ,engine ,that ,drives the ,torpedo4--,next comes the engine that drives the torpedo1 and it1 too1 is run by compressed air4 ,as ,i mentioned before1 the air which runs it is regulated by a reducing valve1 but there is another important part of the power plant1 and this is the heater for heating the compressed air before it is admitted to the engine4 ,illustration3 ,,fig4 #da4 ,,the ,,pendulum ,,control4 ,compressed air is as good to run an engine with as steam1 for both of them have tremendous powers of expansion4 ,as soon as the air is released from the supply tank--which keeps it compressed in a space that is many times smaller than it would take up when it is free--and has passed into the cylinders of the engine1 it begins to expand1 or to spread out in every direction1 exactly as steam does4 ,now when air is pumped into the tank it gets very hot and this heat is stored up in the air as energy2 this makes the air when it is released expand with much force and gives it the power to do useful work4 ,but as the air is let out of the tank through the reducing valve it expands and loses its energy--or latent heat1 as it is called--and this makes it lose its power to keep on expanding to its greatest extent and so it gets weaker and weaker4 ,to overcome this bad feature of compressed air1 a heater is fixed on the engine1 and just as the compressed air reaches the cylinders of the engine it is suddenly heated and this gives it all the expansive force it needs4 ,the heater consists of a small oil-burner which is so fixed that the instant the torpedo is shot from the tube an electric spark ignites the oil1 and there is1 in consequence1 neither the loss of time nor power4 ,the engine is often of the cylinder and piston type and is built quite like an automobile engine1 except that the inlet valve--which lets the air into the cylinders--is disk-shaped so that it can operate all the cylinders one after another4 ,the exhaust ports open outside of the torpedo1 and it sets up a tell-tale white streak of bubbles on the surface of the water4 ,some torpedoes as1 for instance1 the ,bliss-,leavitt1 use a rotary engine4 ,but whichever kind is used1 the power plant develops from #cj to #ej horsepower1 and thus each torpedo weighs about as much and is as costly as a high-priced motor car4 ,the ,propeller-,shaft and ,propellers4--,the ,propeller-,shaft4--,the engine drives the propeller-shaft1 or1 as it is called in ,england1 the cardan-shaft4 ,to the end of this shaft outside of the torpedo is fixed one of the propellers4 ,another hollow shaft is slipped over the first shaft and one end is connected to the engine and to the other and outside end of the shaft another propeller is keyed on4 ,this shaft is driven in the opposite direction to the solid shaft inside of it by gears that is1 a set of cog-wheels4 ,the ,propellers4--,the propellers have four blades2 and the reason two propellers are used is to counteract the force of each other4 ,that is to say1 if only one propeller is used1 the force of the blades striking the water tends to tilt the craft to one side1 and hence by using two propellers this effect is very largely offset4 ,the ,steering and ,diving ,rudders4--,the vertical or steering rudder and the diving or horizontal rudders are hinged to a frame around the propellers as shown in ,fig4 #db4 ,as it takes a lot of power to move these rudders against the varying water currents1 an air engine must be used to work them instead of levers that are connected directly with the gyro1 pendulum1 or water pressure controls4 ,how a ,torpedo ,is ,shot at a ,ship4--,and now comes the most exciting moment of all1 and that is when a torpedo is shot from a submarine at an enemy ship4 ,the latest type of submarine usually has eight torpedo tubes1 four of them fore1 and four aft4 ,these tubes are shaped as shown in ,fig4 #dc1 and are built right into the hull of the craft4 ,now1 when we say that a torpedo is shot from a submarine we do not mean that it is fired from it1 for it does not explode until it hits the ship it is aimed at1 but we simply mean that it is forced out of1 or driven from1 the tube of the boat4 ,illustration3 ,,fig4 #db4 ,,how ,a ,,real ,,torpedo ,,is ,,made4 ,the force that drives the torpedo from the tube is our old friend compressed air1 and this is taken from the torpedo air tanks of the submarine2 they are placed just above the torpedo tube and are connected with the rear part of it4 ,illustration3 ,,fig4 #dc4 ,,the ,,torpedo ,,tube4 ,shooting the ,torpedo4--,now let's see just what happens from the moment an enemy ship is sighted up to the time the torpedo hits it and explodes4 ,an up-to-date torpedo makes about #dj knots1 and it will travel about six miles before its compressed air is used up4 ,but it cannot be aimed and shot with certainty at a distance of over half a mile4 ,so when an enemy ship is sighted1 the submarine creeps up upon her1 with nothing but her periscope out of the water1 until she is within accurate shooting range4 ,in the meantime the speed of the enemy ship has been calculated1 the depth at which the torpedo must travel to strike the ship below the water-line has been determined1 and the angle1 or course1 the torpedo must take to hit the ship is figured out4 ,due allowance must be made for the speed of the ship and the speed of the torpedo to the end that the distance both will travel in a given time may be known4 ,of course1 if the ship is speeding along and the torpedo is shot point-blank at her it will pass a good many yards astern of her4 ,this operation is very much like that of rabbit hunting1 in which you do not fire directly at the running rabbit1 but aim several feet ahead of him1 and he simply runs into the bullet or shot4 ,so it's all his fault if he gets killed4 ,just so with the ship and the torpedo2 for instead of the torpedo running into the ship1 the ship runs into the torpedo1 and so if the ship sinks it isn't the fault of the torpedo--or at least that is the way the ,german captain of a ,u-boat looks at it4 ,before the torpedo is loaded into the torpedo tube the safety pin is taken out of the firing pin and the butterfly-nut is loosened so that it will unscrew easily4 ,the torpedo is then slipped into the tube and the breach-block of the tube is closed4 ,the compressed air is now turned on at the torpedo air tank2 when the air rushes into the torpedo tube behind the torpedo1 but the latter is kept from being forced out by a lock4 ,the ,course of the ,torpedo4--,next the captain sights his ship and finds its speed and its distance from his own craft4 ,to direct the torpedo so that it will hit her target fairly1 an instrument called a torpedo director is used4 ,it is shown in ,fig4 #dd1 and this picture also shows how the torpedo and the ship come together4 ,illustration3 ,,fig4 #dd4 ,,how ,,the ,,torpedo ,,director ,,works4 ,now as the torpedo tube is fixed in the hull of the submarine the whole craft must be turned and aimed at the enemy ship4 ,to do this the torpedo arm of the director is set parallel with the torpedo tube2 then the torpedo speed scale is adjusted at the speed that the torpedo makes and which is known4 ,the speed of the distant ship having been calculated1 the ship speed scale is set at that speed and parallel to the ship's course1 and this brings the sight arm in line with the observer's eye and the line that the ship is sailing4 ,when the ship crosses the line of sight the catch of the lock is released1 the compressed air blows the torpedo out of its tube1 and away she goes4 ,the instant the torpedo has left the tube the engine and other contrivances start to work and it then moves swiftly and surely over a straight course4 ,illustration3 ,,fig4 #de4 ,,the ,,gardiner ,,current-,,controlled ,,torpedo4 ,long before the torpedo reaches its goal the butterfly-nut drops off1 and so when it strikes the ship the firing pin which projects out of the warhead is pushed back with a deal of force and explodes the charge which either sinks the ship or cripples it4 ,a ,torpedo with a ,cannon in ,it4--,lieutenant ,davis1 of the ,u4 ,s4 ,n41 has invented a new kind of warhead for torpedoes1 one that is even more deadly than the style ,i have described4 ,it is made by placing a cannon in the warhead4 ,when the torpedo strikes the ship the cannon shoots a projectile clear through the hull and into the inside of the ship1 where it explodes4 ,as the projectile is fitted with a time fuse1 it does not explode until it gets well into the ship1 and then it does far more damage than the old-style of warhead1 which explodes just as it strikes the hull4 ,the projectile is loaded with #bej pounds of guncotton or ,,tnt but the warhead is not loaded at all4 ,on the submarines that are now being built cradles which hold several extra torpedoes are fitted to the decks1 and in this way the number of torpedoes which can be shot is increased4 ,,chapter ,,vi ,,making ,,the ,,submarine ,,deadlier ,other ,armament of the ,submarine1 ,including a ,complete ,description of ,how the ,guns ,are ,made1 ,housed1 and ,used ,,chapter ,,vi ,,making ,,the ,,submarine ,,deadlier ,,it would naturally be supposed that a submarine carrying eight or more torpedoes is about as destructive an engine as human ingenuity could devise2 but not so1 for there are other munitions of warfare with which it is equipped that make it even deadlier4 ,now1 the word munitions means war materials of every kind--except1 of course1 men and money2 but on a submarine the munitions are limited to 7#a7 the automobile torpedo1 which we have described in the last chapter2 7#b7 rapid-fire machine guns1 and 7#c7 submarine mines4 ,in the present war ,germany has undertaken the gigantic task of sinking all the merchantmen1 not only of the ,allies but of the neutral countries as well1 and it is this ,u-boat policy which has brought her into a state of war with nearly every civilized country on the face of the earth4 ,as the torpedo is such a costly weapon1 it would not do to waste it on sinking any but the largest ships1 or those carrying valuable cargoes2 but the same policy of ,germany1 which is to starve out the ,allies1 also calls for sinking the smaller craft1 such as trawlers and unarmed merchantmen1 and this is done by means of rapid-fire machine guns4 ,these guns are mounted fore and aft on the deck of the submarine1 and they are used to bring down small ships and also to enable the undersea craft to defend herself against submarine chasers1 airplanes1 or occasionally when she is surprised by a destroyer or other armed ship which may get within firing range and attack her before she has time to dive4 ,the submarine mine is as old as1 or older than1 the submarine boat itself2 and it was probably the idea of fixing a bomb onto or planting a mine under a ship that led to the actual building of the first underwater craft4 ,the mine is not1 however1 an explosive destroyer which is used by the submarine boat2 for she could never get close enough to an enemy ship in these days of electric eyes and ears to make use of one4 ,what the submarine does do is to play the peaceful rle of planting the mines--not with the idea of making two grow where only one grew before but of making one ship less where there was one ship more1 and this is done by blowing up the enemy ships which may chance to pass over them4 ,arming the ,submarine with ,guns4--,from what has been said above1 you will see that by the use of rapid-fire guns poor prizes can be easily and cheaply sunk2 further1 a small craft always makes a bad target for a torpedo and thus the odds of making a miss and losing a torpedo are very considerable4 ,the use of rapid-fire guns is1 then1 a very good stroke of business1 everything considered4 ,again1 when a submarine is chased and has no time to dive1 she is in a bad way1 for she is not fast enough to escape1 nor can she stop long enough to aim a torpedo at her foe4 ,it is easy to see1 then1 why her armament#bc should and does include a couple of rapid-fire guns4 ,the ,need of a ,quick-,action ,gun4--,with these conditions staring them in the face1 the designers of submarines have worked hard to equip their craft with not only rapid-firing but1 what is equally as important1 quick-action guns4 ,to get a rapid-fire machine gun was easy1 for this type had been built by the ,maxims these many years2 but to get one that could be swung or lowered under the deck so that it would not offer resistance to the water when the submarine was running submerged1 and then brought up and into action quickly1 was quite a different thing1 and inventors are still at work on it4 ,by this ,i do not want you to take it that submarines are not provided with rapid-fire and quick-action disappearing guns at the present time2 and should you or ,i take a look at them we would say that they are #ii per cent4 perfect and that there is no need for further improvement4 ,but that is because we are neither designers1 nor builders1 nor officers of undersea craft2 and do not forget1 either1 that better things are always in order4 ,now1 there are two kinds of rapid-fire1 quick-action guns used for submarine armament and these can be told from each other by the way they are brought into action4 ,they are 7#a7 the spring action gun1 and 7#b7 the compressed-air action gun4 ,the ,spring ,action ,gun4--,this type of submarine gun is made by the ,krupps of ,essen1 ,germany1 who now are building the ,u-boats for the ,central ,powers4 ,this gun is mounted on the deck1 over an opening in it called a deck-well1 and this arrangement allows the gun to be stowed away in it4 ,this is done to get rid of the resistance the water would have on the gun if it remained fixed on deck when the boat is running submerged4 ,although the deck-well is closed with hatches it is not watertight1 and the fittings1 such as the sights and range finders1 are taken off to keep them from rusting when the gun is in the well4 ,a diagrammatic sketch of the gun and its housing is shown in ,fig4 #df2 the gun is mounted on a swinging frame by trunnions1 and the frame is fixed to a pedestal4 ,a strong spring in the bottom of the well supplies the power needed to throw the gun up and bring it into position4 ,when housed in the well the gun lays on its back1 as shown by the dotted lines1 and this presses down on the spring4 ,the tension of the spring is enough to force the gun up and into place the instant the catch which holds it is released4 ,illustration3 ,courtesy of ,scientific ,american ,a #c ,,inch ,,submarine ,,gun ,,in ,,action ,,showing ,,the ,,deck ,,well ,,and ,,manner ,,of ,,operation ,the sights and other attachments are fixed on the gun after it is brought into position and the whole operation of raising the gun from its well and putting on the fixtures takes just #bj seconds4 ,illustration3 ,,fig4 #df4 ,,how ,,the ,,krupp ,,or ,,german ,,submarine ,,gun ,,is ,,mounted4 ,these guns have a bore of #ge millimeters#bd--;equal to #c inches--and #hh millimeters--equal to #c inches--respectively1 and the shells they use weigh in the neighborhood of #be pounds4 ,the ,compressed ,air ,action ,gun4--,this kind of submarine gun is used on ,british undersea boats4 ,it is mounted over a deck-well but inasmuch as the gun is lowered into the well with all the fittings on it the well has to be made watertight4 ,if you will look at ,fig4 #dg1 you will see how the gun is brought into action4 ,when compressed air is turned on in the cylinder1 it forces the plunger on which the gun is mounted up above the level of the deck4 ,the gun is fitted with fixed sights and a range finder1 and is ready for use the moment it has been brought into place above the deck1 the whole operation taking only #e seconds4 ,illustration3 ,,fig4 #dg4 ,,british ,,and ,,american-,,style ,,deck ,,gun4 ,the guns of the ,allies' submarines have bores of #c and #d inches1 and each one weighs nearly a ton4 ,as a protection from enemy aircraft they have a wide range and can1 if needs be1 fire a shot at #ij degrees1 that is1 straight overhead4 ,how a ,submarine ,lays ,mines4--,the dangerous work of laying mines in an enemy harbor by a submarine is not as spectacular as torpedoing ships but it is an important part of the business of undersea craft4 ,a harbor which has been planted with mines to keep out enemy ships or blow them up if they try to enter it is often remined overnight by enemy submarines1 and in this way a great deal of damage can be done to friendly shipping4 ,but whether the submarine is used for mining its own or enemy harbors1 the outstanding feature of its work is that it does it all under water and therefore the operations cannot be seen by spying eyes4 ,as we said in ,chapter ,,iii1 the mines are stored in a compartment in the hull of the submarine and this can be shut off from the other compartments by a bulkhead door4 ,it also has a hatch opening through the hull to the water outside1 just as the door of a kitchen opens into the back yard4 ,when the submarine has made its way under water to the place where the mines are to be planted1 the hatch is opened and the mine compartment is allowed to fill with water4 ,a mine layer in a diving suit can then get in and out of the flooded compartment1 take the mines one by one through the open hatch1 and place them in position4 ,then there are mines which do not need to be set by a mine layer2 these are simply dropped through the hatch into the water and adjust themselves as to depth4 ,other mines are made that are shot from the torpedo tubes by compressed air and these are used for mining an enemy harbor where the risks of having the submarine blown up is altogether too great to take the chance4 ,kinds of ,submarine ,mines4--,submarine mines--that is1 mines that are planted in harbors and other seaways1 either as a protection from enemy ships or as an offensive measure to blow them up--really have nothing to do with submarine boats except that the latter are used to lay them4 ,but you ought to know about submarine mines1 anyway1 and so we'll digress a little and tell you something of them4 ,first of all1 there are two distinct kinds of mines and these are1 7#a7 contact mines1 and 7#b7 electrically controlled mines4 ,as you can tell by its name a contact mine is one that is exploded by the hull of a ship coming in contact with it--that is1 by running against it4 ,this is the kind of mine that is most often laid by the submarine4 ,an electrically controlled mine is one that is exploded by electricity4 ,for this purpose a pair of wires are connected to it and these lead along the bottom of the harbor to two observation stations on the shore2 when the enemy ship gets directly over the mine the observers close the electric circuit and the mine is exploded4 ,this is the way the ,maine was sunk in ,havana harbor in #ahih1 but the ,maine was not an enemy ship4 ,the result of this rash bit of foolishness led to the war between the ,united ,states and ,spain1 and the loss of her island possessions4 ,how the ,mines ,are ,made4--,the contact mine4--,this kind of a mine consists of a steel shell1 or container1 which holds the charge of high explosive1 the trigger mechanism which explodes it when a ship strikes it1 and the weights and cables needed to sink the mine to the right depth4 ,air chambers are also placed inside the container1 to give the mine buoyancy2 otherwise it would sink at once to the bottom of the sea4 ,illustration3 ,,fig4 #dh4 ,a ,,simple ,,contact ,,mine4 ,in the contact mine the detonator is formed of an arm1 or lever1 called a striker1 and this projects through the shell to the outside4 ,when a ship strikes the arm it drives a firing pin against a percussion cap and explodes it1 and this in turn fires the explosive charge in the mine4 7,see ,fig4 #dh47 ,how the ,contact ,mine ,works4--,the way the mine works is like this3 ,before it is taken out of the compartment of the submarine it is adjusted to float at the proper depth4 ,when the mine is in the water a weight that it carries is released and sinks to the bottom2 the cable which connects the weight and the mine together holds the mine in the right position1 while the air tanks in the mine make it rise as high as the cable will let it go1 as shown in ,fig4 #di4 ,after the mine is planted1 the submarine steals silently and invisibly away4 ,when an enemy ship--or any other1 for that matter1 for the contact mine is no respecter of ships--strikes the trigger of the mine1 it explodes the charge1 and there is one less ship to sail the turquoise seas4 ,the ,electric ,controlled ,mine4--,to the end that a harbor can be planted with mines which will blow up enemy ships and yet be harmless to friendly ships1 mines fired by electricity from the shore were invented4 ,illustration3 ,,fig4 #di4 ,,how ,,the ,,mine ,,adjusts ,,itself4 ,mines of this kind are made about like contact mines in that they contain an explosive charge and a detonator1 but they are much larger and far more powerful1 for they have to be laid on the bed of the harbor1 and instead of being fired by a pin striking a percussion cap they are fired by an electric spark4 ,from each mine laid in the harbor a pair of insulated copper wires run to the shore1 and this electric circuit connects with two shore stations at a distance apart and which with the mine form a triangle4 ,the electric circuit has a key in it at each shore station1 and to explode the mine both of these keys must be pressed down at the same time4 ,illustration3 ,,fig4 #ej4 ,,how ,,the ,,electric ,,mine ,,works4 ,each shore station has a telescope fixed in position so that its line of sight 7shown by the dotted lines in ,fig4 #ej7 passes directly over the mine4 ,now when an enemy ship approaches1 each observer will see it when it sails on or across his line of sight and he will press his key4 ,but it is necessary that both observers see the ship at the same time that it is at the point where their lines of sight cross1 and consequently directly over the mine1 and when this happens they will both press their keys1 the circuit will be closed1 the electric current will fire the mine1 and the ship will change her course to one straight up and speed with all possible haste to the port whence no ship ever clears again4 ,,chapter ,,vii ,,the ,,wonderful ,,eye ,,of ,,the ,,submarine ,a ,complete ,description of ,how to ,make a ,model ,periscope with ,working ,drawings ,together with a ,simple ,explanation of ,how a ,real ,periscope is ,made ,and ,works ,,chapter ,,vii ,,the ,,wonderful ,,eye ,,of ,,the ,,submarine ,,one of the gravest faults the pilots of the first submarines had to contend with was that they were not able to see where their craft was going4 ,but like everything else that is needed for the welfare or warfare of the human race1 inventors got busy and began to scheme and to experiment1 with the big idea of making an instrument which would do for the submarine what the eye does for the brain1 and that is to look around with4 ,how the ,eye of the ,submarine ,got ,its ,name4--,now1 the eye of the submarine is called a periscope and before we go any further let us find out how it came to get this peculiar name for then we shall know more of what we are talking about4 ,the early ,greeks used two words that were very common to them1 and you1 too1 will use them1 before you get through with this chapter1 just as easily as they did4 ,one of these words is peri which means around1 and the other is scope which means to look2 so peri plus scope means to around look1 or1 as we barbarians say it1 look around--which sounds better to us4 ,and there you have the roots of the word periscope4 ,the ,first ,submarine ,eye1 or ,periscope4--,as in the beginning of all things1 good and evil1 the first attempts to make an eye for the submarine1 or a periscope1 were very crude1 and as usual they were nearly1 if not quite worthless4 ,but the periscope was no exception to the first law of invention1 and that is that each attempt1 however much of a failure it may have been in itself1 had the germ of a useful device in it2 and from out of all these efforts finally came that wonderful optical instrument1 the periscope4 ,we say wonderful because with it an observer in the conning tower of a modern submarine1 though it is all but submerged1 can see everything that is taking place on the surface of the water around the whole horizon4 ,the earliest trials at making a periscope were by using a simple arrangement of mirrors of an 8,l0 tube and each at an angle of #de degrees4 ,the best way to understand its construction is to make one for yourself4 ,how to ,make a ,simple ,periscope4--,you can get a lot of fun out of this home-made periscope1 and with it you can out-sherlock ,sherlock ,holmes1 the great detective who was invented by ,conan ,doyle1 for you can see around corners1 over fences1 and even back of yourself just as though you had a movable third eye1 and without so much as ever being seen yourself4 ,make a tube of wood or cardboard #b inches square and #ab inches long1 as shown in ,fig4 #ea4 ,fit two square pieces of looking-glass into the corners of the tube at #de degrees--that is half way between the vertical and the horizontal--and your periscope is finished and ready for use4 ,illustration3 ,,fig4 #ea4 ,,how ,,to ,,make ,a ,,simple ,,mirror ,,periscope4 ,how the ,periscope ,works4--,when1 now1 you hold the long tube of your periscope in a vertical position that is straight up and down1 and the light from an object1 a person1 or a scene at which the upper horizontal tube1 or objective1 as it is called1 is pointed1 strikes the first mirror1 it bends the rays of light at an angle of #ij degrees1 when the light goes straight down the tube as shown by the arrows in ,fig4 #ea4 ,when it strikes the other and lower mirror1 the rays of light are again turned out of their path at an angle of #ij degrees1 when they are reflected out of the lower horizontal tube which forms the eye-piece4 ,if now you will place your eye to this end of the tube1 you will be able to look all around and see what you shall see4 ,see8 ,the ,modern ,lenticular#be ,periscope4--,the toy periscope which we have just described1 and which we hope you will make and use1 does not show what is going on at any great distance1 and while this will not interfere with your pleasure of using it1 it mattered very greatly when it was used as an eye for a submarine craft4 ,to be able to see farther led to the idea of using a telescope in connection with the mirrors in the tube1 and a periscope of this kind was next made and tried out1 and1 let it be said1 the results obtained were a decided improvement as against those where mirrors alone were used4 ,how the ,telescope ,is ,made4--,you may or may not know it1 but an ordinary telescope1 or spy-glass1 as it is called1 is made up of four lenses1 as shown in ,fig4 #eb4 ,the purpose of the large lens in the front end of the tube--or object glass1 to call it by its right name--is to gather in the light of the object and form an image of it4 ,the small lens in the back end of the tube is used to magnify the image formed by the object glass4 ,now1 when a telescope has only an object-glass and an eye-piece1 the magnified image of the object looked at is always upside down2 this is the kind of telescope that astronomers use in their star work and the fact that the image is reversed doesn't really matter anyway because the man in the moon looks about as well when he is standing on his head as he does when he is right side up4 ,illustration3 ,,fig4 #eb4 ,,how ,,an ,,ordinary ,,terrestrial ,,telescope ,,is ,,made ,,and ,,works4 ,but when you want to look at objects here on the earth's surface you want to see them as they are and not upside down4 ,to rectify the image1 which means to make the eye see the object as it is1 two more lenses are placed in the tube1 and so four lenses are used in all4#bf ,about the ,reflecting ,prisms4--,the next big improvement in periscopes came when a total reflecting prism was used in the place of the mirror at each end of the tube4 ,in physics the terms total reflecting means simply that all of the light that strikes a surface is reflected again without loss4 ,while a mirror will reflect only a part of the light that falls on it1 a prism will reflect all of the light that enters it4 ,illustration3 ,,fig4 #ec4 ,,the ,,reflecting ,,prism4 ,a prism is a three-sided piece of glass1 if you forget to count the ends1 as shown at ,a in ,fig4 #ec4 ,when a ray of light enters1 say1 the vertical side of the prism it keeps on going until it strikes the #de-;degree side of it2 this side reflects and bends it and it passes out of the horizontal side1 as shown at ,b4 ,the ,construction of the ,periscope4--,knowing now how a telescope is made and what it does and also knowing what a prism is and how it acts on light1 all you have to do to understand the construction of a submarine periscope is to take a good look at ,fig4 #ed4 ,you will see that a prism is fixed in the upper end of the tube and directly back of the object-glass2 that another prism is fixed to the lower end of the tube and back of the eye-piece2 and that the rectifying lenses of the telescope are set between these two prisms4 ,this picture also shows the path of the light through it4 ,illustration3 ,,fig4 #ed4 ,,how ,a ,,modern ,,periscope ,,is ,,made ,,and ,,works4 ,these lenses and prisms are mounted in a tube about #d inches in diameter and #bj feet long4 ,a horizontal revolving hood is secured to the upper end of the tube and the horizontal eye-piece is fastened to the lower end of it2 a wheel is also fixed to the lower end of the tube1 so that the observer can turn the periscope completely around and so scan the surface of the sea in any direction4 ,the periscope tube is placed in a slightly larger and very strong steel tube1 which passes through the deck of the conning tower and into the latter1 and it is made watertight by means of a stuffing-box4 ,the reason it is necessary to have a fixed outside tube is because the force of the water1 when the craft is submerged and is speeding along under power1 presses against the tube so hard that if only the inside one were used it would bind2 as it is1 there is no pressure on the inside tube and it can therefore turn freely at all times4 ,all recently built submarines have two periscopes1 one of which leads into the conning tower and the other one runs down into the navigating room4 ,hence if one or the other is put out of commission by shell-fire1 or otherwise1 the submarine can still see and find its way about4 ,gauging the ,distance of an ,enemy ,ship4--,an instrument called a telemeter 7pronounced te-lem-e-ter7 is attached to the periscope near the eye-piece1 and the observer can by looking into it measure the distance away of an enemy ship4 ,this is done from the size of the image it makes on the eye-piece4 ,without this instrument the whole submarine1 as large1 as wonderful1 and as costly as it is1 would be of small value1 for by it the captain is able to set his torpedo director very accurately and hence to aim the torpedo so that it will make a sure hit4 ,illustration3 ,courtesy of ,scientific ,american ,,the ,,latest ,,type ,,of ,,periscope4 ,a ,,much ,,magnified ,,image ,,of ,,the ,,object ,,is ,,shown ,,in ,,the ,,inner ,,circle1 ,,while ,,in ,,the ,,outer ,,circle ,,is ,,shown ,,the ,,object ,,plus ,,an 8,,all ,,round0 ,,view ,,of ,,the ,,horizon4 ,a ,,submarine ,,fitted ,,with ,,this ,,periscope ,,may ,,well ,,be ,,said ,,to ,,have ,,eyes ,,in ,,the ,,back ,,of ,,its ,,head ,the ,latest ,type of ,periscope4--,as the periscope just described1 and which is still in use on submarines1 has a very limited field of vision at any given setting--that is to say1 only about th of the horizon can be seen when the instrument is pointed one way--and as a periscope which would show the whole horizon at the same time was badly needed1 a ,british firm of opticians set out to invent one4 ,the hardest part of the task was not to get a complete view of the whole horizon at the same time but to prevent the rays of light which form the images from getting mixed up with one another1 or interfering1 and so producing a blurred and indistinct picture4 ,the new complete-view periscope differs from the older style only in having a circular lens and prism2 these gather in the light1 bend the rays and project them on down through the telescope lens until they reach the lower prism when all of the images are reflected into the eye-piece where the observer sees it as a circular picture4 ,this new improved form of periscope is of great value1 for it gives a safety-first view on all sides of the submarine at the same time and the observer does not need to keep turning the eye-piece1 and this is of great value when a submarine is being closed in on by two or more enemy ships4 ,it is a well-known fact that a large number of submarine accidents have been caused by the limited range of view offered by the old-style periscope1 and in some cases the undersea craft has been rammed or sunk by gun-fire from an enemy ship which she did not see4 ,the new periscope makes it impossible for a destroyer to creep up on the submarine without being caught in the act4 ,nearly all of the undersea craft now being turned out by all of the warring nations are fitted with the new #cfj-;degree#bg vision periscope4 ,the ,limited ,use of the ,periscope4--,notwithstanding all these latest improvements in the periscope1 its use is quite limited1 for it can be used only when the submarine is running awash or partly submerged1 and since the tube of the instrument is only #bj feet high the distance to which a ship can be seen is about five miles4 ,when running partly submerged the tube of the periscope sticks up and out of the water about #aj feet1 when the distance range of vision is then cut down to about two miles1 for the curvature of the earth's surface meets the line of sight and everything that is at a greater distance than this from the submarine is below the horizon and hence invisible4 ,should an enemy destroyer get within firing range of the submarine and the captain of the latter craft wants to watch it1 only the hood of the periscope is poked up above the water2 but of course the distance range is again cut down4 ,the captain of a submarine has to contend with all these adverse features of the periscope even on bright1 clear days and when the sea is calm2 on dark and foggy days1 when a heavy sea is running1 the periscope is next to useless1 for the mist and spray gather on the objective lenses and this makes it next to impossible to see anything4 ,worst of all are the waves which break over the periscope1 and this prevents a ship from being seen even if it is only a little way off4 ,it is in rough weather that a submarine takes the longest chances2 but to put behind him any danger that may be lurking hard by1 the captain prefers to run undersea and come to the surface only when he has to4 ,a scheme to clear the moisture from the objective lenses is a device called a sprayer4 ,it is made and worked so that an observer at the periscope can spray the lenses with alcohol4 ,as water has a very great liking--or affinity1 as it is called--for alcohol1 and as alcohol evaporates almost instantly it carries the particles of water off with it1 and this helps to make the seeing better4 ,the ,new ,enemy of the ,submarine4--,a new enemy of the submarine has recently made its appearance--an enemy that will make it use a periscope of a new order4 ,this latest submarine destroyer is the airplane2 and as the captain cannot now see directly overhead except when his boat is running light or awash1 and the pilot of an airplane can see the submarine when it is submerged to a very considerable depth1 it is easy for him to follow the undersea craft until she comes to the surface and then drop a bomb on her4 ,a story of a running fight between an airplane and a submarine would have put it in ,col4 ,roosevelt's ,ananias ,club a few years ago1 but to-day it has all come to pass1 and it looks now as if a good way to break the backbone of ,germany's ruthless warfare on the sea is to destroy the ,u-boats with a fleet of airplanes4 ,,chapter ,,viii ,,the ,,marvelous ,,tongue ,,and ,,ears ,,of ,,the ,,submarine ,a ,simple ,explanation of ,all the ,devices by ,which the ,submarine ,sends and ,receives ,signals1 ,when on the ,surface and ,undersea ,,chapter ,,viii ,,the ,,marvelous ,,tongue ,,and ,,ears ,,of ,,the ,,submarine ,,since a submarine has an eye to see with1 it is both proper and fitting that it should have a tongue so that it may speak and ears so that it may hear4 ,in fact1 an undersea boat is almost human4 ,the early submarine1 though1 was not only as blind as a cave fish1 but it was as deaf and as dumb as a snail2 and since this was the case1 it had to do whatever talking was necessary by means of a deaf and dumb alphabet1 that is1 by signaling with flags1 or wigwagging1 as it is called4 ,the ,tongue and ,ears of a ,submarine4--,the tongue of a submarine--or rather tongues1 for it has several--is the fanciful name ,i have given to the means1 methods1 and schemes by which messages are sent from one submarine to another submarine or to shore1 and the ears are the devices by which it receives messages from other submarines and from shore stations4 ,there are two conditions under which messages must be sent from and received by a submarine1 and these are 7#a7 when she is running light or awash1 and 7#b7 when she is running submerged4 ,now1 most of the signaling systems can be used only when the submarine is on the surface1 and a couple of them can be used only when she is under water4 ,then1 again1 some systems are good only for daylight signaling1 and others for night signaling2 others will cover very short distances1 but there are systems that will send and receive over long distances4 ,but whatever the system may be there will be found some weak point in it as far as the submarine is concerned4 ,kinds of ,signaling ,systems4--,since no one signaling system will meet the rigid requirements of the submarine1 several systems are used4 ,when the craft is on the surface1 these are3 7#a7 the flag1 or wigwag1 system2 7#b7 the flashlight system2 and 7#c7 the wireless telegraph system4 ,when the submarine is under water the signaling systems used are3 7#a7 the bell1 or violin1 system2 and 7#b7 the electric current system--all of these will be described in order and as we go along4 ,the ,wigwag ,way of ,signaling4--,the oldest way of sending messages at sea is by wigwagging1 that is1 using flags1 and this system is still in use in the navies of all nations for close range daylight communication4 ,the way wigwagging is done is like this3 ,each craft has a signal book which gives the positions of the flags and the meaning of them4 ,these flags are usually manipulated by a signalman 7see ,fig4 #ee7 though sometimes a mechanical apparatus called a semaphore1 which has two movable arms to hold the flags1 is used4 ,illustration3 ,,fig4 #ee4 ,,signaling ,,by ,,means ,,of ,,flags4 ,two flags are used1 one in each hand or on each arm1 and each position of the flags means a letter of the alphabet1 and so by showing the flags in various positions to represent different letters words are spelled out4 ,another scheme that is used to signal with flags is by running1 that is displaying1 a number of different colored flags on a halyard4 ,the combinations of flags--or to use the right word1 permutation1 which means the number of different arrangements of a few flags that are possible--are numerous and each permutation represents some word or a sea-term4 ,now1 you might think that it would take a couple of hundred flags of different colors to represent a message1 and1 further1 that since there are only eight colors which can be told from each other at a distance of half a mile1 signaling by colors could not be done4 ,but this is what you think1 and not what you have figured out1 for if you have eight flags of different colors and display them1 four at a time1 on the signal halyard you can make the surprising number of #afhj permutations2 and this1 you will allow1 is enough to say anything that you may have to say4 ,although a code book is found in every signalman's outfit1 he is a chap who knows all the signals by heart and can send and receive flag messages almost as fast as you can write down the words4 ,the ,flashlight ,system4--,there are two methods used for sending signals at night over short distances1 and both are done by means of light2 named1 these are 7#a7 the colored light system1 and 7#b7 the searchlight system4 ,the ,colored ,light ,system4--,in this system incandescent electric lights of high candle power are placed back of bull's-eyes1 or lenses1 made of colored glass1 and these lights can be switched on and off and so form combinations that spell out words just as the colored flags do4 ,this system is very much used for short range signaling at night4 ,the ,searchlight ,system4--,a searchlight1 that is an electric arc light set in front of a silvered reflector1 can be seen for long distances1 and so it1 too1 is largely used for night signaling4 ,the searchlight1 which can be turned in any direction1 has a movable shutter1 or metal disk in front of it1 fixed to a handle1 and when this is worked up and down like a telegraph key1 the shutter cuts the light off and lets it shine forth accordingly4 ,by working the key1 and hence the shutter1 the light is broken up into dots and dashes of the regular ,morse telegraph alphabet1 and these short and long flashes are read by the operator on the other boat4 ,the ,wireless ,telegraph ,system4--,the wireless telegraph has all the other systems of signaling1 when the submarine is afloat1 beaten by miles4 ,among its advantages are 7#a7 it can be used in the daytime as well as at night2 7#b7 the electric waves it sends out cannot be seen and this makes it harder for an enemy ship to locate the boat it is on1 and 7#c7 its signaling range is not cut off by the curvature of the earth4 ,the ,parts of a ,wireless ,system4--,there are three chief parts to every wireless telegraph system1 and these are 7#a7 the sending apparatus1 or transmitter1 as it is called2 7#b7 the receiving apparatus1 or receptor1 as some 8high-brow0 has named it2 and 7#c7 the aerial wire1 which is used for both sending and receiving4 ,illustration3 ,,fig4 #ef4 ,a1 ,,the ,,transmitter ,,ready ,,to ,,send4 ,b1 ,,the ,,receiver ,,ready ,,to ,,listen ,,in4 ,the sending apparatus is made up of 7a7 a source of current1 which on a submarine is the storage battery2 7b7 an induction coil2 7c7 a telegraph key2 7d7 a tuning coil2 and 7e7 a condenser4 ,the receiving apparatus is formed of 7a7 a tuning coil2 7b7 a condenser2 7c7 a detector2 and 7d7 a pair of head telephone receivers4 ,a wireless telegraph set is shown in ,fig4 #ef1 ,a and ,b4 ,both the sending and the receiving apparatus can be connected with the aerial wire by means of what is called a throw-over switch1 the purpose of which is to connect the aerial to the transmitter when messages are to be sent out and to connect the aerial to the receiver when messages are to be received4 ,thus only one aerial is needed4 ,how ,wireless ,works#bh--,when a wireless message is sent the operator makes and breaks up the current from the storage battery into dots and dashes by means of the telegraph key4 ,this interrupted low pressure current flows through the induction coil and this changes it into a high pressure current which makes a jump spark4 ,the spark in turn changes the high pressure current into high frequency currents1 or electric oscillations1 as they are called2 and as these run forth and back over the aerial wire they set up waves in the ether which are called electric waves4 ,these electric waves are exactly like light waves1 but they are so long that the eye cannot see them4 ,the tuning coil and the condenser are used to give the waves whatever length the government says they must have4 ,when the electric waves that are sent out by the aerial of the transmitting station strike the aerial which is connected with the receiving apparatus of another ship and the operator is listening in1 the waves are changed back again into high frequency currents1 and these run to and fro on the aerial wire and up and down through the tuning coil1 the condenser and the detector4 ,the latter instrument changes the high frequency currents1 which are alternating1 into an interrupted direct current2 and these in turn energize the telephone receiver1 with the result that the dots and dashes sent out by the sending operator are reproduced by the telephone receiver1 when they are heard by the receiving operator who is listening in4 ,the tuning coil and condenser enable the operator to tune his receiving apparatus to the length of wave which the transmitting station is sending out1 and this operation is called tuning in4 ,the wireless station of a submarine is usually located in the navigation compartment4 ,although the aerial is neither high nor long1 messages can be sent to upwards of two hundred miles and received over much greater distances4 ,wireless allows the submarine not only to keep in touch with its base but also to pick up and intercept messages from enemy ships1 and though the operator may not be able to decipher them it is possible for him to determine in about what direction and at about what distance the ship is4 ,illustration3 ,courtesy of ,hilbourne and ,clark ,mfg4 ,co4 ,a ,,marine ,,wireless ,,installation ,another use to which wireless is put is signaling between submarines that are doing patrol duty at the same time but which are too far away from each other to use either flags or lights4 ,wireless telegraphy cannot1 however1 be used when the submarine is under water1 for water absorbs the electric waves in exactly the same way that it absorbs light waves4 ,but taken all in all1 wireless is by far the most important of all the signaling systems yet invented1 and it is the only one by which messages can be sent and received by either day or night1 over long distances and in any kind of weather4 ,underwater ,signaling ,systems4--,as ,i have said before1 there are two kinds of signaling systems used by a submarine when it is under water4 ,while both systems leave much to be desired--for neither can begin to come up to wireless1 either in ease of operation or in signaling range--as they are the only known means by which underwater communication is possible1 there is nothing to do but to use them4 ,the ,bell or ,violin ,system4--,this is a signaling system that is widely used on ocean going vessels of all kinds to send out warning signals in thick weather4 ,it is a system in which a large bell or other vibrating apparatus sets up sound waves which travel in every direction through the water2 when these waves reach another craft they are heard by means of a telephone receiving apparatus4 ,now1 water will carry sound about ten times as far and four times as fast as air2 that is to say1 if a bell is struck a blow in air and the sound waves it sends forth can be heard a distance of half a