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Armour Instituteof Technology CHICAGOILLINOISU. S. A.

The Plan of Organizationembraces

1. The College of Engineering. Offering courses in:Mechanical Engineering Electrical EngineeringCivil Engineering Chemical Engineering andFire Protection Engineering Architecture

These courses are each four years in length, and lead to the degree ofBachelor of Science.2. CommerciaLl Tests,The Department of Tests offers facilities forthe testing of boilers and engine plants, pumping stations, dynamos, motors,and materials of construction ; for the calibration of pressure gauges andelectrical instruments ; for chemical analysis of engineering materialsand for special tests and investigations.3. The Scientific Academy.Preparing students for admission tothe College of Engineering, or to the leading colleges and universities.4. The Evening Cla^sses.Providing courses in engineering andkindred subjects, especially adapted for those who are employed in technicalpursuits during the day, and for those who are studying by correspondence.

The Institute Year Book, or the circular describing theEvening Classes, will be sent upon

application.


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THE TECHNICAL WORLD ADVERTISEMENTS

Compendium af DrawingA COMPLETE CYCLOPEDIARSm For the Library, the Shop, the Studentml^^^^'j^ :

HJSSiM 900 Pages1000 Illustrations. Folding Plates, Etc.SENT

FREEFOR EXAMINATIONSize. 8x 10 inches.OEGULAR price $10.00 reduced nearly one-half in

order to introduce the ^'^ork. No more comprehensivetreatise on drawing ever published. $25.00 would not buy separatevolumes covering the subjects. Practical test questions combine theadvantages of a text book with a Cyclopedia of Drawing.

H. W. Le SOURD. Instructor. >filton Academy, says :" * * have decided to put the books into our drawing room asreference books so you will find check enclosed for another set."INTRODUCTORY OFFER

NOT GOOD AFTER SEPTEMBER 1stBOTH VOLUMES sent free on approval (express prepaid.)Keep them five days.If satisfactory send $1.00 and $1.00 per month for four months there-

after. Otherwise notify us and we wUl transfer them absolutely free.LIST OF AUTHORS AND SUBJECTSPart I Part II

PROF. E. KEXISOX, M. I. T. . . . Xwluninl Dmrla^ PROF. W. H. JAMES, M. I. T Warfclac DrmwfanPROF. H. W. GARDXER, M. I. T. Shadn mad Shadows ' XcckaabaiPROF. D. A. GREGG, M. I. T., Readcrias U Pea aad lak PROF. C. L. GRIFFIX, formerly Pa. State College. Xarhlae DsifaPROF. W. H. LAWREXCE, M. 1. T., PmpwtiTc Urawia^ WM. NEUBECKER. S. Y. Trade School, Slic Betel PUtera DraHi^F. C. BROWX, Architect, Boston, IrcUtectonU Letteria; ' " TlasKithia^

American School of CorrespondenceCHICAGO, ILLINOISMention The Technical World.


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Isn't It Queer?^ Edmund Burke, the English statesman, once said that in political foresight every man wasfifty years behind the times.^[ If he had been a magazine publisher, the chances are that he would either have qualifiedthis statement or else have made it more emphatic.^[ To discern the tide and "take it at the flood," a publisher must sleep with one eye open,and hustle twenty-four hours out of every day. Even then he will meet with many surprises.^ An author said recently to his publisher,


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tr THETECHNICAL WORLD

TABLE OF CONTENTS, AUGUST, 1904The Whitehead Torpedo. By Rob-

ert G. SkerrettThe Govemment and Irrigation Con-

struction. By Guy E. Mitc'hell .The Cooper Hewitt Mercury VaporLamp. By P. H. Thomas . . .A Quarter-Century of Central Station

Engineering. By R. F. Schuchardt,B. S

The Main Picture at the St. LouisExposition. By Cale Gough

Editorial DepartmentThe Machinery of Modern Warfare.By Rulledge Rutherford . .

Auxiliaries of Engine and Boiler Roomson Shipboard. No. II. By Fred-erick D. Herbert, M. E.

Types of German and English Loco-motives. By Frank C. Perkins

Great Technical Schools. LawrenceScientific School, Harvard University, Cambridge, Mass. By Carl SDow, S. B

Shipbuilding on the Great LakesBy Waldon Fawcett

The Education of Technical MenEngineering ProgressThe Auto-Boat ....An AU-Year-Round AutoA Self-Dumping CarA Turbine-Driven YachtA Life-Saving Globe . .Lifting Magnets ....

Page647

660

673

082686

690

696

699

705

715717720721721722723724

Systems of Piping. By Charles LHubbard, M. E

Chalk Talks. No. VI. The Indicator. By Carl S. Dow, S. B. .

Life Stories of Successful Men. TheA. Edison. By Henry M. Hyde

Dinner-Pail PhilosophyScience and InventionBorax in Food HarmfulApparatus for Preventing Seasick

Kegs Made of Steel ....Improved Steam Engine IndicatorNew Desk TelephoneHigh-Speed Motor-Driven PumpConcrete-Steel Railway Tie

Noon-Hour Talks. Habit -A GoodServant or a Bad Master

Consulting DepartmentIndustry and CommerceA Cactus F^arm

Electricity and Vegetation .Wireless Telephony ....Lunkenheimer Exhibit at St. LouisOur Nation's Stock-TakingPanama MinesFree Telephone ServiceAdvances in Wireless TelegraphyThe Marconi CompanyOur Merchant Marine .The Deadly Celluloid . . .

Graduate and Student Notes .Employment Department .Literature

Page726

730

732734

735

735737737733738739

741743

748748784749750750750750751751751

THE TECHNICAL WORLD is a monthly magazine, published the fifteenth of each month by theAmerican School of Correspondence at .\rmour Institute of Technology, and devoted to the pioblems of thetechnical and industrial world, and a treatment of all matters of interest in Applied Science.PRICE : The subscription price is 82 00 per j-ear, payable in advance : single copies, 20 cents.HOW TO R.EMIT : Subscriptions should be sent by draft on Chicago, express order, or moneyorder. Address THE TECHNICAL WORLD5321 Armour Avenue Chicago, Illinois i}

Entered at the Postoffice, Chicago, 111., as second-class mail matter.


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COPYRIGHT, 1904, BY E. CHICKERING.CHARLES W. ELIOT, LL. D.President, Harvard Universiiy.

See Pufre yos.)


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TheTechnical WorldVolume I AUGUST, 1904 No.

The Whitehead TorpedoA Submarine Engine of Destruction v/hich is Doing Very EffectiveWork in the Russo-Japanese War

By ROBERT G. SKERR.ETTFormerly of the Navy Department, Washington, D. C.

THE PART TAKEX by torpedocraft in the present struggle be-tween Russia and Japan hasnaturally brought the torpedo

itself prominently before the world ; andthe public at large is not unreasonablyinterested in that most wonderful instru-ment of destruction which, in its turn,has brought into being the "mosquitofleets" of naval powers.

Historical RetrospectThe disastrously destructive work of

passive submarine mines during the Warof the Rebellion crude though theywere set a number of inventive mindsto thinking ; and, in 1864, Captain Lupuisof the Austrian Navy conceived a styleof small fire ship, or floating torpedo,which should be self-propulsive anddirigible. His idea was to propel thetorpedo by clockwork, and to guide it tothe target by means of lines leading backto a controlling base. After numerousexperiments, he laid his scheme beforethe Austrian naval authorities, whopromptly condemned his method of pro-pulsion and the manner in which he pro-posed to steer his torpedo. In the hourof his greatest difficulty, he met ]\Ir.

Copyright. 1904. by The Technical World,

Whitehead, an Englishman, then incharge of an engineering concern atFiume ; and to Air. Whitehead, as apractical mechanic. Captain Lupuisturned over the problem of making some-thing workable out of his own first crudenotions.

]\Ir. Whitehead promptly abandonedCaptain Lupuis' scheme, and proceededto evolve a torpedo that should run underthe surface, and which, when once startedon its errand of destruction, should beself-controlled in every particular. Thetask he set himself was indeed a difficultone, for it was pioneer work ; but, aftertwo years of nearly ceaseless work andexperimentation, his first torpedo wasready for trial. Having been built insecret, for only his son and a trusted fel-low mechanic were admitted to the mys-tery, its first appearance was all the morestartling.

