,,nature',s ,,miracles1 ,,vol4 ,,iii4   
,electricity                            
and ,magnetism                          
,,by                        ,,elisha    
,,gray1 ,,ph4,d41 ,,ll4,d4              
,,william ,,briggs                      
#bi-cc ,richmond ,st4 ,west1 ,toronto   
,c4 ,w4 ,,coates1 ,montreal1 ,que4      
,s4 ,f4 ,,huestis1 ,halifax1 ,n4,s4     
,,contents4     ,,chapter               
,,page            ,,introduction        
v        ,i4 ,,the ,,author',s ,,design 
#a       ,,ii4 ,,history ,,of           
,,electrical ,,science                #f
      ,,iii4 ,,history ,,of ,,magnetism 
#bj       ,,iv4 ,,theory ,,and ,,nature 
,,of ,,magnetism              #be       
,v4 ,,theory ,,of ,,electricity         
#ci       ,,vi4 ,,electrical ,,currents 
#di      ,,vii4 ,,electric ,,generators 
#fb     ,,viii4 ,,atmospheric           
,,electricity                     #gg   
,,ix4 ,,electrical ,,measurement        
#hc        ,x4 ,,the ,,electric         
,,telegraph                      #hh    

,,xi4 ,,receiving ,,messages            
#ajc      ,,xii4 ,,miscellaneous        
,,methods                      #ajh     
,,xiii4 ,,multiple ,,transmission       
#aad      ,,xiv4 ,,way ,,duplex ,,system
                          #abi          
,,xv4 ,,the ,,telephone                 
#acd      ,,xvi4 ,,how ,,the ,,telephone
 ,,talks                    #ade        
,,xvii4 ,,submarine ,,telegraphy        
#aed    ,,xviii4 ,,short-,,line         
,,telegraphs                      #aei  
,,xix4 ,,the ,,telautograph             
#afe       ,,xx4 ,,some ,,curiosities   
#aga      ,,xxi4 ,,wireless ,,telegraphy
                        #agf     ,,xxii4
 ,,niagara ,,falls                      
,,power--,,introduction          #ahf   
,,xxiii4 ,,niagara ,,falls              
,,power--,,appliances            #aij   
,,xxiv4 ,,niagara ,,falls               
,,power--,,appliances            #aii   
,,xxv4 ,,electrical                     
,,products--,,carborundum           #bji
     ,,xxvi4 ,,electrical               

,,products--,,bleaching-,,powder        
#bah    ,,xxvii4 ,,electrical           
,,products--,,aluminum              #bbc
   ,,xxviii4 ,,electrical               
,,products--,,calcium ,,carbide         
#bbh     ,,xxix4 ,,the ,,new ,,era      
#bcd     ,,introduction4   ,for the     
benefit of the readers of ,vol4 ,,iii1  
who have not read the general           
,introduction found in ,vol4 ,i1 a word 
as to the scope and object of this      
volume will not be amiss4  ,it will be  
plain to any one on seeing the size of  
the little book that it cannot be an    
exhaustive treatise on a subject so     
large as that of ,electricity4 ,this    
volume1 like the others1 is intended for
 popular reading1 and technical terms   
are avoided as far as possible1 or when 
used clearly explained4 ,the subject is 
treated historically1 theoretically1 and
 practically4  ,as the author has lived 
through the period during which the     
science of ,electricity has had most of 
its growth1 he naturally and necessarily

 deals somewhat in reminiscence4 ,all he
 hopes to do is to plant a few          
seed-thoughts in the minds of his       
readers that will awaken an interest in 
the study of natural science2 and       
especially in its most fascinating      
branch--,electricity4  ,if ,vol4 ,i is  
at hand1 please read the ,introduction4 
,it will bring you into closer sympathy 
with the author and his mode of         
treatment4  ,again1 if the reader is    
especially interested in the theory of  
,electricity it will help him very much 
if he first reads ,vols4 ,i and ,,ii1 as
 a preparation for a better             
understanding of ,vol4 ,,iii4 ,all the  
natural sciences are so closely related 
that it is difficult to get a clear     
insight into any one of them without at 
least a general idea of all the others4 
,,nature',s ,,miracles4  ,,electricity  
,,and ,,magnetism4     ,,chapter ,i4    
,,the ,,author',s ,,design4   ,the      
writer has spent much of his time for   
thirty-five years in the study of       

electricity and in inventing appliances 
for purposes of transmitting            
intelligence electrically between       
distant points1 and is perhaps more     
familiar with the phenomena of          
electricity than with those of any other
 branch of physics2 yet he finds it     
still the most difficult of all the     
natural sciences to explain4 ,to give   
any satisfactory theory as to its place 
with and relation to other forms of     
energy is a perplexing problem4  ,it is 
said that ,lord ,kelvin lately made the 
statement that no advance had been made 
in explaining the real nature of        
electricity for fifty years4 ,while this
 statement--if he really made it--is    
rather broad1 it must be acknowledged   
that all the theories so far advanced   
are little better than guesses4 ,but    
there is value in guessing1 for one     
man's guess may lead to another that is 
better1 and1 as it is rarely the case   
that each one does not give us a little 
different view of the matter1 it may be 

that out of the multiplicity of guesses 
there may some time be a suggestion     
given to some investigator that will    
solve the problem1 or at least carry the
 theme farther back and establish its   
true relationship to the other forms of 
energy4 ,i cannot but think that there  
is yet a simple statement to be made of 
,energy in its relation to ,matter that 
will establish a closer relationship    
between the different branches of       
physical science4 ,and this1 most       
likely1 will be brought about by a      
better understanding of the nature of   
the interstellar substance called       
,ether1 and its relation to all forms   
and conditions of sensible matter and   
energy4  ,in the talks that will follow 
it will be the endeavor of the writer to
 give such a simple and popular         
exposition of the phenomena and         
applications of electricity1 in a       
general way only1 that the popular      
reader may get1 at least1 an elementary 
understanding of the subject so far as  

it is known4 ,as we have said1 the      
descriptions will have to be elementary1
 for nothing else can be done without   
such elaborate technical drawings and   
specifications as would be impossible in
 our limited space1 and would not be    
clear to the ordinary reader who knows  
nothing of the science4  ,thousands who 
are employed in various ways with       
enterprises1 the foundations of which   
are electrical1 know nothing of         
electricity as a science4 ,a friend of  
mine1 who is a professor of physics in  
one of our colleges1 was traveling a few
 years ago1 and in his wanderings he    
came across some sort of a factory where
 an electric motor was employed4 ,being 
on the alert for information1 he stepped
 in and introduced himself to the       
engineer1 and began asking him questions
 about the electric motor of which he   
had charge4 ,the professor could talk   
ohm1 amperes1 and volts smoothly1 and he
 fired some of these electrotechnical   
names at the engineer4 ,the engineer    

looked at him blankly and said3 ,you    
can't prove it by me4 ,i don't know what
 you're talking about4 ,all ,i know is  
to turn on the juice and let her buzz4  
,how much juice is wasted in this       
cut-and-dry world of ours and how much  
could be saved if only all were even    
fairly intelligent regarding the laws of
 nature6 ,a great deal of the business  
of this world is run on the let her buzz
 theory1 and the public pays for the    
waste4 ,it will continue to be so until 
a higher order of intelligence is more  
generally diffused among the people4 ,a 
fountain can rise no higher than its    
source4 ,a business will never exceed   
the intelligence that is put into it1   
nor will a government ever be greater   
than its people4  ,let us begin the     
subject of electricity by going somewhat
 into its past history4 ,it is always   
well to know the history of any subject 
we are studying1 for we often profit as 
much by the mistakes of others as by    
their successes4 ,i shall also give the 

theories advanced by different          
investigators1 and if ,i should have any
 thoughts of my own on the subject ,i   
shall be free to give them1 for ,i have 
just as good a right to make a guess as 
any one4 ,it must be confessed1 however1
 that the older ,i grow the less ,i feel
 that ,i know about the subject of      
electricity1 or anything else1 in       
comparison with what ,i see there is yet
 to be known4 ,i once met a young man   
who had just graduated from college1 and
 in his conversation he stated that he  
had taken a course in electricity4 ,i   
asked him how long he had studied the   
subject4 ,he said three months4 ,i asked
 him if he understood it--and he said   
that he did4 ,i told him that he was the
 man that the world was looking for2    
that ,i had studied it for thirty years 
and did not understand it yet4  ,a      
little learning is a dangerous          
thing--for it puffs us up1 and we feel  
that we know it all and have the world  
in our grasp2 but after we have tried   

our little learning on the world for a  
while and have received the many hard   
knocks that are sure to come1 we are    
sooner or later brought up in front of  
the mirror of experience1 and we see    
ourselves as others see us1 and are not 
satisfied with the view4  ,whatever the 
theories may be regarding electricity1  
and however unsatisfactory they may be1 
there are certain well-defined facts and
 phenomena that are of the greatest     
importance to the world4 ,these we may  
understand3 and to this end let us      
especially direct our efforts4          
,,chapter ,,ii4  ,,history ,,of         
,,electrical ,,science4   ,electricity  
as a well-developed science is not old4 
,those of us who have lived fifty years 
have seen nearly all its development so 
far as it has been applied to useful    
purposes1 and those who have lived over 
twenty-five years have seen the major   
portion of its development4  ,thales of 
,miletus1 #fjj ,b4,c41 discovered1 or at
 least described1 the properties of     

amber when rubbed1 showing that it had  
the power to attract and repel light    
substances1 such as straws1 dry leaves1 
etc4 ,and from the ,greek word for      
amber--elektron--came the name          
electricity1 denoting this peculiar     
property4 ,theophrastus and ,pliny made 
the same observations2 the former about 
#cba ,b4,c41 and the latter about #gj   
,a4,d4 ,it is also said that the        
ancients had observed the effects of    
animal electricity1 such as that of the 
fish called the torpedo4 ,pliny and     
,aristotle both speak of its power to   
paralyze the feet of men and animals1   
and to first benumb the fish which it   
then preyed upon4 ,it is also recorded  
that a freed-man of ,tiberius was cured 
of the gout by the shocks of the        
torpedo4 ,it is further recorded that   
,wolimer1 the ,king of the ,goths1 was  
able to emit sparks from his body4      
,coming down to more modern             
times--,a4,d4 #afjj--we find ,dr4       
,gilbert1 an ,englishman1 taking up the 

investigation of the electrical         
properties of various substances when   
submitted to friction1 and formulating  
them in the order of their importance4  
,in these experiments we have the       
beginnings of what has since developed  
into a great science4 ,he made the      
discovery that when the air was dry he  
could soon electrify the substances     
rubbed1 but when it was damp it took    
much longer and sometimes he failed     
altogether4 ,in #agje ,francis          
,hawksbee1 an experimental philosopher1 
discovered that mercury could be        
rendered luminous by agitating it in an 
exhausted receiver4 7,it is a question  
whether this phenomenon should not be   
classed with that of phosphorescence    
rather than electricity47 ,the number of
 investigators was so great that all of 
them cannot be mentioned4 ,it often     
happens that those who do really most   
for a science are never known to fame4  
,a number of people will make small     
contributions till the structure has by 

degrees assumed large proportions1 when 
finally some one comes along and puts a 
gilded dome on it and the whole         
structure takes his name4 ,this is      
eminently true of many of the more      
important developments in the science   
and applications of electricity during  
the last twenty-five or thirty years4   
,following ,hawksbee may be mentioned   
,stephen ,gray1 ,sir ,isaac ,newton1    
,dr4 ,wall1 ,m4 ,dupay and others4      
,dupay discovered the two conditions of 
electrical excitation known now as      
positive and negative conditions4 ,in   
#agde the ,leyden jar was invented4 ,it 
takes its name from the city of ,leyden1
 where its use was first discovered4 ,it
 is a glass jar1 coated inside and out  
with tin-foil4 ,the inside coating is   
connected with a brass knob at the top1 
through which it can be charged with    
electricity4 ,the inner and outer       
coatings must not be continuous but     
insulated from each other4 ,the author's
 name is not known1 but it is said that 

three different persons invented it     
independently1 to wit1 a monk by the    
name of ,kleist1 a man by the name of   
,cuneus1 and ,professor ,muschenbroeck  
of ,leyden4 ,this was an important      
invention1 as it was the forerunner of  
our own ,franklin's discoveries and a   
necessary part of his outfit with which 
he established the identity of lightning
 and electricity4 ,every ,american      
schoolboy has heard1 from ,fourth of    
,july orations1 how ,franklin caught the
 forked lightning from the clouds and   
tamed it and made it subservient to the 
will of man4 ,how my boyish soul used to
 be stirred to its depths by this       
oratorical display of electrical        
fireworks6  ,franklin had long          
entertained the idea that the lightning 
of the clouds was identical with what is
 called frictional electricity1 and he  
waited long for a church spire to be    
erected in his adopted home1 the ,quaker
 ,city1 in order that he might make the 
test and settle the question4 ,but the  

,quakers did not believe in spires1 and 
,franklin's patience had a limit4       
,franklin had the theory that most      
investigators had at that time1 that    
electricity was a fluid and that certain
 substances had the power to hold it4   
,there were two theories prevalent in   
those days--both fluid theories4 ,one   
theory was that there were two fluids1 a
 positive and a negative4 ,franklin held
 to the theory of a single fluid1 and   
that the phenomenon of electricity was  
present only when the balance or natural
 amount of electricity was disturbed4   
,according to this theory1 a body       
charged with positive electricity had an
 excessive amount1 and1 of course1 some 
other body somewhere else had less than 
nature had allotted to it2 hence it was 
charged with negative electricity4 ,a   
,leyden jar1 for instance1 having one of
 its coatings 7say the inside7 charged  
with positive or  electricity1 the other
 coating will be charged with negative  
or - electricity4 ,the former was only a

 name for an amount above normal and the
 latter a name for a shortage or lack of
 the normal amount4  ,as we have said1  
,franklin believed in the identity of   
lightning and electricity1 and he waited
 long for an opportunity to demonstrate 
his theory4 ,he had the ,leyden jar1 and
 now all he needed was to establish some
 suitable connection between a          
thunder-cloud and the earth4  ,previous 
to #agej ,franklin had written a paper  
in which he showed the likeness between 
the lightning spark and that of         
frictional electricity4 ,he showed that 
both sparks move in crooked lines--as we
 see it in a storm-cloud1 that both     
strike the highest or nearest points1   
that both inflame combustibles1 fuse    
metals1 render needles magnetic and     
destroy animal life4 ,all this did not  
definitely establish their identity in  
the mind of ,franklin1 and he waited    
long for an opportunity1 and finally1   
finding that no one presented itself1 he
 did what many men have had to do in    

other matters2 he made one4  ,in the    
month of ,june1 #ageb1 tired of waiting 
for a steeple to be erected1 ,franklin  
devised a plan that was much better and 
probably saved the experiment from      
failure2 for the steeple would probably 
not have been high enough4 ,he          
constructed a kite by making a cross of 
light cedar rods1 fastening the four    
ends to the four corners of a large silk
 handkerchief4 ,he fixed a loop to tie  
the kite string to and balanced it with 
a tail1 as boys do nowadays4 ,he fixed a
 pointed wire to the upper end of one of
 the cross sticks for a lightning-rod1  
and then waited for a thunder-storm4    
,when it came1 with the help of his boy1
 he sent up the kite4 ,he tied a loop of
 silk ribbon on the end of the string   
next his hand--as silk was known to be  
an insulator or non-conductor--and      
having tied a key to the string he      
waited the result1 standing within a    
door to prevent the silk loop from      
getting wet and thus destroying its     

insulating qualities4 ,the cloud had    
nearly passed and he feared his long    
waited for experiment had failed1 when  
he noticed the loose fibers of the      
string standing out in every direction1 
and saw that they were attracted by the 
approach of his finger4 ,the rain now   
wet the string and made a better        
conductor of it4 ,soon he could draw    
sparks with his knuckle from the key4   
,he charged a ,leyden jar with this     
electrical current from the             
thunder-cloud1 and performed all the    
experiments with it that he had done    
with ordinary electricity1 thus         
establishing the identity of the two and
 confirming beyond a doubt what he had  
long before believed was true4 ,in after
 experiments ,franklin found that       
sometimes the electricity of the clouds 
was positive and at other times         
negative4 ,from this experiment         
,franklin conceived the idea of erecting
 lightning-rods to protect buildings1   
which are used to this day4  ,the news  

spread all over ,europe1 not through the
 medium of electricity1 however1 but as 
soon as sailing vessels and             
stage-coaches could carry it4 ,many     
philosophers repeated the experiments   
and at least one man sacrificed his life
 through his interest in the new        
discovery4 ,in #agec ,professor ,richman
 of ,st4 ,petersburg erected on his     
house a metal rod which terminated in a 
,leyden jar in one of the rooms4 ,on the
 #cast of ,may he was attending a       
meeting of the ,academy of ,sciences4   
,he heard a roll of thunder and hurried 
home to watch his apparatus4 ,he and one
 of the assistants were watching the    
apparatus when a stroke of lightning    
came down the rod and leaped to the     
professor's head4 ,he was standing too  
near it and was instantly killed4       
,passing over many names of men who     
followed in the wake of ,franklin we    
come to the next era-making discovery1  
namely1 that of galvanic electricity4   
,in the year #agij an incident occurred 

in the household of one ,luigi ,galvani1
 an ,italian physician and anatomist1   
that led to a new and important branch  
of electrical science4 ,galvani's wife  
was preparing some frogs for soup1 and  
having skinned them placed them on a    
table near a newly charged electric     
machine4 ,a scalpel was on the table and
 had been in contact with the machine4  
,she accidentally touched one of the    
frogs to the point of the scalpel1 when1
 lo6 the frog kicked1 and the kick of   
that dead frog changed the whole face of
 electrical science4 ,she called her    
husband and he repeated the experiment1 
and also appropriated the discovery as  
well1 and he has had the credit of it   
ever since1 when really his wife made   
the discovery4 ,galvani supposed it to  
be animal electricity and clung to that 
theory the rest of his life1 making many
 experiments and publishing their       
results2 but the discovery led others to
 solve the problem4  ,alessandro ,volta1
 a professor of natural philosophy at   

,pavia1 ,italy1 was1 it must be said1   
the founder of the science of galvanic  
or voltaic electricity4 ,stimulated by  
the discovery of ,galvani he attributed 
the action of the frog's muscles1 not to
 animal electricity1 but to some        
chemical action between the metals that 
touched it4 ,to prove his theory1 he    
constructed a pile made of alternate    
layers of zinc1 copper1 and a cloth or  
pasteboard saturated in some saline     
solution4 ,by repeating these           
trios--copper1 zinc1 and the saturated  
cloth--he attained a pile that would    
give a powerful shock4 ,it is called the
 ,voltaic ,pile4  ,i have a clear idea  
of the construction of this form of     
pile1 founded on experience4 ,it was my 
habit when a boy to make everything that
 ,i found described1 if it were         
possible4 ,the bottom of my mother's    
wash-boiler was copper1 and just the    
thing to make the square plates of      
copper to match the zinc ones1 made from
 another piece of domestic furniture    

used under the stove4 ,i shocked my     
mother twice--first with the voltaic    
pile that ,i had constructed1 and again 
when she found out where the metal      
plates came from4 ,the sequel to all    
this was--but why dwell upon a painful  
subject6  ,galvanism and voltaic        
electricity are the same4 ,volta was the
 first to construct what is termed the  
galvanic battery4 ,the unit of          
electrical pressure or electromotive    
force is called the volt1 and takes its 
name from ,volta1 the great founder of  
the science of galvanic or voltaic      
electricity4 ,from this pile constructed
 by ,volta innumerable forms of         
batteries have been devised4 ,the       
evolution of the galvanic battery in all
 its forms1 from ,volta to the present  
day1 would fill a large volume if all   
were described4  ,the discoveries of    
,michael ,faraday 7#agia-ahfg71 the     
distinguished ,english chemist and      
physicist1 led to another phase of the  
science that has revolutionized modern  

life4 ,faraday made an experiment that  
contains the germ of all forms of the   
modern dynamo1 which is a machine of    
comparatively recent development4 ,he   
found that by winding a piece of        
insulated wire around a piece of soft   
iron and bringing the two ends 7of the  
wire7 very close together1 and then     
placing the iron across the poles of a  
permanent magnet and suddenly jerking it
 away1 a spark would pass between the   
two ends of the wire that was wound     
around the piece of soft iron4 ,here was
 an incipient dynamo-electric           
machine--the germ of that which plays   
such an important part in our modern    
civilization4  ,having brought our      
history down to the present day1 it     
would seem scarcely necessary to recite 
that which everybody knows4 ,it is well1
 however1 to call a halt once in a while
 and compare our present conditions of  
civilization with those of the past4    
,our world is filled with croakers who  
are always sighing for the good old     

days4 ,but we can easily imagine that if
 they could go back to those days their 
croaking would be still louder than it  
is4  ,before the advent of electricity  
many things were impossible that are    
easy now4 ,in the old days the world was
 very1 very large2 now1 thanks to       
electricity1 it is knocking at the door 
of every man's house4 ,the lumbering    
stage-coach that was formerly our       
limited express--limited to thirty or   
forty miles a day--has been supplanted  
by one that covers #ajjj miles in the   
same time1 and this high rate of speed  
is made possible only by the use of the 
electric telegraph4  ,in the old days   
all ,europe could be involved in a great
 war and the news of it would be weeks  
in reaching our shores1 but now the     
firing of the first gun is heard at     
every fireside the world over1 almost   
before the smoke has cleared away4 ,our 
planet is threaded with iron nerves that
 run over mountains and under seas1     
whose trembling atoms1 thrilled with the