mile1 then the same bell if it is struck when it is submerged in water will send out waves to a distance of five miles4 ,illustration3 ,,fig4 #eg4 ,,the ,,submarine ,,bell4 ,the sending apparatus consists of either a bell 7see ,fig4 #eg71 the striking mechanism of which is worked by electricity1 or of a large saw-toothed wheel which revolves rapidly against a tight wire and in consequence sets up a musical note4 ,this latter kind is called a violin transmitter4 ,whichever is used is lowered through a hatch in the hull of the submarine1 and the bell is rung or the wheel is rotated by an electro-mechanism1 which sends out sound waves to distances of from #e to #ae miles4 ,the receiving apparatus 7shown in ,fig4 #eg7 is formed of an ordinary telephone transmitter1 and this is fixed in a small iron tank filled with water and bolted to the inside of the skin of the hull4 ,there is one of these transmitters on each side of the ship1 and each one is connected with a battery and a pair of head telephone receivers placed in the navigating compartment4 ,illustration3 ,,fig4 #eh4 ,,how ,,the ,,sending ,,and ,,receiving ,,bell ,,system ,,works4 ,when the bell or violin of another submarine1 or the base ship1 sends out its message in the ,morse alphabet the sound waves1 as you will see by looking at ,fig4 #eh1 travel through the water and strike the hull of the ship1 go through its skin1 set the water to vibrating in the tank1 and this1 acting on the telephone transmitter1 makes it vary the electric current of the battery2 the varying current flowing through the telephone receivers reproduces the distant sound of the bell or the violin wheel1 and the operator on the submarine hears it4 ,the receiving apparatus also serves to detect the presence of an enemy ship when it comes within torpedoing range by the sound waves set up by and by which are sent out through the water by the rapid turning of the ship's propellers4 ,the ,electric ,current1 or ,conductivity1 ,system4--,in this submarine telegraph system the water1 which is a fairly good conductor of electricity1 is made to carry an ordinary battery current between the sending and the receiving stations4 ,illustration3 ,,fig4 #ei4 ,,the ,,underwater 8,,wireless40 ,since the water conducts the current of electricity1 it is easy to see why it is called a conductivity system4 ,it is also called an underwater wireless system1 but while it is wireless in the sense that there are no connecting wires between the two stations1 you must not confuse it with the real wireless system1 which uses electric waves1 for in the former the energy decreases as the cube of the distance and in the latter only as the square of the distance4 ,the ,parts of the ,conductivity ,system4--,there are three principal parts to this system1 and these are 7#a7 the sending apparatus2 7#b7 the receiving apparatus1 and 7#c7 the submerged copper plates which conduct the current from the sender into the water and from the water into the receptor4 ,the sending apparatus consists of 7a7 a source of direct current1 and the storage battery supplies this2 7b7 a reactance1 or kick coil1 as it is commonly called2 7c7 a rotating interruptor1 and 7d7 an ordinary telegraph key4 ,the receiving apparatus is made up of 7a7 a telephone induction coil1 and 7b7 a pair of head telephone receivers4 ,all of this is shown in ,fig4 #ei4 ,one of the submerged copper plates is fixed to the bow of the submarine's hull1 and the other is secured to the stern1 in order to get the plates as far apart as possible4 ,these plates are connected to a throw-over switch1 so that either the sender or the receptor can be connected to the plates as the operator wishes4 ,how the ,system ,works4--,the instruments of the sending apparatus are connected up as shown in ,fig4 #ei4 ,now when a message is to be sent from one submarine to another1 the operator sets the rotary interruptor1 which is run by an electric motor1 to spinning1 and this makes and breaks the current several hundred times a minute as long as he holds the key down which closes the circuit4 ,the result is that each dot and dash he makes is formed of a large number of separate currents1 and as these flow through the reactance coil1 it gives each one a little kick and sends it out into the water through the copper plates2 the currents then spread out between and from the plates in closed lines which extend to very considerable distances1 as shown in ,fig4 #ei4 ,when these electric currents reach the plates of the receiving apparatus on the submarine where the operator is listening in1 they flow up the wires and through the primary winding of the telephone induction coil2 these broken up direct currents flowing through the primary coil set up alternating currents in the secondary coil and also raise the low pressure currents into high pressure currents--that is1 currents of a higher voltage1 as it is called4 ,these alternating high pressure currents then flow through the telephone receiver1 and by varying the strength of the magnet of the latter the dots and dashes of the sending station are reproduced and the receiving operator hears them as a musical buzz4 ,,chapter ,,ix ,,the ,,crew ,,of ,,the ,,submarine ,how the ,crew of a ,submarine is ,signed1 ,slept and ,fed4 ,the ,mother or ,base ,ship and ,its ,uses4 ,the ,complement of the ,submarine2 ,how ,new ,men ,are ,trained1 and the ,duties of the ,crew ,,chapter ,,ix ,,the ,,crew ,,of ,,the ,,submarine ,,you will remember1 back there in the first chapter1 we told you about ,fulton's submarine and how one man operated it1 so naturally he was his own superior officer and able-bodied seaman both rolled into one4 ,since those early days of underwater navigation wonderful advances have been made1 not only in submarine construction1 but in the crew that mans her as well1 for not only are there many men in the crew of a submarine of to-day1 but each man is highly trained for the work he has to do4 ,at the present time the personnel1 which means the force of men employed as well as their fighting qualities taken as a whole1 includes a list of no less than #dh officers and seamen1 and each and every one of them is a picked man4 ,the smaller submarines1 of course1 carry a smaller complement of men1 for there is neither as much work to be done nor is there room to bunk them4 ,conditions on ,early ,submarine ,craft4--,what with the great array of instruments1 apparatus1 and machines that must form the equipment of the submarine to make her an efficient fighting unit1 there is but little space left in her for her crew1 and this was especially so in the early days4 ,owing to the fact that space was1 and still is1 at a premium1 the crew of a submarine does not list a man who has not one or more important parts to play in the actual operation of the boat2 for every addition to the crew means that much less comfort for each one1 and interferes moreover1 with the carrying out of orders in a rapid and effective manner4 ,when ,crews ,were ,hard to ,sign4--,there were no conveniences provided on the first submarines for their crews2 indeed1 as we look back now on those pioneer attempts1 it seems verily as if no thought at all was given to the health and safety of the men who manned them4 ,it was enough1 albeit1 to get a boat that could be submerged and which stood a fair chance of coming to the surface again2 so of course there was not enough air1 and the little there was was bad2 the quarters1 if there were any at all1 were very small and close1 and there was a deal of danger attending the most ordinary maneuvers4 ,now1 the able-bodied seaman knew all these things only too well1 and1 what was more1 he had heard tall yarns spun around of the terrors of the new and strange craft1 and these did not tend to strengthen his desires to hurry up and enlist in that arm of the naval service4 ,when the various governments began to take a real interest in the submarine and to keep up an active flotilla1 they began to realize that unless the comfort and the safety of the men were looked after better than they had been in the past the submarine service would soon be shorthanded and badly crippled4 ,so as a sop for the bad conditions which the crew must stand1 the men were offered a large bonus--that is1 extra money besides the regular pay--and also extra privileges4 ,in truth1 the offers were so generous and alluring that it was not long before seafaring men began to rush to the call1 and from that time to this there has never been the least trouble in getting crews for undersea fighting craft4 ,as the construction of the submarine moved on apace and it grew in size1 and as new inventions and improvements were made to supply pure air and enough of it1 all the discomforts vanished1 until a berth on an undersea craft is as agreeable1 nearly1 as it is on a man-o'-war4 ,what the ,base-,ship ,is ,for4--,while1 of course1 the chief object of a submarine is1 as you can tell by its very name1 to travel undersea when needs be1 it is1 as you have already learned1 not fitted to run for more than forty-eight hours at a stretch when totally submerged1 and as a matter of fact it spends most of its time afloat and in the awash condition4 ,from this you will see that living on a submarine is for the greater part of the time just about the same--though a little more confined--as it is aboard any other craft4 ,her actual cruising radius--that is the distance she can sail from her base of supplies--is seldom more than #b1ejj miles2 and she is limited to this mileage simply because of the lack of storage for the food and fuel she needs4 ,for this reason every submarine must have a supply base1 and this usually is a ship which is supplied with the necessities of life and power4 ,the base-ship1 as it is called1 is also a floating dock1#bi has a complete machine shop1 and every other conceivable thing that she needs to take care of her flotilla of submarine children4 ,a mother ship is shown in ,fig4 #fj4 ,the base-ship follows after her submarines1 not directly on their heels1 but so that they will be within easy cruising distance of her4 ,it may seem that #b1ejj miles--nearly the span of the ,atlantic--is a long distance1 and it is for a submarine to make one continuous trip2 but ten short runs of #bej miles each will use up her supplies and then she will have to return to her base for more4 ,illustration3 ,,fig4 #fj4 ,,the ,,base ,,ship1 ,,showing ,,how ,,submarines ,,can ,,enter ,,bow ,,for ,,dry-,,dock ,,repairs ,,or ,,hidden ,,transportation4 ,in times of peace a submarine never strays far from her base-ship1 indeed1 she spends most of her time laying alongside of her except when at practice4 ,at such times the submarine and the base-ships are considered integral#cj parts of each other1 and under these conditions most of the crew stay aboard the ship4 ,thus it is that a submarine sailor's life is nearly all spent above water1 and it is not such an unhappy one at that4 ,how ,men ,are ,trained for ,submarine ,duty4--,the base-ship is also used as a training ship for rookies--that is green hands--and on it they are let into the secrets and mysteries of the working1 sailing1 and fighting machinery of the submarine4 ,the rookies are taken in hand by the officers and the more highly skilled sailors of the submarine and drilled in whatever they are to do until it becomes second nature to them1 for a fluke of any kind might spell disaster for the whole crew and craft4 ,the ,complement of a ,submarine4--,the word complement 7notice that it is spelled with an e instead of an i7 means not some pretty bit of flattery but the full number of men that is needed to man the boat4 ,the complement of a submarine is not very different from that of a torpedo boat or other small naval craft4 ,there is1 first of all1 the commander1 or commanding officer1 who is in charge of and is responsible for the crew and his boat4 ,his word is law and he is as able a navigator and tactician--as an expert in directing a submarine1 with skill and shrewdness is called--as it is possible to get4 ,his brain is the master brain of the mighty craft1 for it is he who plans what his crew must do1 and when they must do it to the end that the enemy ship shall be sunk4 ,then there are the officers under him--lieutenants 7pronounced lef-ten-ants1 with the accent on the second syllable1 by stage folks in naval plays7--and these correspond to the first and second mates1 etc41 of a sailing ship4 ,these officers are also thoroughly competent navigators1 and should anything happen to their superior officer1 any one of them could take command of the submarine and give a good account of himself4 ,the rest of the crew is made up of engineers and oilers1 torpedo-men and gunners1 wireless and signalmen1 cooks and able-bodied seamen4 ,the engineers not only must know how to run the engines to get the most power with the least fuel1 but they must be machinists of the highest class in order to make repairs of every kind should the boat be damaged by shell fire4 ,the torpedo-crew1 as the men who have charge of the torpedoes are called1 take care of these mighty missiles from the time they are lowered into the hull from the base-ship to the moment they are shot from the tubes on their courses to sink the enemy ships4 ,this crew also takes care of the trimming tanks1 which must1 as we have explained before1 be filled with water to offset the effect of lightening the submarine by the sudden discharge of the torpedoes4 ,the gunners1 of course1 look after the guns and are expert gun pointers4 ,all of the new submarines are equipped with wireless and this is worked by two or more experienced wireless men who are on constant duty while the boat is afloat and who operate the conductivity telegraph system when the craft is running submerged4 ,the submarine is kept in constant touch with the mother ship1 as the base-ship is sometimes called1 and as the latter has a much more powerful sending apparatus it can1 in turn1 communicate with the land either directly or by relaying the message by another ship4 ,the wireless operators also keep busy listening for the first faint signals sent out by enemy ships which may come within range of their instruments1 and though they will not be able to read the messages if they are sent in cipher code#ca they can at least know of the proximity of the ship4 ,breaking in ,raw ,recruits4--,when there is peace on earth and good will toward men the submarine never gets very far away from its base-ship1 about its only excursions being for drill and practice1 which is made up of maneuvering the submarine and torpedo practice4 ,illustration3 ,courtesy of ,leslie's ,weekly ,,the ,,crew ,,of ,a ,,submarine4 7,,note ,,sailor ,,going ,,below ,,through ,,hatch ,,in ,,after-,,deck47 ,to maneuver the craft means to make adroit moves and changes of position1 that is1 the boat is put from the afloat into the awash1 submerged1 and totally submerged conditions by and for the benefit of both the new men and old hands4 ,the submarine's place at sea--that is1 her longitude and latitude--is found solely by log distances and compass courses while the boat is running submerged1 and her course is corrected for drift and leeway2 navigating the submarine by these means is called dead reckoning4 ,torpedo practice consists of firing torpedoes with dummy heads1 that is1 heads which do not contain a charge of explosive1 at floating targets which the submarine or a lighter tows out to sea and anchors fast4 ,whether the torpedoes hit or miss they come to the surface after having been shot and are picked up again and returned to the submarine4 ,by constant practice the men of the torpedo-crew become highly skilled in hitting the target with