Lieutenant Armstrong, late of the Brit-ish X'avv, savs"The first Whitehead torpedo was of a very

different shape indeed from those of the pres-ent daj'. It was built of steel, was 14 inches indiameter, 16 inches at the fins, and weighed 300pounds. Its explosive charge was 18 poundsof dynamite. The motive power was com-pressed air charged to a pressure of about 700

(6^)


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648 THE TECHNICAL WORLDpounds to the square inch; and the air cham-ber was made of ordinary boiler plate. Thespeed of the torpedo, when running underfavorable circumstances, was but six knots,and that only for short distances. * * *"The torpedo, although a marvel of ingenu-

ity, was, on the other hand, exceedingly erraticin its performances. In one important par-ticular it continually failed, and that was inthe regularity with which it kept its properdepth in the water. At times it would runskimming along the surface, whilst at othersit dived down to the depths and explored thebottom. Not, by the way, that the torpedoesof the present day do not sometimes do thesame; but still it is the exception and not the

leaked out in time, and the details of themechanism proved to be beautifully andwonderfully simple.Interesting as the gradual development

of this torpedo has been, space now willnot permit us to dwell upon the variousstages of its developmentin whichmany others besides Mr. Whitehead haveworked. From a weapon of most erraticperformance even under favorable con-ditions, it has grown to be the marvelous-ly precise instrument of to-day; and,within its range, so experts claim, it is

COPYRIGHT, 1904, BY R. G. Sr. S. TORPEDO-BOAT FOOTE.

rule, and whenever they indulge in suchvagaries they are at once examined and re-adjusted."Encouraged by the Austrian Govern-ment, who gave the torpedo extensivepractical trial, Mr. Whitehead graduallyevolved an improved order of theweapon, and, among other things, workedout the primary idea of the "balancechamber"that part of the torpedowhich now controls its uniform depth ofsubmergence. So precious was thissecret deemed, that, until a few years ago,the most elaborate precautions weretaken to keep the details from the world.A room with carefully shielded windowskept the curious from seeing in, while asentry stood continually on guard at thedoor. Like most secrets of the sort, it

even more accurate than the best of mod-ern ordnance and is less affected by localconditions. At this very time our ownnaval authorities are experimenting withan improved designthe result purelyof American inventive geniuswhichpromises to make the Whitehead in thisnew form even better and more formida-ble than those that have already scoredso effectually in the Far East.The modern 18-inch Whitehead has aspeed of 28.5 knots for a distance of 800

yards, carries an explosive charge of 132pounds of gun-cotton, weighs somethingover 1.200 pounds, with air stowed inthe air chamber to a pressure of 1,500pounds to the square inch. This mechan-ical fish, which is nearly 17 feet long, is


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THE WHITEHEAD TORPEDO 649made of the finest steel, and is expelledfrom the toqjedo tube either by the im-pulse of a small charge of powder or thethrust of a blast of compressed air.The matter now of interest is a generalnotion of how the torpedo works in thefulfillment of its mission of bearing that

even to its friends, the moment its warhead and primer are shipped. In orderto prevent the striking rod from workingback against the explosive primer of ful-minate of mercur}-, two safet\' devicesare provided. The first is a small pro-peller threaded on to the striking rod.

COURTESY OF "COU.IER'S WEEKLY."DECK TUBE AND PROJECTILE OF .\ TORPEDO-BOAT.deadly charge of gim-cotton certainly tothe target of an enemy's ship.

The HeadThe torpedo is ordinarily supplied withtwo headsthe "practice" head and the

and holding the latter in place until,through the action of the water, after thetorpedo has nm about fourteen yards,thispropeller unscrews itself and to that ex-tent frees the rod. This device is in-tended to make sure that the torpedo gets

LONGITUDINAL SECTION OF 18-INCH WHITEHEAD TORPEDO.P, Ranger or striking rod. g. Safety pin. G, Gun cotton charge. D, Priming charge. R.AirfUsk. J. Charging valve. K. Hydro-static valve. H, Pendulum. M, Engrines. N , Mechanism for controlUng submergence and stoppage. S, Submergence valve.X, Valve case. T. Air lever. O , Immersion servo-motor. L. Pressure regulator. V.Gvroscope. T, Spring for startinggyroscope. TJ, Direction servo-motor. F, Controlling rod to vertical rudders. E. Propellershaft. B, Shaft gearing."war" head. The former is filled onlywith water, while the latter bears thatpowerful charge of gun-cotton. It mustbe plain that without some form of pro-tection against accidental discharge, atorpedo becomes a dangerous neighbor.

safely clear of the firing ship. Xow,when a torpedo is in a submerged tube,the swash of the water, if the vessel beunder way, might work this safety pro-peller loose ; and accordingly, as an addedprecaution, there is a stout shearing pin


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650 THE TECHNICAL WORLDof copper which holds the rod in placeuntil the heavy blow of actual contactbreaks the pin and drives the plungeragainst the primer. For target practice,of course, the war head, ordinarilystowed securely below in a special maga-zine, is replaced by a nose which can behammered and banged without risk of

dry gun-cotton, which is sensitive, andthe initial detonating primer of somethirty odd grains of fulminate of mer-cury, which, when ignited by percussion,expands to 2,500 times its normal size,and deals to the dry gun-cotton a fright-ful blow, and that, in turn detonates theotherwise insensitive wet gun-cotton.

LONGITUDINAL SECTION, SHOWING INTERNAL ARRANGEMENT OF TORPEDO-BOAT DESTROYER.life; and a most recent design of prac-tice head will be made of copper, and willbe soft enovigh to collapse on contact witha ship's side. The object is to use thetorpedo thus supplied, in mimic battle,and to have a means of scoring manyactual hits with safety and without lossof the torpedo.As has been said, the explosive chargeconsists of 132 pounds of gun-cotton.

The Air ChamberImmediately aft of the head comes the

air chamber, which, while carrying air ata pressure of 1,500 pounds to the squareinch, must be able to withstand withoutdeformation a test pressure of 2,250pounds. It is notorious that, while themodern 18-inch Whitehead has carriedfor some years air enough to propel theweapon for 2,000 yards, the torpedo, be-

COPVRIGHT, 1904, R. G. SKERRtTT, PREPARING FOR A RUN.Naval Torpedo Station, Newport, R. I.

This charge is of wet gun-cotton, whichis notoriously insensitive to ordinaryshock and can be roughly handled withthe utmost safety. To make this massdestructive, a very violent blow is neces-sary to detonate it. Herein comes themission of the primer of six ounces of

cause of errors in lateral directions,which multiplied with the distance, wascalled upon to run only for 800 yards.This, however, was changed with theintroduction of a wonderfully clever cor-rective instrument, of which we shallspeak later. The cylinder, or air cham-


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THE WHITEHEAD TORPEDO 651ber, is constructed of the finest of com-pressed steel, which is finally workeddown to a thickness of three-tenths of aninch. When fully charged, it becomesitself an explosive body of no mean force,as more than one accident has proved.