 electric fire1 speak to us daily and   
hourly of the great throbbing life of   
the whole civilized world4  ,electricity
 has given us a voice that can be heard 
a thousand miles1 and not only heard1   
but recognized4 ,it has given us a pen  
that will write our autograph in ,new   
,york1 although we are still in         
,chicago4 ,it has given us the best     
light1 both from an optical and a       
sanitary standpoint1 that the world has 
ever seen4 ,the old-fashioned1 jogging  
horse-car has been supplanted by the    
electric trolley1 and we no longer have 
our feelings harrowed with pity for the 
poor old steeds that pulled those       
lumbering coaches through the streets1  
with men and women crowded in and       
hanging on to straps1 while everybody   
trod on every other body's toes4    ,in 
olden times we took a car   ,drawn by a 
horse1 if going far1     ,and felt that 
we were blest2   ,now the conductor     
takes the fare   ,and puts a broomstick 
in the air--     ,and lightning does the

 rest4    ,in other days1 along the     
street1   ,a glimmering lantern led the 
feet1     ,when on a midnight stroll2   
,but now we catch1 when night is nigh1  
,a piece of lightning from the sky      
,and stick it on a pole4    ,time was   
when one must hold his ear   ,close to a
 whispering voice to hear1     ,like    
deaf men--nigh and nigher2   ,but now   
from town to town he talks   ,and puts  
his nose into a box     ,and whispers   
through a wire4  ,so jogs the old world 
along4 ,we sometimes think it is slow1  
but when we look back a few years and   
see what has been accomplished it seems 
to have had a marvelously rapid         
development4  ,something like fifty     
years ago a professor of physics in one 
of our colleges was giving his class a  
course in electricity4 ,the electric    
telegraph was too little known at that  
time to cut much of a figure in the     
classroom1 so the stock experiments were
 those made with the frictional electric
 machine and the ,leyden jar4 ,one day  

the professor had1 in one hour's time1  
taken his class through a course of     
electricity1 and at the end he said3    
,gentlemen1 you were born too late to   
witness the development of this great   
science4 ,i often wonder if the good    
professor is ever allowed to part the   
veil that separates us from the great   
beyond and to look down upon this busy  
world of ours in which electricity plays
 such an important part in our every-day
 life2 and if so1 what he thinks of that
 little speech he made to the boys fifty
 years or more ago4  ,if we make an     
analysis of the history of the science  
of electricity we shall see that it has 
progressed in successive eras1          
shortening as they approach our time4   
,for a period of #bcjj years1 from      
,thales to ,franklin1 but little or no  
progress was made beyond the further    
development of the phenomena of         
frictional electricity--the most        
important invention being that of the   
,leyden jar4 ,from ,franklin to ,volta  

was forty-eight years1 and from ,volta  
to ,faraday about thirty-two years4     
,from this time on the development was  
very rapid as compared with the old     
days4 ,soon after ,faraday1 ,morse1     
,henry1 ,wheatstone1 and others began   
experiments that have grown1 during     
fifty or sixty years1 into a most       
colossal system of electric telegraphs1 
telephones1 electric lights and electric
 railroads4 ,in the latter days marvel  
has succeeded marvel with such rapid    
strides that the ink is scarcely dry    
from the description of one before      
another crowds itself upon our          
attention4 ,where it will all end no one
 knows1 but that it has ended no one    
believes4 ,the human mind has become so 
accustomed to these periodic revelations
 of the marvelous that it must have the 
stimulus once in a while or it suffers  
as the toper does when deprived of his  
cups4 ,the commercial instinct of the   
news-vender is not slow to see the      
situation1 and if the development is too

 slow to suit the public demand his     
fertile brain supplies the lack4 ,so    
that every few days we hear of some     
great discovery made by some one it may 
be unknown to fame4 ,it has served its  
purpose4 ,the public mind has had its   
mental toddy and has been saved from a  
fit of intellectual delirium tremens    
that it was in danger of from lack of   
its accustomed stimulus4  ,having given 
you a very limited outline of the       
history of electricity1 from ancient    
times down to the present1 we will      
endeavor now to give you an elementary  
notion of the science as it stands      
to-day4 ,to the common mind the science 
is a blank page4 ,so little is known of 
it by the ordinary reader1 who is fairly
 intelligent in other matters1 that to  
account for anything that we do not     
understand it is only necessary to say  
that it is an electrical phenomenon and 
he accepts it4 ,electricity is a synonym
 for all that we cannot understand4     
,inasmuch as magnetism is so closely    

related to electricity in its uses as   
related to every-day life1 we will carry
 the two subjects along together1 as the
 one will to a large extent help to     
explain the other4 ,in our next chapter 
we will look at the history of          
magnetism4     ,,chapter ,,iii4         
,,history ,,of ,,magnetism4   ,it is    
said that the word magnetism is derived 
from the name of a ,greek shepherd1     
called ,magnes1 who once observed on    
,mount ,ida the attractive properties of
 loadstone when applied to his iron     
shepherd's crook4 ,it is more likely    
that the name came from ,magnesia1 a    
country in ,lydia1 where it was first   
discovered4 ,it was also called ,lapis  
,heracleus4 ,heraclea was the capital of
 ,magnesia4 ,loadstone is a magnetic ore
 or oxide of iron found in the natural  
state1 and has at some time by natural  
processes been rendered magnetic--that  
is1 given the power of attracting iron1 
and1 when suspended1 of pointing to the 
,north and ,south ,poles4 ,the power of 

the natural magnet was known at a very  
early age in the history of man4 ,it was
 referred to by ,homer1 ,pythagoras1 and
 ,aristotle4 ,pliny also speaks of it1  
and refers to one ,dinocares1 who       
recommended to ,ptolemy ,philadelphus to
 build a temple at ,alexandria and      
suspend in its vault a statue of the    
queen by the attractive power of        
loadstones4 ,there is also mention of a 
statue being suspended in like manner in
 the temple of ,serapis1 ,alexandria4   
,it is claimed that the ,chinese knew of
 and used the magnetic needle in the    
earliest times and that travelers by    
land employed this needle suspended by a
 string to guide them in their journeys 
across the country a thousand years     
before ,christ4 ,notwithstanding the    
claims of the ,chinese and ,arabians to 
the discovery of the use of the magnetic
 needle1 modern authors question whether
 the ancients were familiar with any    
artificial construction of a magnetic   
needle1 however much they may have      

studied and used the loadstones4 ,no    
doubt the loadstone in its natural state
 was used by mariners to steer their    
ships by1 long before its artificial    
counterpart was invented4 ,in a history 
of the discovery of ,iceland1 by ,are   
,frode1 who was born in #ajfh1 it is    
stated that a mariner by name of ,folke 
,gadenhalen sailed from ,norway in      
search of ,iceland in the year #hfh1 and
 that he carried with him three ravens  
as guides1 for he says1 in those times  
seamen had no loadstones in the northern
 countries4 ,the magnetic needle as     
applied to the mariner's compass was    
known in the eleventh century1 as proved
 by various authors4 ,in an old ,french 
poem1 the manuscript of which still     
exists1 the mariner's compass is clearly
 mentioned4 ,the author was ,guyot1 of  
,provence1 who was alive in #aaha4      
,like electricity1 magnetism has had a  
long history1 but little use was made of
 it till modern times beyond that of the
 mariner's compass4 ,it can readily be  

seen what an important factor it was in 
the science of navigation4 ,long after  
the discovery of the compass needle     
there were many perplexing problems     
arising1 and all sorts of theories were 
advanced to account for the various     
phenomena4 ,the variation of the needle 
was one of these problems4 ,it is said  
that ,columbus was the first to discover
 the variation of the needle1 as well as
 ,america4 ,this is disputed1 however1  
as every man's pretensions usually are4 
,however this may be1 ,columbus had to  
invent some plausible theory to account 
for this variation to prevent a mutiny  
among his crew4 ,they were very         
superstitious and thought that they were
 sailing into a new world where the laws
 of nature were different from those of 
,spain4 ,one phenomenon that disturbed  
,columbus was the dip of the needle4 ,as
 we move in a northerly direction a     
magnetic needle dips1 and it was the    
observation of this phenomenon in       
different latitudes that finally        

resulted in the invention of the dipping
 needle4 ,it is well known that one pole
 of a magnetic needle points to the     
north and the other to the south4 ,in   
other words1 what is called the north   
pole of a needle points to one of the   
magnetic poles of the earth which is in 
the direction of the north pole1 though 
not the same as the geographical pole4  
,a dipping needle revolves on an axis so
 that it can point to any declination4  
,if we should construct one that is     
perfectly balanced1 so as to lie in a   
perfectly horizontal direction before it
 is magnetized1 it will dip--in this    
latitude--downward toward the north     
after magnetization4 ,if we keep moving 
northward it will continue to dip       
downward till we come to the true       
magnetic pole1 when what is called the  
north pole of the needle will point     
directly downward4 ,if we go back to the
 equator the needle will lie            
horizontally again4 ,we call the end of 
the needle that points to the north the 

north pole4 ,it is really the south     
pole1 because unlike poles attract each 
other4 ,if the magnetic poles of the    
earth are at the north and south        
geographical poles1 the south pole of   
the needle will point north4 ,but it is 
less confusing to call the end of the   
needle that points north the north pole4
 ,the nomenclature is purely arbitrary4 
,it was not until it was learned that   
magnets could be made by electricity    
that they became commercially important 
outside of their use in navigation4 ,the
 advent of electricity has brought      
magnetism to the front as one of the    
great factors in our modern             
civilization4 ,and we might say with    
equal force that the discovery of       
magnetism has brought electricity to the
 front4 ,the truth is that they depend  
upon each other4 ,electricity would be  
robbed of a large part of its importance
 as a factor in modern life if it were  
not for its relation to magnetism4 ,even
 electric lighting would be impossible1 

commercially1 if it were not for the    
part magnetism plays in the production  
of electricity for this purpose4 ,it    
could not be successfully carried on    
with any battery but the                
storage-battery1 and the storage-battery
 is dependent upon the dynamo1 and the  
dynamo is a magneto-electric machine4   
,when we come to analyze the relation   
between magnetism and electricity we    
cannot separate them without robbing    
each of a large part of its usefulness4 
,they are interdependent forces4  ,as in
 the case of electricity there have been
 many theories regarding magnetism4 ,one
 philosopher in the old days accounts   
for the variation of the compass-needle 
on the theory that there are two globes1
 one revolving within the other1 and    
that any derangement of their normal    
movements in relation to each other     
affects the needle4 ,evidently there    
were cranks in those days as well as    
now4 ,another theory of magnetism was   
that there were two fluids--a boreal and

 an austral--one developing north       
polarity and the other south polarity4  
,in the next chapter the nature of      
magnetism in the light of modern        
investigation will be discussed4        
,,chapter ,,iv4  ,,theory ,,and ,,nature
 ,,of ,,magnetism4   ,iron and steel    
have a peculiar property called         
magnetism4 ,it is an attraction in many 
ways unlike the attraction of cohesion  
or the attraction of gravitation4 ,it is
 very certain that magnetism is an      
inherent property of the molecules of   
iron and steel1 and1 to a small degree1 
other forms of matter4 ,that is to say1 
the molecules are little natural magnets
 of themselves4 ,it is as unnecessary to
 inquire why they are magnets as it is  
to inquire why the molecules of all     
ordinary substances possess the         
attraction of cohesion4 ,the one is as  
easy to explain as the other4 ,people of
 all ages have insisted upon making a   
greater mystery of all electrical and   
magnetic phenomena than they do of other

 natural forces4 ,ampere's theory is    
that electric currents are flowing      
around the molecules which render them  
magnetic2 but it is just as easy to     
suppose that magnetism is an inherent   
quality of the molecule4 7,the word     
molecule is here used as referring to   
the smallest particle of iron47  ,these 
little molecular magnets1 so small that 
#ajj1jjj million million million of them
 can be put into a cubic inch of space1 
have their attractions satisfied by     
forming into little molecular rings1    
with their unlike poles together1 so    
that when the iron is in a natural or   
unmagnetized condition it does not      
attract other iron4 ,if ,i should take a
 ring of hardened steel and cut it into 
two or more pieces and magnetize them1  
each one of the pieces would be an      
independent magnet4 ,if now ,i put them 
together in the form of a ring they will
 cling together by their mutual         
attraction for each other4 ,before ,i   
put them together into a ring each piece

 would attract and adhere to other      
pieces of iron or steel4 ,but as soon as
 they are put together in the ring they 
are satisfied with their own mutual     
attraction1 and the ring as a whole will
 not attract other pieces of iron4      
,suppose the pieces forming the ring--it
 may be only two1 if you choose--are as 
small as the molecules we have          
described1 the same thing would be true 
of them4 ,each molecular ring would have
 its magnetic attractions satisfied and 
would not attract other molecules       
outside of its own little circle4 ,when 
the iron is in the neutral state it will
 not as a mass attract another piece of 
iron1 because the millions of little    
natural magnets of which it is made up  
have their attractive force all turned  
in upon themselves4  ,now1 if we make a 
helix1 or coil1 of insulated wire and   
put a piece of iron into it1 and pass a 
current of electricity through the      
helix1 the iron becomes a magnet4 ,why8 
,because the electric current has the   

power to break up these molecular       
magnetic rings and turn all their like  
poles in one direction1 so that their   
attractions are no longer satisfied     
among themselves1 and with a combined   
effort they reach outside and attract   
any piece of iron that is within reach4 
,in this state we say it is magnetized4 
,most people think that we have put     
something into the iron1 but we have    
not2 we have only developed and made    
active its inherent power4 ,it must be  
kept in mind that it takes power to     
develop this magnetic power from its    
state of neutrality and that something  
is never made from nothing4 ,when this  
power is developed it will do work in   
falling back to its natural state4 ,the 
power is natural to the molecules of the
 metal4 ,it is only being exerted in a  
new direction4 ,the millions of little  
natural magnets have been forced to     
combine their attractions into one whole
 and exert it on something outside of   
themselves4 ,they are under a strain in 

this condition1 like a bent bow1 and    
there is a tendency to fly back to the  
natural position1 and if it is soft iron
 and not steel1 they will fly back as   
soon as the power that wrenched them    
apart and is holding them apart is taken
 away4 ,this power is the electric      
current4 ,now break the current1 and the
 little natural magnets1 that have been 
so ruthlessly torn from their home      
circle attachments1 fly back to them    
again with the speed of lightning1 and  
the iron rod as a whole is no longer a  
magnet4 ,the power to become so under   
the electrical strain is in it          
still--only latent4  ,the kind of magnet
 that we have been describing is called 
an electromagnet4 ,it is a magnet only  
so long as the electric current is      
passing around it4 ,there is another    
kind of magnet called a permanent magnet
 that will remain a magnet after the    
current is taken away4 ,the permanent   
magnet is made of steel and hardened2   
then its poles are placed1 to the poles 

of a powerful magnet1 either electro or 
permanent1 when its molecular rings are 
wrenched apart and arranged in a        
polarized position as heretofore        
described4 ,now take it away from the   
magnet and it will be found to retain   
its magnetism4 ,the molecules tend to   
fly back the same as those of the soft  
iron1 but they cannot because hardened  
steel is so much finer grained than soft
 iron1 and the molecules are so close   
together that they are held in position 
by a friction that is called its        
coercive force4 ,the soft iron is       
comparatively free from this coercive   
force1 because its molecules are free to
 move on each other1 so that when they  
are wrenched out of their natural       
position they fly back by their own     
attractions as soon as the force holding
 them apart is taken away4 ,the         
molecules of hardened steel are unable  
to fly back1 although they tend to do it
 just as much as in the iron1 and so it 
is called a permanent magnet4 ,its      

molecules also are under a strain1 like 
a bent bow4 7,the form of such a magnet 
is usually that of a horse-shoe1 or ,u47
  ,let us use a homely illustration that
 may help us to understand4 ,let ten    
boys represent the molecules in a piece 
of iron4 ,let them pair off into five   
pairs and each one clasp his mate in his
 arms2 each one1 say1 is exerting a     
force of ten pounds1 and it would       
require a force of twenty pounds to pull
 any one of the pairs apart4 ,the five  
pairs are exerting a force of one       
hundred pounds1 but this force is not   
felt outside of themselves4 ,now let    
them unclasp themselves and take hold of
 a rope that is tied to a post1 and all 
pull with the same force that they were 
using1 to wit1 ten pounds each1 and all 
pull in the same direction1 and they    
would put a strain of one hundred pounds
 upon the post1 the same power that they
 were exerting upon themselves before   
they combined their efforts on something
 outside of themselves4 ,so with the    

magnet4 ,so long as the force of each   
molecule is wholly spent upon its       
neighbor there is nothing left for      
exterior use4 ,but as soon as they all  
line up and pull conjointly in the same 
direction their combined force is felt  
outside4 ,the analogy may not be        
perfect1 but it will help you to get a  
mental picture of what takes place in   
iron when it is magnetized4  ,we have   
now described the magnet and the        
inherent power residing in the molecular
 structure of iron4 ,it is this magic   
power slumbering in its molecules and   
the ability of the electric current to  
arouse them to action at will and to    
hold them in action and at will let them
 fly back to their normal position1 that
 gives to electricity and               
magnetism--twin sisters in nature's     
household--their great value as the     
servants of man4 ,there would be no     
virtue in winding up a weight if it     
could not run down and do work in its   
fall4 ,simply bending a bow would never 

send the arrow flying over its course2  
it must be released as well4 ,the magnet
 could not accomplish the great work it 
does if we could only charge it and not 
have the ability to discharge it4       
,without this ability the electric motor
 would not revolve1 the electric light  
would not burn1 the click of the        
telegraph would not be heard1 the       
telephone would not talk1 nor would the 
telautograph write4  ,i have said that  
the permanent magnet would hold its     
charge after once having been           
magnetized4 ,this is true only in a     
sense and under favorable conditions4   
,if made of the best of steel for the   
purpose and hardened and tempered in    
just the right way1 it will hold its    
charge if it is given something to do4  
,if a piece of iron is placed across its
 poles it also becomes a magnet and its 
molecules turn and work in harmony with 
those of the mother magnet4 ,these      
magnetic lines of force reach around in 
a circuit4 ,even before the iron1 or    

keeper1 as it is called1 is put across  
its poles there are lines of force      
reaching around through the air or ether
 from one pole to another4 7,for a      
description of ,ether see ,chap4 ,v47   
,this is called the field of the magnet1
 and when the iron is placed in this    
field the lines of force pass through it
 in a closed circuit1 and if the keeper 
is large enough to take care of all the 
lines of force in the field the magnet  
will not attract other bodies1 because  
its attraction is satisfied1 like its   
prototype in the molecular ring         
described above4  ,we speak of lines of 
force1 not that force is necessarily    
exerted in a bundle of lines but as a   
convenient way of telling the strength  
of a magnetic field4 ,the practical     
limit of the magnetization of soft iron 
7called saturation7 is #ah1jjj lines to 
the square centimeter4 ,as long as we   
give our magnet something to do1 up to  
the measure of its capacity1 it will    
keep up its power4 ,we may make other   

magnets with it1 thousands1 yea1        
millions of them1 and it not only does  
not lose its power but may be even      
stronger for having done this work4 ,if1
 however1 we hang it up without its     
keeper1 and give it nothing to do1 it   
gradually returns to its natural        
condition in the home circle of         
molecular rings4 ,little by little the  
coercive force is overcome by the       
constant tendency of the molecule to go 
back to its natural position among its  
fellows4  ,the magnet furnishes many    
beautiful lessons1 as indeed do all the 
natural phenomena4 ,every man has within
 him a latent power that needs only to  
be aroused and directed in the right way
 to make his influence felt upon his    
fellows4 ,like the magnet1 the man who  
uses his power to help his fellows up to
 the measure of his limitations not only
 has been a benefactor to his race1 but 
is himself a stronger and better man for
 having done so4 ,but1 again1 like the  
magnet1 if he allows these ,god-given   

powers to lie still and rust for want of
 legitimate use he gradually loses the  
power he had and becomes simply a moving
 thing without influence or use in a    
world in which he vegetates4 ,but let us
 leave philosophy and go back to        
science4  ,one of the striking          
exhibitions of magnetism is found in the
 earth4 ,the earth itself is a great    
magnet2 and there is good reason for    
believing that it is an electromagnet of
 great power4 ,the magnetic poles of the
 earth are not exactly coincident with  
the geographical poles1 and they are not
 constant4 ,there is a gradual deviation
 going on1 but as it follows a certain  
law mariners are able to tell just what 
the deviation should be at a certain    
time4 ,the magnetic pole revolves around
 the polar axis of the earth once in    
about #cbj years4 ,a thermal current    
7one produced by heat7 of electricity   
seems to flow around the earth caused by
 the irregularities of temperature at   
the earth's surface1 as the sun makes   

his daily round4 ,these earth currents  
vary at times1 and other phenomena are  
the occasion4 ,this will be discussed   
when we come to electric storms4  ,the  
value of the earth's magnetism is seen  
most in the science of navigation4 ,a   
magnetic needle is only a slender       
permanent magnet suspended very         
delicately1 and when not under local    
influence it points north and south on  
the magnetic axis4 ,the law of its      
action may be explained as follows3     
,take a straight bar magnet of fairly   
good power and suspend a magnetic needle
 over it4 ,the needle will arrange      
itself parallel to the bar magnet4 ,the 
north pole of the needle will point     
toward the south pole of the bar magnet4
 ,in the presence of the magnet the     
needle is not affected by the earth1 but
 yields to a superior force4 ,if1       
however1 the bar magnet is taken out of 
the way of the needle it will           
immediately arrange itself north and    
south4 ,of course if the earth's        

magnetic axis changes the needle will   
vary with it4 ,this variation is uniform
 and in navigation is reduced to a      
science1 so that the mariner knows how  
much to allow for the variation4        
,columbus1 as heretofore mentioned1 was 
supposed to have first noticed this     
variation and it made him trouble4 ,he  
did not know how to account for it1 and 
as his crew thought the laws of nature  
were changing because they were so far  
from home he saw the necessity for some 
sort of explanation4 ,so1 like the brave
 man that he was1 he hatched up a theory
 that satisfied the crew1 and although  
in the light of the closing years of the
 nineteenth century it was a            
questionable one1 it worked well enough 
in practice to serve his purpose4  ,we  
have already stated that the earth was a
 great magnet1 and that probably it was 
an electromagnet1 caused by earth       
currents circulating around the globe4  
,you want to know how the earth can be a
 magnet unless it has an iron core like 