the cigar-shaped projectile1 and they are not allowed to get rusty for want of constant practice4 ,to add to the knowledge which actual practice gives the raw recruits1 as well as the more experienced men1 the officers lecture to them on every subject that has to do with the design1 construction1 and operation of every working part of the submarine4 ,in this way the crew is trained to do their several individual duties with clock-like precision and is fit and ready at a moment's notice to handle the craft for all she is worth when war comes4 ,the ,conditions in ,war ,time4--,when the dove of peace has had its tail-feathers plucked out by the god of war and the enemy nations are arrayed in battle formation against each other1 then the submarine and her crew are welded into a destroying unit of the most treacherous and dangerous kind that the sea has ever known4 ,the conditions on board a submarine are quite different in war time from those when the nations are at peace4 ,in the first place1 when submarine chasers and aircraft are scouting the seas in search of underwater boats it is not only dangerous but often impossible for a submarine to keep in touch with the base-ship by wireless4 ,we say dangerous because wireless messages flashed forth and back would betray its presence to an enemy ship1 and we say impossible in virtue of the fact that the craft often has to run under water for as long a time as she can stay down4 ,when cruising on the surface the sharpest lookout must be kept every moment of the time for an enemy ship1 which may be torpedoed if it is a merchant vessel1 or the submarine must dive and get away from it1 if it should be a chaser or other kind of armed and armored boat that is looking to sink her4 ,under these strenuous conditions the crew is keyed up to the highest pitch and the severest discipline is maintained on board4 ,torpedoing1 diving1 submerging1 and all the other drills that have been learned under the easy routine of make-believe war now become stern realities upon which the very safety of the submarine depends and hence the lives of the crew4 ,,chapter ,x ,,how ,,the ,,submarine ,,attacks ,how the ,submarine ,works with the ,fleet as a ,means of ,defense and ,offense and as a ,scout4 ,its ,use as a ,blockader and ,a ,weapon ,against ,merchantmen ,,chapter ,x ,,how ,,the ,,submarine ,,attacks ,,when the naval powers were waking up to the fact that the submarine was worthy of some consideration1 undersea tactics was a thing that was yet to be invented4 ,these early craft had a very short range of travel and because of their poor construction and lack of power they were not at all adapted for ocean-going1 hence they could not accompany the fleet of warships on their maneuvers4 ,they were1 however1 thought very well of for coast patrols1 and this was the duty given them to perform2 each submarine had a stretch of coast which it was to watch and tactics and maneuvering were not needed for this service4 ,even when it was expected an attack might be made1 the only thing that was required of them was to be on the lookout1 signal the forts on shore1 dive and get out of harm's way4 ,but as the size1 range1 and speed of the submarine was increased she gradually took her place along with the auxiliary#cb craft of the fleet1 or squadron1#cc and began to take part in the maneuvers with it4 ,it was then that certain fixed duties were assigned to her1 and her relation to the other boats became more clearly defined and definitely fixed4 ,as late as the ,spanish-,american ,war1 and that was only a score of years ago1 the submarine played but a sorry part4 ,a few years later1 however1 when the ,russo-,japanese ,war was fought1 the underwater fighting craft showed for the first time in the game of naval warfare the kind of stuff it was made of4 ,in the years of peace and prosperity that passed between the end of the ,russo-,japanese ,war and the beginning of the great world war of the nations that is now going on1 the submarine was experimented with and improved upon until it has thrown all the other types of naval craft1 from the dreadnaughts on down into the shade where there isn't any shade4 ,the result of it all is1 as you probably know1 that the submarine has developed a kind of warfare all its own and which it carries on entirely without help4 ,imagine1 if you can1 that in the greatest war that has ever been waged giant battleships are sewed up in the harbors of the enemy while her submarine flotillas are everywhere at sea and carrying on a most effective blockade6 ,such is the rise of the submarine4 ,the ,uses of the ,submarine4--,there are two chief uses to which the submarine is put1 and these are 7#a7 as a reserve defense or offense for the fleet1 and 7#b7 as an offensive weapon for the purpose of maintaining a blockade4 ,how ,she ,works with the ,fleet4--,in the first instance1 that is1 where the submarine is used as a means of defense and of offense with a fleet or squadron1 her tactics are well defined and clear-cut4 ,her activities under these conditions are rather limited1 for she is not built speedy enough to keep up with a swiftly steaming fleet4 ,this1 then1 in the very nature of things1 keeps the submarine from playing an otherwise all-important rle of scout-ship4 ,further1 this lack of speed on her part prevents her from engaging in battle as an actual part of the fleet or squadron1 for very often it is the speed of the attacking men-of-war that makes for victory1 and a flotilla of submarines that lagged behind would prove more of a hindrance than an aid4 ,but what the submarine can and does do to great advantage is to attack an enemy fleet either as a defensive or an offensive measure1 depending on the relative strengths of the fleets which oppose each other4 ,the ,submarine ,flotilla as a ,means of ,defense4--,now let us see first what happens when a fleet with a flotilla of submarines attacks another fleet which is without them4 ,if the attacking fleet is the weakest--that is1 its guns are the lightest--then the submarine flotilla will take a defensive stand1 though the opposing fleet is making the attack4 ,the submarines will lay off to the rear of the attacking fleet1 and then if the gun-fire from the enemy waxes so warm that the attacking fleet is forced to retire the submarines are in a good position to aid the fleet in its retreat1 as shown in ,fig4 #fa4 ,illustration3 ,,fig4 #fa4 ,,the ,,submarine ,,as ,a ,,defensive ,,weapon4 ,now1 as soon as the pursuing ships come within range1 the submarines let go their torpedoes at them and these either blow them up1 cripple them1 or scare them off4 ,in a maneuver of this kind the commander of the fleet executes his retreat in such a way that the heavier-armed pursuing fleet must pass near his submarines1 which are usually submerged and are therefore invisible4 ,the ,submarine ,flotilla as a ,means of ,offense4--,if1 now1 the attacking fleet is stronger than the defensive fleet1 then the submarines of the attacking fleet will also take an offensive part4 ,in this case the submarines will take up a position to the rear of the defensive fleet4 ,the commander of the attacking fleet will then use such force on the enemy fleet that it will retreat along the path where the submarines lay1 when they will1 of course1 torpedo them1 as shown in ,fig4 #fb4 ,both these methods of attack have been used with signal success in the war that is now going on4 ,illustration3 ,,fig4 #fb4 ,,the ,,submarine ,,as ,,an ,,offensive ,,weapon4 ,the ,submarine as a ,scout4--,although the submarine is useless as a scout for a swiftly moving fleet still it can render great service as a scout on its own hook4 ,by way of illustration let us suppose that the enemy has a harbor that is well protected by forts and guns1 that her fleet is laying to in it1 that we want to know how many ships the fleet is made up of1 and1 finally1 what class of ships they belong to4 ,it is the duty then of a submarine to get into the harbor and take a general survey of the situation4 ,you may wonder how the craft is to do this1 since the harbor is mined2 but by skilful handling1 the captain will usually get through safely1 find out all that he wants to know and run out again4 ,besides thoroughly reconnoitering a harbor1 the submarine can lay a few contact mines1 as we explained in a chapter that has gone before1 in positions of which the enemy fleet is in entire ignorance and which will be more than likely to result in the destruction of at least a part of the fleet4 ,further1 the submarine is used to destroy fields of mines which have been laid by the enemy in a harbor4 ,this is done by mines thrown from the torpedo tubes among those that have been planted and which explode by the concussion4 ,the ,submarine as a ,blockader4--,the most important use to which the submarine has ever been put and one that was never thought of seriously until the present conflict is that of a blockader4 ,ever since the beginning of this war ,germany has realized the tremendous need of keeping the neutral#cd countries from supplying the ,allies with munitions and food supplies1 and she has prepared for years a blockade of a new and very effective kind1 and this is by destroying merchantmen by submarines4 ,england and the other ,allies have done the same thing with the ,central ,powers--which is not a very hard thing to do because ,germany's fleet of warships is cooped up in her various ports and dare not venture forth1 and so the task is left entirely to her submarine flotilla4 ,and what makes it still harder for the ,german submarines is that the ,allies keep on the constant watch for these enemy undersea craft1 and this they do with their submarine destroyers1 and the ,united ,states is after them with her submarine chasers1 to say nothing of ,england's aircraft attacks4 ,altogether it is very hard for the enemy submarines to keep in touch with their respective bases or to receive orders as to their courses of action4 ,when on blockade duty1 then1 the captain of a submarine is in very truth1 the commander of his craft and it is strictly up to him to determine what her tactics shall be4 ,as long as he does his work well1 which means that he sinks a fair number of all the ships that enter his zone1 his superior officer1 wherever he is1 will have no quarrel with him as to when or how he does the work4 ,so you see the tactics used by the captain of a submarine while doing this kind of work depend entirely on the conditions he encounters at the moment1 and on the quick decision and judgment of the captain depends the success or failure of the attack4 ,how a ,submarine ,attacks a ,merchantman4--,as a general thing submarines travel alone when merchantmen are to be torpedoed4 ,the sea is mapped out into zones1 as certain areas or parts of the sea are called1 and each zone1 or part1 is usually assigned to a single craft2 the submarine patrols this zone constantly1 and the captain and his officers keep their weather eye open for passing merchantmen or vessels which might in any way aid or carry supplies to the enemy4 ,to do this the captain of the submarine stops every ship that comes his way and has her papers and cargo examined1 and in this way finds out whether the ship is what she seems to be or if she carries contraband--that is arms1 ammunition1 and war supplies of any kind--or not4 ,the way in which this interesting procedure is done is as follows3 ,the submarine1 let us say1 has sighted a ship1 and seeing that it is to all intents an unarmed merchantman she rises to the surface and trains her rapid-fire guns on the craft4 ,next she signals the ship to stand by and at the same time she runs toward her4 ,now the captain of the ship has three courses open to him3 7#a7 to put on full speed and try to get away1 trusting to luck to prevent his craft from being shot full of holes or torpedoed2 7#b7 to take a still greater chance and try to ram the submarine with the sharp1 steel-shod bow of his ship and so either disable or sink her1 and 7#c7 to comply gracefully to the request and heave to4 ,if the latter is done1 the collapsible boat of the submarine is rigged up and a couple of the officers and crew row over to the ship1 when they are hauled aboard and go through her4 ,should they find nothing of a suspicious or contraband nature1 the boat returns to the submarine and the ship is allowed to go her way4 ,illustration3 ,courtesy of ,leslie's ,weekly ,a ,,german ,u-,,boat 8,,breaking ,,water0 ,,preparatory ,,to ,,examining ,,the ,,cargo ,,of ,,an ,,enemy ,,ship ,but1 on the other hand1 if contraband is found on board1 the captain of the submarine will do one of these two things3 7#a7 he will warn the crew of the enemy ship that he is either going to open fire on her with his guns or torpedo her1 and to take to the life-boats1 or 7#b7 he will sink her without warning if the whim so seizes him4 ,often the captain of the destroyed craft is taken aboard the submarine and held as a hostage4 ,when ,submarines ,attack in ,pairs4--,another strategic scheme that is used to torpedo enemy craft is to work submarines in pairs4 ,this is not done1 as a rule1 except where the ships may1 in virtue of their armament1 prove dangerous to a single submarine and then they are sunk without warning4 ,tactics of two different kinds are used in the actual stopping of the craft4 ,the first is for the submarines to lay off from each other at a distance of from three to five miles 7as shown at ,a in ,fig4 #fc74 ,then when the submarine1 with her periscope above water1 spots an enemy ship1 she signals to the other submarine1 which is submerged1 and gives her the exact speed and course of the armed vessel4 ,the submarine with her periscope above water cannot be seen by the ship because she is too far off1 and the nearby submarine cannot be seen because she is totally submerged2 so the first submarine directs the second submarine how to train her torpedo tubes on the enemy ship and when to shoot the torpedoes at her4 ,by these tactics a ship can be sunk without either of the submarines being seen4 ,the other and second way by which an armed ship can be attacked is by having a pair of submarines travel together1 one directly over and separated from the other by a distance of only twenty or thirty feet 7as shown in ,fig4 #fc74 ,illustration3 ,,fig4 #fc4 ,a1 ,b1 ,,how ,,the ,,submarines ,,travel ,,in ,,pairs4 ,now1 when a ship is sighted by the craft nearest the surface she comes up boldly and demands the hostile vessel to heave to4 ,should1 instead1 the enemy ship open fire and cripple or destroy the submarine1 the submerged submarine takes up the fight and shoots a couple of torpedoes at the aggressive ship and so puts an end to her1 if possible4 ,the tactics we have told you about are only a couple of the many used by present-day submarines2 we should like to go on and write a book about them but if we did we're afraid the ,imperial ,german ,government might not like it1 so we'll stop here4 ,,chapter ,,xi ,,the ,,new ,,submarine ,,chasers ,a ,description of the ,allied ,submarine ,chasers ,both on ,sea and in the ,air ,,chapter ,,xi ,,the ,,new ,,submarine ,,chasers ,,it is the boast of ,germany that she will win the present war by sinking not only all of the ships of the ,allies1 but those of any other country which may trade with them4 ,now1 the ,united ,states demands the freedom of the seas for every ,american citizen and for every ship that flies the stars and stripes and to make good this demand is what brought us into the war4 ,if ,germany could destroy all of the merchantmen of the ,allies--and we are now one of them--as she wants to do1 she would doubtless be the victor4 ,she hopes to but will never be4 ,the