The Balance ChamberNext abaft the air chamber comes the

balance chamber, so long a well-guardedsecret ; and in this water-tight space arethe depth-controlling mechanism andsome of the important valves. Let ussee how the balance mechanism works.Primarilv it consists of two parts : a deli-cately pivoted pendulum or weight, and

can be set to work effectually at depthsof from six to fifteen feet. The valveis connected to one of the arms of thependulum. Now, as the torpedo startsbelow its designed depth, the externalwater pressure, pushing against the In-dia rubber diaphragm and the opposingspring, causes the valve rod to move justto the extent to which the water pressureoverbalances the set spring ; and this mo-tion, in turn, is transmitted to the hori-zontal rudders. The torpedo is in thisway caused to return to its old depth,where the spring again balances the ex-ternal water pressure, and the ruddersreturn to their normal position. If the

U. S. TORPEDO-BOAT DESTROYER PERRY."' Bainbridge " Class of 16 vessels. Length, 245 ft. Breadth, 23 ft. 7H in. Draft, 6 ft. 6 in. Displacement, 420 tons.Contract speed, 29 knots. Coal, 139 tons, .\rmament : 2 long 18-in. Whitehead torpedo tubes

:

2 3-in. rapid fire guns; s 6-pounders. Complement, 73.

a valve afifected by hydrostatic pressure.The pendulum, by its upper arm, is con-nected with a controlling rod leading di-rectly to the horizontal rudders at thetail of the torpedo, which, moving up anddown, control the weapon in a verticaldirection. If the torpedo plunges by thehead, the pendulum, which moves lon-gitudinally, swings forward and bringsthe horizontal rudder up, forcing thetorpedo toward the surface until theweapon lies horizontal once more. This,however, could not by itself keep the tor-pedo at a uniform depth ; and at thispoint the hydrostatic valve comes intoplay. This valve, while open to the in-fluence of the sea, is yet shielded fromthe water by a stout India rubber dia-phragm. The active agent of this valveis a spring, carefully standardized, which

torpedo rises, the spring overcomes thelessened external pressure, and movesthe rudders in the opposite direction,thus forcing the torpedo back to its de-signed submergence. Neither the springnor the pendulum, in itself, is powerfulenough to work the rudders directlyagainst the pressure of the passing waterwhen at full speed. To aid them in thiswork, there is provided a small servo-motor, with air impulse, which, beingsupplied with air through a small valvecontrolled by the pendulum and the hy-drostatic valve, has ample power to movethe rudders.

The Starting ValveThis valve turns the air on to the en-

gines. It is primarily actuated by a smalllever which projects beyond the upper


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652 THE TECHNICAL WORLDsurface of the torpedo, and which istrippedthereby opening the air ductas the torpedo passes out of the tube. Ifthe air, at this time, however, were turnedon full, the engines would be made to raceat the violent rate of 2,000 revolutions aminute, which might rack the torpedoand some of the delicate operative mech-anisms. To prevent this, there is, justback of the starting-valve lever, a smallflat tripper, which, in turn, controls adelay-action valve that checks the pas-sage of air until this tripper has beenthrown back by the action of the waterafter the torpedo has plunged and the

The EnginesThe engines are of the three-cylinder

Brotherhood type and beautifully com-pact ; and, while the cylinders are lessthan four inches in diameter and thepistons have a stroke of only three inches,still they develop an energy of fully 56indicated horse-power. These enginesdrive directly a single shaft, which, inturn, drives directly only one of the twopropellers. The other screw, fitted to asleeve actuated by gearing that engagesthe primary shaft, is driven in the oppo-site direction. This is because the pro-pellers are "rights" and "lefts," so that

..I:!J>


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THE WHITEHEAD TORPEDO 658and near the forward end, is the gA-ro-scopic mechanism for controUing the ver-tical rudders for horizontal steering.

way, the weapon might be deflected fromits true courseespecially so, if the tor-pedo took a roll on entering the water,

COORTE9Y OF "COLLIER'S WEEKL WHEN JACK'S ASHORE.Single-Stick Exercise in the Brooklyn Navy Yard.

The GyroscopeThe g}TOSCope, commonly known as

the Obry gear, is, as the latter name sug-gests, not the invention of Mr. White-head ; and, wonderful as the diving mech-anism is, the Obry gear is still more so,having done more to widen the range ofthe torpedo and to make it more cer-tainly formidable than any other of itsmarvelous mechanical features.

thus causing the horizontal or depth rud-der to become pro tern a vertical or a lat-eral rudder. The Obry gear has now re-duced these errors to a minimum ; but,like all beautifully and delicately adjustedmechanisms, it requires a deal of care andthe most careful sort of handling.The Obry gear is really a finely bal-anced bronze top, weighing less than two

COPYRIGHT, 1904, BY R. DESTROYER" AT AN'CHOR.Until the Obry gear appeared, the

lateral course of the torpedo was veryerratic. Dents or other imperfections inthe surface of the torpedo shell wouldcause it to steer badly. On striking thewater, especially if the vessel were under

gimbals as is the ordinary ship's compass,and, of course, free to move in any di-rection. This top is set spinning by apowerful spring, set free by the samelever that turns on the air as the torpedopasses out of the tube ; and a velocity- of


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654 THE TECHNICAL WORLDrevolution of 2,200 turns a minute is thusgiven to the gyroscope. The axis of theObry or the gyroscopic wheel itself is inline with the longitudinal axis of thetorpedo ; and, no matter how the torpedoswings to right or left, the gyroscope,because of its inherent directive force, re-mains in its original position, which is,of course, the direction in which the tor-pedo was first aimed. Its corrective forceis exercised in this way. To the outerring or gimbal in which the gyroscopeis hung, is attached a rod leading to aservo-motor ; and, as the torpedo swingsto right or left, the gyroscope, remainingstationary, causes the servo-motorjust

Already this article has exceeded itsspace limit, and yet has left much to betold of these "steel babies," each of whichhas its own characteristics, and each ofwhich must accordingly be humored andcoaxed into perfect working accordinglyas they prevail.

It may be of interest to know that theNavy Department is now experimentingwith a turbine-driven torpedo with analcohol superheater, by which still greaterrange and higher speeds will be attained.For a distance of 1,200 yards a speed of35 knots is promised ; and for a range of4,000 yards a torpedo is being built thatwill give a speed of 26 knots. In these

COPYRIGHT, 1904. BY R, G. SKERRETT. BRITISH TORPEDO-BOAT DESTROYER FAME.as with the diving ruddersto operate arod leading to the vertical rudders,which, in turn, are brought to a line withthe Obry, thereby bringing the torpedoback to the direction of original aim.Under the circumstances, the course ofa torpedo is more or less a continuouszigzag; but, because of the rapid cor-rections of the Obry, the curves of de-parture are slight. As a result of theintroduction of the Obry gear, the rangeof the torpedo has been increased consid-erably, and, in a run of 800 yards, a lat-eral deflection of more than eight yards isprohibitive.

cases, the air chambers are considerablyenlarged, and the air is to be stowed inthem at a working pressure of 2,250pounds to the square inch.Such are the constant advances thatare being made ; and it will be with suchperfected instruments of destruction thatwe shall meet our enemy if he come inthe reasonably near future. One especialsignificance of the development of thetorpedo is that it widens the range ofeffectiveness of all craft designed to usethis device in warfare ; and to none will itapply with more force than to the rapidlyevolving perfect submarine.


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The Government and IrrigationConstructionPossibilities of Reclaiming the Arid and Semi-Arid Lands of the West

and South-svest.Import of the National Irrigation ActBy GUY E. MITCHELLON JUNE 17, two years ago, a lawwas passed by Congress provid-

ing for the construction, by theFederal Government, of irriga-

tion dams and ditches in the sixteen aridand semi-arid States and Territories ofthe West. The statement of the propo-nents of this law, that with its passage theAmerican Government became committedto a work, the greatest of any internal

has been specifically applied by the Secre-tary of the Interior, the cabinet officialcharged with the execution of the law,to the construction of huge irrigationworksin Nevada, Arizona, New Mex-ico, Wyoming. North Dakota, Idaho,Washington, and other Statescostingin every instance millions of dollars. Thegreat Tonto dam and canal near Phoenix,Arizona, it is estimated, will cost between

STACKING ALFALFA IN THE YELLOWSTONE VALLEY, MONTANA.Alfalfa, a plant allied to the Clover family, is the great irrigated forage crop of the West. It thrives best under condi-

tions of comparative drouth, and hence is a reliable staple crop in semi-arid regions.

problem yet undertaken by the nation,was greeted with somewhat increduloussmiles and was set down as the phan-tasies of over-enthusiasm. The new lawcarried with it an appropriation of about$6,000,000 ; it also provided that allmoneys received from the sales of thepublic lands of the arid region should beautomatically covered into this "reclama-tion fund." Sales of these lands havebeen large, and the fund now amounts toabout $25,000,000. All of this money

$3,000,000 and $3,500,000. As the workof surveying and reconnoissance has pro-gressed, the claim of the irrigationists ofthe importance of this work does notseem perhaps so extravagant when it isseen that this government policywhich,doubtless, will later become as broad andcomprehe-'sive as our river and harborconstructioncontemplates the reclaim-ing of many million acres of Westerndesert waste, and transforming it intothousands of productive farms and homes.