an electromagnet4 ,magnetism or magnetic
 lines of force may be developed without
 the presence of iron4 ,when we pass a  
current of electricity through a wire1  
magnetic lines of force are thrown out  
at right angles with the direction of   
the current4 ,this will be fully        
explained further on4 ,if we wind the   
wire into a coil1 or helix1 these       
magnetic lines are concentrated4 ,if now
 we suspend this helix1 or1 better1     
float it on water so that it can move   
freely1 and pass a current of           
electricity through it1 the helix will  
arrange itself north and south the same 
as a magnetic needle4 ,its attractive   
properties are feeble in comparison with
 that of the iron1 but it obeys the laws
 of a magnet4 ,the earth is probably a  
magnet of this kind1 consisting mostly  
of lines of force4  ,however1 the iron  
in the earth is affected magnetically1  
as we have evidence in the loadstone4   
,the earth has the power also to        
magnetize iron through the medium of its

 magnetic field1 that reaches out in    
lines of force from pole to pole like   
those of the artificial magnet4 ,if we  
hold a bar of iron in line with the     
magnetic axis of the earth and dip it in
 line with the dipping needle and then  
strike it a few blows on the end1 it    
will be found to be feebly magnetic4    
,the blows have partly loosened the     
molecules and during the moment that    
they unclasped themselves the earth's   
magnetism has through its lines of force
 caught them for a time and held them a 
little out of their natural position--as
 they are in a state of rest4 ,the      
peculiar changing light that we         
sometimes see in the northern sky1 that 
is called the ,aurora ,borealis         
7,northern ,light71 is indirectly due to
 intense magnetic lines of force that   
radiate from the north magnetic pole of 
the earth4 ,those lines of force are    
able to cause the rarified air molecules
 to become feebly incandescent1 giving  
them the appearance that we see in a    

tube that is a partial vacuum when      
electricity is passed through it4 ,while
 these auroral displays may be seen     
almost any night in the far north1 they 
vary greatly in their intensity1 so it  
is only once in a while that they are   
visible in the temperate latitudes4     
,what are called magnetic storms occur  
occasionally1 and at such times the     
telegraph service will sometimes be     
paralyzed on all the east and west lines
 for many hours4 ,strong earth-currents 
will flow east and west1 and be so      
powerful and so erratic that it is      
sometimes impossible to use the         
telegraph4 ,it sometimes happens that   
the operators can throw off their       
batteries and work on the earth-current 
alone4 ,sometimes it is necessary to    
make a complete metallic circuit to get 
away from the influence of the earth in 
order to use the telegraph4 ,currents   
equal to the force of #b1jjj cells of   
ordinary battery have been developed    
sometimes in telegraph wires4 ,this of  

course is a mere fraction of what is    
passing through the earth under the wire
 through which the current flowed4 ,on  
the #agth and #ahth of ,november1 #ahhb1
 a magnetic storm occurred that extended
 around the globe1 as it was felt       
wherever there were telegraph wires4    
,these magnetic storms are attended by  
brilliant displays of the aurora1 and   
this fact strengthens the theory that   
the earth is a great electromagnet2 for 
the stronger the electrical current the 
more powerful we should expect the      
magnetism to be1 and this is shown by   
the action of the magnetic needle at    
such times4 ,the stronger the magnet the
 more intense will be the lines of      
force1 and naturally the more intense   
the light1 if indeed these lines of     
force are the cause of the light4 ,there
 is evidently some close relation       
between the two4  ,another coincidence  
is that at the times of these storms    
there is an unusual display of          
sun-spots4 ,these sun-spots seem to be  

great holes that have been blown through
 the photosphere of the sun4 ,the       
photosphere is a great luminous body of 
gaseous matter that is believed to      
envelop the sun1 so that we do not see  
the core of the sun unless it is when we
 look into one of these spots4 ,in some 
way1 evidently1 the sun affects the     
earth by radiating magnetic lines of    
force which are cut by the earth's      
revolution1 and so creating currents of 
electricity4 ,the sun is the            
field-magnet1 and the earth is the      
revolving armature of nature's great    
dynamo-electric machine4 ,it would seem 
that the radiant energy that comes out  
through these spots or these holes in   
the sun's envelope1 are more potent to  
develop earth-currents than the ordinary
 rays2 and so1 when for a brief while in
 the revolution of the earth about the  
sun1 these extra potent rays strike the 
earth1 an unusual energy is developed1  
and these unusual phenomena are the     
consequence4 ,these phenomena seem to   

occur periodically2 some years 7about   
eleven7 intervening4  ,all the forces   
and phenomena of nature are thus seen to
 be in a state of unrest4 ,and it is to 
this unrest1 which does not stop with   
visible things1 but pervades even the   
atoms of matter throughout the universe1
 that we are indebted for the ability to
 carry on all the activities of life1   
and for life itself4 ,for universal     
quiet would mean universal death4 ,the  
cyclone and tornado that devastate and  
strike terror to a whole region are only
 eccentricities of nature when she is   
setting her house to rights4 ,the play  
of natural forces has disturbed her     
equilibrium1 and she is but making an   
effort to restore it4     ,,chapter ,v4 
,,theory ,,of ,,electricity4   ,in the  
series of chapters on ,heat 7,vol4 ,,ii7
 and in the chapter on ,magnetism the   
word molecule was frequently used       
synonymously with atom4 ,in chemistry a 
distinction is made1 and as we can      
better explain the theory1 at least1 of 

electricity by keeping this distinction 
in mind we will refer to it here4  ,it  
has been stated that there are between  
sixty and seventy elementary substances4
 ,an elementary substance cannot be     
destroyed as such4 ,it can be united    
with other elements and form chemical   
compounds of almost endless variety4    
,the smallest particle of an elementary 
substance is called in chemistry an     
atom4 ,the smallest particle of a       
compound substance is called a molecule4
 ,the atom is the unit of the element1  
and the molecule is the unit of the     
compound as such4 ,it follows1 then1    
that there are as many different kinds  
of atoms as there are elements1 and as  
many different kinds of molecules as    
there are compounds4 ,if the elements   
have a molecular ,structure then two or 
more atoms of the same kind must combine
 to make a molecule of an elementary    
substance4 ,two atoms of hydrogen       
combine with one of oxygen to form one  
molecule of water4 ,it cannot exist as  

water in any smaller quantity4 ,if we   
subdivide it1 it no longer exists as    
water1 but as the original gases from   
which it was compounded4  ,we have shown
 in the series on ,sound1 ,heat and     
,light that they are all modes of       
motion4 ,sound is transmitted in        
longitudinal waves through air and other
 material substance as vibration4 ,heat 
is a motion of the ultimate particles or
 atoms of matter1 and ,light is a motion
 of the luminiferous ether transmitted  
in waves that are transverse4           
,electricity is also undoubtedly a mode 
of motion related in a peculiar way to  
the atoms of the conductor4  ,notice    
that there is a difference between      
conduction and radiation4 ,the former   
transmits energy by a transference of   
motion from atom to atom or molecule to 
molecule within the body1 while the     
latter does it by a vibration of the    
ether outside--as light1 radiant heat1  
and electromagnetic lines of force4     
,for the benefit of those persons who   

have not read ,vol4 ,,ii1 where the     
nature of ether is discussed somewhat1  
let us refer to it here1 as it plays an 
important part in the explanation of    
electrical phenomena4 ,ether is a       
tenuous and highly elastic substance    
that fills all interstellar and         
interatomic space4 ,it has few of the   
qualities of ordinary matter4 ,it is    
continuous and has no molecular         
structure4 ,it offers no perceptible    
resistance1 and the closest-grained     
substances of ordinary matter are more  
open to the ether than a coarse sieve is
 to the finest flour4 ,it fills all     
space1 and1 like eternity1 it has no    
limits4 ,some physicists suppose--and   
there is much plausibility in the       
supposition--that the ether is the one  
substance out of which all forms of     
matter come4 ,that the atoms of matter  
are vortices or little whirlpools in the
 ether2 and that rigidity and other     
qualities of matter all arise in the    
ether from different degrees or kinds of

 motion4  ,electricity is not a fluid1  
or any form of material substance1 but a
 form of energy4 ,energy is expressed in
 different ways1 and1 while as energy it
 is one and the same1 we call it by     
different names--as heat energy1        
chemical energy1 electrical energy1 and 
so on4 ,they will all do work1 and in   
that respect are alike4 ,one difficulty 
in explaining electrical phenomena is   
the nomenclature that the science is    
loaded down with4 ,all the old names    
were adopted when electricity was       
regarded as a fluid1 hence the word     
current4 ,it is spoken of as flowing    
when it does not flow any more than     
light flows4  ,if a man wants to write a
 treatise on electricity--outside of the
 mere phenomena and applications--and   
wants to make a large book of it1 he    
would better tell what he does not know 
about it1 for in that way he can make a 
volume of almost any size4 ,but if he   
wants to tell what it really is1 and    
what he really knows it is1 a primer    

will be large enough4 ,this much we     
know--that it is one of many expressions
 of energy4  ,chemistry teaches that    
heat is directly related to the atoms of
 matter4 ,atoms of different substances 
differ greatly in weight4 ,for instance1
 the hydrogen atom is the unit of atomic
 weight1 because it is the lightest of  
all of them4 ,taking the hydrogen atom  
as the unit1 in round numbers the iron  
atom weighs as much as #ef atoms of     
hydrogen1 copper a little over #fc1     
silver #ajh1 gold #aig4 ,heat acts upon 
matter according to the number of atoms 
in a given space1 and not as its weight4
 ,knowing the relative weights of the   
atoms of the different metals named1 it 
would be possible to determine by weight
 the dimensions of different pieces of  
metal so that they will contain an equal
 number of atoms4 ,if we take pieces of 
iron1 copper1 silver and gold1 each of  
such weight as that all the pieces will 
contain the same number of atoms1 and   
subject them to heat till all are raised

 to the same temperature1 it will be    
found that they have all absorbed       
practically the same quantity of heat   
without regard to the different weights 
of matter4 ,it will be observed that the
 piece of silver1 for instance1 will    
have to weigh nearly twice as much as   
the iron in order to contain the same   
number of atoms1 but it will absorb the 
same amount of heat as the piece of iron
 containing the same number of atoms1 if
 both are raised to the same            
temperature4 ,in view of the above fact 
it seems that heat acts especially upon 
the atoms of matter and is a peculiar   
form of atomic motion4 ,heat is one kind
 of motion of the atoms1 while          
electricity may be another form of      
motion of the same4 ,the two motions may
 be carried on together4 ,the earth has 
a compound motion4 ,it revolves upon its
 axis once in twenty-four hours1 and it 
also revolves around the sun once each  
year4 ,so you see that there are        
different kinds of motion that may be   

communicated to the same body--all      
producing different results4  ,the      
motion of the individual atom as heat   
may be1 and is1 as rapid as light itself
 when the temperature is sufficiently   
high1 but it does not travel along a    
conductor rapidly as the electro-atomic 
motion will4 ,if we apply heat to the   
end of a metal rod it will travel slowly
 along the rod4 ,but if we make the rod 
a conductor of electricity it travels   
from atom to atom with a speed nearer   
that of the light ray through the ether4
 ,some modern writers have attempted to 
explain all the phenomena of electricity
 as having their origin in a certain    
play of forces upon the ether1 and there
 is no doubt but that the ether plays an
 important part in all electrical       
phenomena as a medium through which     
energy is transferred2 but ether-waves  
that are set in motion by the electrical
 excitation of ordinary matter are no   
more electricity than the ether-waves   
set up by the sun in the cold regions of

 space are heat4 ,they become heat only 
when they strike matter4 ,heat1 as such1
 begins and ends in matter2--so 7,i     
believe7 does electricity4  ,do not be  
discouraged with these feeble attempts  
to explain the theory of electricity4   
,all ,i even hope to do is to establish 
in your minds this fundamental thought1 
to wit1 that there is really but one    
,energy1 and that it is always expressed
 by some form of motion or the ability  
to create motion4 ,motions differ1 and  
hence are called by different names4    
,if ,i should set an emery-wheel to     
revolving and hold a piece of steel     
against it the piece of steel would     
become heated and incandescent particles
 would fly off1 making a brilliant      
display of fireworks4 ,the heat that has
 been developed is the measure of the   
mechanical energy that ,i have used     
against the emery-wheel4 ,now1 let us   
substitute for the emery-wheel another  
wheel of the same size made of          
vulcanized rubber1 glass or resin4 ,i   

set it to revolving at the same speed1  
and instead of the piece of steel1 ,i   
now hold a silk handkerchief or a       
catskin against the wheel with the same 
force that ,i did the steel4 ,if now ,i 
provide a ,leyden jar and some points to
 gather up the electricity that will be 
produced 7instead of the heat generated 
in the other case71 it would be found   
that the energy developed in the one    
case would exactly balance that of the  
other1 if it were all gathered up and   
put into work4 ,the electricity stored  
in the jar is in a state of strain1 like
 a bent bow1 and will recoil1 when it   
has a chance1 with a power commensurate 
with the time it has been storing and   
the amount of energy used in pressing   
against the wheel4  ,if now ,i connect  
my two hands1 one with the inside and   
the other with the outside of the jar1  
this stored energy will strike me with a
 force equal to all the energy ,i have  
previously expended in pressing against 
the wheel1 minus the loss in heat4 ,if  

,i did it for a long enough time this   
electrical spring would be wound up to  
such a tension that the recoil would    
destroy life if one put himself in the  
path of its discharge4 ,if all the heat 
in the first case were gathered up and  
made to bend a stiff spring1 and one    
should put himself in its way when      
released1 this mechanical spring would  
strike with the same power that the     
electrical spring did when the ,leyden  
jar was discharged4 ,this statement     
assumes that all the energy in the      
second experiment was stored as         
electricity in the jar4 ,you will be    
able to see from the above illustration 
that heat1 electrical energy1 and       
mechanical energy are really the same4  
,then you ask1 how do they differ8      
,simply in their phenomena--their       
outward manifestations4  ,while there is
 much that we cannot know about any of  
the phenomena of nature1 it is a great  
step in advance if we can establish a   
close relationship between them4 ,it    

helps to free electricity from many     
vagaries that exist in the minds of most
 people regarding it2 vagaries that in  
ignorant minds amount to superstition4  
,while it possesses wonderful powers1   
they give it attributes that it does not
 possess4 ,not long ago a favorite      
headline of the medical electrician's   
advertisement was ,electricity ,is      
,life1 and it was a common thing to see 
street-venders dealing out this life in 
shocking quantities to the innocent     
multitudes--ten cents' worth in as many 
seconds4  ,science divides electricity  
into two kinds--static and dynamic4     
,static comes from a ,greek word1       
meaning to stand1 and refers to         
electricity as a stationary charge4     
,dynamic is from the ,greek word meaning
 power1 and refers to electricity in    
motion4 ,when ,franklin made his        
celebrated kite experiment1 the         
electricity came down the string1 and   
from the key on the end of the string he
 stored it in a ,leyden jar4 ,while the 

electricity was moving down the string  
it was dynamic1 but as soon as it was   
stored in the ,leyden jar it became     
static4 ,current electricity is dynamic4
 ,a closed telegraphic circuit is       
charged dynamically1 while the prime    
conductor of a frictional electric      
machine is charged statically4 ,the     
distinction is arbitrary and in a sense 
a misnomer4 ,when we rub a piece of hard
 rubber with a catskin it is statically 
charged because the substances are what 
are called non-conductors1 and the      
charge cannot be conducted readily away4
 ,all substances are divided into two   
classes1 to wit1 conductors or          
non-electrics1 and non-conductors or    
electrics1 more commonly called         
dielectrics4 ,these1 however1 are       
relative terms1 as no substance is      
either a perfect conductor or a perfect 
non-conductor4  ,the metals1 beginning  
with silver as the best1 are conductors4
 ,ebonite1 paraffine1 shellac1 etc41 are
 insulators1 or very poor conductors4   

,the best conductors offer some         
resistance to the passage of the current
 and the best insulators conduct to some
 extent4 ,if we make a comparison of    
electric conductors we find that the    
metals that conduct heat best also      
conduct electricity best4 ,this1 it     
seems to me1 is a confirmation of the   
atomic theory of electricity so far as  
it means anything4 ,if a good conductor1
 as silver1 is subjected to intense cold
 by putting it into liquid air1 its     
conductivity is greatly increased4 ,it  
is well known that heating a conductor  
ordinarily diminishes its power to      
conduct electricity4 ,this shows that1  
in order that electrical motion of the  
atom may have free play1 the heat motion
 must be suppressed4     ,,chapter ,,vi4
  ,,electric ,,currents4   ,the simplest
 form of an electric machine is one in  
which the operator is a prominent part  
of the operation4 ,electricity1 like    
magnetism1 operates in a closed circuit1
 even when it is static--so-called4     

,take a stick of sealing-wax1 say1 in   
your left hand1 and rub it with a piece 
of fur or silk with your right hand1 and
 you have the simplest form of electric 
machine--the one that was known to the  
ancients1 and the one from which the    
science1 great as it is to-day1 had its 
beginnings4 ,the stick of sealing-wax is
 one element of the battery1 and the    
piece of fur or silk is the other1 while
 your hands1 arm and body form the      
conductor that connects the two poles1  
and the friction is the exciting agent  
and may be said to take the place of the
 fluid of a battery4 ,the electrical    
conditions are not wholly static1 as a  
slow current is passing around through  
your arms and body from one pole to the 
other4 ,even if the conditions were     
wholly static there would be polarized  
lines of force1 in a state of strain1   
reaching around in a closed circuit4    
,if we rub the wax with the fur and then
 take it away the wax has a charge of   
electricity and will attract light      

objects4 ,if we had rubbed a piece of   
metal or some good conductor it would   
have been warmed instead of electrified4
 ,in both cases the particles of the    
substances have been affected1 and if   
the atomic theory is correct--and it    
seems plausible--in the former case the 
atoms are partly put into electrical    
motion and partly into a state of       
electrical strain that we call static   
7standing7 electricity2 while in the    
latter case the atoms are put into the  
peculiar motion that belongs to heat4   
,the former we call electricity1 and the
 latter we call heat4 ,the              
electro-atomic motion under some        
circumstances readily turns to heat1    
which seems to be the tendency of all   
forms of energy4 ,the electric light is 
a result of this tendency4 ,all         
non-conductors1 or electrics1 have a    
complex molecular structure1 and1 while 
their atoms when subjected to friction  
are put into a state of electrostatic   
strain1 they are not able readily to    

respond as a conductor of dynamic       
electricity4 ,the electric-light        
filament in the incandescent lamp is a  
much poorer conductor than the copper   
wire that leads up to it4 ,the copper   
wire is readily responsive to the       
electrical influence1 but the carbon    
filament is not4 ,so electrical action  
that freely passes along the wire1 is   
resisted and becomes heat action in the 
filament1 and light is the attendant of 
intense heat4 ,but1 to go back to the   
sources of electricity4  ,frictional    
electric machines have been constructed 
in great variety4 ,all1 however1 embrace
 the essentials set forth in the        
sealing-wax experiment1 and would be    
difficult to describe without cuts4 ,let
 us1 therefore1 consider another source 
of electricity1 which was the outgrowth 
of the discovery of ,galvani 7or rather 
his wife71 and reduced to concrete form 
by ,volta4 ,we refer to the galvanic or 
voltaic battery4 ,if we put a bar of    
zinc into a glass vessel and pour       

sulphuric acid and water into it1 there 
will be a boiling1 and an evolution of  
hydrogen gas1 and energy is released in 
the form of heat1 so that the fluid and 
the glass vessel become heated4 ,now let
 us put a bar of copper or a stick of   
carbon into the glass1 but not in       
contact with the zinc2 connect the ends 
7that are not immersed7 of the two      
elements--copper and zinc--with a metal 
wire or any conductor1 and a new        
condition is set up4 ,heat is no longer 
evolved to the same extent1 but most of 
the energy becomes electrical in        
character1 and an electrical chain of   
action takes place in the circuit that  
has now been formed4 ,taking the zinc as
 the starting point1 the so-called      
current flows from the zinc through the 
fluid to the copper and from the copper 
through the wire to the zinc4  ,a chain 
of polarized atomic activity is         
established in the circuit1 similar to  
the closed circuit of magnetic lines of 
force1 only the latter is static1 while 

the former is dynamic4  ,you ask what is
 the difference8 ,well1 it is much      
easier to ask a question than it is to  
answer it4 ,you will remember that in   
the chapter on magnetism it was stated  
that the molecules of a magnet were     
little natural magnets1 and that their  
attractions were satisfied within       
themselves2 that when their local       
attachments were broken up and all their
 like poles turned in one direction they
 could act upon other pieces of iron    
outside of the magnet4 ,outside and     
between the poles there are magnetic    
lines of force reaching out from one    
pole to the other4 ,if we put a piece of
 iron across the poles these lines of   
force are gathered up and pass through  
the iron4 ,this is purely a static      
condition4 ,let us go back to the cell  
of battery4 ,when the elements are in   
position 7the copper1 the acidulated    
water and the zinc71 and the two wires  
attached to the two metals which are the
 two poles of the battery not yet       

connected1 there is a condition induced 
in these two wires that did not exist   
before the acidulated water was poured  
in1 although the circuit is not yet     
established4 ,if we test the two wires  
we find a difference of potential--a    
state of strain1 so to speak--that did  
not exist before the acid acted on the  
zinc and liberated what was stored      
energy4 ,it is in a static condition1   
like the magnet1 and electrical lines of
 force are reaching out from both wires 
so that the ether is in a state of      
strain between the two poles4 ,the air  
molecules may partake of it1 but we have
 to bring in the ether as a substance1  
because the same conditions would       
practically exist if the two wires were 
in a vacuum4 ,if now we connect the two 
wires1 we have established a metallic   
circuit between the two poles of the    
battery1 the static conditions are      
relieved1 the lines of force are        
gathered up into the wire1 and the      
phenomenon that we call a current is    