blockade by her submarines is growing more and more serious and many plans and schemes have been put forth to outwit1 offset1 or to break it down by destroying her destroyers4 ,there are at the present time#ce only about thirty million tons of shipping#cf in the world which can be used to supply the ,allies of ,europe with munitions of war4 ,the ,german ,u-boats are picking off ships1 both neutral and otherwise at the rate of half a million tons a month1 and at this rate of destruction shipping cannot last more than a few years4 ,hence the great need of breaking the blockade and of doing it quickly4 ,schemes for ,outwitting the ,submarine4--,many plans have been thought of and tried out to get the best of the tough old submarine and so defeat it2 and among these are3 7#a7 ,to build ships that are so heavily armored that they can withstand the attack of torpedoes4 7#b7 ,to build ships which have a light enough draft and are speedy enough to outdodge and to outrun the swift torpedo4 7#c7 ,to outrig the ships below the water-line with nets which prevent the torpedoes from striking the hulls hard enough to explode them4 7#d7 ,to fit the ships with wireless ears which will detect the presence and determine the position of the submarine before it gets within torpedoing range and so give them a chance to escape4 7#e7 ,any number of other impracticable schemes4 ,now1 you may ask why these schemes are useless4 ,among the reasons are these1 7a7 steel armor has yet to be made that will withstand the violent explosive power of the torpedo1 7b7 ships with a draft light enough and a speed great enough to get out of the way of a torpedo could not be used as freighters1 7c7 nets on ships make them slow and unwieldy1 and as soon as they were used the torpedoes were fitted with steel cutters which enabled them to go through as easily as before1 7d7 the art of wireless has not yet advanced to the point where it is possible for a ship to detect the presence and position of a submerged submarine1 7e7 every other scheme that has been put to the acid test has had a glaring fault in it4 ,plans for ,destroying the ,u-,boats4--,now1 the right way to break the ,german blockade is to destroy the ,u-boats1 and plans along this line have been devised and carried out with better success4 ,the submarine can be destroyed in several ways4 ,among the most important are 7#a7 by laying mine-fields2 7#b7 by arming merchantmen with rapid-fire guns2 7#c7 by destroying the base-ships which mother the submarines2 7#d7 by hunting them down with submarine chasers1 and 7#e7 by dropping bombs or shelling them from aircraft4 ,laying ,mine ,fields in ,harbors4--,this plan is very good for protecting harbors against submarine attacks2 but as nearly all the merchantmen are sunk from #bjj to #cjj miles off the coast1 the use of mines for the protection of shipping is very limited4 ,arming ,merchantmen with ,guns4--,arming merchantmen has met with some success1 but as a matter of fact it is a very uncertain means of protection1 and the large number of armed ships which are sunk weekly shows that the plan is weak4 ,as a merchantman1 or freighter1 is usually a slow craft1 and a submarine can easily out-maneuver it even when the submarine is on the surface1 and when she is submerged she cannot be seen1 it must be clear that ordinary rapid-fire guns cannot easily hit her4 ,destroying the ,mother ,ships4--,to destroy the base-ships is1 though it may sound like a paradox1 one of the best and at the same time one of the least practical plans of getting rid of the submarines that infest a certain zone4 ,it must be clear if the base-ships are destroyed that the submarines they mother would speedily come to an end4 ,knowing full well that the ,allies would try to find out her bases1 both on land and sea1 ,germany has hidden most of them well1 and those that are not hidden are protected by guns of such caliber#cg as to prove a source of danger to even a fleet of first line dreadnaughts4 ,since the bases are too hard to find and too hard to destroy when once found1 other easier and more practical plans have been devised1 tried and found fairly successful4 ,kinds of ,submarine ,chasers4--,and now we come to a class of naval craft to which the name submarine chaser has been given1 and she has proved to be the best and most practical plan yet worked out to kill off the submarine4 ,there are two very different kinds of submarine chasers1 and these are 7#a7 boats which travel on the surface of the water1 and 7#b7 craft which travel through the air4 ,the first kind only1 though1 is called a submarine chaser1 while the second kind may be either a dirigible balloon or a warplane4 ,illustration3 ,courtesy of ,leslie's ,weekly ,,three ,,eighty-,,foot ,,gasolene ,,chasers ,,on ,,their ,,way ,,to ,,patrol ,,duty ,the #hj-;,foot ,submarine ,chaser4--,the submarine chaser is simply a boat whose success as a destroyer depends on four factors1 and these are 7a7 how fast she can go2 7b7 how light her draft is2 7c7 how well she is armed1 and 7d7 how fast she can be built4 ,two kinds of these chasers have been built1 and both have shown their real worth4 ,the first is known as the #hj-;foot submarine chaser4 #eej of these noble craft have already been built for ,england and sent over to operate against the ,u-boat in ,british waters4 ,they are powered with gasoline engines and are built just about like the high-speed pleasure boats that are now so common here on this side of the ,atlantic1 that is1 they have a three-quarter cruising cabin and cockpit as shown in ,fig4 #fd4 ,they are very seaworthy1 and the powerful gasoline engines installed in them give them speed enough to outrun the fastest submarines that have yet been built4 ,each one carries a rapid-fire gun of the #c-;inch type4 ,the #aaj-;,foot ,submarine ,chaser4--,the only fault with the #hj-;footer is that its small size makes it impossible to store away enough fuel to give it a large cruising radius1 and so a new type of submarine chaser is being built which is #aaj feet long4 ,its general appearance is shown in ,fig4 #fe4 ,illustration3 ,,fig4 #fd4 ,,eighty-,,foot ,,gasoline ,,submarine ,,chaser4 ,illustration3 ,,fig4 #fe4 #aaj-;,,foot ,,steam ,,submarine ,,chaser4 ,this boat is powered with steam engines and oil-burning boilers which drive the chaser at the very fast speed of #be knots4 ,the craft is armed with a battery of two #c-;inch guns mounted on the fore and aft decks4 ,the large size of this chaser makes it easy for it to cruise for long distances1 while its speed is #h knots faster than that of the fleetest submarine and this makes it a foe that is truly to be feared4 ,how the ,chaser ,chases a ,submarine4--,the way a submarine chaser chases a submarine is like this3 each chaser is given a certain area of seaway to patrol4 ,this she does1 and if she is lucky she will soon see the periscope of an enemy submarine poking its hood above the water to take a peek around the horizon4 ,this is the signal for the chaser to bear down on that periscope at full speed1 the gunners doing their level best to hit the periscope or any other part of the submarine which shows itself above water4 ,as it takes time for the submarine to dive or to get her own guns into action1 the chaser stands a pretty good chance of either crippling or even sinking her4 ,further1 the submarine cannot use her torpedoes on the chaser1 for the latter craft is so short and has such a shallow draft that her hull does not offer much of a target for a torpedo1 even though she were standing still1 and much less when she is bearing down on the submarine at full speed4 ,every once in a while a chaser is able to surprise a submarine when she has come to the surface for a breather and to recharge her storage batteries4 ,when this happens it is simply another case of the cat eating the canary4 ,if the submarine is within two miles of the chaser she cannot get ready to dive and she must either get her own guns in action or else she must try to outrun the chaser1 getting ready to dive as she runs and trusting to the ,kaiser that she may not be hit in the meantime4 ,this last course proves disastrous to the submarine nine times out of ten1 and so she usually gets her guns into action and a regular little sea battle is fought right then and there4 ,shooting the ,guns of the ,chaser4--,having found1 chased1 and caught the submarine1 the next thing to do is to put her out of commission4 ,on the guns with which the chaser is armed1 and on her gunners1 depend to a large extent the success or the failure of the attack4 ,a gun which had a long range and a flat trajectory#ch was quick in action1 and rapid-firing1 was thought to be all that a gun should be for submarine execution2 and it was all right for shooting at conning towers and similar targets which showed themselves above the water-line1 but it was useless for a gun of this kind to try to hit anything that was even a few feet under water4 ,the reasons for this are somewhat deep and scientific but if you will read carefully1 look at the diagrams shown in ,figs4 #ff and #fg1 and do a little thinking as you go along you will be able to visualize the whole thing--that is1 to see it4 ,illustration3 ,,fig4 #ff4 ,,how ,a ,,flat ,,trajectory ,,affects ,,the ,,projectile4 ,now1 the way this gun was made was to rifle the barrel of it1 and this gave a turning motion to the projectile when it was fired1 that is1 it spun around on its long axis1 and the trajectory was flat1 which means that the path of the projectile in its flight from the gun to its target was only slightly curved4 ,illustration3 ,,fig4 #fg4 ,,how ,a ,,bow ,,trajectory ,,affects ,,the ,,projectile4 ,both of these things made the projectile deviate from its course the instant it struck the water1 or ricochet 7pronounced rik-o-shy7 as it is called2 that is1 it bounced from the water in exactly the same way that a flat stone skips along when you throw it close to the surface of a pond or lake4 ,the right kind of gun to use on submarine chasers is not rifled1 and the projectile should be given a trajectory1 or path1 that is much the same as that of an arrow2 the result is that a shot can be fired at a submarine which is submerged to a depth of #bj feet or so and be effective because the curve of the path is such that the projectile drops straight1 or nearly straight1 down on the submarine and penetrates the water as shown in ,fig4 #fg4 ,submarine ,air ,chasers4--,besides the submarine chasers just described1 there are two other kinds that have shown great possibilities as destroyers of undersea craft4 ,these are 7#a7 the airship1 or dirigible balloon1 and 7#b7 the airplane1 and it is more than likely that in the near future1 should the war keep on1 the latter craft alone will be used for submarine chasers4 ,where a boat chaser cannot see a submarine at all when she is submerged1 an airplane can fly directly over her1 follow her every movement1 and see her when she is at a considerable depth4 7,see ,fig4 #fh47 ,as the airplane is much more steady in the air than a submarine is on the water and as the former is much quicker and speedier than the latter1 a battle between these two very different kinds of craft is an unequal one with the odds greatly in favor of the warplane4 ,a ,way to ,lift the ,u-,boat ,blockade4--,here1 then1 is a real1 ready way that the submarine can be destroyed and ,germany's blockade lifted4 ,to put an end quickly and for all time to the ,u-boat menace1 the ,united ,states ought to build several thousand airplanes at once and arm these with bombs and rapid-fire guns like the ,lewis#ci and send this fleet to patrol the seas4 ,illustration3 ,,fig4 #fh4 ,,how ,,air ,,craft ,,can ,,spot ,a ,,submerged ,,submarine4 ,if this were done there wouldn't be enough ,u-boats left in a month's time to flag a ,norwegian fishing trawler4 ,so the thing for your ,uncle ,sammy to do is to build a great fleet of airplanes1 and in the shortest possible time4 ,there is still another way to break the blockade1 and this will be described in the next chapter4 ,,chapter ,,xii ,,the ,,last ,,word ,,in ,,submarines ,the ,adventures of the 8,deutschland0 and ,some ,schemes for a ,merchant ,submarine ,service ,,chapter ,,xii ,,the ,,last ,,word ,,in ,,submarines ,,it is less than twenty years agone that the first five baby ,hollands were built in this country for1 and delivered to1 ,england1 and from that time dates the beginning of the art of modern submarine construction4 ,since then the size1 speed1 and cruising radius of each succeeding type of submarine has grown greater and ever greater1 until from a craft hardly larger than a power pleasure boat there has been evolved a truly wonderful undersea vessel of magnificent proportions4 ,uncle ,sam's ,latest ,submarines4--,the result of this marvelous development is that the latest of ,uncle ,sam's submarines are of the #abjj and #aejj tons displacement type and they have a speed of #ba knots on the surface4 ,these giant submarines have a cruising radius of about #d1jjj miles and are fitted with every instrument1 device1 apparatus and machine that human ingenuity can think of1 or at least that has been invented1 which goes to make for their operating and fighting qualities and for the safety and comfort of their crews4 ,from this you will see that since the year of #aijj the size of these craft has been increased about four times1 their speed doubled1 and their efficiency raised to half again as much4 ,based on the rapid strides that have been made since the war has been going on1 it does not take any great foresight to predict that in the near future1 if the ,u-boat blockade is not broken1 submarines of upwards of #ejj feet in length and #aj1jjj tons' displacement will form the merchant fleet of the ,united ,states4 ,the ,great ,blockades of the ,warring ,nations4--,the great blockades by which the ,allies have bottled up the ,german ,empire by their superior naval forces1 and by which ,germany is trying to shut off the trading of other countries with the ,allies by her ,u-boat warfare1 have prevented either side from scoring a victory4 ,but with ,germany's usual dogged determination for overcoming the difficulties that beset her1 she built a submarine which could travel without a convoy1 that is1 without any base-ship to go along with her to provision and supply her needs1 for #e1jjj miles at least4 ,this giant submarine carried a cargo worth a million dollars or more1 sunk out of sight as she left her home port1 slipped underneath the grim warships of the ,allies which menaced ,german shipping1 and in this way ran the blockade4 ,then one fine day there bobbed up in ,american waters near ,chesapeake ,bay a monster merchant submarine--the largest underwater craft ever built and the first of her kind ever seen4 ,she was in very truth a nine days' wonder4 ,the ,first of the ,merchant ,submarines4--,the ,deutschland1 as she was named1 was a marvel of engineering skill1 and she was hailed as the first of a great fleet of merchant submarines which was to break the ,allies' blockade4 ,starting from ,bremen1 ,germany1 and traveling underwater through the ,english ,channel for a distance of #ij miles without even once coming to the surface1 she made the entire voyage without mishap and docked at ,baltimore just #af days later4 ,when you think of how carefully she had to be handled and how cautiously she had to proceed so that she might escape destruction at the hands of her surface enemies1 you must admit that she made the run in really remarkable time4 ,some ,facts ,about the ,deutschland4--,this great merchant submarine is #cae feet long1 #cj feet through the beam1 and draws#dj #ag feet of water4 ,she is1 therefore1 