(655)


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656 THB TECHNICAL WORLDVast Areas Already Irrigated

While irrigation is new as a govern-ment undertaking, farming by its meansis as old as the world's history ; and evenin the United States, where its practicewas begun as a substitute for rainfall,great progress has already been madethrough private enterprise. The lastcensus figures show that, in round num-bers, 7,500,000 acres are irrigated in thewestern half of the country ; and manymagnificent stream barrages have beenerected to control the floods and formartificial lakes, from which the water canbe drained to be applied to the thirstysoil in fertile valleys lying below them.The greatest disciple of American irri-gation was John Wesley Powell, for

the Hydrographic branch of the Geo-logical Survey a well-equipped and well-informed bureau ready to take up im-mediately the great work of irrigationengineering construction.During the last twenty years the Sur-vey has directed its researches through-

out the arid West; and Major Powell'smantle now rests upon the competentshoulders of Frederick Haynes Newell,the present National Hydrographer,whose tutelage began under MajorPowell some fifteen years ago.

Construction and DevelopmentThe work of the Geological Survey

has been of unquestioned benefit to manyof the great private irrigation enterprises

TYPICAL ATTEMPT AT FARMING WITHOUT IRRIGATION.Farm Site near St. Anthony, Idaho.

many years Director of the United StatesGeological Survey. While not an engi-neer. Major Powell was an eminenthydrographer, and, in his wide travelsthroughout the arid region, foresaw in aremarkably accurate degree the ultimatedevelopment through irrigation of thatgreat region. Many of the sections in theWest, which, as a result of his necessarilysomewhat hasty and superficial recon-noissances, he prophetically pictured ashaving great futures before themthrough the storage and utilization oftheir water supplies, are now upon thethreshold of that development throughthe subsequent accurate surveys of theGeological Survey ; and it was due to hislove for, and belief in, that broad aridregion, that Congress has appropriated atdifferent times during the past fifteenyears, over a million dollars for its ex-ploration and survey. When the nationalIrrigation Bill became a law, it found in

that have been projected, some ofwhich have been carried to successfulcompletion. There are two distinctphases, however, of the irrigation ques-tionnamely, engineering construction,and the application of water to land. Suc-cesses in the two branches are by nomeans coincidental. It is an unfortunatefact that many of the private irrigationworks of the West, while they have beengreat successes from an engineeringstandpoint, have been failures as irriga-tion enterprises. This latter fact is dueto an insufficiency of the very data whichthe Government is careful to secure be-fore entering upon any work of construc-tion. An illustrative case is the Sweet-water dam near San Diego, California.This is a magnificent structure of solidmasonry ; but, owing to a lack of knowl-edge concerning the average flow of theSweetwater River, and to the too greatconfidence and glowing representations


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THE GOVERNMENT AND IRRIGATION CONSTRUCTION 657r, rather, misrepresentationsof the

promoters of the project, the orange andlemon groves served by it have sufferedterribly from the want of water, andhave in manv cases reverted from five

The national Government, in its irri-gation operations, is peculiarly fitted toundertake and carry out these greatworks. There are many things to beconsidered besides the mere engineering

THE IRRIGATED "ORAN'GE" VALLEY OF REDLANDS, CALIFORNIA.Watered largelj* bj- pumping from underground sources. Twenty years ago a desert worth only SLOO an acre.hundred dollars an acre land to theoriginal desert condition. For some sevenyears the rainfall on the Sweetwaterwatershed was insufficient, not only tofill the dam and supply the orange or-chards, but even to create a run-off andcover the broad bottom of the reservoir.This splendid dam stands as a monu-ment to the folly of irrigation construc-tion in an arid region without sufficientmeteorological and stream-gauging data,and is but an exaggerated example of alarge number of projects in the Westand particularly the Southwest.

Full Hydrographic Data EssentialToo full and complete data cannot be

accumulated before entering upon anysuch great work, for the most seriousand heartbreaking experiences are likelyto follow upon hasty or ill-advised workof that kind, entailing untold loss andhardship upon the enthusiastic and hope-ful settlers, who in many cases staketheir all upon the expectation of a goodand constant water supply, which, whentoo late, thev discover to be a chimera.

problems involvedthe construction ofa dam across a canyon, and of greatcanals to carry the water impounded tothe farm laterals. The catchment area

1


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'^t


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THE GOVERNMENT AND IRRIGATION CONSTRUCTION 659

AN IRRIGATED ONION PATCH IN CALIFORNIA.ment is the great land and forest ownerand it must with a strong arm conservethe forests covering these watersheds,and thus protect the water supply. Pri-vate capital engaged in lumbering opera-tions is too apt to denude entire mountainranges and foothills of their forest cover,regardless of the rights of the irrigatorsin the plains and valleys below.Seventy-Four Million Acres IrrigableThe President has said in his oflficial

messages that the administration of theremaining public lands and of the na-tion's forests constitutes the greatest ofour internal questions ; and this state-ment cannot be gainsaid by any studentof the subject. According to the detailedestimates of the Geological Survey, thereare some 74 million acres in the W^estwhich can yet be reclaimed from thedesert by irrigation, if all the availablewaters of that region are fully utilizedby storage and otherwise. The Govern-ment still owns in fee simple some 500million acres in that region ; and. whileit has been policy to make it easy in every

way for the settler to acquire his justshare of the public domain for the pur-pose of making a home, yet it is recog-

Redwood Stave Pipe Line.A golden serpent carrying water to the orange orchardsnear Corona, California.nized that the public land laws have beentoo loose in their construction and toobroadly administered, and that largeareas have been absorbed for purposes


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6G0 THE TECHNICAL WORLDof private speculation and gain at the ex-pense of, rather than in the interests of,the home builder.The Congress recently adjourned wit-nessed a preliminary struggle betweenwhat may be termed the forces and in-fluences of the speculator and those ofthe home maker in the attempt to securethe repeal of certain laws which are rec-ognized as inimical to the full settlementand development of the West. Bills wereintroduced for the repeal of the Timber

can be accomplished in the coming shortsession of Congress, remains to be seen.The opponents of the repeal of theselaws are bending every effort to preventtheir consideration in any form, and it isa question when their repeal can be ef-fected. That gross frauds have trans-pired under each and every one of them,is a fact beyond question ; and a long lineof Presidents, Secretaries of the Interior,and Commissioners of the General LandOfifice, after valiant endeavor to admin-

CEMENT IRRIGATION DITC LUCKY" BALDWIN'S RANCH, SOUTHERN CALIFORNIA.No Loss of Water.

and Stone Act, the commutation clauseof the Homestead Act, and the DesertLand Act. _ In spite of the President'sstatement in his first annual message,that these three laws had, in the interestsof the speculator, been abnormally per-verted from the intent with which theywere enacted, and in spite of his specificrecommendation to the present Congress,backed up by the report of a special LandCommission, for the repeal of the Timberand Stone Act, the land speculators andthe live-stock interests prevented anyfinal action on these measures. What

ister them rigorously, have recognizedtheir inherent defects and have officiallyrecommended their repeal.