established and we have dynamic or      
moving electricity4  ,having established
 the so-called electric current we will 
now try to show you that there really is
 no current4 ,the idea of a current     
involves the idea of a fluid substance  
flowing from one point to another4 ,when
 you were a boy did you never set up a  
row of bricks on their ends1 just far   
enough apart so that if you pushed one  
over they all fell one after another8   
,now1 imagine rows of molecules or      
atoms1 and in your imagination they may 
be arranged like the bricks1 so that    
they are affected one by the other      
successively with a rapidity that is    
akin to that of light-waves1 and you can
 conceive how a motion may be           
communicated from end to end of a wire  
hundreds of miles in length in a small  
fraction of a second1 and no material   
substance has been carried through the  
wire--only energy4 ,we do not mean to   
say that the row of bricks illustrates  
the exact mode of molecular or atomic   

motion that takes place in a conductor4 
,what we mean is1 that in some way      
motion is passed along from atom to     
atom4  ,to give you a better conception 
of an electric current1 let us go back  
of the galvanic cell to the electric    
machine4 ,if both poles of the machine  
are attached to rods terminating in     
round knobs we can set the machine in   
action and keep up a steady stream of   
disruptive discharges that will1 if     
their frequency is great enough1 perform
 the function of a current1 and we have 
dynamic electricity from a statical     
machine2 when the acid of the galvanic  
battery breaks down a molecule of zinc1 
energy is set free1 and in the battery  
we have what corresponds to a disruptive
 discharge of infinitesimal proportions4
 ,this discharge would have been        
immediately converted into heat energy  
if the copper element had been left out 
of the battery1 but as it is1 it        
impresses itself on the atomic brick    
next to it1 which establishes a chain of

 atomic movement throughout the circuit4
 ,this may constitute1 if you please1 a 
line of electrical force4 ,but as       
thousands of these disruptive discharges
 are taking place simultaneously as many
 different lines of force are           
established4 ,you must not conceive of  
these chains of atoms as simply thrown  
down like the bricks and left lying     
there1 but that the atom is active2 that
 it has the power to pick itself up     
again in an infinitesimally short time  
and is again knocked down 7following the
 illustration of the bricks7 by the next
 discharge along its line or chain of   
atoms4  ,if you could get a mental      
picture of this action you would see    
that the whole conductor is in a most   
violent state of atomic motion of a     
peculiar kind4 ,at the same time a part 
of this electrical motion is being      
converted into a heat motion of the     
atoms1 and finally it all returns to    
heat unless some of it is stored up     
somewhere as potential energy4 ,if the  

current has driven a motor that has     
wound up a weight1 a part is stored up  
in the weight1 which has the ability to 
do work if it is allowed to run down4   
,if it drives machinery as it runs down1
 the mechanical motion is the expression
 of the stored energy4 ,when the weight 
has run down the energy will be         
represented by the heat created by      
friction of the journals of the wheels  
and pulleys and the heating of the air4 
,if the weight is allowed to fall       
suddenly it will heat the air to some   
extent1 but mostly the earth and the    
weight itself will be heated4 ,if the   
source of energy 7the battery7 is great 
and the pressure high and the conductor 
is too small to carry the energy        
developed in the battery as electricity1
 heat is developed1 and if the heat is  
sufficiently intense1 light also4  ,we  
have seen 7,vol4 ,,ii7 that heat motion 
when it reaches a sufficiently high rate
 throws the ether into a vibratory      
motion that we call light4 ,however1    

this vibratory motion of the ether is   
set up long before it reaches the       
luminous stage2 in other words1 there   
are dark rays of the ether4 ,we find    
that the electro-atomic motions of a    
conductor have the power to impress     
themselves upon the ether4              
,illustration3 ,fig4 #a4      ,a is the 
primary line2 a1 the battery3 b1 the    
key4 ,b is the     secondary line in    
which is placed the galvanometer c4     
,let us try another experiment to show  
that this is the case1 not only1 but    
that the impressed ether can transfer   
these impressions to still another      
conductor4 ,suppose we stretch two      
parallel wires for1 say1 half a mile1 or
 any distance1 only a few feet apart1   
and make of each a complete circuit by  
rounding the end of the course and      
returning the wire to the starting point
 7as shown in ,fig4 #a74 ,put in one of 
these circuits a battery1 and a         
circuit-breaker 7a common               
telegraph-key71 and in the other circuit

 a galvanometer 7an instrument for      
detecting the presence and measuring the
 intensity of a galvanic current1 by    
means of a dial and a deflecting needle 
or pointer74 ,now if we touch the key   
and close the circuit in ,a1 the needle 
of the galvanometer in ,b will swing in 
one direction from zero on the dial2 and
 if we release the key1 breaking the    
circuit in ,a1 the needle will swing    
back in the opposite direction4 ,in     
neither case will the needle stay       
deflected1 but will at once return to   
zero4  ,this shows that when the battery
 current was allowed to complete its    
circuit through wire ,a by closing its  
key1 an electrical action was instantly 
felt in wire ,b1 although there was no  
material connection between them other  
than the air1 which is a non-conductor4 
,the current in the second circuit is   
called an induced current4 ,why this    
current8 ,according to one theory1 when 
we close the primary circuit the        
surrounding ether is thrown into a      

peculiar state of strain that we will   
call magnetic or electrical lines of    
force4 ,when the ether wave strikes the 
second wire there is a molecular        
movement from a state of rest to a state
 of static strain4 ,during the time that
 the molecules are moving from the      
normal to the strained position in      
sympathy with the ether we have the     
condition of a dynamic current1 which   
lasts only a moment4 ,this state of     
strain continues till the circuit is    
opened 7breaking the wire-line71 when   
all the electrical lines of force vanish
 and the molecular strain of the second 
wire is relieved1 and we again have the 
conditions1 momentarily1 for a current  
of the opposite polarity1 and the needle
 will swing in the opposite direction   
because the molecules or atoms have1 in 
their recoil to the natural state1 moved
 in an opposite direction4  ,going back 
to ,fig4 #a1 let us further study the   
phenomena under other conditions4 ,in   
our first circuit 7,a7 there is a       

battery and a circuit-breaker1 which is 
a common telegraph-key4 ,now close the  
key so that a current will be           
established4 7,remember that current is 
only a name for a condition of dynamic  
charge47 ,place a piece of soft iron    
across the wire at right angles with the
 direction of the wire1 when of course  
it will be at right angles with the     
direction of the current1 and you will  
find now that the iron is more or less  
magnetic1 depending upon the amount of  
current passing through the wire4 ,if we
 wind a number of turns of insulated    
wire through which the current is       
passing around the iron the magnetism   
will be increased4 ,in practice there   
are a certain number of turns and a     
certain sized wire that will give the   
best results with a given number of     
cells of battery 7or a given voltage or 
pressure71 operating in a closed circuit
 of a given resistance4 ,all these      
questions are worked out mathematically 
in many standard books on the subject4  

,it is not the intention in these talks 
to develop the science mathematically   
but to set out the fundamental physical 
facts and applications of electricity4  
,under the conditions above named       
magnetism is developed in the soft iron 
bar4 ,if we open the key the current    
will cease and the magnetism will       
vanish--that is to say1 the molecules   
will turn back to their neutral position
 by their own attractions1 as has been  
described in a previous chapter4        
,magnetism developed in this way is     
called electromagnetism4 7,see ,chap4   
,,iv47 ,if we use a piece of hardened   
steel instead of the soft iron it will  
become magnetic and remain so when the  
circuit is opened1 because the natural  
tendency of the molecules to turn back  
to the neutral position is not great    
enough to overcome the coercive force1  
or molecular friction1 of hardened      
steel1 as has been also described in a  
previous chapter4 ,to make the best     
electromagnet we need qualities of iron 

just the opposite from those of the     
permanent magnet4 ,for the former we    
need the purest of soft iron1 well      
annealed 7heated to redness and slowly  
cooled1 making it less brittle71 so that
 its molecules are free to turn2 while  
for the latter we need hardened steel1  
so that when the molecules are once     
wrenched into the magnetic condition    
they cannot1 of themselves1 turn back to
 the neutral state4 ,the great value of 
the electromagnet lies in its ability to
 readily discharge1 or go back to the   
neutral state1 when the current is      
broken4  ,let us now go back to the     
beginning of our experiment4 ,when we   
closed the key and established the      
current through the wire we found that a
 piece of iron held at right angles to  
the wire1 although not touching it1     
became magnetic4 ,we have already said  
that when the circuit was open1 the     
battery being in circuit1 there were    
electrical lines of force established in
 the ether1 between the two poles of the

 battery1 and that they were gathered up
 into the conducting wire when the      
circuit was closed4 ,we now find that   
there are other lines of force of a     
different nature established in the     
ether when the circuit is closed4 ,these
 we call magnetic lines of force1 or the
 magnetic field of the charged wire1 and
 they are established at right angles to
 the direction of the current4 ,these   
magnetic lines of force acting through  
the ether from an electrically charged  
conductor are able to break up the      
natural molecular magnetic rings1       
referred to in ,chapter ,,iv1 and turn  
all their like poles in the same        
direction--thus making one compound     
magnet of the iron which in the neutral 
state consisted of millions of little   
natural magnets whose attractions were  
satisfied by a joining of their unlike  
poles4  ,most writers account for all of
 the phenomena of induced currents in a 
second wire as coming directly from     
these magnetic lines of force developed 

upon closing the circuit4  ,so much for 
theory based upon a set of facts that   
make the theory seem probable4 ,if you  
don't like it give us a better one4 ,if 
it is correct the writer claims no      
credit2 it is merely a compilation of   
suggestions from many sources1 including
 his own experience4 ,we are simply     
seeking after truth4 ,the man who is an 
earnest seeker after scientific truth   
cannot afford to pursue his             
investigations with any prejudice in    
favor of one theory more than another1  
unless the facts sustain him1 and then  
he is not acting from prejudice1 but is 
led by the facts4 ,many people make pets
 of their theories2 and they become     
attached to them as they do their       
children2 and they look upon a man who  
destroys them by a presentation of the  
facts as an enemy4 ,i once knew a lady  
who became so attached to her family    
doctor that1 she said1 she would rather 
die under his treatment1 if necessary1  
than to be cured by any other doctor4   

,there are many people who are imbued   
with this kind of spirit not only in    
matters scientific1 but in matters      
religious as well4 ,such people are not 
the kind who contribute to the world's  
progress1 but are the hindrances that   
have to be overcome4     ,,chapter      
,,vii4  ,,electric ,,generators4   ,of  
the sources of electricity we have      
mentioned two3 ,friction1 and ,galvanism
 or chemical action4 ,there are hundreds
 of forms of the latter species of      
apparatus for generating electrical     
energy1 so we will mention only a few of
 the more prominent ones4 ,it is not our
 intention to go into the chemistry of  
batteries4 ,there are too many          
exhaustive works on this subject lying  
on the shelves of libraries that are    
accessible to all4 ,all galvanic        
batteries act on one general            
principle--the generation of electricity
 by the chemical action of acid on metal
 plates2 but the chemistry of their     
action is very different4 ,in all       

batteries the potential energy of one   
element is greater than the other4 ,the 
acid of the battery dissolves the       
element of greater potentiality1 and its
 energy is freed and under right        
conditions takes on the form of         
electricity4 ,the potential of zinc1 for
 instance1 is greater than that of      
copper1 and the measure of the          
difference is called the electromotive  
force1 the unit of which is the volt4   
,electromotive force is another name for
 pressure2 the symbol for which is      
,e4,m4,f4  ,if we were to put two zinc  
plates in the battery fluid and connect 
them in the ordinary way there would be 
no electricity evolved 7assuming that   
they were perfectly homogeneous71       
because they are both of the same       
potential1 or have the same possible    
amount of stored electrical energy      
measured by its working power4 ,if one  
of the zinc plates were softer than the 
other1 a feeble current would be        
developed1 for one would be more readily

 acted upon by the acids than the other4
 ,the battery that has been most used in
 ,america for telegraphic purposes is   
called the gravity-battery4 ,it is      
constructed by putting a copper plate in
 some form at the bottom of a jar1      
usually of glass1 and filling it partly 
full of the crystals of sulphate of     
copper1 commonly called bluestone4      
,zinc1 usually cast in some open form1  
so as to expose a large surface to the  
solution1 is suspended in the upper part
 of the jar1 which is then filled with  
water till it covers the zinc4 ,the zinc
 is the positive metal1 but it is called
 the negative pole4 ,the energy         
developed by the zinc passes from zinc  
to copper and out on the circuit from   
the copper pole4 ,hence the copper came 
to be called the positive pole1 although
 in relation to zinc it is negative4    
,copper would1 however1 be positive to  
some other metal whose potential was    
less4 ,so you see that metals are       
relative1 not absolute1 in their        

character as positive and negative      
elements4  ,the galvanic battery has    
been almost entirely superseded in this 
country for telegraphic purposes by the 
dynamo1 a machine developing electrical 
currents by mechanical power4 ,another  
form of battery that is extensively used
 for some kinds of heavy current work is
 called the storage-battery4 ,the man   
who did the most1 perhaps1 to bring the 
storage-battery to its present state of 
perfection was ,plante1 a ,frenchman1   
who died only a short time ago4         
,although very many types of battery    
have been developed1 it is found that1  
after all1 the lines on which he        
developed it make the most efficient    
battery4 ,there is a common notion that 
electricity is stored in the            
storage-battery4 ,energy is stored1 that
 will produce electricity when it is set
 free1 just the same as energy is stored
 in zinc4 ,the storage-battery1 when    
ready for action1 is one form of acid or
 primary battery4 ,it has been made by  

passing a current of electricity through
 it until the chemical relations of the 
two lead plates have been changed so    
that the potential of one is greater    
than that of the other4 ,a simple       
storage-battery element is made up of   
two plates of lead held out of contact  
with each other by some insulating      
substance the same as the elements of an
 ordinary battery4 ,the cell is filled  
with dilute sulphuric acid1 and there   
will be no electrical action till the   
cell has been charged by running a      
current of electricity through it and   
forming a lead oxide on one plate4 ,now1
 take off the charging battery and      
connect the two poles1 and electricity  
will flow until the oxide has partly    
changed back into spongy metallic lead1 
when it must be renewed by recharging4  
,i remember perfectly well the first    
galvanic battery ,i ever saw1 for it was
 of my own construction4 ,it is now     
nearly fifty years ago1 and yet it seems
 but yesterday--such is the flight of   

time4 ,i related to you in another      
chapter how ,i made a voltaic           
battery--or pile1 as it was called--by  
cutting up my mother's boiler and her   
stove-zinc1 and the domestic incident   
that followed4 ,well1 a little later ,i 
made a real galvanic battery as follows3
 ,i lived in the country and far from   
town or city1 and my facilities were    
extremely limited1 so that ,i pursued my
 scientific investigations under great  
difficulties4 ,my only text-book was an 
old ,comstock's ,philosophy4 ,in the    
book was a crude cut of a ,morse        
register and a short description of its 
construction1 including the battery4 ,i 
determined to make a register1 and ,i   
did4 ,it was all constructed of wood    
except the magnet and its armature and  
the embossing-point1 which latter was   
made of the end of a nail4 ,the thing   
that seemed out of reach was the        
electromagnet4 ,i had no money2 and     
there was no one that believed ,i could 
do it1 and if ,i could what good would  

come of it8 ,i made friends with a      
blacksmith by keeping flies off a horse 
while he nailed the shoes on1 and       
blowing the bellows and occasionally    
using the sledge for him4 ,when ,i      
thought the obligation had accumulated a
 sufficient voltage 7to express it      
electrically7 ,i communicated to the    
blacksmith the situation and what ,i    
wanted4  ,the good-natured old fellow   
was not long in bending up a ,u magnet  
of soft iron and forging out an         
armature4 ,the next step was to wind the
 ,u with insulated wire4 ,the only thing
 that ,i had ever seen of the kind was  
an iron wire called bonnet wire that was
 wrapped with cotton thread4 ,this1     
however1 was not available1 so ,i       
captured a piece of brass bell-wire and 
wound strips of cotton cloth around it  
for insulation--and in that way         
completed the magnet4  ,now everything  
was ready but the battery4 ,i went at   
its construction with a feeling almost  
akin to awe1 for ,i could not believe   

that it would do as described in the    
book4 ,i procured a candy-jar from the  
grocer and found some pieces of sheet   
zinc and copper4 ,these ,i rolled       
together into loose spirals and placed  
one inside the other so that they would 
not touch1 when ,i was ready for the    
solution4 ,the druggist trusted me for a
 half pound of blue vitriol1 and ,i put 
it into my battery and filled it with   
water4 ,i waited awhile for it to       
dissolve1 and then connected my magnet  
in circuit1 when--to my astonishment and
 delight--it would lift a pound or more4
 ,it was a great triumph4 ,i never have 
had one since that gave me the same     
satisfaction4 ,but ,i had my triumph all
 to myself4 ,i was still the same tinker
 7a name ,i had long carried71 and a    
nuisance to be endured but not          
encouraged4  ,the dynamo is the form of 
generator now in general use where heavy
 currents of electricity are needed4 ,it
 is aptly described by a writer in      
,modern ,machinery1 ,mr4 ,john ,a4      

,grier1 as a thing that when at rest is 
a lifeless piece of mechanism2 in action
 it has a living spirit as full of      
mystery as the soul of man4 ,this is a  
poetic way of describing it that conveys
 to the mind a sense of the power and   
beauty of natural law in action1 that   
would not come from a mere recital of   
the cold scientific facts4 ,the facts1  
however1 are necessary3 but let us draw 
from them all the poetry and all the    
practical lessons that we can as we go  
along2 for it is this blending of the   
poetic with the practical that lends a  
charm to our every-day grind1 and       
lightens the load of many a weary hour4 
,the dynamo is a machine that converts  
mechanical into electrical energy1 and  
the great practical value of energy in  
this form is that it can be distributed 
through a conductor economically for    
many miles4 ,we can transmit mechanical 
power by means of a rope or cable for a 
limited distance1 but at tremendous loss
 through friction4 ,we can transmit     

power through pipes by compressed air or
 steam1 but there is a great loss1      
especially in the case of steam1 by     
condensation from cold4 ,none of these  
methods are available for long          
distances4 ,another advantage           
electricity has over other forms of     
energy is the speed with which it can be
 transmitted from one place to another4 
,in this respect it has no rival except 
light4 ,but we have not been able to    
harness light and make it available to  
carry either freight or news1 except in 
the latter case for a short distance by 
flashing it in agreed signals4  ,the    
heliostat can be used when the sun      
shines to transmit news by flashes of   
sunlight chopped up into the ,morse code
 and thrown from point to point by a    
moving mirror4 ,but this is limited as  
to distance2 besides1 the sun does not  
always shine4 ,it has the disadvantage  
in that respect that the old            
semaphore-telegraph did that was in use 
in ,wellington's day4 ,these semaphores 

were constructed in various ways1 but a 
common form was that of moving arms that
 could be seen from hill to hill or     
point to point4 ,by a code of moving    
signals news was repeated from point to 
point and it can be easily imagined that
 many mistakes occurred1 to say nothing 
of the time it required for repetition4 
,when the battle of ,waterloo was       
fought--so the story goes--news was sent
 to ,england by means of the            
semaphore-telegraph4 ,the dispatch read1
 ,wellington defeated-- ,at that point  
in the message a thick fog came up and  
lasted for three days1 so that no       
further news could be sent or received4 
,in the telegraphic parlance of to-day  
the line was busted4 ,for three long    
days all ,london was in deep mourning1  
when finally the fog lifted1 which      
repaired the telegraphic line1 and the  
balance of the dispatch was             
received--the ,french at ,waterloo4     
,mourning changed to rejoicing and the  
,english have rejoiced ever since when  

they think of either ,wellington or     
,waterloo4  ,but to return to the       
dynamo4 ,the name dynamo is an          
abbreviation for dynamo-electric        
machine4 ,a machine for producing       
dynamic electricity4 ,there are many    
forms of the dynamo1 just as there are  
in the evolution of every important     
machine1 and there will be many more4   
,but the fundamental1 underlying        
principle of them all is contained in an
 experiment made by ,faraday4 ,faraday  
took the soft iron keeper of a permanent
 magnet and wound insulated wire around 
it and brought the two ends of the wire 
close together4 ,he now placed the      
keeper1 with the wire wound around it1  
across the poles of the permanent       
magnet1 and wrenched it away suddenly1  
when he observed a spark pass between   
the ends of the wires4 ,this would occur
 when he approached the poles as well as
 when he took it away4 ,he discovered   
that the currents were momentary and    
occurred at the moment of approach or   

recession1 and that the currents        
developed by the approach were of       
opposite polarity to those occurring at 
the recession4 ,when the keeper was put 
on the poles of the magnet it was       
magnetized by having its molecular rings
 broken up and the poles of the little  
natural magnets all turned in one       
direction4 ,during the time that the    
molecules of the keeper are changing    
they are in a dynamic or moving         
condition4 ,by some mysterious action of
 the ether between the iron and the wire
 wrapped around it there is a           
corresponding molecular action in the   
wire that is dynamic for a moment only1 
and during that moment we have the      
phenomenon of an electric current4 ,when
 the magnet and soft iron are separated 
this molecular state of strain is       
relieved and the molecules of both the  
iron and the wire wound about it return 
to normal1 and in the act of returning  
we have a dynamic or moving condition1  
resulting in a current1 only in the     