as large as many of our coastwise steamers1 so that she is something more than a mere underwater boat--indeed1 she is a veritable submarine ship4 ,her hull is shaped more nearly like that of a real ship than any submarine craft that was ever built before her1 as ,fig4 #fi shows2 but she has a conning tower1 periscopes and wireless masts like any of the other of the tribe of submarines4 ,illustration3 ,,fig4 #fi4 ,,the ,,merchant ,,submarine ,,deutschland4 ,illustration3 ,courtesy of ,scientific ,american ,,navigating ,,the 8,,deutschland0 ,,by ,,means ,,of ,,the ,,deck ,,control4 7,,note ,,open ,,hatch ,,leading ,,to ,,conning ,,tower47 ,her wireless aerial is held in place between two steel masts1 each of which is #ej feet high and both of which can be folded down on the deck4 ,the mast on her for'ard deck is fitted with a crow's nest for a lookout1 as though she were a real ship4 ,her ,captain and ,his ,crew4--,the inside of her hull is very much like an ordinary merchantman4 ,for'ard are large and comfortable quarters for the officers1 of whom there are nine1 including ,captain ,koenig--a man you can't help but admire4 ,abaft the ship are the quarters for the crew1 and both fore and aft in her hold are compartments for the cargo she carries4 ,her ,valuable ,cargo4--,in making her first trip over from ,bremen her cargo consisted of dyestuffs1 medicines1 synthetic stones#da and other merchandise which took up small storage room and yet which was very valuable4 ,these she unloaded in ,baltimore1 and her return cargo was made up of crude rubber1 tin1 and nickel--materials much needed by the ,german ,government for purposes of warfare4 ,she also served the very useful purpose of a packet1 for by means of her ,captain ,koenig was able to hand personally to ,count von ,bernstorff1 the ,german ,ambassador to the ,united ,states at that time1 important instructions which would otherwise have been hard to get through4 ,again1 what was of even greater urgency was that the ,count was able to get rid of certain documents which would have made matters quite uncomfortable for him if they had been found in his possession some months later when the break came between the ,united ,states and ,germany4 ,her ,great ,engines4--,the ,deutschland is driven by two #fjj-;horsepower ,diesel engines1 each of which has four cylinders4 ,she is able to make a speed of #ad knots on the surface1 but when submerged her speed is only about half as much4 ,she is supplied with enough liquid fuel and solid foods to enable her to cruise for #e1jjj miles without making port4 ,such is the ,deutschland1 and to her belongs the distinction of being the first underwater merchantman4 ,under the skilful command of her captain1 she served her country nobly and well for the purpose for which she was built4 ,how the ,united ,states ,can ,break the ,blockade4--,right now the ,united ,states and the ,allies have to face the same gigantic problem that was forced upon ,germany at the beginning of the war1 and that is to break the enemy's blockade4 ,the scheme of keeping the sea-roads clear for shipping by destroying the ,u-boats has proved a slow and hard process1 and so new plans have been mapped out by our naval engineers and others with which to defeat the blockade4 ,the ,wooden ,ship ,idea4--,the first plan1 and one which is being carried out with great energy1 is the building of hundreds of little wooden ships1 each of which is #be feet shorter than the ,deutschland and has a cargo carrying capacity of #c1ejj tons1 and a speed of #d knots less than the surface speed of the great ,german submarine4 ,the main idea seems to be to turn these little boats out fast enough so that the number the ,u-boats sink will be so small that the loss will not be felt4 ,the glaring fault of this idea is that while the ,u-boats are sinking #ejj1jjj tons of shipping a month1 ,american ship-builders can build only #bjj1jjj tons a month1 and this is figuring it out with a liberal margin4 ,while these small wooden craft of the vintage of #ahej would relieve the stress that is now felt in shipping circles they would not by any means remove it4 ,the ,submarine ,plan4--,simon ,lake1 the inventor of the submersible1 has enlarged upon the ,german plan1 and his plan is one which our ,government ought to carry out1 because1 in the humble opinion of the writer1 it is the only feasible one thus far advanced4 ,mr4 ,lake has organized a company to build a fleet of undersea merchantmen1 each boat of which will be ten times as large as the ,deutschland and can carry a cargo of #g1ejj tons4 ,mr4 ,lake says that with the co-operation of the ,government he can build #ajj of these giant craft in the first year1 and that at the end of three years he can have a fleet of #ejj of them built and in service4 ,that is to say1 in this short time he can have #d1jjj1jjj tons of cargo sailing the seas with absolute safety4 ,this plan of the great submarine builder is the key which will unlock the horns of our dilemma4 ,the only drawback seems to be the ability of a company to turn out so complex a mechanism as the submarine1 and of such an enormous size1 fast enough to make up for the rapidly disappearing tonnage of the ,allies4 ,in the meantime the submarine chasers and the wooden and steel ships that are now being built may help to some extent to take care of our shipping until the great commercial submarines of ,lake can be built and put into the trans-,atlantic service4 ,when ,submarine ,meets ,submarine4--,when ,greek meets ,greek then comes the tug of war1 so the old saw goes1 and it is just as true that the way to break the blockade of the ,u-boats is to pit the cunning of submarines against them4 ,with all our shipping going by the undersea route1 the ,u-boats will lose their sting1 the blockade will be broken1 the power of the ,allies will outweigh that of ,germany1 and the war will speedily come to an end4 ,and may that time come soon6 ,,the ,,end ,,index ,air chasers1 submarine1 #aie ,air1 compressed1 #fg ,air compressor pumps1 #fg ,air control mechanism of a model submarine1 #cb1 #db ,aircraft attacks1 #agg ,air flashes1 #fg ,airplane1 the1 #aie versus submarine1 #aci ,air pressure required to drive torpedo1 #aja ,airship1 the1 #aie ,air tanks of a torpedo1 #ajh ,action1 the model torpedo in1 #if ,aerial1 wireless1 #ee ,allies' blockade1 #bjj ,allies1 the1 #a1 #agf1 #ahe1 #bjj ,ananias club1 #aci ,anchor1 mushroom1 #fi ,angle1 definition of1 #ei ,angle indicator1 #fj ,armament1 definition of1 #aag ,arming merchantmen with guns1 #ahg ,artemus ,ward1 #bc ,attacks1 how a submarine1 #aga ,automatic gyro control1 #aja pendulum control1 #ajb ,automobile torpedo1 #ib1 #aae ,auxiliary1 definition of1 #aga ,awash condition1 #fb ,awash1 definition of1 #bc ,baby ,holland1 #aii ,back pressure1 #fh ,balance chamber1 #aja ,ballast pumps1 what they do1 #ff ,ballast tank of a model submarine1 #bh ,ballasting the model submarine1 #dj ,balloon1 dirigible1 #ahi ,base ship1 what it is for1 #afa ,bell for submarine signaling1 #aea ,bell or violin signaling system1 #aea ,blackheads1 #ib ,blind fish of ,mammoth ,cave1 #eh ,blockade1 how the ,u4 ,s4 can break the ,u-boat1 #bjd the ,allies'1 #bjj ,blockade1 the submarine plan to break the ,u-boat1 #bje the wooden ship idea1 #bjd a way to lift the ,u-boat1 #aie by ,u-boats1 #bjj ,blockades of the warring nations1 great1 #bjj ,body of a model torpedo1 #ib ,bomb1 clock-work of a submarine1 #aj submarine1 #i ,bomb idea1 the1 #aaf the old1 #ia ,book of wireless1 #adi ,bores of ,allies' submarine guns1 #abj ,boy of the ,prehistoric ,age1 #c ,boy1 the second submarine1 #a when he learned to swim1 #c ,bushnell's submarine1 #g ,bushnell1 submarine boat inventor1 #h ,bulkhead door1 electrically operated1 #ei ,bulkhead in model submarine1 putting in1 #cd ,buoyancy1 #fc experiment in1 #fg natural1 #fg reserve1 #fc1 #fg ,buoyancy tanks1 what they are for1 #ff ,caliber1 definition of1 #ahh ,campbell and ,ash1 ,english submarine boat inventors1 #ad ,carburetor1 for gasoline engine1 #gf what it does1 #gh ,centennial ,exposition1 #ac ,central ,powers of ,europe1 #a ,central ,powers1 the1 #agf ,chaser1 how it chases a submarine1 #aib shooting the guns of the1 #aic ,chasers1 submarines1 #aaf ,chasers for submarines1 air1 #aie ,cipher code1 definition of1 #aff ,clock-work of a submarine bomb1 #aj ,collapsible boat1 #agh ,colored light signaling system1 #adf ,commanding officer1 the1 #afd ,commutator of model electric motor1 #ci ,compass1 #ee ,compass courses1 #afg ,compass1 gyroscopic1 #eh ,compartment1 diving control1 #fj mine1 #fh torpedo1 #fh ,compartments1 watertight1 #ec ,compressed air1 #fg ,compressed air action gun1 #aai ,compressed air for driving engine1 #aje ,compressed air tanks1 #ajj ,compression stroke of engine1 #gh ,conditions of the submarine1 four1 #fb ,conductivity system1 how it works1 #aee parts of1 #aee ,conductivity system of signaling1 #aed ,connecting up the power plant circuit of the model submarine1 #db ,conning tower of a model submarine1 #db ,conning tower1 outside of the1 #ed peep into the1 #ef ,contact mines1 #abb ,contact mine1 how it works1 #abc ,contraband1 definition of1 #agh ,course of a torpedo1 #aaj ,crews1 hard to sign1 when1 #afj ,crew of a submarine1 #fi ,davis1 torpedo inventor1 #aaa ,deck of a model submarine1 #bh1 #ce ,defense1 the submarine flotilla as a means of1 #agc ,depth indicator1 #fj ,depth meter1 #ei ,depuy de ,lme1 ,french submarine inventor1 #af ,destroyers1 submarine1 #agg ,destroying mother ships1 #ahh ,detonating or firing mechanism1 #ih ,deutschland1 cruising radius of the1 #bjd her great engines1 #bjd her valuable cargo1 #bjc some facts about the1 #bja the captain and crew of the1 #bjc the largest submarine1 #bja ,diesel engine1 #hj how it works1 #hj ,diesel1 ,german gas engine inventor1 #hj ,dirigible balloon1 #ahi ,dives1 how a submarine1 #fd1 #fh ,dive is made1 why a shallow1 #fe ,dive1 time it takes for submarine to1 #ff ,diving control compartment1 #fj ,diving rudder1 #ec1 #ei of a model torpedo1 #ie ,diving rudders1 fore1 #fd ,diving wheel1 #fj ,doyle1 inventor of ,sherlock ,holmes1 #acj ,draw1 definition of1 #bja ,dry cells for model electric motor1 #ce ,dry cells1 where to buy1 #ce ,dummy heads1 #afg ,dynamo1 definition of1 #he1 #hf ,dynamo motor and storage battery system1 #he ,eagle1 first warship to be attacked by a submarine1 #i ,ears of a submarine1 #adc ,electric controlled mine1 #abd ,electric motor1 #cd1 #he commutator of an1 #ci discovery of the1 #ad where to buy an1 #ce ,electric motor current of a model submarine1 #dc ,electric motor for model submarine1 #ce ,electric motors1 #ad1 #ef ,electric power plant1 why it is needed1 #he ,electric submarine1 invention of the1 #ad ,electric switch of model submarine1 #cf ,electrically controlled mines1 #abb ,electricity for the submarine1 #ae ,enemy ships1 gauging the distance of1 #acf ,enemy of the submarine1 a new1 #aci ,engines1 #gc ,engine ,building for ,boys1 #gd ,engine1 carburetor for gasoline1 #gf ,engines1 compressed air for driving1 #aje ,engine1 ,diesel1 #hj that drives the torpedo1 the1 #ajd faults of the steam1 #gd four cycle1 #ge gasoline1 #ge ,engines1 horse power of1 #hc last word in submarine1 #hj ,engine works1 how the ,diesel1 #hj how a gasoline1 #ge ,exhaust stroke1 #gh ,experiment in buoyancy1 #fg ,explosive1 amount needed for a torpedo1 #ih high powered1 #ig ,explosive compounds1 #ih ,eye1 the first submarine1 #acj ,eye of submarine1 #ee wonderful1 #abi ,firing mechanism1 #ih ,first ,holland submarine1 #e ,first submarine boat1 #e ,fish1 air bladder of1 #b the first submarine1 #a ,fish of ,mammoth ,cave1 blind1 #eh ,floating dock1 #afb ,flashlight system of signaling1 #adf ,fly1 ,how to1 #aif ,freedom of the seas1 #ahe ,fuel mixture1 #gf ,fulton's experiments on the ,seine ,river1 #aj ,fulton's first steam boat1 #ab ,fulton's first submarine1 #aj ,fulton's ,nautilus1 #aj ,fulton plans to rescue ,napoleon1 #ab ,fulton1 submarine boat inventor1 ,robert1 #aj ,galley of a submarine1 #gj ,game1 naval war1 #if ,garrett1 ,english submarine boat inventor1 #ab ,garrett's steam propelled submarine1 #ab ,gas and electric power combined for the submarine1 #ae ,gas engine1 #cd for the submarine1 #ae ,gas engines1 two cycle1 #hb ,gasoline1 #gi ,gasoline engine1 #ge how it works1 #ge ,gauging the distance of enemy ships1 #acf ,granddaddy of the modern submarine1 #f ,german ,empire1 the1 #bjj ,german policy1 #aae ,grecian galleys of old1 #e ,greek meets ,greek1 when1 #bjf ,gun1 compressed air action1 #aai the ,lewis machine1 #aif need of a quick-action1 #aag spring action1 #aah ,guncotton1 #ig ,guns1 arming merchantmen with1 #ahg ,guns1 arming the submarine with1 #aaf ,guns1 bores of ,allies' submarine1 #abj rapid-fire machine1 #aae ,guns of the chaser1 shooting the1 #aic ,gyro control1 automatic1 #aja ,gyroscope1 action of a1 #ajb compass1 #eh toy1 #ajb ,heart of a submarine1 #gc ,high tension current1 #gi ,high tension magnets1 #gf ,holland and ,lake combined type of boats1 #ag ,holland submarine1 #ea the first1 #e ,holland1 submarine inventor1 #af baby1 #aii ,horse power of submarine engines1 #hc ,horsman ,co41 toy dealers1 #ajb ,how to ,fly1 #aif ,how the hull is made1 #eb ,how to make and work a model submarine1 #bc ,how a real submarine is made and works1 #ea ,how to work your model submarine1 #dg ,hull1 definition1 #ea how it is made1 #eb inside the1 #ee of a model submarine1 #bd ,hydroplanes of a submarine1 #fd ,hydrostatic control1 #ajc ,ichthyoid form1 #b ,inside the hull1 #ee ,installing the motor in model submarine1 #ci ,integral1 definition of1 #afd ,inventing for ,boys1 #eh ,inventors of the submarine1 #d ,inventors of submarine1 ,american1 #g ,knot1 definition of1 #ac ,koenig1 captain of the ,deutschland1 #bjc ,krupp1 ,german gun makers1 #aah ,lake1 his plan for undersea merchantmen1 #bje submarine inventor1 #af submersible1 #ea submersible boat1 #af ,latent heat1 #ajf ,latitude1 how found1 #afg ,laying mine fields in harbors1 #ahg ,lee1 operator of ,bushnell's submarine1 #aj ,lenticular1 definition of1 #acb ,lewis machine gun1 #aif ,lewis1 machine gun inventor1 #aif ,lieutenants1 how to pronounce1 #afe ,light condition1 #fa ,listening in1 #aej ,log distances1 #afg ,longitude1 how found1 #afg ,lupius1 ,austrian torpedo inventor1 #ib ,magic of ,science1 a book1 #acc ,magneto electro machine1 #gi ,magneto1 high tension1 #gf ,magnetic lines of force1 stray1 #eh ,main parts of a submarine1 #eg ,maine was sunk1 way the1 #abb ,making the superstructure of a model submarine1 #da ,mammoth ,cave1 blind fish of1 #eh ,maneuver1 definition of1 #aff ,mayflower1 landing of the1 #e ,merchant submarine1 the first1 #bja ,merchantman1 how a submarine attacks a1 #agg ,mercuric fulminate1 #ii ,millimeter1 definition of1 #aai ,mine compartment1 #fh ,mine1 electric controlled1 #abd ,mine fields in harbors1 laying1 #ahg ,mine layer1 #fi1 #abj ,mine works1 how a contact1 #abc ,mines1 how they are made1 #abb how a submarine lays1 #abj kinds of submarine1 #aba submarine1 #aae ,model submarine1 air control mechanism of a1 #cb ballast tank for a1 #bh ballasting the1 #dj conning tower of a1 #dc how to make and work1 #bc how to work your1 #dg hull of a1 #bd installing motor in1 #ci painting your1 #dg parts of a1 #bd periscope of1 #dh power plant in1 #cd power plant of a1 #bd propeller for a1 #de propeller-shaft for1 #ci pusher control for1 #cf rudder for the1 #de superstructure of a1 #da torpedo1 how to make a1 #ib ,model torpedo1 in action1 the1 #if body of a1 #ib motor for a1 #ie rudders of a1 #ic ,mother ships1 destroying1 #ahh ,mother ship1 what it is1 #afb ,motor for a model torpedo1 #ie ,motor1 rubber strand1 #ie ,munitions1 definition of1 #aae ,mushroom anchor1 #fi ,napoleon1 attempts to rescue with a submarine1 #ab ,nautical mile1 #ac ,nautilus1 ,fulton's first submarine1 #aj ,naval war game1 #if ,navigating room1 #fj ,neutral1 definition of1 #agf ,nordenfelt1 ,swedish submarine boat inventor1 #ac ,nose and tail blocks of a model submarine1 #bf ,offense1 the submarine flotilla as a means of1 #agd ,painting your model submarine1 #dg ,paleozoic era1 submarine of1 #b ,parts of a model submarine1 #bd ,parts of a submarine1 #eb ,pendulum control1 automatic1 #ajd ,percussion caps1 #ajj ,permutation in signaling1 #ade ,periscope1 #ee1 #abi complete view1 #acg the first1 #acj how it got its name1 #abi how it is made1 #acd how to make a simple1 #acj how it works1 #aca ,periscope1 latest type of1 #acf limited use of the1 #ach of the model submarine1 #dh the modern1 #acb ,personnel of a submarine crew1 #aei ,pilgrims on ,plymouth ,rock1 #e ,pipes for model submarine1 #cb ,pipes1 where to buy them1 #cb ,pirate1 submarine1 #d ,plans for a model submarine1 #bc ,plantol1 inventor of the storage battery1 #ad ,power plant1 #cc ,power plant circuit of model submarine1 #dd ,power plant in model submarine1 #cd ,power plant of a model submarine1 #bd1 #cb how it is hooked up1 #cf ,power plant is needed1 why an electric1 #he ,power stroke of engine1 #gg1 #gh ,power unit1 #ge ,prehistoric boy1 #b ,prime mover1 #ge ,prisms1 reflecting1 #acc ,projectile1 how a bow trajectory affects a1 #aid ,projectile1 how a flat trajectory affects a1 #aid ,propeller for a model submarine1 #de ,propeller-shaft of a model submarine1 #ci ,propeller-shaft of a torpedo1 #ajf ,propellers of a torpedo1 the1 #ajf ,pterodactyl1 largest flying creature1 the1 #c ,pumps1 air-compressor1 #fg ,pusher control of a model submarine1 #cf ,quadrant1 #fj ,quick-action guns1 #aag ,raw recruits1 breaking in1 #aff ,reducing valve1 #aja ,reflecting prisms1 #acc ,reserve buoyancy1 #fc1 #fg ,rise of the submarine1 #agb ,rookies1 what they are1 #afd ,roosevelt1 inventor of the ,ananias ,club1 #aci ,rubber strand motor1 #ie ,rudder1 diving1 #ei for the model submarine1 #de ,rudders1 fore diving1 #fd diving1 #ec of a model torpedo1 #ic ,rudders1 of the torpedo1 steering and diving1 #ajg ,scout1 the submarine as a1 #age ,sea anchor1 #fi ,searchlight signal system1 #adf ,semaphore for signaling1 #add ,servo-motor1 the1 #ajc ,setting ballast tank in the hull of model submarine1 #cd ,shape of a submarine1 #eb ,shipping1 definition of1 #ahe tonnage per month1 #bje ,ships1 gauging the distance of enemy1 #acf ,shooting for ,boys1 #aic ,shooting1 the guns of the chaser1 #aic the torpedo1 #ia a torpedo at a ship1 #ajg ,signaling with colored lights1 #adf with the flashlight system1 #adf permutation in1 #ade with the searchlight system1 #adf semaphore for1 #add by underwater 8wireless10 #aed wigwag1 #add ,signaling1 with the wireless telegraph system1 #adg ,signaling systems1 kinds of1 #add underwater1 #aea ,skins1 inner and outer1 #ec ,skin of a model submarine1 #bg ,solder1 how to1 #bh ,soldering fluid1 #bh ,spark plug1 #gi ,specifications for a model submarine1 #bc ,spirit level1 #fj ,spring action gun1 #aah ,squadron1 definition of1 #agb ,steamboat1 ,fulton's first1 #ab ,steam engine1 faults of1 #gd ,steam propelled submarine1 first1 #ab ,steering rudder of a model torpedo1 #ie ,steering rudders1 #ec ,steering wheel1 #ee ,storage batteries1 #ad1 #cd1 #gd1 #he1 #hf ,storage battery and dynamo motor system1 #he ,storage battery1 inventor of the1 #gd ,submarine air chasers1 #aie ,submarine1 air control mechanism of a1 #cb ballast tank for a1 #bh ,submarine1 ballasting the1 #dj as a blockader1 the1 #agf ,submarine bases1 destroying1 #abf ,submarine bell1 #aea ,submarine boat1 the first1 #e what it is1 #af ,submarine bomb1 #i ,submarine chaser1 #hj-;foot1 #ahi #aaj-;foot1 #ahi ,submarine chasers1 #aaf1 #agg kinds of1 #ahh ,submarine in ,chesapeake ,bay1 a giant1 #bjj clock-work of a1 #aj complement of a1 #afd conning tower of a model1 #db construction of ,bushnell's1 #h ,submarine craft1 early conditions on1 #aei crew of a1 #fi crew1 personnel of1 #aei cruising radius of a1 #afb ,submarine destroyers1 #agg the ,deutschland1 #bja development of the1 #d ,submarine duty1 how men are trained for1 #afd electric power for the1 #ae ,submarine engines1 last word in1 #hj ,submarine eye1 the first1 #acj the first merchant1 #bja first steam propelled1 #ab the first torpedo fired by a1 #i first torpedo tube1 #ac ,submarine flotilla as a means of defense1 the1 #agc ,submarine flotilla as a means of offense1 #agd four states of the1 #fa ,fulton's ,nautilus1 #aj ,fulton's turned down1 #aj ,submarine galley1 #gj gas power for the1 #ae a giant1 #bjj granddaddy of the modern1 #f ,submarine1 with guns1 arming the1 #aaf ,bushnell's1 #g ,bushnell's second1 #h guns1 bores of ,allies'1 #abj heart of a1 #gc ,holland1 #ea ,holland type of1 #af how it attacks1 #aga how it attacks a merchantman1 #agg how it came to be1 #a how a chaser chases a1 #aib how it dives1 #fd1 #fh how to make and work a model1 #bc how it is submerged1 #fe how to work your model1 #dg hull of a model1 #bd hydroplanes of a1 #fd installing motor in model1 #ci invention of the electric1 #ad invention of the screw-driven1 #i inventors of the1 #d ,lake type of1 #af the largest1 #bja ,submarine lays mines1 how a1 #abj ,submarine is made and works1 how a real1 #ea main parts of a1 #eg marvelous tongue and ears of the1 #adc ,submarine meets submarine1 when1 #bjf ,submarine mines1 #aae ,submarine mines1 kinds of1 #abj a modern1 #ah new enemy of the1 #aci ,nordenfelt1 #ac painting your model1 #dg ,submarine of the ,paleozoic era1 parts of1 #eb parts of a model1 #bd periscope of the model1 #dh ,submarine pirate1 #d power plant of a model1 #bd power plant in model1 #cd propeller for a model1 #de propeller-shaft for a model1 #ci pusher control for a model1 #cf to rescue ,napoleon1 attempts with a1 #ab rise of the1 #agb ,robert ,fulton's first1 #aj rudder for the model1 #de in the ,russo-,japanese ,war1 #agb schemes for outwitting the1 #ahf as a scout1 the1 #age shape of a1 #eb in the ,spanish-,american ,war1 #agb superstructure of a model1 #da time it takes to dive1 #ff torpedo1 how to make a model1 #ib uses of the1 #agj ,van ,drebel's1 #e what it is1 #a wonderful eye of1 #abi ,submarine works with the fleet1 how the1 #agc ,submarines1 airplanes1 a new enemy of1 #aci ,submarines1 ,american inventors of1 #g cruising radius of ,uncle ,sam's1 #aii the first1 #a ,submarines for the trans-,atlantic service1 #bjf types of1 #af your ,uncle ,sammy's latest1 #aii when they attack in pairs1 #agi ,submerged condition1 #fb ,submerge1 definition of1 #ea how the boat is kept1 #fe ,submersible boat1 ,lake1 #af what it is1 #af ,submersible1 ,lake1 #ea ,suction stroke of engine1 #gg ,superstructure of a model submarine1 #da ,superstructure1 what it is1 #ec ,synthetic stones1 definition of1 #bjc ,tactician1 definition of1 #afd ,targets1 floating1 #afg ,telescope1 how it is made1 #acb how it is made and works1 #acc ,tell-tale1 #ei ,timer for gasoline engines1 #gi ,time fuse1 #aab ,,tnt for torpedoes1 #ig ,tongue of a submarine1 #adc ,torpedo in action1 the model1 #if ,torpedo1 air pressure required to drive1 #aja ,torpedo air tanks1 #ajh automobile1 #ib1 #aae body of the1 #ajj body of a model1 #ib ,torpedo with a cannon in it1 #aaa ,torpedo compartment1 #fh course of a1 #aaj ,torpedo director1 a1 #ajj engine that drives the1 #ajd ,torpedo fired by a submarine1 the first1 #i first submarine1 #ib how it is aimed1 #aji how to make a model submarine1 #ib high powered explosive for the1 #ig how a real one is made1 #ajh how it is shot at a ship1 #ajg is made1 how a real1 #ig making and shooting the1 #ia motor for a model1 #ie ,torpedo practice1 #afg propellers of a1 #ajf ,torpedo1 rudders of a model1 #ic steering and diving rudders for a1 #ajg ,torpedo1 warhead of1 #ic1 #ig weight of1 #fh ,torpedo tube1 the1 #ajh submarine1 first1 #ac ,torpedoes1 ,,tnt for1 #ig ,totally submerged condition1 #fb ,trajectory1 bow1 #aid ,trajectory1 flat1 #aia ,trans-,atlantic submarine service1 #bjf ,trimming tanks1 #eh ,trimming tanks are used1 why1 #fb ,tuning in1 #aej ,two-cycle gas engines1 #hb ,u-boat blockade1 #bjj a way to lift the1 #aie ,u-boat1 ,german captain of a1 #aji ,u-boat menace1 #aie ,u-boat1 what it is1 #a ,u-boats1 ,german1 #ahe plans for destroying the1 #ahg ,uncle ,sammy's latest submarines1 #aii ,uncle ,sammy1 your1 #aif ,underwater signaling system1 #aea ,valve1 reducing1 #aja ,van ,drebel1 submarine boat inventor1 #e ,van ,drebel's experiments on the ,thames ,river1 #f ,van ,drebel's submarine1 #e ,violin transmitter1 #aeb ,violin or bell signaling system1 #ea ,von ,bernstorff1 ,ex-,german ,ambassador to the ,united ,states1 #bjc ,warhead of a torpedo1 #ic1 #ig ,warplane1 #ahi ,water pressure control1 #ajc ,war time conditions1 #afg ,war between ,u4 ,s4 and ,spain1 #abb ,watertight compartments1 #ee ,watertight doors1 #ef ,whitehead1 ,american torpedo inventor1 #ib ,wigwag signaling1 #add ,windjammers of old1 #gj ,wireless aerial1 #ee ,wireless1 how it works1 #adi ,wireless telegraph system1 #adg ,wireless system1 parts of1 #adg ,wireless in war time1 #afh ,work your model submarine1 how to1 #dg ,worm gears1 #ef ,zd1 ,gustave1 ,french submarine inventor1 #af ,,footnotes3 #a ,central ,powers3 ,germany1 ,austria1 and ,bulgaria4 #b ,allies3 ,governments united by a treaty or having common interests4 ,england1 ,france1 ,belgium1 ,russia1 ,italy1 the ,united ,states1 and ,japan are called the ,allies4 #c ,u-,boat3 ,so called because it is an undersea boat1 or ,unterseeboote1 as the ,germans call their submarines4 #d ,paleozoic4--,the next to the lowest geological series of strata4 #e ,the ,pterodactyl was one of these and it was the largest living thing that ever flew4 ,it is pronounced ,ter-o-dak-til4 #f ,a knot is the speed of a boat when she is making #a nautical mile in #a hour4 ,a nautical mile is #f1jhj feet4 #g ,the design1 construction and operation of submarine torpedoes will be found in ,chapter ,v4 #h ,the storage battery was invented by ,gaston ,plant in #ahfj4 ,the electric motor was discovered in #ahgf1 by whom nobody knows4 #i ,these pipes can be bought cut to length and threaded to suit of ,the ,chicago ,model ,works1 #aff ,west ,madison ,street1 ,chicago1 ,ills41 or of ,luther ,h4 ,wightman1 #acb ,milk ,street1 ,boston1 ,mass4 #aj ,the ,l4 ,e4 ,knott ,apparatus ,company1 of ,boston1 ,mass41 sell a standard motor1 as they call it in their catalogue1 for #c4ge4 ,it weighs #a pounds and takes up a space of about #c inches square4 ,powerful little motors can be bought at almost any electrical supply house1 and you can use one of these by building up the base4 #aa ,cells of this kind that measure #b x #b x #f inches on the sides can be bought of the ,manhattan ,electrical ,supply ,company1 of #ag ,park ,place1 ,new ,york ,city4 #ab ,a machinist's saw for sawing metal4 #ac ,the pulley can be bought of dealers in model makers supplies4 ,see footnote on page #cb4 #ad ,you can certainly get it of the ,f4 ,w4 ,devoe and ,c4 ,t4 ,raynolds ,company1 #aja ,fulton ,street1 ,new ,york ,city4 #ae ,the top of the conning tower is called the bridge4 #af ,the hull is the body or shell of a boat or ship4 #ag ,for a description of the gyroscopic compass1 see ,inventing for ,boys1 by the present author and published by the ,frederick ,a4 ,stokes ,company1 ,new ,york4 #ah ,any figure formed by two straight lines which meet is an angle1 also the space between them4 #ai ,for a simple theory of how the steam engine works1 see ,engine ,building for ,boys1 by the present author and published by ,small1 ,maynard ,co41 ,boston4 #bj ,any kind of machine which develops its power at first hand is a prime mover1 as1 for instance1 the water wheel1 steam engine1 and gas engine4 ,an electric motor energized by a storage battery1 or a compressed air motor are only subsidiary movers4 #ba ,a dynamo is an electric machine1 which generates a direct current of electricity1 like a battery4 #bb ,it can be bought of the ,e4 ,i4 ,horsman ,co41 ,toy ,dealers1 ,union ,square1 ,new ,york4 #bc ,the guns and other munitions on a boat are called her armament4 #bd ,the millimeter is the #a-ajjj part of a meter4 ,the meter is the fundamental unit of length used in the metric system of measurement4 ,it is #ci4cg inches4 #be ,lenticular 7pronounced len-tik-u-lar7 means having lenses4 #bf ,telescopes and their construction are fully explained in ,the ,magic of ,science1 by the present author1 and published by ,fleming ,h4 ,revell ,co41 ,new ,york4 #bg #cfj degrees a complete circle4 #bh ,for a complete description of how to make and use wireless apparatus1 and how it works1 see ,the ,book of ,wireless1 by the present author1 and published by ,d4 ,appleton ,co41 ,new ,york4 #bi ,a floating dock is built with a water compartment on each side and a platform on the bottom1 thus leaving a large open space in between to hold a submarine or other vessel4 ,by partly filling the compartments with water the platform sinks into the water deep enough so that the vessel can pass over and on top of it2 then by pumping the water out of the compartments the floating dock is raised and the platform with the vessel on it is lifted out of the water where she can be examined and repaired if necessary4 #cj ,integral means a part of a whole thing which is needed to make it complete4 #ca ,a cipher code is one in which the message is telegraphed in the ,morse alphabet of dots and dashes as usual1 but the words which form the message are given other meanings which have been previously agreed upon1 and this prevents the enemy from knowing what is sent4 #cb ,the word auxiliary in this sense means other smaller and less important craft which give aid to and supports the larger and more powerful ships of the fleet4 #cc ,a squadron is one of the divisions of a fleet4 #cd ,a country that neither helps nor hinders the countries that are at war is said to be neutral4 #ce ,july1 #aiag4 #cf ,a boat's capacity for cargo4 #cg ,the caliber of a gun is the gage1 or diameter of the bore of its barrel4 ,thus a gun of #c-;inch caliber means that the bore is #c inches in diameter2 a gun that has a caliber of #de centimeters means that its bore is #de centimeters across4 ,a centimeter is #a_/ajj of a meter and a meter is #ci4cg inches4 #ch ,for a full description of the trajectory of bullets1 see ,shooting for ,boys1 by the present authors1 and published by ,moffat1 ,yard ,co41 ,new ,york #ci ,a full description of the ,lewis machine gun for airplane work will be found in ,how to ,fly by the present author and published by ,d4 ,appleton and ,co41 of ,new ,york4 #dj ,this means she sinks into the water #ag feet4 #da ,these are real rubies1 sapphires1 and other gems made of chemicals in an oxyhydrogen furnace4 99 99 99 99 99 ,transcriber's ,notes3 ,obvious punctuation errors repaired4 ,page #bi1 8to-together0 changed to 8together0 7bring the ends together7 ,page #id1 8,,ppropeller0 changed to 8,,propeller0 7,,cover ,,and ,,propeller7 ,page #aae1 8no0 changed to 8not0 7not so1 for there7 ,page #abb1 8betwen0 changed to 8between0 7war between the ,united7 ,page #abd1 8torquoise0 changed to 8turquoise0 7the turquoise seas7 ,page #acf1 8,guaging0 changed to 8,gauging0 7,gauging the ,distance of7 ,page #aci1 8runing0 changed to 8running0 7boat is running light7 ,page #aee1 the word of 8telegraph0 was split over two lines and the first half was not italicized but the rest of the phrase for 8telegraph key0 was4 ,this was edited to italicize the whole phrase4 ,page #bah1 8,tactitian0 changed to 8,tactician0 7,tactician1 definition7 ,index1 all items out of alphabetical sequence were rearranged4