Public Lands for Home-Makers!The foundation principle years ago

laid down by the advocates of the na-tional irrigation movement, proclaimedthat, while the great irrigation works ofthe West, too vast and complicated forprivate enterprise, should be built by theGovernment, at the same time the nationshould reserve its remaining land foractual settlers; and the laws should be


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THE GOVERNMENT AXD IRRIGATION CONSTRUCTION 661so readjusted as to preclude speculationin land and water, to the end that theirrigable land should be divided up intosmall and productive farms for genuinesettlers and farmers, who would liveupon them and would use the water for

up into i6o-acre farms (or less, within thediscretion of the Government) ; and the set-tler on one of these tracts will have ten yearsin which to reimburse the Government for hispro rata share of the expense of construction$3,200, or at the rate of $320 a year. Wfthinten years this million dollars will all have been

OPEN IRRIGATION FLUME'REPLACED BY REDWOOD PIPE FLCME.The pipe line allows practically no waste of water.

crop-growing and establish permanenthomes.The provisions of the Irrigation Laware stringent in this regard, and thespeculators have virtually admitted thatthis law holds out small hopes for them.It provides that no man can acquire titlefor more than 160 acres under a modi-fication of the Homestead Law, and thenonly after ten years' residence, and im-provement, and the payment to the Gov-ernment in ten annual installments ofhis share of the actual cost of the irriga-tion dam and main-line ditches fromwhich he receives his water. From thisit will also be seen that the law createda revolving fund. The $25,000,000 nowavailable, even without additions, will,in the course of years, reclaim vast areasof land, for it will be used over and overagain. As fast as the works are com-pleted and the money paid back to theGovernment, it will be used over againfor the construction of some new project.To cite a hypothetical caseA dam and a canal cost a million dollars;the project reclaims 50,000 acres, the cost be-ing $20 per acre. This area will be divided

covered back into the "Reclamation fund/' andmost of it will, by that time, be already em-ployed in the construction of some other dam.

The Government to be RepaidThese provisions of the act thus show

a business-like feature, under which theGovernment is to receive back from thesettler every dollar which it invests inthese irrigation enterprises. In otherwords, the expenditure will be of thenature of a government loan to the set-tler without interest.Some of the government irrigationworks will reclaim only governmentlands, which will then be entered by thesettler under the Homestead Act : inothers, some of the land to be reclaimedis already in private ownership. Thisland must come under the governmentterms if it is to receive the benefit of thegovernment storage ; that is, it must bedivided into the government units, notexceeding 160 acres, and pay for its pro-portionate share of the construction. Itis here that the older land laws abovementioned are found to work against thebest interests of the home maker and the


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662 THE TECHNICAL WORLD

CONSTRUCTING MORENO ROCK-FILL DAM. SAN DIEGO COUNTY, SOUTHERN CALIFORNIA.Explosion, August 4, 1897, of 25 tons of giant powder, displacing 200,000 tons of rock.

acquired without residence or cultivation,or with only a pretense thereat. Theyare entered by speculators who do notdesire to live upon them after they shallhave been irrigated, but who propose tostand between the Government and thereal settler, taking their profit out of thelatter, and endangering the success of thenational irrigation policy.The reason for the failure of so manyof the large private irrigation schemesin the West, is traceable largely to theexcessive price demanded for the landsand water, shutting out the settler with-out capital other than his strong armsand resolute heart to enable him to carvea home out of the desert. The conse-quence has been that the irrigated landshave not been fully colonized, and theincome has been insufificient to keep upthe interest on the irrigation bonds, thecost of repairs, and the annual chargeson the works. While the Governmentis in a position where it cannot be forcedinto foreclosure, the success of its workwill depend upon the prompt coloniza-tion of the lands when the water isturned upon them, and upon the repay-ment, by the settlers, of its investment.If the grim speculator stands between,asking an exorbitant price for landswhich he has entered under these variousland acts by an evasion of the spirit if

First Preparations for Bed-Rock Drilling onColorado River.The full plans of the Government contemplate the Irriga-

tion of about 1,200,000 acres of alluvial land in therich semi-tropical basin of the Lower Col-orado in California and Arizona.

country. Lands which it is thought willprobably be irrigated by the Government,are entered under these acts ; and title is


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THE GOVERNMES'T AXD IRRIGATION CONSTRUCTIONnot of the letter of the law, the successof every such government work will beimperiled and menaced.Government Reservations Insufficient

It is true that the Irrigation Act empowers the Government to reserve fromsuch specutetive entry any lands which itis proposed to irrigate ; but this can bedone only after sufficient preliminan.-surv-ey to warrant the Government inproclaiming- its intention to irrigate. Themost extensive and exhaustive sur\^eysthroughout the entire arid West must becarried on, not only during the years im-mediately ahead, but for decades, beforeall the land capable of uUimate irrigationcan be determined upon. In the mean-time the shrewd land dealers of the vari-ous localities are more or less conversantwith the local situations; and, as soonas a government sur\-eyor alights from atrain and proceeds to make even a pre-liminarv reconnoissance of some reser\-oir

the sites prove advantageous, can be com-pleted and title secured. In this manner,under the various methods and schemes

Site of one of the Proposed Government Dams cnthe lovter colorado river.for public land absorption, the enterpris-ing land dealer will continue to standbetween the Government and the home

PROPOSED GOVERNMENT CANAL FROM ST. MARY'S RIVER, MONTANA.site and tributary- lands, speculators im-mediately awake to the possibility ofmaking large fortunes, and assume con-trol of the proposed irrigable lands bymeans of dummy land entries, which, if

maker as long as these speculative landlaws remain upon the statute book.The days of engineering constructionin the W'est unaccompanied by the vitalquestions of sufficient water supply and


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664 THE TECHNICAL WORLD

SWEETWATER DAM, SAN DIEGO. SOUTHERN CALIFORNIA, LOOKING UP STREAM.A Monumental Example of the Folly ot Irrigation Schemes Based on Insufficient Meteorological and HydrographicData.assured colonization, have passed. Be-fore advertising for bids for dam andditch building, the Secretary of the In-terior must work out the problem of thecertain success of the irrigation com-munities to be supplied from the govern-ment reservoir.

Substantial Engineering ConstructionOn the other hand, with the adminis-tration of the public domain based upon

the principle that the lands of the nationshall be preserved for the men andwomen who will go upon them and maketheir homes and live there, the engineer-

SWEETWATER DAM, LOOKING DOWN STREAI


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THE GOVERNMENT AXD IRRIGATION CONSTRUCTION 665ing features of the work, though greatin extent, present a comparatively simpleproblem. Unlike much of the privateirrigation construction with which the

rebuilding by the time the irrigators havefinished their annual payments and owntheir proportionate share in the damsand ditches.

PROPOSED GOVERNMENT RESERVOIR, SAN CARLOS, ARIZONA.To irrigate more than lOO.OCO acres. From Geological Survey plan.

West has been cursed, the governmentworks will be built for all time. Follow-ing the preliminary work of the hydrog-raphers, the most eminent consultingengineers in the world are called to passupon the plans worked out by the con-struction engineers of the GeologicalSurvey. Where great dams 200, 250, or300 feet in height are to be wedged inbetween the granite or tough sandstonewalls of mountain canyons, they will be-come as fixed and everlasting as thetowering rocks which they connect. Hy-drographer Newell has stated as an il-lustrative parallel, that the governmentirrigation works are to be built somewhatafter the manner of the modern railroadwith an idea to the most substantialconstruction and low cost of mainte-nance. In other words, it is not pro-posed to build structures which willeither be carried away by flood or require

Origin of the Geological Survey-In favorably reporting a bill for the

creation of the Geological Survey, from^0.


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THE TECHNICAL WORLDAbrani S. Hewitt of New York deliveredthese statesmanlike remarks

"I never contemplate the great maps of theUnited States which hang in this hall, orconsider the natural resources of this broadcontinent, without a deep feeling of wonder,love, and praise. * * *"When we come to contemplate the wholefield of these natural resources available forfood, for industry, and for commerce ; whenwe attempt to grasp in one act of thought thelength and breadth of the riches with whichthe Maker of the universe has loaded this con-tinent on which happily our lot is cast; whenwe try to realize how every possible want, everymaterial aspiration of man is bounteously pro-vided for; when we consider how measurelessare the values which spring into being at thetouch of modern industry, and how thesevalues when once created are solid and realand become incorporated into the enduringstructure of human society; we may begin toestimate properly the measure of responsibilitywhich rests upon this nation and its chosenrulers, not merely to preserve unharmed thepriceless boon of civil liberty which leaves theindividual citizen free to do his share in thework of development, but to adopt such meas-ures as will prevent the waste of natural re-sources, rlear the way of progress, and pro-rnote the triumphs of civilization. * * *

"Nations may spring into being, generatedby the force of ideas alone; but the vigorousmanhood, the mature growth of a State, canbe nurtured and built up only upon the abun-dant and manifold productions of the earth.Nations become great and independent as theydevelop a genius for grasping the forces andmaterials of nature within their reach, andconverting them into a steady flowing streamof wealth and comfort."