opposite direction4 7,see ,chap4 ,,vi47 
,now mount the permanent magnet in a    
frame and mount the soft iron with the  
wire on it 7which in this shape is an   
electromagnet7 on a revolving arm and so
 set it on the arm that its ends will   
come close to1 but not touch1 the poles 
of the permanent magnet4 ,now revolve   
the arm1 and every time the             
electromagnet or keeper approaches the  
permanent magnet a current of one       
polarity will be momentarily developed  
in the wire of the electromagnet1 which 
is moving4 ,when it is opposite the     
poles1 it has reached the maximum charge
 and1 now1 as it passes on it discharges
 and a current of the opposite polarity 
is developed in the wire4 ,the more     
rapidly we revolve the arm the more     
voltage 7electrical pressure7 the       
current it develops will have4  ,it will
 be plain to all that we might make the 
electromagnet stationary and revolve the
 permanent magnet and get the same      
result4 ,if the permanent magnet were   

strong enough and the electromagnet the 
right size as to iron1 windings1 etc41  
and we revolve the arm with sufficient  
rapidity1 we could get an alternating   
current of electricity that would       
produce an electric light4 ,i have not  
and cannot here give you the            
construction of a modern                
alternating-current dynamo4 ,i have     
simply described the simplest form of   
dynamo1 and all of them operate upon the
 fundamental principle of a permanent   
magnetic field and an electromagnet1    
moving in a certain relation to each    
other4 ,the field may revolve or the    
electromagnet may revolve1 whichever is 
the most convenient to construct4 ,the  
field-magnet may be a permanent magnet  
or an electromagnet1 made permanent     
during the operation of the dynamo by a 
part of the current generated by the    
machine being directed through a coil   
surrounding soft iron2 or the           
field-current may come from an outside  
source4 ,this is the kind of            

field-magnet universally used for dynamo
 work1 as a much stronger magnetism is  
developed in this way than it is        
possible to obtain from any system of   
permanent steel magnets4  ,the usual    
construction is to have a stationary    
field-magnet and then a series of       
electromagnets mounted and revolving    
upon a shaft in the center of the       
magnetic field4 ,the rotating part is   
called the armature1 and is so wound    
with insulated wire that successive     
induced currents are created in the     
armature windings and discharged through
 brushes which rest on revolving        
segments that connect with the armature 
windings4 ,these induced currents       
succeed each other with such rapidity as
 to amount in practice to a steady      
current4 ,however1 the separate         
pulsations are easily heard in any      
telephone when the circuit is near to   
that of a dynamo circuit4 ,the dynamo   
current is not nearly so steady as the  
battery current1 although both are      

probably made up of separate discharges4
 ,in the dynamo there is a discharge    
every time the electromagnet of the     
armature cuts through the lines of force
 of the magnetic field1 and in the      
galvanic battery every time a molecule  
is broken up and its little measure of  
energy is set free4 ,in the dynamo the  
pulsations are so far apart as to make a
 musical tone of not very high pitch1   
but in the galvanic battery the pitch of
 the tone1 if there is one1 would       
require a special ear to hear it--one   
tuned1 it may be1 up near the rate of   
light vibration4  ,there are two types  
of dynamo1 one generating a direct and  
the other an alternating current4 7,by  
alternating we mean first a positive and
 then a negative current impulse47 ,we  
cannot enter into a technical           
description of the dynamo in a popular  
treatise such as this4  ,the dynamo has 
evolved from the germ discovered by     
,faraday1 till to-day it is a machine1  
the construction of which requires the  

highest class of engineering skill4     
,when in action it seems like a great   
living presence1 scattering its energy  
in every direction in a way that is at  
once a marvel and a blessing to mankind4
 ,but we must not give all the credit to
 the dynamo4 ,as the moon shines with a 
reflected light1 so the dynamo gives off
 energy by a power delegated to it by   
the steam-engine that rotates it1 and   
the steam-engine owes its life to the   
burning coal1 and the burning coal is   
only giving up an energy that was stored
 ages ago by the magic of the sunbeam2  
and the sun--8 ,well1 we are getting    
close on to the borders of theology1 and
 being only scientists we had better    
stop with the sun4  ,there is still     
another way of generating electricity   
besides those that we have named2 which 
are friction1 chemical action1 and the  
magneto-electric mode of generating a   
current4 ,electricity may be generated  
by heat4 ,if we connect antimony and    
bismuth bars together and apply heat at 

the junction of the metals and then     
connect the free ends of the two bars to
 a galvanometer1 it will indicate a     
current4 ,these pairs can be multiplied1
 and in this way increase the voltage or
 pressure1 and1 of course1 increase the 
current1 if we assume that there is     
resistance in the circuit to be         
overcome4 ,if there were absolutely no  
resistance in the circuit--a condition  
we never find--there would be no        
advantage in adding on elements in      
series4  ,substances differ in their    
resistance to the passage of            
electricity--the less the resistance the
 better the conductor4 ,the ,german     
electrician1 ,g4 ,s4 ,ohm 7#aghi-ahed71 
investigated this and propounded a law  
upon which the unit for resistances is  
based1 and this unit takes his name and 
is called the ohm4  ,any two metals     
having a difference of potential will   
give the phenomena of                   
thermo-electricity4 ,antimony and       
bismuth having a great difference of    

potential are commonly used4 ,the use   
made of thermal currents is chiefly for 
determining slight differences of       
temperature4 ,an apparatus called the   
thermo-electric pile has been           
constructed out of a great number of    
pairs of antimony and bismuth bars4     
,this instrument in connection with a   
galvanometer makes a most delicate means
 of determining slight changes of       
temperature4 ,if one face of a          
thermopile is exposed to a temperature  
greater than its own1 the needle will   
move in one direction2 if to a          
temperature lower than its own1 the     
needle will be deflected in the opposite
 direction4 ,if both faces of the pile  
are exposed to the same changes of      
temperature simultaneously1 of course no
 electrical manifestations will occur4  
,the earth is undoubtedly a great       
thermal battery that is kept in action  
by the constant changes of temperature  
going on at the earth's surface1 caused 
by its rotation every twenty-four hours 

on its axis4 ,the sun1 of course1 is at 
some point heating the earth1 which at  
other points is cooling1 making a       
constant change of potential between    
different points4 ,if we heat a metal   
ring at one point a current of          
electricity will flow around            
it--especially if it is made of two     
dissimilar metals--until the heat is    
equally distributed throughout the ring4
  ,some years ago1 when the ,postal     
,telegraph ,company first began         
operations between ,new ,york and       
,chicago1 the writer made observations  
twice a day for some time of the        
temperature and direction of the        
earth-current4 ,the first two wires     
constructed gave only two ohms          
resistance to the mile1 which           
facilitated the experiments4 ,i found   
that in almost every instance the       
current flowed from the point of higher 
temperature to the lower4 ,if the       
temperature in ,new ,york were higher at
 the time of observations than in       

,chicago the current would flow         
westward1 and if the conditions were    
reversed the current would be reversed  
also4     ,,chapter ,,viii4             
,,atmospheric ,,electricity4   ,nature  
has another mode of generating          
electricity1 called atmospheric4 ,the   
normal conditions of potential between  
the earth and the upper atmosphere seem 
to be that the atmosphere is positively 
electrified and the earth negatively4   
,these conditions change1 apparently    
from local causes1 for short periods    
during storms4 ,in some way the sun's   
rays have the power directly or         
indirectly to give the globules of      
moisture in the air a potential         
different from that of the earth4  ,in  
clear weather we find the air near to   
the earth in a neutral condition1 but   
gradually assuming the condition of a   
positive charge as we ascend2 so that   
the upper air and the earth are         
oppositely charged like the two sides of
 a ,leyden jar or two leaves of a       

condenser4 ,this condition is           
intensified and localized when a        
thunder-cloud passes over the earth4    
,the moisture globules have been charged
 with potential energy by the power of  
the sun's rays when evaporation took    
place2 but in this state the energy is  
neither heat nor electricity1 but a     
state of strain like a bent bow or a    
wound-up spring4 ,when these moisture   
globules condense into drops of water   
the potential energy is set free and    
becomes active either as heat or        
electricity4 ,the cloud gathers up the  
energy into a condensed form1 and when  
the tension gets too great a discharge  
takes place between the cloud and the   
earth or from one cloud to another1     
which to an extent equalizes the energy4
  ,in most cases of thunder and         
lightning it is only a discharge from   
cloud to cloud unequally charged4 ,this 
does not relieve the tension between the
 earth and the cloud1 but distributes it
 over a larger area4 ,the reason for    

this constant electrical difference     
between the earth and the upper regions 
of atmosphere is not well understood1   
except that primarily it is an effect of
 the sun's rays4 ,evaporation may and   
probably does play a part1 and the same 
causes that give rise to the auroral    
display may contribute in some way to   
the same result4 ,evaporation does not  
always take place at the earth's        
surface4 ,cloud formations may be       
evaporated in the upper air into        
invisible moisture spherules1 and       
charged at the time with potential      
energy4 ,if we go up into a high        
mountain when the conditions are right1 
we can witness the effect of this       
condition of electrical charge or strain
 between the upper regions of the       
atmosphere and the earth1 and the       
tendency to equalize the potentials     
between the clouds and the earth4 ,often
 one's hair will stand on end1 not from 
fright1 but from electricity passing    
down from the upper regions to the      

earth4 ,when the tension is very great a
 loud hissing sound as of many musical  
tones of not very good quality may be   
heard1 and a brush or fine-pointed      
radiation of electricity may be seen    
from every point1 even from your        
finger-ends4 ,the thunder is not usually
 so loud on high mountains for two      
reasons--one because the air is rare1   
but the chief reason is that the        
mountain acts as a great lightning-rod  
and gradually discharges the cloud or   
atmosphere1 for often the phenomena may 
occur when the sky is clear4  ,i        
remember being on top of what is called 
the ,mosquito ,range1 between ,alma and 
,leadville in ,colorado1 during the     
passage of a thunder shower4 ,there was 
no heavy thunder1 but a constant        
fusillade of snapping sounds1           
accompanied by flashes not very intense4
 ,i could feel the shocks1 but not      
painfully4 ,a part of the time ,i was in
 the cloud and became for the time being
 a veritable lightning-rod4 ,after the  

cloud passed it crawled down the        
mountainside as if clinging to it1 all  
the time bombarding it with little      
electric missiles4 ,after the cloud left
 the mountain and passed over the valley
 ,i could hear loud thunder1 because the
 charge would have to accumulate quite a
 quantity1 so to speak1 before it could 
discharge4 ,these heavy discharges when 
the cloud is some distance from the     
earth would be dangerous to life1 while 
the light ones1 when the cloud is in    
contact with the earth1 are not4  ,many 
wonderful and destructive effects come  
from these lightning discharges and many
 lives are lost every year from this    
cause4 ,i do not suppose it is possible 
to be on one's guard continually1 but   
many lives are needlessly lost either   
from ignorance or carelessness4         
,although there is a just prejudice     
against lightning-rods as ordinarily    
constructed1 it is still just as        
possible to protect your house and its  
inmates from the destroying effects of  

lightning as from rain4 ,if1 for        
instance1 we lived in metal houses that 
had perfect contact all round them with 
moist earth1 or better1 with a          
water-pipe that has a large surface     
contact with the earth1 the lightning   
would never hurt the house or the       
inmates4 ,in such a case you simply     
carry the surface of the earth to the   
top of your house1 electrically         
speaking1 and neutralization takes place
 there in case the lightning strikes the
 house4 ,a house that is heated with hot
 water can easily be made               
lightning-proof by a little work at the 
top and bottom of the heating system4   
,all the heavy metal of the house should
 be a part of the lightning-rod4 ,points
 should be erected at the chimneys1 and 
if there is a metal roof they should be 
connected with it4 ,then connect the    
roof with rods from several points with 
the ground4 ,here is where most rods    
fail4 ,the ground connection is not     
sufficient4 ,the earth is a poor        

conductor1 and we have to make up by    
having a large metal surface in contact 
with it4 ,it is best to have the rod    
connected with the water pipe1 if there 
is one1 and have it connected with metal
 running all around the house as low    
down as the bottom of the cellar1 for   
sometimes there is an upward stroke1 and
 you never can tell where it is coming  
up4 ,if you have a heating system it    
should be thoroughly grounded and the   
top pipe connected with the rods at the 
chimneys4 ,these rods need not be       
insulated as is the usual practice4  ,if
 you are outdoors during a thunder-storm
 never get under a tree1 but if you are 
twenty or thirty feet away it may save  
your life1 because1 if it comes near    
enough to strike you1 it will probably  
take the tree in preference4 ,it seeks  
the earth by the easiest passage4 ,an   
oil-tank and a barn are dangerous       
places1 if the one has oil in it and the
 other is filled with hay and grain4 ,a 
column of gas is rising that acts as a  

conductor for lightning4 ,of course if  
the barn is properly protected with rods
 it will be safe4 ,sometimes a cloud is 
so heavily charged that the lightning   
comes down like an avalanche1 and in    
such a case the rods must have great    
capacity and be close together to fully 
protect a building4  ,there is a popular
 notion that rods draw the lightning and
 increase the damage rather than        
otherwise4 ,this is a mistake4 ,points  
will draw off electricity from a charged
 body silently4 ,it would be possible to
 so protect a district of any size in   
such a way that thunder would never be  
heard within its boundaries if we should
 erect rods enough and run them high    
enough into the upper air4 ,the         
points--if they were close enough       
together--would silently draw off the   
electricity from a cloud as fast as it  
formed1 and thus effectually prevent any
 disruptive discharge from taking place4
     ,,chapter ,,ix4  ,,electrical      
,,measurement4   ,having given a short  

account of some of the sources of       
electricity1 let us now proceed to      
describe some of the practical uses to  
which it is put1 and at the same time   
describe the operation of the appliances
 used4 ,before proceeding further1      
however1 we ought to tell how           
electricity is measured4 ,we have pounds
 for weight1 feet and inches for lineal 
measure1 and pints1 quarts1 gallons1    
pecks and bushels for liquid and dry    
measure1 and we also have ohms1 volts1  
amperes and ampere-hours for            
electricity4  ,when a current of        
electricity flows through a conductor   
the conductor resists its flow more or  
less according to the quality and size  
of the conductor4 ,silver and copper are
 good conductors4 ,silver is better than
 copper4 ,calling silver #ajj1 copper   
will be only #gc4 ,if we have a mile of 
silver wire and a mile of iron wire and 
want the iron wire to carry as much     
electricity as the silver and have the  
same battery for both1 we will have to  

make the iron wire over seven times as  
large4 ,that is1 the area of a          
cross-section of the iron wire must be  
over seven times that of the silver     
wire4 ,but if we want to keep both wires
 the same size and still force the same 
amount of current through each we must  
increase the pressure of the battery    
connected with the iron wire4 ,we       
measure this pressure by a unit called  
the volt1 named for ,volta1 the inventor
 or discoverer of the voltaic battery4  
,the volt is the unit of pressure or    
electromotive force4 7,in all these     
cases a unit is a certain amount or     
quantity--as of resistance1             
electromotive force1 etc4--fixed upon as
 a standard for measuring other amounts 
of the same kind47  ,the iron wire      
offers a resistance that is about seven 
times greater than silver to the passage
 of the current4 ,to illustrate by water
 pressure3 ,if we should have two       
columns of water1 and a hole at the     
bottom of each column1 one of them seven

 times larger than the other1 the water 
would run out much faster from the      
larger hole if the columns were the same
 height4 ,now1 if we keep the column    
with the larger hole at a fixed height a
 certain amount of water will flow      
through per second4 ,if we raise the    
height of the column having the small   
hole we shall reach a point after a time
 when there will be as much water flow  
through the small hole per second as    
there is flowing through the large hole4
 ,this result has been accomplished by  
increasing the pressure4 ,so1 we can    
accomplish a similar result in passing  
electricity through an iron wire at the 
same rate it flows through a silver wire
 of the same size1 by increasing the    
pressure1 or electromotive power2 and   
this is called increasing the voltage4  
,the quality of the iron wire that      
prevents the same amount of current from
 flowing through it as the silver is    
called its resistance4 ,the unit of     
resistance1 as mentioned in the last    

chapter1 is called the ohm1 and the more
 ohms there are in a wire as compared   
with another1 the more volts we have to 
put into the battery to get the same    
current4  ,the unit for measuring the   
current is called the ampere1 named     
after the ,french electrician1 ,a4 ,m4  
,ampere 7#aghi-ahcf74  ,now1 to make    
practical application of these units4   
,the volt is the potential or pressure  
of one cell of battery called a standard
 cell1 made in a certain way4 ,the      
electromotive force of one cell of a    
,daniell battery is about one volt4 ,one
 ohm is the resistance offered to the   
passage of a current having one volt    
pressure by a column of mercury one     
millimeter in cross-section and #ajf4c  
centimeters in length4 ,ordinary iron   
telegraph-wire measures about thirteen  
ohms to the mile4 ,now connect our      
standard cell--one volt--through one ohm
 resistance and we have a current of one
 ampere4 ,unit electromotive force      
7volt7 through unit resistance 7ohm7    

gives unit of current 7ampere74 ,it is  
not the intention to treat the subject  
mathematically1 but ,i will give you a  
simple formula for finding the amount of
 current if you know the resistance and 
the voltage4 ,the electromotive force   
divided by the resistance gives the     
current4 ,c  ,e_/,r or current 7amperes7
 equals electromotive force 7volts7     
divided by the resistance 7ohms74  ,but 
still further3 ,one ampere of current   
having one volt pressure will develop   
one watt of power1 which is equal to    
#a_/gdf of a horse-power4 7,the watt is 
named in honor of ,james ,watt1 the     
,scottish inventor of the               
steam-engine--#aghf-ahac74 ,in other    
words1 #gdf watts equal one horse-power4
 ,by multiplying volts and amperes      
together we get watts4  ,if we want to  
carry only a small current for a long   
distance we do not need to use large    
cells1 but many of them4 ,we increase   
the pressure or voltage by increasing   
the number of cells set up in series4   

,if we have a wire of given length and  
resistance and find we need #ajj volts  
to force the right amount or strength of
 current through it1 and the            
electromotive force of the cells we are 
using is one volt each1 it will require 
#ajj cells4 ,if we have a battery that  
has an ,e4 ,m4 ,f4 of two volts to the  
cell1 as the storage-battery has1 fifty 
cells would answer4 ,if we want a very  
strong current of great volume1 so to   
speak1 for electric light or power1 and 
use a galvanic battery1 we should have  
to have cells of large surface and lower
 resistance both inside and outside the 
cells4  ,when dynamos are used they are 
so constructed that a given number of   
revolutions per minute will give the    
right voltage4 ,in fact1 the dynamo has 
to be built for the amount of current   
that must be delivered through a given  
resistance4 ,the same holds good for a  
dynamo as for a galvanic battery4 ,if   
any one factor is fixed1 we must adapt  
the others to that one in order to get  

the result we want4 ,there are many     
other units1 but to introduce them here 
would only confuse the reader4 ,the     
advanced student is referred to the     
text-books4  ,with this much as a       
preliminary we are prepared to take up  
the applications of electricity1 which  
to most people will be more interesting 
than what has gone before4     ,,chapter
 ,x4  ,,the ,,electric ,,telegraph4     
,in the year #afag ,strada1 an ,italian 
,jesuit1 proposed to telegraph news     
without wires by means of two           
sympathetic needles made of loadstone so
 balanced that when one was turned the  
other would turn with it4 ,each needle  
was to have a dial with the letters on  
it4 ,this would have been very nice if  
it had only worked1 but it was not based
 on any known law of nature4  ,many     
attempts at telegraphing with           
electricity were made by different      
people during the eighteenth century4   
,about #agdh ,franklin succeeded in     
firing spirits by means of a wire across

 the ,schuylkill ,river1 using1 as all  
the other experimenters had done1       
frictional electricity4 ,in #agec an    
anonymous letter was written to ,scott's
 ,magazine describing a method by which 
it was possible to communicate at a     
distance by electricity4 ,the writer    
proposed the use of a wire for each     
letter of the alphabet1 that should     
terminate in pith balls at the receiving
 end1 and under the balls were to be    
strips of paper corresponding to the    
letters of the alphabet4 ,the message   
was to be sent by discharging static    
electricity through the wire            
corresponding to the first letter of a  
word when the paper would be attracted  
to the pith ball and read by the        
observer4 ,then the wire corresponding  
to the second letter of the word was to 
be charged in like manner1 and so on    
till the whole message was spelled out4 
,this was the first practical 7i4e41    
possible7 suggestion for a telegraph4   
,the writer also proposed to have the   

wires strung on insulators1 which was a 
great advance over the other attempts4  
,the communication was anonymous1 as no 
doubt1 like many others1 the author     
feared the ridicule of his neighbors4   
,it requires a vast amount of moral     
courage to stand up before the world and
 openly advocate some new theory that   
has never come within the experience of 
any one before4 ,it requires much now1  
but it required more then2 for a man in 
those days would have been roasted for  
what in these days he would be toasted4 
,the rank and file of humanity have been
 opposed to innovations in all ages1 but
 no progress could have been made       
without innovations4 ,there always has  
to be a first time4 ,galileo is said to 
have been forced to retract1 on his     
knees1 some theory he advanced about the
 motion of the earth1 and its relation  
to the sun and other heavenly bodies4   
,notwithstanding this retraction the    
seed-thought sown by ,galileo took root 
in other minds1 which led to the triumph

 of scientific truth over religious     
fanaticism4  ,the writer in ,scott's    
,magazine did not have the opportunity  
to put his ideas into practice1 so the  
glory of the invention fell to others4  
,such men as this unknown writer are    
made of finer stuff1 and they stand     
alone on the frontier of progress4 ,they
 do not fear the bullets of an enemy    
half so much as the gibes of a friend4  
,much of their work is done quietly and 
without notice1 and when something of   
real importance is worked out           
theoretically and experimentally1 some  
one seizes upon it and proclaims it from
 the housetops and attaches to it his   
name2 but perhaps years after the real  
inventor 7the man who taught the        
so-called inventor how to do it7 is     
dead1 some one writes a book that       
reveals the truth1 and then the         
hero-loving people erect a monument to  
his memory4  ,such a man was our own    
,professor ,joseph ,henry1 so long the  
presiding genius at the ,smithsonian    