If these broad ideas shall prevail andbe applied to our Western lands, andshall be carried a step further, to the endthat the nation shall utilize its greatestnational assetits land and its waterdeveloping it to such an extent that theformer may become populated with thecitizens of the Republic, living on theland, drawing their livelihood therefrom,and contributing to the general wealth,as laid down in the principles embodiedin the national Irrigation Act, the presentgeneration will witness a vast Westerngrowth which will be another manifesta-tion to the world of the mighty andgrowing resources of this continent.

The Cooper He^vitt Mercury Vapor LampAn Invention -which may Revolutionize Modern Lighting Methods, and -which

Broadens the Range of Our Kno-wledge of Physical Phenomena

By P. H. THOMASTHE COOPER HEWITT MER-CURY VAPOR LAMP is oneof the most striking of the manyrecent newcomers in the field of

Applied Science. Most of the readers ofThe Technical World know of thisnew type of electric lamp through the re-ports of demonstrations by Mr. Hewittand others, and more recently, perhaps,through its actual commercial use forvarious purposes.

Practically all earlier forms of lampinvolve the production of light by meansof incandescent solidsfor example, in-candescent carboneither in flames, inthe electric arc, or in the thin filamentsof incandescent lamps ; or, sometimes,other material raised to incandescence byheat, as in the Welsbach mantle. In theCooper Hewitt lamp, on the other hand,the electric current causes light to beemitted by the vapor of mercury at an


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COOPER HEWITT MERCURY VAPOR LAMP 667extremely low pressure in an exiiaustedtube. The lamp, as ordinarily construct-ed for actual use, consists of a glass tubeabout an inch in diameter and from twoto four feet long. The tube is carefullysealed and the air exhausted, a littleliquid mercury being enclosed, fromwhich there evaporates a small quantityof mercury vapor.The Cooper Hewitt lamp first attractsattention through its unusual color, orrather its unexpected effect upon thecolor of objects seen under its light. But,seriously, its chief scientific interest re-sults from the fact that it elucidates anew group of phenomena previously littleunderstood. It has a great practicalvalue because it provides an extremelyabundant and efficient light of a qualitymost excellently fitted for many kindsof work.

Forms of Vacuum LampsThe passage of electricity through avacuum is the underlying principle of the

Cooper Hewitt light. There are, how-ever, other types of apparatus in whichelectricity passes through a vacuum, sothat this alone will not serve to distin-guish Mr. Hewitt's apparatus from thatof other scientists. The well-known"Geissler tubes." "Crookes tubes," and"cathode-ray tubes" are examples of pre-viously used types of apparatus in whichelectricity passes through a vacuum.The Geissler tube consists of a sealedglass container, often made in fantasticshapes, having a wire leading throughthe glass at each end. and containing asmall quantity of rarefied gas of somekind or other within the chamber. Anintermittent current of electricity causesin this a faint glow, whose color varieswith the composition of the gas inside,often giving most beautiful effects. Thesetubes, however, give so little light as tobe shown to advantage only in the dark.The Crookes tube also consists of aglass container, usually less complicatedin form than the Geissler tube, in whichas perfect a vacuum as possible is pro-duced. It has terminals similar to thoseof the Geissler tube, and, when operatedby a current, serves, similarly to the lat-ter, to give a weak phosphorescent light.The cathode-ray tube is similar to theCrookes tube in construction, but, instead

of giving fluorescence, serves for the pro-duction of rays for other purposes.

Superiority of the Mercury VaporLampBy none of the types of apparatus just

. described can a useful quantity of illu-mination be produced, while, on the otherhand, from the Cooper Hewitt lamp avery abundant light is obtained. What isthe essential difference between them?It is twofold. In the operation of theGeissler and Crookes tubes, a high-volt-age intermittent current of small powxrmust be usedsuch a current as is ob-tained from an induction coil by usinga current interrupter in the supply cir-cuit according to the methods well knownfor such coils. As a result, no consider-able amount of power can be convertedinto light, on account of the practicallimitations of the induction coil and alsoof the tubes themselves. The CooperHewitt lamp, on the other hand, operateswith direct current at relatively low volt-agesfor example, on lOO-volt to 120-volt circuits, such as are regularly usedfor incandescent lamps. As a conse-quence, comparatively large amounts ofpower can be utilized for the productionof light in such a form as to be readilyavailable. The efficiency of the CooperHewitt lamps is very much higher thanthat of the other types of vacuum ap-paratus.

D. MacFarlan Moore has recently pro-duced a lamp upon the principle of theGeissler tube, which is a marked advanceover the laboratory type, but which can-not compare in illuminating power andefficiency with the Cooper Hewitt mer-cury vapor lamp. It has considerableactinic power, however, and can be usedfor photographic purposes with consider-able effectiveness.The second difference, and, scientific-ally speaking, the distinguishing differ-ence, between the two types of vacuumapparatus, lies in the condition of the"negative electrode resistance," so called.In a Cooper Hewitt lamp a very great re-sistance to the starting of current existsat the "negative electrode." which re-sistance may disappear during operationunder the proper conditions. The fullerexplanation of this phenomenon must be


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THE TECHNICAL WORLDdeferred a little. In the old type ofvacuum-tube apparatus, this "negativeelectrode resistance" resists the passageof current and must be continuously

troduce the electricity into the vacuum.One of these electrodes"the negative,"so called, that is, the electrode connectedto the negative supply wireis usually of

FIG. 1. DIAGRAM OF COOPER HEWITT LAMP.overcome ; hence the use of the very highpotentials of the induction coils. Inthe Cooper Hewitt lamp this resistanceis practically eliminated after the startof the apparatus, as it is reduced to per-haps a one-thousandth part of its initialvalue. This fact explains why the CooperHewitt apparatus is much the more effi-cient. Commercial FormsThe general form of apparatus as used

for illuminating purposes may be seenin Fig. I. There is a glass tube with anenlargement on one end, sealed perfectlyair-tight. This tube, in the lamp shown,

mercury, since the negative disintegratesor "evaporates" during operation, andwould ultimately disappear were it notliquid so as to be continually reformed bythe flowing back of the evaporated ma-terial. The other electrode may be ofmercury or any other conductor of elec-tricity. In the lamp in Fig. i, an iron cupabout ^ inch in diameter is used. Theenlargement at one end of the tube givescondensing space for cooling the mer-cury that evaporates from the negativeelectrode, and is called the "condensingchamber."

It is necessary to use a resistance and

t


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COOPER HEWITT MERCURY VAPOR LAMPincandescent lamp has a strong reddishor yellow cast. When objects, however,are viewed by the Cooper Hewitt light,it is found that many have their colorsmodified, while some have their colorsgreatly altered. Black and white are notaffected. Many greens and blues arebrought out very beautifully, while yel-lows are given a greenish cast, and redsare turned black or ver>- much darkened.This is especially true of flesh tints in thehuman skin, and the effect is most start-ling to one unaccustomed to it. The"color" IS wholly taken out of the skin.

In spite of this startling characteristic,the quality of the light is very desirablefor many purposes, as it is found excep-tionally easy for the eyes, and one soonbecomes accustomed to the color distor-tion. For factory lighting, machineshops, etc., the economy and the absenceof shadows, which result from the longtube and the lack of exceedingly brightpoints, give the lamp a great advantage.Figs. 3 and 4 show two forms adaptedfor general illumination. These lampsoperate normally on 3.5 amperes directcurrent from 100- to 120-volt mains.Their efficiency is about five tenths tosix tenths of a watt per candle-power.The Cooper Hewitt light has verygreat actinic power ; that is, it is rich inthe violet and ultra-violet rays which aresupposed to be the active agents in pho-tography, blue printing, etc. In Figs.5 and 6 are shown arrangements adaptedto portrait work and photo-engraving re-spectively. The photograph reproducedin Fig. 8 was taken by means of the light

Fig. 3. Horizontal Type of Lamp in Operation.Iron cnp, positive electrode.Condensing chamber at

right-hand end.

from the lamp itself shown in the man'shands.