,institution at ,washington4 ,he worked 
out all the problems of the present     
,american telegraphic system and        
demonstrated it practically4 ,everything
 that made the so-called ,morse         
telegraph a success had long before been
 described and demonstrated by ,henry4  
,yet with the modest grace that was     
ingrained in the man he yielded all to  
the one who was instrumental in         
constructing the first telegraph line   
between ,baltimore and ,washington4     
,great credit is due to such men as     
,morse and ,cyrus ,w4 ,field--neither of
 them inventors1 but promoters of great 
systems of communication that are of    
unspeakable benefit to mankind4 ,henry  
pointed out the way1 and ,morse carried 
it into effect4 ,morse has had no more  
credit than was due him1 but has ,henry 
had as much as is due him8 ,no great    
invention was ever yet the work1 wholly1
 of one man4 ,we ,americans are too apt 
to forget this4  ,i shall always        
remember ,henry as a most unassuming1   

kindly1 genial man1 and ,i shall never  
forget his kindness to me4 ,in #ahgd ,i 
began my researches in telephony1 having
 applied for a patent for an apparatus  
for transmitting musical tones          
telegraphically4 ,this consisted of a   
means of transmitting musical tones     
through a wire and reproducing them on a
 metal plate 7stretched on the body of a
 violin to give it resonance7 by rubbing
 the plate with the hand--the latter    
being a part of the circuit4 ,the       
examiner refused the application at     
first on the ground that the inventor or
 operator could not be a part of his    
machine4 ,i took my apparatus and went  
to ,washington1 first calling upon      
,professor ,henry1 never having met him 
before4 ,he received me most kindly1 and
 allowed me to string wires from room to
 room in the institute1 and when he had 
witnessed the experiments he seemed as  
delighted as a child4 ,i now brought the
 patent office official over to the     
,smithsonian and soon convinced him that

 the inventor could be a part of his own
 machine4  ,the same year ,i went       
abroad1 and ,henry gave me a letter to  
,tyndall4 ,it was very fortunate for me 
that he did1 for ,tyndall was very shy  
at first1 and it was only ,henry's      
letter that gave me a hearing for a     
moment4 ,the history of the few days    
that followed this first interview with 
,tyndall at the ,royal ,institution     
would make very interesting reading1 if 
,i felt at liberty to publish it4       
,suffice it to say that he was convinced
 in a few minutes after he had reached  
the experimental stage that not all my  
work had been anticipated by            
,wheatstone1 as he asserted before      
seeing the experiments4 ,wheatstone had 
transmitted the tones of a piano1       
mechanically1 from one room to another  
by a wooden rod placed upon the         
sound-board and terminating in another  
room in contact with another            
sound-board4 ,but this was very         
different from transmitting musical     

tones and melodies from one city to     
another through a wire1 as ,i could do  
with my electrotelephonic apparatus4    
,it is a curious fact that the world is 
divided into two great classes1 leaders 
and followers4 ,or we might say1        
originators and copyists2 the former    
division being very small1 while the    
latter is very large4 ,as late as #ahbj 
the ,european philosophers were trying  
to construct a telegraphic system based 
upon two ideas1 announced a long time   
before1 to wit1 the use of static or    
frictional electricity1 and a wire for  
every letter4 ,it does not seem to have 
occurred to any one to devise a code    
consisting of motions differently       
related as to time1 and to use simply   
one wire4  ,in #ahai ,oersted discovered
 the effect of a galvanic current on a  
magnetic needle1 and published a        
pamphlet concerning his discovery4 ,this
 stimulated others1 and ,ampere applied 
it to the galvanometer the same year4   
,arago applied it to soft iron1 and here

 was the germ of the electromagnet4 ,we 
see that as far back as #ahbj we had the
 galvanic battery and the electromagnet1
 the two great essentials of the modern 
telegraph4  ,however1 there remained    
another great discovery to be made      
before these elements could be utilized 
for telegraphic purposes4 ,one cell of  
battery was used1 and the magnet was    
made by winding one layer of wire       
spirally around the iron1 so that each  
spiral was out of touch with its        
neighbor4 ,barlow of ,england1 a ,fellow
 of the ,royal ,society1 tried the      
effect of a current through a wire #bjj 
feet long1 and found that the power was 
so diminished that he was discouraged1  
and in a paper gave it as his opinion   
that galvanism was of no use for        
telegraphing at a distance4 ,this paper 
stimulated others1 and it was reserved  
for our own ,joseph ,henry1 already     
referred to1 to show not only how to    
construct a magnet for long-distance    
telegraphy1 but also how to adapt the   

battery to the distance4 ,he showed us  
that by insulating the wire and using   
several layers of whirls1 instead of    
one1 and by using enough cells of       
battery coupled up in series to get more
 voltage1 as we now express it1 it was  
possible to transmit signals to a       
distance4 ,he not only set forth the    
theory1 but he constructed a line of    
bell-wire #ajfj feet long and worked his
 magnet by making the armature strike a 
bell for the signals1 which is the basis
 of the modern sounder4  ,nothing was   
needed but to construct a line and      
devise a code to be read by sound1 to   
have practically our modern ,morse      
telegraph4 ,this line was constructed in
 #ahca4 ,in #ahce ,henry1 who was then  
at ,princeton1 constructed a line and   
worked it as it is to-day worked1 with a
 relay and local circuit1 so that at    
that period all the problems had been   
worked out4 ,but1 like the              
speaking-telephone in its early         
inception1 no one appreciated its real  

importance4 ,henry himself did not think
 it worth while to take out a patent4   
,two years later the ,secretary of the  
,treasury sent out a circular letter of 
inquiry to know if some system of       
telegraphic communication could not be  
devised4 ,the learned heads of the      
,franklin ,institute of ,philadelphia1  
the oldest scientific society in        
,america1 advised that a semaphore      
system be established between ,new ,york
 and ,washington1 consisting of forty   
towers with swinging arms1 the same as  
used in the days of ,wellington4 ,among 
other replies to the circular letter of 
the secretary was one from ,samuel ,f4  
,b4 ,morse4 ,morse was not a scientist  
or even an inventor1 at least not at    
that time4 ,he was an artist of some    
note4 ,in #ahcb1 while crossing the     
ocean1 ,morse1 in connection with one   
,dr4 ,jackson of ,boston1 devised a code
 of telegraphic signs intended to be    
used in a chemical telegraph system4    
,some years later ,morse adapted        

,henry's signal-instrument to a         
recorder1 called the ,morse register1   
and this was the instrument used in the 
early days of the ,morse telegraph4     
,what ,morse seems to have really       
invented was the register1 which made   
embossed marks on a strip of paper1 and 
the code of dots and dashes representing
 letters1 now known as the ,morse       
alphabet1 although this latter is       
questioned4 ,morse took his apparatus to
 ,washington and exhibited it to the    
members of ,congress in the year #ahch1 
but it was four years before a bill was 
passed that enabled him to try the      
experiment between ,baltimore and       
,washington4 ,we will let him describe  
in his own words the closing day of     
,congress4 ,he says3  ,my bill had      
indeed passed the ,house of             
,representatives and it was on the      
calendar of the ,senate1 but the evening
 of the last day had commenced with more
 than #ajj bills to be considered and   
passed upon before mine could be        

reached4 ,wearied out with the anxiety  
of suspense1 ,i consulted one of my     
senatorial friends4 ,he thought the     
chance of reaching it to be so small    
that he advised me to consider it as    
lost4 ,in a state of mind which ,i must 
leave you to imagine1 ,i returned to my 
lodgings to make preparations for       
returning home the next day4 ,my funds  
were reduced to the fraction of a       
dollar4 ,in the morning1 as ,i was about
 to sit down to breakfast1 the servant  
announced that a young lady desired to  
see me in the parlor4 ,it was the       
daughter of my excellent friend and     
college classmate1 the commissioner of  
patents1 ,henry ,l4 ,ellsworth4 ,she had
 called1 she said1 by her father's      
permission1 and in the exuberance of her
 own joy1 to announce to me the passage 
of my telegraph bill at midnight1 but a 
moment before the ,senate adjourned4    
,this was the turning-point of the      
telegraph invention in ,america4 ,as an 
appropriate acknowledgment of the young 

lady's sympathy and kindness--a sympathy
 which only a woman can feel and        
express--,i promised that the first     
dispatch by the first line of telegraph 
from ,washington to ,baltimore should be
 indited by her2 to which she replied3  
',remember1 now1 ,i shall hold you to   
your word4' ,about a year from that time
 the line was completed1 and1 everything
 being prepared1 ,i apprised my young   
friend of the fact4 ,a note from her    
inclosed this dispatch3 ',what hath ,god
 wrought8' ,these were the first words  
that passed on the first completed line 
in ,america4  ,the first telegraph-line 
in ,america was put into operation in   
the spring of #ahdd at the beginning of 
,polk's administration4 ,i remember as a
 boy having the two cities1 ,baltimore  
and ,washington1 pointed out to me on   
the map1 and how the story of the       
telegraph impressed me4 ,congress       
appropriated #cj1jjj for the            
construction of the line1 and #hjjj to  
keep it running the first year4 ,it was 

placed under the control of the         
postmaster-general1 and the line was    
thrown open to the public4 ,the tariff  
was fixed at one cent for every four    
words4 ,it was open for business on     
,april #a1 #ahdd1 and for the first few 
days the revenue was exceedingly small4 
,on the morning of the first day a      
gentleman came in and wanted to see it  
work4 ,the operator told him that he    
would be glad to show it at the regular 
tariff of one cent for four words4 ,the 
gentleman grew angry and said that he   
was influential with the administration1
 and that if he did not show him the    
working free of charge he would see to  
it that he lost his job4 ,his bluff did 
not succeed4 ,the operator referred him 
to the postmaster-general1 and thus the 
stormy interview ended4 ,no patrons came
 in for the next three days1 but a great
 number stood around hoping to see the  
instrument start up1 but no one was     
willing to invest a cent--probably from 
fear of being laughed at4  ,on the      

fourth day the same gentleman who had   
threatened the young man with dismissal 
came back and invested a cent1 and this 
was the first and only revenue for four 
days4 ,the message that was sent only   
came to one-half cent1 but as the       
operator could not make change the      
stranger laid down the cent and         
departed4 ,his name ought to be known to
 fame as the first man patron of the    
telegraph4      ,illustration3 ,fig4 #b4
      ,a gives a diagram view of a      
,morse telegraph-line with three        
stations4 ,b is the battery2 ,c ,c ,c1  
the transmitting keys in the     three  
offices2 ,d ,d ,d1 the relay magnets2 ,e
 ,e ,e1 the armatures     that are      
actuated by the magnets4  ,the operation
 of the ,morse telegraph is very simple 
if we grant all that has gone before4   
,all that is needed is the wire1 the    
battery1 and the key1 as shown in ,fig4 
#b 7page #ii71 and a relay--an extra    
electromagnet which receives the        
electric current and by its means puts  

into or out of action a small local     
battery on a short circuit in which is  
placed the receiving or recording       
apparatus4 ,thus we have a wire starting
 from the earth in ,new ,york and       
passing through a battery1 a key and a  
relay1 and thence to ,boston on poles1  
with insulators on which the wire is    
strung1 and through another instrument1 
key and battery in ,boston1 the same as 
at the ,new ,york end1 and into the     
ground1 leaving the earth to complete   
one-half of the circuit4 ,when the keys 
at both ends are closed the batteries   
are active and the armatures or keepers 
are attracted so that the armature      
levers rest on the forward stops4 7,see 
diagram ,fig4 #b47 ,if either one of the
 keys is opened the current stops       
flowing and the magnetism vanishes from 
all the electromagnets on the line1 and 
a spring or retractile of some kind     
pulls the armatures away from the       
magnets and the levers rest on their    
back stops4 ,in this way all the levers 

of all the magnets are made to follow   
the motions of any key4 ,if there are   
more than two magnets in circuit 7and   
there may be twenty or more7 they all   
respond in unison to the working of one 
key1 so that when any one station is    
sending a dispatch all the other        
stations get it4  ,but there is a call  
for each office1 so that the operator   
only heeds the instrument when he hears 
his own call4 ,operators become so      
expert in reading by sound that they may
 lie down and sleep in the room1 and1   
although the instrument is rattling away
 all the time1 he does not hear it till 
his own call is made1 when he           
immediately awakes4  ,in the old days   
messages were received on slips of paper
 by the ,morse register by means of dots
 and dashes4 ,gradually the operator    
learned to read by sound1 till now this 
mode of receiving is almost universal   
the world over4 ,reading by sound was of
 ,american origin4 ,it is a spoken      
language1 and when one becomes          

accustomed to it it is like any other   
language4 ,this code language has some  
advantages over articulate speech1 as   
well as many disadvantages4 ,a gentleman
 who was connected with a ,louisville   
telegraph office told me that one of the
 best operators he ever knew was as deaf
 as a post4 ,he would receive the       
message by holding his knee against the 
leg of the table upon which the sounder 
was mounted1 and through the sense of   
feeling receive the long and short      
vibrations of the table1 and by this    
means read as well or better than       
through the ear1 because he was not     
distracted by other sounds4  ,a story is
 told of the late ,general ,stager that 
at one time he was on a train that was  
wrecked at some distance from any       
station4 ,he climbed a telegraph pole1  
cut the wire and by alternately joining 
and separating the ends sent a message1 
detailing the story of the wreck1 to    
headquarters1 and asked for assistance4 
,he then held the two ends of the wire  

on each side of his tongue and tasted   
out the reply--that help was coming4    
,any one who has ever tasted a current  
knows that it is very pronounced4  ,a   
story similar to this is told of the    
early days when the ,bain chemical      
system was used between ,washington     
,city and some other point4 ,this system
 made marks on chemically-prepared      
paper2 as the current passed through it 
left marks on the paper from the        
decomposition of the chemicals4 ,some of
 the preparations emitted an odor during
 the time that the current passed4 ,the 
occurrence to which we refer took place 
at presidential election time4 ,at some 
station out of ,washington an operator  
was employed who had a blind sister1 and
 this sister knew the ,morse alphabet   
well before she became blind4 ,one      
evening a signal came to get ready for a
 message containing the returns from the
 election4 ,in the hurry1 and just as   
the message had started1 the lamp was   
upset and they were in total            

darkness--at least1 the brother was4    
,the sister1 poor girl1 had been in     
darkness a long time4 ,the blind sister 
leaned over the stylus through which the
 current flowed to the paper and smelled
 out as well as spelled out the message1
 and repeated it to her astonished      
brother4  ,by the old semaphore system  
the motions were sensed through the eye 
as well as the early method of cable    
signaling4 ,it will be seen from the    
above that the ,morse code may be       
communicated through any one of the five
 senses4     ,,chapter ,,xi4            
,,receiving ,,messages4   ,with but few 
exceptions the ,morse code is the one   
almost universally used the world over4 
,as it is used in ,europe1 it is        
slightly changed from our ,american     
code1 but they all depend upon dots1    
dashes1 and spaces1 related in different
 combinations1 for the different        
letters4 ,notwithstanding its universal 
use it is not free from serious         
difficulties in transmission unless it  

is repeated back to the sender for      
correction2 and then in some cases it is
 impossible to be sure1 owing to        
difficulties of punctuation and         
capitalizing1 and the further difficulty
 of running the signals together1       
caused1 it may be1 by faulty            
transmission1 induced currents from     
other wires1 swinging crosses or        
atmospheric electricity4 ,sometimes it  
is a psychological difficulty in the    
mind of the receiving-operator4 ,the    
telegraph companies have to suffer      
damages from all these and many other   
unforeseen causes4  ,prescott tells some
 curious things that happened in the    
early days1 growing out of the          
peculiarities of the receiving-operator4
 ,at one time he was reporting by       
telegraph one of ,webster's speeches    
made at ,albany in #aheb in which there 
were many pithy interrogative sentences1
 and he was desirous of having the      
interrogation-points appear4 ,so to make
 sure1 whenever he wished an            

interrogation-point he said question at 
the end of almost every sentence4 ,next 
day he was horrified on reading the     
speech to see the ends of the sentences 
bristling with the word question4  ,some
 time back in the fifties a gentleman in
 ,boston telegraphed to a house in ,new 
,york to forward sample forks by        
express4 ,the message when received by  
the ,new ,york merchant read3 ,forward  
sample for ,k4 ,s4 by express4 ,the ,new
 ,york merchant did not know who ,k4 ,s4
 was1 nor did he gather from the        
dispatch what kind of sample he wanted4 
,so he went to the telegraph office to  
have the matter cleared up4 ,the ,boston
 operator repeated the message1 saying  
sample forks4 ,that's the way ,i        
received it and so delivered it--sample 
for ,k4 ,s41 said ,new ,york4 ,but1 says
 ,boston1 ,i did not say for ,k4 ,s42 ,i
 said f-o-r-k-s4 ,new ,york had read it 
wrong in the start and could not get it 
any other way4 ,what a fool that ,boston
 fellow is4 ,he says he did not say for 

,k4 ,s41 but for ,k4 ,s4 ,boston had to 
resort to the ,united ,states mail      
before the mystery was solved4          
,curiously enough1 the old method of    
recording the dots and dashes on the    
paper strip was not so reliable as the  
present mode of reading by sound4 ,a man
 can put his individuality to some      
extent into a sounder1 and when one     
becomes used to his style it is much    
easier to read him accurately by sound  
than by the paper impressions4 ,some    
people never could learn to read either 
by paper or sound4 ,an instance of this 
kind is given of a middle-aged man who  
was employed by a railroad company as   
depot master and telegraph operator1 in 
the old days of the paper strip4 ,one   
day he rushed out and hailed the        
conductor of a train that had just      
pulled into the station1 and told him   
that ---- train had broken both         
driving-wheels and was badly smashed up4
 ,the conductor could read the mystic   
symbols1 so he took the tape and        

deciphered the dispatch as follows3 ,ask
 the conductor of the ,boston train to  
examine carefully the connecting-rods of
 both driving-wheels1 and if not in good
 condition to await orders4 ,it is      
further related of this same operator   
that when he got into real difficulty   
with his tape he used to run over to the
 regular commercial office to have his  
messages translated4 ,one day he rushed 
into his neighbor's office trailing the 
tape behind him and saying3 ,i am sure  
an awful accident has happened by the   
way the message was rattled off4 ,a     
playful dog had torn off a large part of
 the strip as it trailed along1 so only 
a part was left4 ,it read1 ,good        
morning1 ,uncle ,ben4 ,when are you---- 
,the dog had swallowed the balance of   
the dispatch4  ,sometimes the ,morse    
code is not only funny but disastrous4  
,a gentleman wanted to borrow money of  
some capitalists who1 not knowing his   
financial standing1 telegraphed to a    
banker who they knew could post them4   

,they received an answer1 ,note good for
 large amount4 ,the gentleman borrowed a
 large amount1 but afterward when it    
came to be investigated it was found    
that the dispatch was originally written
 not1 instead of note1 which made all   
the difference in the world4  ,it has   
been stated that any one of the five    
senses may be called into service to    
interpret the ,morse code into words and
 ideas4 ,a story is told by ,mr4        
,prescott that he says is true1 as he   
knew the party4 ,a friend of his1 by    
name ,langenzunge1 who knew the ,morse  
code1 had served under ,general ,taylor 
7who at this time was ,president7 at    
,palo ,alto1 in ,mexico4 ,the general   
had just promised him an office2 soon   
after he left ,washington for the west  
over the ,baltimore and ,ohio on a      
freight train2 the ,president was taken 
seriously ill1 and his friend hearing of
 it was troubled not only because he    
loved the old general1 but on account of
 the change in his own prospects4 ,the  

train stopped somewhere on the ,potomac 
at midnight and remained there for four 
hours4 ,uneasy and sad1 he wandered down
 the track and climbed a pole1 cut the  
wire and placed the ends each side of   
his tongue and tasted out the fatal     
message--,died at half-past ten4 ,the   
shock 7not the electric7 was so great   
that he almost fell from the pole4      
,what a situation6 ,a man climbs a pole 
at midnight miles from the sick friend  
he loves1 puts his tongue to inanimate  
wire1 and is told in concrete           
language--through the sense of          
taste--that his friend is dead4 ,this is
 only one of the many1 many wonderful   
episodes of the telegraph4     ,,chapter
 ,,xii4  ,,miscellaneous ,,methods4     
,it never rains but it pours4 ,almost   
simultaneously with the demonstration of
 the ,morse telegraph other types were  
devised4 ,there were the needle systems 
of ,cooke and ,wheatstone1 the chemical 
telegraph of ,alexander ,bain1 and soon 
the printing telegraph of ,house1 and   

later that of ,hughes4 ,the latter is in
 use on the continent of ,europe1 and a 
modification of it has a very limited   
use on some ,american lines4 ,the ,bain 
telegraph used a key and battery the    
same as the ,morse system1 but it did   
not depend upon electromagnetism as the 
,morse system does4 ,when in operation a
 strip of paper was made to move under  
an iron stylus at the receiving-end of  
the line4 ,the paper was saturated with 
some chemical that would discolor by the
 electrolytic action of the current4    
,when a message was sent the paper was  
set to moving by a clock mechanism or   
otherwise1 under the stylus that was    
pressing on the paper as it passed over 
a metal roller or bed-plate4 ,the       
transmitting-operator worked his key    
precisely as in sending an ordinary     
message by the ,morse system4 ,the      
effect was to send currents through the 
receiving-stylus chopped into long or   
short marks1 or the dots and dashes of  
the ,morse code1 and recorded on the    

tape in marks that were blue or brown1  
according to the chemical used4 ,a few  
lines were established in this country  
on the ,bain system1 but it never came  
into general use4  ,a number of systems1
 called automatic1 grew out of the ,bain
 system4 ,bain himself devised1 perhaps1
 the first automatic telegraph4 ,the    
fundamental principle of all automatic  
telegraphs depends upon the preparation 
of the message before sending1 and is   
usually punched in a strip of paper and 
then run through between rollers that   
allow the stylus to ride on the paper   
and drop through the holes that         
represent the dots and lines of the     
,morse alphabet4 ,every time the stylus 
drops through a hole in the paper it    
makes electrical contact and sends a    
current1 long or short1 according to the
 length of the hole4 ,the object of the 
automatic system was to send a large    
amount of business through a single wire
 in a short time4 ,it does not save     
operators1 as the messages have to be   

prepared for transmission1 and then     
translated at the receiving-end and put 
into ordinary writing for delivery4     
,the automatic system is not used except
 for special purposes1 and the one that 
seems to be the most favored is that of 
,wheatstone4 ,the system is in use in   
,england and in ,america to a limited   
degree4  ,early in the history of the   
telegraph a printing system was devised4
 ,wheatstone and others had proposed    
systems of printing telegraphs in       
,europe1 but these never passed the     
experimental stage4 ,the first printing 
telegraph introduced in ,america was    
invented by ,royal ,e4 ,house of        
,vermont1 and first introduced in #ahdg 
on a line between ,cincinnati and       
,jeffersonville1 a distance of #aej     
miles4 ,in #ahdi a line for commercial  
use was established between ,new ,york  
and ,philadelphia1 and for some years   
following many lines were equipped with 
the ,house printing telegraph           
instrument4 ,the late ,general ,anson   