Starting ResistanceThe Cooper Hewitt apparatus has ver}'

unusual electrical characteristics, fore-most of which is its resistance to starting.As already hinted, when normal oper-

ating voltage is applied to such a lamp,no current whatever flows. This con-dition remains unchanged as the voltageis raised, until, finally, when the strainreaches several thousand volts, the lampstarts, whereupon the voltage may im-mediately be dropped to its normal op-erating value and the lamp will continueto run. The lamp may readily be startedby a single high-potential impulse froman induction coil. It is found that the

Fig. 4. Horizontal Lamp for Gener.\l Illumination

resistance resides practically altogether atthe surface of the "negative electrode."The lamp may be started by anothermethod without the use of the momentaryhigh potential. If by any means a metal-lic circuit be completed between the elec-trodes within the tube so that current canflow without entering the vacuum spaceproper, and if this circuit be then brokenbetween the electrodes, it is found thatthe current is not thereby interrupted,but flows across the break through thevapor space, which is the equivalent ofstarting the apparatus. Some tv-pes ofCooper Hewitt lamp are started by thefirst method, that is, by means of themomentary high potential, which is se-cured from an induction coil and quick-break switch : while others are started,by tilting in such a manner that the mer-cury used in the negative electrode flowsto the positive, forming a complete con-ducting bridge of mercury between the


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670 THE TECHNICAL WORLDtwo electrodes, through which the cur-rent starts. The lamp is then tilted backto its original position. As the mercurybridge breaks, the current enters thevacuum space, and, as the mercury runsback to its proper place at one end, thecurrent traverses the full length of thetube and is in normal operation.

Voltage of the LampThe lamp has also peculiar character-

istics in addition to the "negative elec-

FiG. 5. Skylight Outfit for Photographer's Studio,TO Replace Daylight.

trode resistance," as the resistance tostarting is called. For instance, the volt-age across the lamp with currents largerthan three amperes is almost constant,independent of the current flowing. Thisis different from an ordinary resistance,such as that found in the incandescentlamp, and resembles more nearly the re-sistance of a motor or battery. That is,the Cooper Hewitt lamp has no trueohmic resistance. The voltage across thelamp is not exactly constant, howeverand there is a minimum voltage for eachlamp occurring when the current isneither very great nor very small. Thisminimum voltage is the point at whichthe lamp should be operated for the mostefficient production of light. Fig. 7 showsthe relation between voltage and currentin one of the more common types ofCooper Hewitt lamp. The distance of

the curved line above the horizontal lineindicates the voltage corresponding toany current indicated upon the horizontalline.The reason the voltage on the lamp be-comes greater with heavy currents, isthat the mercury becomes excessively hot,causing considerable vaporization, whichincreases the resistance of the tube tothe current ; evidently an increase of at-mospheric temperature which will also in-crease the temperature of the mercury,will have an effect of the same kind. Itwill readily be seen that this peculiarproperty of the Hewitt light, by whichthe voltage across the lamp decreases asthe current is increasing, means that if thelamp be placed across constant-potentialsupply mains, an excessive current willtend to flow, since the more the currentflows the less the resistance. It is to cor-rect this tendency that the ohmic resist-ance is used in series with the lamp.By experimental analysis it is foundthat the voltage across the lamp consistsof three parts : The voltage drop acrossthe negative electrode, which is nearlyindependent of current ; the voltage dropacross the positive electrode, which alsois nearly independent of current ; and thevoltage upon the vapor column, which ishigh on small currents and less on lowercurrents. The voltage on the vapor de-pends entirely upon the vapor pressurethe greater the pressure the greater thevoltage. These three voltages add upto make the total voltage upon the lamp.

The Modern Theory of ElectricityIt is most interesting to apply to the

Hewitt lamp the new theory of electric-ity, which has recently been proposed as aresult of the work done upon cathode-ray tubes and radio-active substances.According to this theorv, which has al-ready been hinted at in 'I'iie TechnicalWorld, electricity must be considered asconstituted of extremely small particles,or "electrons," not over one-thousandthpart the weight of a hydrogen atom. Acurrent of electricity is a moving streamof these electrons. In traversing avacuum they pass from the negative tothe positive electrode, and are spoken ofas "negative" electricity. Instead of call-ing them negative electricity, it is muchsimpler for many purposes to assume that


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COOPER HEWITT MERCURY VAPOR LAMP 671the old convention adopted long ago asto the direction of the electric currentin a circuit is opposite to the true direc-tion, and simply to assume that electronsare electricity and that electricity actuallyflows in the direction opposite to thatnow generally stated in the textbooks.In the cathode-ray tubes the electronstravel with enormous velocity, manythousands of miles a second.A perfectly cold mercury vapor lampis like a Crookes tube, except as re-gards its negative electrode resistanceand electricity, in passing through ether,gives no light, and meets no resistancefrom the vacuum other than that offeredby the electrodes. Now, if the lamp be-comes somewhat warm, and the mercurymolecules are evaporated from the elec-trodes into the vacuum space, these mole-cules will interfere with the passage ofthe electrons, causing collisions whichwill check the electrons for the moment,heat the mercury molecules, and, further,cause them to give flashes of light (lightbeing now supposed to be caused by theagitation of the atoms of the light-givingsubstance). The electromotive force ex-isting between the electrodes will, how-ever, urge on the electrons, which willfinally, after striking other mercurymolecules, reach the positive electrode.The more molecules there are evaporatedfrom the electrodes, the greater will bethe hindrance to the passage of the elec-trons, and the greater the voltage lostin the tube ; also the greater will be thenumber of flashes of light given out bythe vibrating particles. This action ex-plains the increase in voltage on the lamp,which has been stated to follow an in-crease in its temperature ; it also explainswhy a good vacuum is necessary in theoperation of the lamp. It would take atremendous force to drive the electronsthrough the same length of tube filledwith air at atmospheric pressure, on ac-count of the vast number of moleculesof oxygen and nitrogen to obstruct theirpassage. Color TheoryTo make clear the peculiar color effectsof the Cooper Hewitt lamp, it is neces-sary to state briefly the theory of lightas it explains the color of objects.We see objects only on account of thefact that they reflect light to our eyes.

Strictly speaking, objects have no colorof their own. \Ve judge of their colorby the color of the light which comesfrom them. Light itself may be saidto have color, but objects, of themselves,do not. Daylight as well as most arti-ficial light is a mixture of rays of allcolors from red to violet in various pro-portions. The particular mixture foundin sunlight is called white. Now, in gen-eral, objects have the power of absorbingor destroying light rays of some colors,which strike them, and of reflecting otherrays. The result is that the light whichcomes to our eyes from these objects is

Fig. 6. Photo-Engraver's Outfit.

no longer that same mixture of coloredrays that it was originally, but certaincolors have been destroyed, leaving somecolor in excess, and the object is said tohave this color.

For example, grass absorbs nearly allother colors of light which fall upon it,and reflects only the green, so that wesay the grass is green. The grass itself


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672 THE TECHNICAL WORLDhas no color, but only the power of re-flecting green, and of absorbing all othercolors that fall upon it. There are somesubstances which can reflect all colors;and these appear white when seen by sun-light, because sunlight itself is white.There are also some substances whichabsorb all colors ; and these seem black,as no light is reflected from them. If,instead of daylight, we have a red light,and it should fall upon grass, the redwould be absorbed, and no light wouldbe reflected to the eye, so that the grasswould appear black. Similarly, if seenby yellow or violet light, it would appearblack ; seen by green light, it would, ofcourse, appear green. A white objectcan be seen by any color of light andhas the color of this light. A black ob-ject looks the same in any light, as allcolors are absorbed and none reflectedby it.

All objects emit light when they arehot enough. Solid and liquid substancesgive out white light, a good deal likesunlightthat is, consisting of a mixtureof all colors. Gases, however, arepeculiar to themselves ; they give onlyone particular color, or sometimes two,three, four, or occasionally even moreparticular colors, but never very many,whereas sunlight contains thousands andthousands of shades. The result is thatwhen various objects are seen by a lightfrom a hot gas, they have the opportunity

VoLTA&E OF Cooper Hewitt Lamp WITHVAHYING CURRENTS- Z LAMPS FOK 110 VOLTS.