,stager was a ,house operator at one    
time4 ,all printing telegraph           
instruments1 while differing greatly in 
detail1 have certain things in common1  
to wit3 a means for bringing the type   
into position1 an inking device1 a      
printing mechanism1 a paper feed1 and a 
means for bringing the type-wheels into 
unison4 ,there are two general types of 
printing instruments1 the step-by-step1 
and the synchronously moving            
type-wheels4 ,the ,house printer was a  
step-by-step instrument and consisted of
 two parts1 a transmitter and a         
receiver4 ,the transmitter consists of a
 keyboard like a piano1 with            
twenty-eight keys4 ,these keys are held 
in position by springs4 ,under the keys 
is a cylinder having twenty-eight pins  
on it corresponding to the twenty-six   
letters of the alphabet and a dot and a 
space4 ,this cylinder was driven by some
 power4 ,in those days it was by        
man-power4 ,it was carried by a         
friction1 so that it could be easily    

stopped by the depression of any one of 
the keys that interfered with one of the
 pins4 ,one revolution of the cylinder  
would break and close the current       
twenty-eight times1 making twenty-eight 
steps4  ,the receiving-instrument       
consisted of a type-wheel and means for 
driving it4 ,it was somewhat            
complicated1 and can only be described  
in a general way4 ,if the cylinder of   
the transmitter was set to rotating it  
would break and close twenty-eight times
 each revolution4 7,there were fourteen 
closes and fourteen breaks1 each break  
and each close of the current           
representing a step47 ,the type-wheel of
 the receiver was divided into          
twenty-eight parts1 having twenty-six   
letters and a dot and space1 each break 
moved it one step and each close a step2
 so that if the cylinder1 with its      
twenty-eight pins1 started in unison    
with the type-wheel1 with its           
twenty-eight letters and spaces1 they   
would revolve in unison4 ,the keys were 

lettered1 and if any one was depressed  
the pin corresponding to it on the      
cylinder would strike it and stop the   
rotation of the cylinder1 which stopped 
the breaking and closing of the circuit1
 which in turn stopped the rotation of  
the type-wheel--and not only stopped it1
 but also put it in a position so that  
the letter on the type-wheel            
corresponding to the letter on the key  
that was depressed was opposite the     
printing mechanism4 ,the printing was   
done on a strip of paper1 which was     
carried forward one space each time it  
printed4 ,the printing mechanism was so 
arranged that so long as the wheel      
continued to rotate it was held from    
printing1 but the moment the type-wheel 
stopped it printed automatically4  ,the 
messages were delivered on strips of    
paper as they came from the machine4    
,in #ahee ,david ,e4 ,hughes of         
,kentucky patented a type-printing      
telegraph that employed a different     
principle for rotating the type-wheel4  

,the electric current was used for      
printing the letters and unifying the   
type-wheels with the                    
transmitting-apparatus4 ,the            
transmitter1 cylinder1 and the          
type-wheel revolved synchronously1 or as
 nearly so as possible1 and the printing
 was done without stopping the          
type-wheel4 ,whenever a letter was      
printed the type-wheel was corrected if 
there was any lack of unison4  ,this    
type of machine in a greatly improved   
form is still used on some of the       
,western ,union lines1 especially       
between ,new ,york1 ,boston1            
,philadelphia1 and ,washington4 ,it is  
also in use in one of its forms in most 
of the ,european countries4             
,,chapter ,,xiii4  ,,multiple           
,,transmission4   ,although the printing
 and automatic systems of telegraphing  
are used in ,america to some extent1 the
 larger part is done by the ,morse      
system of sound-reading and copying from
 it1 either by pen or the typewriter4   

,in the early days only one message     
could be sent over one wire at the same 
time1 but now from four to six or even  
more messages may be sent over the same 
wire simultaneously without one message 
interfering with the other4 ,like most  
other inventions1 many inventors have   
contributed to the development of       
multiple transmission1 till finally some
 one did the last thing needed to make  
it a success4 ,the first attempts were  
in the line of double transmission1 and 
many inventors abroad have worked on    
this problem4  ,moses ,g4 ,farmer of    
,salem1 ,mass41 proposed it as early as 
#aheb1 and patented it in #aheh4 ,gintl1
 ,preece1 ,siemens and ,halske and      
others abroad had from time to time     
proposed different methods of double    
transmission1 but no one of them was a  
perfect success4 ,when the line was very
 long there was a difficulty that seemed
 insurmountable4 ,in the common parlance
 of telegraphy1 there was a kick in the 
instrument that came in and mutilated   

the signals4 ,about #ahgb ,joseph ,b4   
,stearns of ,boston made a certain      
application of what is called a         
condenser to duplex telegraphy that     
cured the kick1 and from that time to   
this it has been a success4 ,farther    
along ,i will tell you what occasioned  
this kick and how it was cured4 ,if this
 or some other method could be applied  
as successfully to cure the many chronic
 kickers in the world it would be a     
great blessing to mankind4  ,it has     
always been a mystery to the uninitiated
 how two messages could go in opposite  
directions and not run into one another 
and get wrecked by the way4 ,if you will
 follow me closely for a few minutes ,i 
will try to tell you4  ,we have already 
stated that an electromagnet is made by 
winding an insulated wire around a soft 
iron core4 ,if we pass a current of     
electricity through this wire the core  
becomes magnetic1 and remains so as long
 as the current passes around it4 ,in   
duplex telegraphy we use what is called 

a differential magnet4 ,a differential  
electromagnet is wound with two         
insulated wires and so connected to the 
battery that the current divides and    
passes around the iron core in opposite 
directions4 ,now if an equal current is 
simultaneously passed through each of   
the wires of the coil in opposite       
directions the effect on the iron will  
be nothing1 because one current is      
trying to develop a certain kind of     
polarity at each pole of the magnet1    
while the current in the other wire is  
trying to develop an opposite kind in   
each pole4 ,there is an equal struggle  
between the two opposing forces1 and the
 result is no magnetism4 ,this assumes  
that the two currents are exactly the   
same strength4  ,if we break the current
 in one of the coils we immediately have
 magnetism in the iron2 or if we destroy
 the balance of the two currents by     
making one stronger than the other we   
shall have magnetism of a strength that 
measures the difference between the two4

  ,without specifically describing here 
the entire mechanism--since this is not 
a text-book or a treatise--we may say   
that a duplex telegraph-line is fitted  
with these differentially wound         
electromagnets at every station4 ,when  
,station ,a 7,fig4 #c7 is connected to  
the line by the positive pole of its    
battery1 ,station ,b will have its      
negative pole to line and its positive  
to earth4 ,when ,a depresses his key to 
send a message1 half the current passes 
by one set of coils around his          
differential magnet through a short     
resistance-coil to the earth1 and the   
other half by the contrary coil around  
the magnet to the line1 and so to       
,station ,b4 ,the divided current does  
not affect ,a's own station1 being      
neutralized by the differential magnet1 
but it does affect ,b1 whose instrument 
responds and gives him the message4     
,now ,b may at the same time send a     
message to ,a by half of his own divided
 current from his own end of the line4  

,illustration3 ,fig4 #c4                
,represents a duplex #ejj-mile          
telegraph-line4 ,a and ,b are the two   
terminal stations2 ,b ,b'1 the          
batteries2 ,k ,k'1 the keys2 ,d ,d'1    
the small resistance-coils1 equal to the
 battery-resistance when     the latter 
is not in circuit2 ,r ,r'1 resistances  
each equal to     the #ejj-mile line2   
and ,c ,c'1 condensers giving the       
artificial     lines ,r ,r' the same    
capacity as the #ejj-mile line4  ,the   
puzzle to most people is3 ,how can the  
signals pass each other in different    
directions on the same wire8 ,but the   
signals do not have to pass each other4 
,in effect1 they pass2 but in fact1 it  
is like going round a circle--the earth 
forming half4 ,a sends his message over 
the line to ,b4 ,b sends his message to 
,a through the earth and up ,a's        
ground-wire4 ,the operative who is      
sending with positive pole to line      
pushes his current through--so to       
speak--while the operative who is       

sending with the negative pole to line  
pulls more current in the same direction
 through the line whenever he closes his
 key4  ,this may not be a strictly      
scientific statement2 but1 as long as we
 speak of a current flowing from        
positive to negative poles 7which is the
 invariable course electricity takes71  
it is the way to look at the matter     
understandingly4  ,the short            
resistance-coil at each end1 fortified  
by a condenser made of many leaves of   
isolated tin-foil1 to give it capacity1 
offers precisely the same resistance to 
the current as the #ejj miles of wire   
line2 so that the twin currents that run
 around the differential magnet exactly 
neutralize each other and make no effect
 in the office the message starts from2 
while one of them takes to the earth1   
and the other to the line to carry the  
message4  ,this condenser is necessary1 
because the short resistance-coil       
affects the current immediately1 while  
the long line with its greater amount of

 metal does not give the same amount of 
resistance till it is filled from end to
 end1 which requires a fraction of a    
second4 ,during this time1 however1 more
 current is passing through the         
differential coil connected with the    
line than through the short             
resistance-coil2 and the unequal flow   
causes the relay armature to jump1 or   
kick4 ,the condenser1 with the many     
leaves of tin-foil1 supplies the greater
 metal surface to be traversed by the   
short line current1 causes the flow to  
be equal in both circuits at all times1 
and thus cures the kick4 ,it is this    
quality of a condenser that enables us  
to give to an artificial line of any    
resistance all the qualities1 including 
capacity1 and exhibit all the phenomena 
of a real line of any length1 and it was
 this quality that enabled ,mr4 ,stearns
 to take the kick out of duplex         
transmission and thus change the whole  
system1 which created a new era in      
telegraphy4  ,we have just spoken of the

 capacity of a circuit1 and stated that 
it was determined by the mass of metal  
used4 ,this capacity is measured by a   
standard of capacity that is arbitrary  
and consists of a condenser1 constructed
 so that a given amount of surface of   
tin-foil may be plugged in or out4 ,the 
practical unit of capacity is called the
 micro-farad1 the real unit is the      
farad1 and takes its name from ,faraday4
  ,but let us go back to multiple       
systems of transmission4 ,there are many
 other systems of simultaneous          
transmission aside from the duplex1 and 
all of them are classed under the       
general head of multiple telegraphy4    
,first there is the quadruplex1 that    
sends two messages each way             
simultaneously1 making one wire do the  
work of four single wires--as they were 
used at first4 ,the quadruplex is very  
extensively used by the ,western ,union 
,telegraph ,company and others4 ,it     
would be difficult to explain it in a   
popular article1 so we will not attempt 

it4 ,there is another form of multiple  
telegraph that was used on the ,postal  
,telegraph line when it first           
started--which was invented and         
perfected by the writer--that can be    
more easily explained4  ,in #ahgd ,i    
discovered a method of transmitting     
musical tones telegraphically1 and the  
thing that set my mind in that direction
 was a domestic incident4 ,it is a      
curious fact that most inventions have  
their beginnings in some incident or    
observation that comes within the       
experience of some one who is able to   
see and interpret the meaning of such   
incidents or observations4 ,i do not    
mean to say that inventions are usually 
the result of a happy thought1 or       
accident2 the germ may be1 but the germ 
has to have the right kind of soil to   
take root in and the right kind of      
culture afterward4 ,it is a rare thing  
that an invention1 either of commercial 
or scientific importance1 ever comes to 
perfection without hard work--midnight  

oil and daylight toil2 and it is rarely1
 if ever1 that a discovery or an        
invention based upon a discovery does   
not have1 sooner or later1 a practical  
use1 although we sometimes have to wait 
centuries to find it put4 ,we had to    
wait forty-four years after the galvanic
 battery was discovered before it became
 a useful servant of man4 ,it was fifty 
years or more after the discovery by    
,faraday of magneto-electricity before  
it found a useful application beyond    
that of a mere toy1 but now it is one of
 the most useful servants we have1 as   
shown in its wonderful development in   
electric lighting and electric          
railroads1 to say nothing of its heating
 qualities and the useful purpose it    
serves in driving machinery4 ,the       
interesting discoveries of ,professor   
,crookes in passing a current of        
electricity through tubes of high vacua 
waited many years before they found a   
practical use in the ,x-ray1 that       
promises to be of great service in      

medicine and surgery4  ,the transmission
 of musical harmonies telegraphically1  
while in itself of great scientific     
interest1 was of no practical use1 but  
it led to other inventions1 of which it 
is the base1 that are transcendently    
useful in every-day life4 ,the          
transmission of harmonic sounds by      
electricity underlies the principle of  
the telephone4 ,there is a vast         
difference1 in principle1 between the   
transmission of simple melody1 which is 
a combination of musical tones          
transmitted successively--one tone      
following another--and the transmission 
of harmony1 which involves the          
transmission of two or more tones       
simultaneously4 ,the former can be      
transmitted by a make-and-break current4
 ,in the latter case one tone has to be 
superposed upon another and must be     
transmitted with a varying but a        
continuously closed current4 ,i make a  
distinction between a closed circuit and
 a closed current4 ,in the case of the  

arc-light the circuit is open 7that is1 
broken71 technically speaking1 but the  
current is still flowing4 ,the reason   
why the ,reiss and other metallic       
contact telephone transmitters cannot   
successfully be used for telephone      
purposes is that metal points will not  
allow of sufficient separation of the   
transmitting points without breaking the
 current as well as the circuit4 ,carbon
 contacts admit of a much wider         
separation without actually stopping the
 flow of the current1 which latter is a 
necessity for perfect telephonic        
transmission1 and it was the use of     
carbon that made that form of           
transmitter a success4  ,there are other
 forms1 or at least one other form that 
does not depend upon the length of the  
voltaic arc formed when the electrodes  
are separated4 ,of this we will speak   
another time4 ,now let us go back to the
 domestic incident referred to above4   
,one evening in the winter of #ahgc-d ,i
 came home from my laboratory work and  

went into the bathroom to make my toilet
 for dinner4 ,i found my nephew1 ,mr4   
,charles ,s4 ,sheppard1 together with   
some of his playmates1 taking electrical
 shocks from a little medical           
induction-coil that ,i heard humming in 
the closet4 ,he had one terminal of the 
coil connected to the zinc lining of the
 bathtub--which was dry at that         
time--while he held the other in his    
left hand1 and with his right was taking
 shocks from the lining of the tub by   
rubbing his hand against the zinc4 ,i   
noticed that each time he made contact  
with the tub1 as he rubbed it for a     
short distance1 a peculiar sound was    
emitted from under his hand1 not unlike 
the sound made by the electrotome that  
was vibrating in the closet4 ,my        
interest was immediately aroused1 and ,i
 took the electrode out of his hand and 
for some time experimented with it1     
going to the cupboard from time to time 
to change the rate of vibration of the  
electrotome1 and thus change the quality

 of the sound4 ,i noticed that the sound
 or tone under my hand1 if it could be  
so called1 changed with each change of  
the rate of vibration4 ,the thing that  
most interested me was that the peculiar
 characteristics of the noise were      
reproduced4 ,in those few minutes ,i    
laid out work enough for years of       
experiment1 and as a result ,i was late 
to dinner4  ,this discovery opened up to
 my mind the possibility of three       
things--the transmission of music and of
 speech or articulate words through a   
telegraph-wire1 and the transmission of 
a number of messages over a single wire4
 ,i constructed a keyboard consisting of
 one octave and made a set of reeds     
tuned to the notes of the scale1 and    
then when some one would play a melody  
,i could reproduce it in two ways3 ,one 
by placing my body in the circuit and   
rubbing a metal plate--it might be the  
bottom of a tin pan1 a joint of         
stovepipe or otherwise--anything that   
was metal and would vibrate would give  

the effect4 ,another way was to connect 
an electromagnet 7having a diaphragm or 
reed across its poles7 in the circuit at
 the receiving-end and mount it on some 
kind of a soundboard4 ,i made a great   
number of different kinds of receivers  
that were capable of receiving either   
musical or articulate sounds1 as has    
many times been proven by experiment4 ,i
 carried two sets of experiments along  
together2 the one looking toward a      
system of multiple telegraphy and the   
other the transmission of articulate    
speech4 ,let us first look into the     
multiple telegraph and take the other up
 under the head of the telephone4  ,when
 the electrical keyboard was completed  
,i found that ,i could transmit not only
 a melody but a harmony2 that more than 
one tone could be transmitted           
simultaneously4 ,this discovery opened  
up a long series of experiments with the
 view of sending a number of messages   
simultaneously by means of musical tones
 differing in pitch4 ,i had already     

demonstrated that several tones could be
 transmitted at once1 but they would    
speak all alike 7with the same loudness7
 on the receiving-instrument4 ,i now    
went to work on an instrument that      
responded for one note only and         
succeeded beyond my expectations4 ,i    
made three different kinds of           
receiving-instruments4 ,the first was a 
steel strap about eight inches long by  
three-eighths wide4 ,this strap was     
mounted in an iron frame in front of an 
electromagnet4 ,a thumbscrew enabled me 
to stretch the strap till it would      
vibrate at the required pitch4 ,if1 for 
instance1 the sending-reed vibrated at  
the rate of #ajj times per second and   
the strap of the receiver was stretched 
to a tension that would give #ajj       
vibrations per second when plucked1 it  
would then respond to the vibrations of 
the sending-reed but not to those of    
another reed of a different rate of     
vibration4 ,if we take mounted          
tuning-forks tuned in pairs of different

 pitches1 say four pairs1 so that each  
fork has a mate that is in exact accord 
with it1 and place them all in the same 
room1 and sound one of them for a few   
seconds and then stop it1 upon examining
 the other forks you will find all of   
them quiet except the mate of the one   
that was sounded4 ,this one will be     
sounding4 ,if we now sound four of the  
forks and then stop them the other four 
will be sounding from sympathy because  
the mate of each one of them has been   
sounded4 ,if only two forks differing in
 pitch are sounded only two of the      
others will sound in sympathy4 ,in the  
first case only one set of sound-waves  
were set up in the air1 and the fork    
that found itself in accord with this   
set responded4 ,when four forks         
differing in pitch were sounded there   
were four sets of tone-waves superposed 
upon each other existing in the air1 so 
that each of the remaining forks found a
 set of waves in sympathy with its own  
natural rate of vibration and so        

responded4  ,now apply this principle to
 the harmonic telegraph and you can     
understand its operation4 ,at the       
transmitting-end of a line of wire there
 are a certain number of forks or reeds 
kept vibrating continuously4 ,these     
reeds each have a fixed rate of         
vibration and bear a harmonic relation  
to each other so as not to have         
sound-interference or beats4 ,at the    
receiving-end of the line there are as  
many electromagnets as there are        
transmitting-reeds1 and each magnet has 
a reed or strap in front of it tuned to 
some one of the transmitting-reeds1 so  
that each transmitting-reed has a mate  
in exact harmony with it at the         
receiving-end of the line4 ,keys are so 
arranged at the transmitting-end as to  
throw the tones corresponding to them to
 line when depressed4 ,in other words1  
when the key belonging to battery ,b and
 vibrator #a is depressed 7see ,fig4 #d7
 the effect is to send electrical       
pulsations through the line             

corresponding in rate per second to that
 of the vibrator4 ,the same is true of  
battery ,b' and vibrator #b4 ,during the
 time any key is depressed--we will say 
of tone ,no4 #a--this tone will be      
transmitted through the line and be     
reproduced by its mate--the one tuned in
 accord with it--at the                 
receiving-station4 ,by a succession of  
long and short tones representing the   
,morse code a message can be sent4      
,numbers two1 three and four might be   
sending at the same time1 but they would
 not interfere with number one or with  
each other4 ,in #ahgf-g the writer      
succeeded in sending eight simultaneous 
messages between ,new ,york and         
,philadelphia by the harmonic method4   
,illustration3 ,fig4 #d4      ,in this  
diagram1 #a and #b are tuned reeds2     
#a;,a #b;,a are receivers     tuned to  
the reeds #a and #b respectively2 #a and
 #a;,a are in unison1     also #b and   
#b;,a1 but the two groups 7the #as and  
the #bs7 differ     from each other in  

pitch4  ,there were two ways of reading 
by the harmonic method4 ,one was by the 
long and short tone-sounds and the other
 by the ordinary sounder4  ,the         
vibration of the receiving-reed was made
 to open and close a local circuit like 
a common ,morse relay and thus operate  
the sounder4 ,it is useless to try to   
send a message if the sender and        
receiver are out of tune with each other
 in this system4  ,what is true in      
science is true in life4 ,if we are out 
of tune with our surroundings we only   
beat the air1 and our efforts are in    
vain4 ,we get no sympathetic response4  
,,chapter ,,xiv4  ,,way ,,duplex        
,,system4   ,a novel form of double     
transmission was invented by the writer 
soon after the completion of the        
harmonic system1 and was an outgrowth of
 it4 ,it is still in use on some of the 
railroad-lines4 ,an ordinary railroad   
telegraph-line has an instrument in     
circuit in every office along the road1 
chiefly for purposes of                 