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AMERICAN CENTRAL STATION ENGINEERING 673number of single sounds all of the samepitch. This will give the effect of a con-tinuous sound, which represents thesteady light from the lamp. This uni-formity of pitch corresponds to thepeculiar single colors given by the mer-cury vapor. Evidently, the greater thenumber of bells, the greater the amountof sound, and the greater the force re-quired to drive the bullets through thespace. This increase of force correspondsto the increase of lamp voltage with anincrease of mercury pressure.Would space permit, this theory of

electrons might be carried much furtherto explain the properties of the lamp ; butenough has been said to show how read-ily the theory explains its chief charac-teristics.

In addition to the furnishing of a newtype of artificial light, the Cooper Hewittapparatus may be applied to other usefulpurposes, such as the conversion of alter-nating current into direct current, etc.This, together with the new light thrownon the physical phenomena of the passageof electricity through a vacuum, makesMr. Hewitt's work of surpassing interest.

A Quarter-Century of American CentralStation Engineering

The Marvelously Rapid Progress in Electrical Engineering -which has Revolu-tionized Industrial Conditions.

By R. F. SCHUCHARDTPERHAPS few of the younger gen-eration of men engaged in the

various branches of electricalwork realize that the central sta-tion industry, so large and permanent aninstitution of our present civic life, isbarely a quarter of a century old. Mar-velous, indeed, has been the progress ofthis industry, and its wheels of inventionand development are still whirlingrapidly on. No engineer who values hisreputation would venture to prophesywhat the next quarter-century will bringus.

Twenty-five years ago the commercialelectric lamp was unknown. To-daythere are in service in the United Statesalone nearly twenty million incandescentlamps, to say nothing of the tens of thou-sands of arc lamps and the few hundredthousand horse-power in electric motors.To-day nearly every city of any impor-tance in America has an electric plant

furnishing light and power to its citi-zens. ^Magnificent stations have sprungup in our large cities, representing mil-lions of dollars in investment ; and elec-tricity is being distributed to nearly everycorner of those cities. It may be of in-terest, then, to look back over the his-tory of this industry, and see some of thesteps by which it reached its presentsplendid growth.

In all the world's history of industrialprogress, perhaps no chapter is more fullof scientific and heroic romance than thatdealing with the birth of the electric lightindustry. To the youth of to-day nostory could give greater inspiration thanthat of the men who were the leadingfiguresthe great minds and the ener-getic workersduring the early days ofcentral station development. These mencontributed as much toward the nation'sgrowth as did our warriors and ourstatesmen. Most of them are still with


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674 THE TECHNICAL WORLDus, and are still active in solving en-gineering problems. It was the goodfortune of the readers of the ElectricalWorld and Engineer to see, in its recent30th anniversary issue, some interestingreminiscences of these early workers, andthus have brought home to them theyouthful age of the industry. It is not thepurpose of this paper, however, to relatebiography, but rather to treat of themore prosaic subject of the growth of the

rgFig. 1. Connections of Edison Constant-PotentialSystem Patented in 1880.central station from its small beginningsto the magnificent proportions of to-day.

Brush Arc SystemIn 1879 there was erected in Cleve-land, Ohio, a series-arc system designed

"!l'^'


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AMERICAN CENTRAL STATION ENGINEERING 675

Fig. 4. Tile Duct System Laid in Conxrete.Edison Constant-Potential SystemThe master mind of Thomas Edison

soon saw that a series system with high

voltage on each line would never becomecommercial for general house lighting;so he set about to design a system whichshould properly meet the required con-ditions. On February 5, 1880, he pat-ented a constant-potential system consist-ing of feeders and mains, with the loadconnected in parallel, or multiple arc, be-tween the two wires forming the positiveand the negative conductors, as shown inFig. I. How well this succeeded is evi-denced by the present almost universalniEDig. 5. Connections of 3-Wire D. C. System.use of this system of connection. A low-resistance lamp would obviously not doon a constant-potential circuit ; and Edi-son, therefore, had first to develop a high-resistance lamp. His success in thisis well-known history. His patent for thelamp is dated November 4, 1879. InDecember of that year he had a numberof these lamps on exhibition at his labo-ratory in Menlo Park, and the followingyear he equipped his house and groundswith the lamps. The newspapers of the

FIG. 6. DYNAMO ROOM. OLD ADAMS STREET STATION. CHICAGO EDISON COMPANY.


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676 THE TECHNICAL WORLDtime were filled with accounts of whatthe "Wizard of Menlo Park" had accom-plished, and visitors flocked to the townin great numbers to see the lights.

started January 12, 1882, at HolbornViaduct in London, England. The sec-ond and the third Jumbo dynamos (sonamed because of their bulk), built by

FIG. 7. NORTH SIDE STATION, CHICAGO EDISON COMPANY, CLARK AND OAK STREETS.The first Edison plant for the public

supply of current was located at Apple-ton, Wis., where, in 1881, was installedone of the first of the lanky bipolar dy-iF"


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AMERICAX CEXTRAL STATION ENGINEERING 677for some years been done with lead-cov-ered cables drawn into ducts laid in thestreets, the connections being made inmanholes. Fig. 3 shows a duct systemmade of cement-lined iron pipes laid in abed of concrete; and in Pig. 4 is a similarduct line made of tile. The short sec-tions of the tile can be seen lying at theside, while a manhole under constructionis shown in the foreground.The Edison Electric IlluminatingCompany of Xew York had been or-

Three-Wire Direct-Current SystemLate in 1882 Edison made a series of

experiments with a view toward a moreeconomical distribution system, and hethen devised the well-known three-wiresystem, in which two generators are con-nected in series, and a conductor is con-nected to their common join, and run outinto the system as the neutral wire. Thisis illustrated in Fig. 5. By connectingthe lights so that the load on the twosides of the svstem is nearlv balanced, a

FIG. 9. SWITCHBOARD AT HARRISON STREET STATION.A comparison with the early form of switchboard, illustrated in Fig. 8, shows advance made in design in 1S93.

ganized, and the historic station on PearlStreet was built. On September 4. 1882,the station first sent out current to its59 customers, with a total connected loadof 1,284 lamps. The dynamos, of whichthere were six, were of the Jumbo t>-pe,each of 75 K. W. capacity, direct-con-nected to Porter-Allen engines of 200H. P. each, running at a speed of 350revolutions per minute. The success ofthis station led to the establishment ofothers, and in 1883 a few Edison stationswere started in Europe. The alternating-current station did not appear until later.

saving of about sixty per cent was ef-fected in the amount of copper necessaryto transmit the same energy. This is dueto the fact that, in the three-wire sys-tem, the current is transmitted at 220volts instead of at 1 10, thus requiring forthe same number of watts only half asmany amperes ; and therefore a smallerwire can be used. If the load on the twosides of the system is not balanced, thedifference between the current in thepositive conductor and that in the nega-tive will come back to the dynamos overthe neutral wire. Dr. John Hopkinson,


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678 THE TECHNICAL WORLDin England, and Werner von Siemens,in Germany, devised similar systems atabout the same time.

It was not until 1884 that electric mo-tors were first used in New York ; and

using 220-volt motors on the Edisonsystem, connecting them to the two outermains instead of between one outer andthe neutral ( 1 10 volts) , as had heretoforebeen done.

FIG. 10. REAR OF GENERATOR GALLERY, HARRISON STREET STATION SWITCHBOARD.the arc lamp designed for parallel con-nection on the constant-potential circuitwas not introduced until 1889. The suc-cess of the constant-potential arc lampsmade it possible for central stations to doall classes of business with one system ofdistributionwhich was an importantstep in the march of progress. In 1890the Duane Street Station was built in theheart of the Edison system, with a totalengine capacity of 11,800 H. P. in direct-connected units.

In Boston the Edison Electric

19040800 - The Whitehead Torpedo Deck Tube

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