train-dispatching4 ,as we have          
heretofore explained1 whenever any one  
office is sending1 the dispatch is heard
 in all of the offices4 ,the ,way duplex
 system permits of the use of the line  
for through business simultaneously with
 the operation of the local offices4    
,that is to say1 any station along the  
line may be telegraphing with any other 
station by the ordinary ,morse method1  
and at the same time messages may be    
passing back and forth between the two  
end offices4  ,this is accomplished by  
the following method3 ,at each end of   
the line there is a tuned reed1 such as 
we have described in our last chapter1  
that is kept constantly in vibration by 
a local battery during working hours4   
,this vibrator is so arranged in        
relation to the battery that whenever   
the key belonging to it is depressed the
 current all through the line is        
rendered vibratory4 ,there is also in   
circuit at each end of the line a       
harmonic relay1 that is tuned in accord 

with the vibrating reed of the sender4  
,if either key belonging to this part of
 the system is opened1 as in the act of 
sending a message1 these harmonic       
relays1 being tuned in sympathy with the
 sending-vibrator1 will respond1 thus   
sending ,morse characters made up of a  
tone broken into dots and dashes4 ,this 
tone can be read directly from the      
relay1 or1 as is usually the case1 it   
causes the sounder to operate in the    
common way4  ,you will at once inquire  
why the ordinary ,morse instruments in  
the local offices are not affected by   
these vibratory signals1 and also why   
the harmonic instruments at the end     
office are not affected by the working  
of the local offices4 ,the local office 
does not open the circuit entirely1 but 
simply cuts out a resistance by the     
operation of the special harmonic key4  
,when a resistance is thrown into an    
electric circuit it weakens the current 
in proportion to the amount of          
resistance interposed4 ,you will see    

that there is some current still left in
 the line when the key is open1 but the 
spring of the relay at the local office 
is so adjusted as to pull the armatures 
away from the magnets whenever the      
current is weakened by throwing in the  
resistance1 so that by this means an    
ordinary ,morse telegraphic relay may be
 worked without ever entirely opening   
the circuit4 ,in the ,way duplex system 
there is a resistance at each station   
that is cut in and out by the operation 
of its key1 which causes all the        
instruments in the line to work         
simultaneously except the two harmonic  
relays located one at each end of the   
line4 ,these will not respond to        
anything but the vibratory signal4  ,in 
order to prevent the ,morse relays at   
the local offices from responding to the
 vibratory current a condenser is       
connected around them4 ,this condenser  
serves two purposes3 ,it enables the    
short impulses of the vibrating current 
to pass around the relays without having

 to be resisted by the coils of the     
magnets1 and between the pulsations each
 condenser will discharge through the   
relay at the local offices1 and thus    
fill in the gap between the pulsations1 
producing the effect on the relay of a  
steady current4 ,when a line is thus    
equipped it may be treated in every     
respect as two separate wires1 one of   
them doing way business and the other   
through business4 ,it is a curious      
blending of science and mechanism4      
,another interesting application was    
made of the system of transmission by   
musical tones--by ,edison1 some years   
ago4 ,we refer to the transmission of   
messages to and from a moving           
railroad-train with the head office at  
the end of the line4 ,in this case the  
message was transmitted a part of the   
distance through the air2--another      
instance of wireless telegraphy4 ,the   
operation was as follows3 ,one of the   
wires strung on the poles nearest to the
 track was fitted up with a vibrator and

 key at the end of the line similar to  
that of the ,way duplex just described4 
,in one of the cars was another battery1
 key and vibrator1 and as only one tone 
was used1 no tone-selecting device or   
harmonic relay was needed1 but instead  
an ordinary receiving-telephone was used
 to read the long and short sounds sent 
over the lines4 ,one end of the battery 
in the car was connected through the    
wheels to the earth1 while the other end
 was connected to the metal roof of the 
car4 ,being thus equipped1 we will      
suppose our train to be out on the road 
forty or fifty miles from either end of 
the line1 moving at the rate of forty   
miles an hour4 ,the operator at         
,chicago1 say1 wishes to send a message 
to the moving train2 he operates his key
 in the ordinary manner1 which makes the
 current on the line vibratory during   
the time the key is depressed4 ,these   
electrical vibrations cause magnetic    
vibrations1 or ether-waves1 to radiate  
in every direction from the wire1 at    

right angles to the direction of the    
current1 like rays of light4 ,when they 
strike the roof of the car they create  
electrical impulses in the metal by     
induction 7described in ,chap4 ,,vi74   
,these impulses pass through a telephone
 located in the car to the ground4 ,a   
,morse operator listening1 with the     
telephone to his ear1 will hear the     
message through the medium of a musical 
tone chopped up into the ,morse code4   
,in like manner the operator in the car 
may transmit a message to the roof of   
the car and thence through the air to   
the wire1 which will be heard1 by any   
one listening1 in a telephone which is  
connected in that circuit1--and1 as a   
matter of fact1 it will be heard from   
any wire that may be strung on any of   
the poles on either side of the road4   
,some years ago an experiment of this   
kind was made on one of the roads       
between ,milwaukee and ,chicago4  ,what 
wonderful things can be done with       
electricity6 ,as a servant of man it is 

reliable and accurate--seeming almost to
 have the qualities of docility--when   
under intelligent direction1 that is in 
accord with the laws of nature2 but     
under other conditions it changes from  
the willing servant to a hard master1   
hesitating not to destroy life or       
property without regard to persons or   
things4     ,,chapter ,,xv4             
,,telephony4   ,in the foregoing        
chapters ,i have described the method of
 transmitting musical tones             
telegraphically and its applications to 
multiple telegraphy1 as well as to a    
mode of communicating with a moving     
railroad-train4 ,as ,i stated in a      
former chapter1 after discovering a     
method of transmitting harmony as well  
as melody1 ,i had in mind two lines of  
development1 one in the direction of    
multiple telegraphy1 and the other that 
of the transmission of articulate       
speech4 ,i will not attempt to give the 
names of all the people who have        
contributed to the development of the   

telephone 7as this alone would fill a   
volume7 but only describe my own share  
in the work--leaving history to give    
each one due credit for his part4 ,while
 ,i do not intend1 here1 to enter into  
any controversy regarding the priority  
of the invention of the telephone1 ,i   
wish to say that from the time ,i began 
my researches1 in the winter of #ahgc-d1
 until some time after ,i had filed my  
specification for a speaking or         
articulating telephone1 in the winter of
 #ahge-gf1 ,i had no idea that any one  
else had done or was doing anything in  
this direction4 ,i wish to say further  
that if ,i had filed my description of a
 telephone as an application for a      
patent instead of as a caveat1 and had  
prosecuted it to a patent1 without      
changing a word in the specification as 
it stands to-day1 ,i should have been   
awarded the priority of invention by the
 courts4 ,i am borne out in this        
assertion by the highest legal          
authority4 ,in law1 a caveat 7,latin    

word1 meaning ,let him beware7 is a     
warning to other inventors1 to protect  
an incomplete invention2 whereas in fact
 the invention to be protected may be   
complete4 ,an application for a patent  
is presumed by the law to be for a      
completed invention2 but it may be1 and 
very often is1 incomplete4 ,it would    
often make a very great difference if   
decisions were rendered according to the
 facts in the case rather than according
 to rules of law and practice1 that     
sometimes work great injustice to       
individuals4  ,as has been said in      
another chapter1 in the summer of #ahgd 
,i went to ,europe in the interest of   
the telephone1 taking my apparatus1 as  
then developed1 with me4 ,i came home   
early in the fall and resumed my        
experimental work4 ,many interesting as 
well as amusing things occurred during  
these experiments4  ,i remember that in 
the fall or early winter of #ahgd ,i was
 in ,milwaukee with my apparatus        
carrying on some experiments on a wire  

between ,milwaukee and ,chicago4 ,i had 
my musical transmitter along1 and one   
evening1 for the entertainment of some  
friends at the ,newhall ,house1 a wire  
was stretched across the street from the
 telegraph office into one of the rooms 
of the hotel4 ,a great number of tunes  
were played at the telegraph-office by  
,mr4 ,goodridge1 who was my assistant at
 that time1 which were transmitted      
across the street1 as before stated4 ,in
 those days it was a common practice in 
telegraphy to use one battery for a     
great number of lines4 ,for instance1   
starting with one ground-wire which     
connected with1 say1 the negative pole  
of the battery1 from the positive pole  
two1 three or a half-dozen lines might  
be connected1 running in various        
directions1 connecting with the ground  
at the further end1 thus completing     
their circuits4 ,for use in transmitting
 tones across the street that evening we
 connected our line-wire on to the      
telegraph company's battery1 which      

consisted of #ajj or more cells1 and    
which had four or five more lines       
radiating from the end of the battery to
 different parts of ,wisconsin4 ,our    
line was tapped on to the battery       
7without changing any of its            
connections7 twenty cells from the      
ground-wire4 ,in transmitting1 each     
vibration would momentarily shut off    
these twenty cells from the lines that  
were connected with the whole battery4  
,the effect of this 7an effect that we  
did not anticipate at the time7 was to  
send a vibratory current out on all the 
lines that were connected with that     
single battery as well as across the    
street4 ,a great many familiar tunes    
were played during the course of an hour
 or two which1 unconsciously for us1    
were creating great consternation       
throughout the ,state of ,wisconsin1 in 
many of the offices through which these 
various lines passed4  ,next morning    
reports and inquiries began to come in  
from various towns and cities west1     

northwest and north1 giving details of  
the phenomena that were noticed on the  
instruments located in the various      
offices along the lines4 ,they reported 
their relays as singing tunes2 one party
 said he thought the instruments were   
holding a prayer-meeting from the fact  
that they seemed to be singing          
hymn-tunes for quite a while1 but this  
notion was finally dissipated1 because  
they grew hilarious and sang ,yankee    
,doodle4  ,one operator1 up in the pine 
woods of northern ,wisconsin1 did not   
seem to take the cheerful view of it    
that some of the others did4 ,he was    
sitting alone in the telegraph-office   
that evening when he thought he heard   
the notes of a bugle in the distance2 he
 got up and went to the door to listen1 
but could hear nothing2 but on coming   
back into the room he heard the same    
bugle notes very faintly4 ,he was       
inclined to be somewhat superstitious   
and grew very nervous2 finally1 on      
looking around1 he located the sound in 

his relay1 but this did not help matters
 with him4 ,with superstitious awe he   
listened to the instrument for a few    
moments1 while it gave out the solemn   
tones of ,old ,hundred1 then it suddenly
 jumped into a hilarious rendering of   
,yankee ,doodle4 ,this was too much for 
our nervous friend1 and hastily putting 
on his overcoat1 he left the office for 
the night4  ,on another occasion1 when  
,i was giving a lecture in one of the   
cities outside of ,chicago1 where       
exhibitions of music transmitted from   
,chicago were given1 one of the         
operators along the line was very much  
astonished by his switchboard suddenly  
becoming musical4 ,orders had been given
 for the instruments in all the local   
offices to be cut out of the particular 
line that ,i was using4 ,hence the      
instrument in this particular office was
 not in the circuit through which the   
tunes were being transmitted4 ,the wire1
 however1 ran through his switchboard1  
and owing probably to a loose           

connection1 or an induced effect1 there 
was a spark that leaped across a short  
space at each electrical pulsation that 
passed through the line1 thus           
reproducing the notes of the various    
tunes played4  ,you will remember in one
 of the chapters on sound 7,volume      
,,ii471 it is stated that a musical tone
 is made up of a succession of sounds   
repeated at equal intervals1 and that   
the pitch of the tone is determined by  
the number of sound-impulses per second4
 ,applying this law to the sparks1 you  
will be able to see how the switchboard 
played tunes for the operator4  ,in the 
foregoing experiments in transmitting   
musical tones telegraphically1 ,i used a
 great many different varieties of      
receivers4 ,some of them were designed  
with metal diaphragms mounted over      
single electromagnets1 not unlike the   
receiver of an ordinary telephone4      
,these instruments would both transmit  
and receive articulate speech when      
placed in circuit with the right amount 

of battery to furnish the necessary     
magnetism4 ,however1 they were not used 
in that way at the time they were first 
made--in #ahgd4 ,these ,i called common 
receivers1 as they were designed to     
reproduce all tones equally well4 ,i    
designed and constructed another form of
 receiver1 based somewhat upon the      
theory of the harmonic telegraph4  ,this
 consisted of an electromagnet of       
considerable size1 mounted upon a wooden
 rod about ten feet long4 ,mounted upon 
this rod were also resonating boxes or  
tubes made of wood of the right size to 
have their air-cavities correspond with 
the various pitches of the              
transmitting-reeds1 so that each tone   
would be re-enforced by some one of     
these air-cavities1 thus giving a louder
 and more resonant effect to the musical
 notes4  ,here were two types of        
receiver1 one that would receive one    
sound as well as another1 but none of   
them so loud1 while the other was       
constructed on the principle of         

selection and re-enforcement1 so that a 
particular note would be sounded by the 
box having a cavity corresponding to the
 pitch of the tone1 and was much louder 
and of much better quality than ,i could
 get from the diaphragm receiver4 ,one  
of these receivers pointed to the       
harmonic telegraph and the other to the 
speaking telephone4 ,i knew that ,i had 
a receiver that would reproduce         
articulate speech or anything else that 
could be transmitted4  ,my first        
conceptions of an articulate            
speech-transmitter were somewhat        
complicated4 ,i conceived of a funnel   
made of thin metal having a great number
 of little riders1 insulated from the   
funnel at one end and resting lightly in
 contact with the funnel at the other   
end4 ,these riders were to be made of   
all sizes and weights so as to be       
responsive to all rates of vibration4   
,in the light of the present day we know
 that such an arrangement would have    
transmitted articulate speech1 but      

perhaps not so well as a single point   
would do when properly adjusted4 ,my    
mind clung to this idea till in the fall
 of #ahge1 when an observation ,i made  
upon the street changed the whole course
 of my thinking and solved the problem4 
,the incident ,i refer to took place in 
,milwaukee1 where ,i was then           
experimenting4 ,one day while out on an 
errand ,i noticed two boys with         
fruit-cans in their hands having a      
thread attached to the center of the    
bottom of each can and stretched across 
the street1 perhaps #ajj feet apart4    
,they were talking to each other1 the   
one holding his mouth to his can and the
 other his ear4 ,at that time ,i had not
 heard of this lovers' telegraph1       
although it was old4 ,it is said to have
 been used in ,china #bjjj years ago4   
,the two boys seemed to be conversing in
 a low tone with each other and my      
interest was immediately aroused4 ,i    
took the can out of one of the boy's    
hands 7rather rudely as ,i remember it  

now71 and putting my ear to the mouth of
 it ,i could hear the voice of the boy  
across the street4 ,i conversed with him
 a moment1 then noticed how the cord was
 connected at the bottom of the two     
cans1 when1 suddenly1 the problem of    
electrical speech-transmission was      
solved in my mind4 ,i did not have an   
opportunity immediately to construct an 
instrument1 as ,i had a partner who was 
furnishing money for the development of 
the harmonic telegraph and would not    
listen to any collateral experiments4 ,i
 remember sitting down by this partner  
one day and telling him what ,i could do
 in the way of transmitting speech      
through a wire4 ,i told him ,i thought  
it would be very valuable if worked out4
 ,he gave me a look that ,i shall never 
forget1 but he did not say a word4 ,the 
look conveyed more meaning than all the 
words he could have said1 and ,i did not
 dare broach the subject again4         
,however1 as soon as ,i found           
opportunity1 without saying a word to   

anybody except my patent lawyer1 ,i     
filed a description1 accompanied by     
drawings1 of a speaking telephone which 
stands in history to-day as the first   
complete description on record of the   
operation of the speaking telephone4 ,it
 described an apparatus which1 when     
constructed1 worked as described1 and it
 is a matter of history that the first  
articulate speech electrically          
transmitted in this country was by a    
transmitter constructed on the principle
 described1 and almost identically after
 the drawings in my caveat4 ,while the  
transmitter described in this caveat was
 not the best form1 it would transmit   
speech1 and it contained the foundation 
principle of all the telephone          
transmitters in use to-day4  ,there are 
two methods of transmitting speech4 ,one
 is known as the magneto method and the 
other that of varying the resistance of 
the circuit4 ,my first transmitter was  
devised on the latter principle4  ,i    
append to this extracts from my         

specification filed ,feb4 #ad1 #ahgf3   
,to ,all ,whom ,it ,may ,concern3--,be  
it known that ,i1 ,elisha ,gray      of 
,chicago1 in the ,county of ,cook and   
,state of ,illinois1 have      invented 
a new art of transmitting vocal sounds  
telegraphically1 of which the following 
is a specification3 ,it      is the     
object of my invention to transmit the  
tones of the      human voice through a 
telegraphic circuit1 and reproduce them 
at the receiving-end of the line1 so    
that actual conversations      can be   
carried on by persons at long distances 
apart4 ,i have      invented and        
patented methods of transmitting musical
      impressions or sounds             
telegraphically1 and my present         
invention      is based upon a          
modification of the principle of said   
invention1 which is set forth and       
described in letters patent      of the 
,united ,states1 granted to me ,july    
#bg1 #ahge1 respectively      numbered  
#aff1jie and #aff1jif1 and also in an   

application for      letters patent of  
the ,united ,states1 filed by me1 ,feb4 
#bc1      #ahge4 99 99 99 ,my present   
belief is that the most effective method
      of providing an apparatus capable 
of responding to the various      tones 
of the human voice is a tympanum1 drum1 
or diaphragm1      stretched across one 
end of the chamber1 carrying an         
apparatus      for producing            
fluctuations in the potential of the    
electric      circuit and consequently  
varying in its power4 99 99 99 ,the     
vibrations thus imparted are transmitted
 through an electric      circuit to the
 receiving-station1 in which circuit is 
included      an electromagnet of       
ordinary construction1 acting upon a    
diaphragm to which is attached a piece  
of soft iron1 and which      diaphragm  
is stretched across a receiving         
vocalizing chamber      ,c1 somewhat    
similar to the corresponding vocalizing 
chamber      ,a4       ,the diaphragm at
 the receiving-end of the line is thus  

thrown      into vibrations             
corresponding with those at the         
transmitting-end1 and audible sounds or 
words are produced4       ,the obvious  
practical application of my improvement 
will be to      enable persons at a     
distance to converse with each other    
through a telegraphic circuit1 just as  
they now do in each      other's        
presence1 or through a speaking-tube4   
,i claim as my invention the art of     
transmitting vocal sounds or            
conversations telegraphically through an
 electric circuit4  ,this specification 
was accompanied by cuts of the          
transmitter and receiver connected by a 
line-wire and showing one person talking
 to the transmitter and another         
listening at the receiver4 ,these cuts  
may be seen in various books on the     
subject of telephony4     ,,chapter     
,,xvi4  ,,how ,,the ,,telephone ,,talks4
   ,everybody knows what the telephone  
is because it is in almost every man's  
house4 ,but while everybody knows what  

it is1 there are very few 7comparatively
 speaking7 that know how it works4 ,if  
you remember what has been said about   
sound and electromagnetism it will not  
be hard to understand4  ,when any one   
utters a spoken word the air is thrown  
into shivers or vibrations of a peculiar
 form1 and every different sound has a  
different form4 ,therefore1 every       
articulate word differs from every other
 word1 not only as a shape in the air1  
but as a sensation in the brain1 where  
the air-vibrations have been conducted  
through the organ of hearing2 otherwise 
we could not distinguish between one    
word and another4 ,every different word 
produces a different sensation because  
there is a physical difference1 as a    
shape or motion1 in the air where it is 
uttered4 ,if one word contains #ajjj    
simultaneous air-motions and another    
#aejj you can see that there is a       
physical or mechanical difference in the
 air4  ,the construction of the simplest
 form of telephone is as follows3 ,take 

a piece of iron rod one-half or         
three-quarters of an inch long and      
one-quarter inch thick1 and after       
putting a spool-head on each end to hold
 the wire in place wind it full of fine 
insulated copper wire2 fasten the end of
 this spool to the end of a straight-bar
 permanent magnet4 ,then put the whole  
into a suitable frame1 and mount a thin 
circular diaphragm 7membrane or plate7  
of iron or steel1 held by its edges1 so 
that the free end of the spool will come
 near to but not touch the center of the
 diaphragm4 ,this diaphragm must be held
 rigidly at the edges4  ,now if the two 
ends of the insulated copper wires are  
brought out to suitable binding-screws  
the instrument is done4  ,the permanent 
steel magnet serves a double purpose4   
,when the telephone was first used      
commercially1 the instrument now used as
 a receiver was also used as a          
transmitter4 ,as a transmitter it is a  
dynamo-electric machine4 ,every time the
 iron diaphragm is moved in the magnetic

 field of the pole of the permanent     
magnet1 which in this case is the free  
end of the spool 7the iron of the spool 
being magnetic by contact with the      
permanent magnet71 there is a current   
set up in the wire wound on the spool2 a
 short impulse1 lasting only as long as 
the movement lasts4 ,the intensity of   
the impulse will depend upon the        
amplitude and quickness of the movement 
of the diaphragm4 ,if there is a long   
movement there will be a strong current 
and vice versa4 ,if a sound is uttered1 
and even if the multitude of sounds that
 are required to form a word1 be spoken 
to the diaphragm1 the latter partakes in
 kind of the air-motions that strike it4
 ,it swings or vibrates in the air1 and 
if it is a perfect diaphragm it moves   
exactly as the air does1 both as to     
amplitude and complexity of movement4   
,you will remember that in the chapter  
on sound-quality 7,vol4 ,,ii7 it was    
said that there were hundreds and       
sometimes thousands of superposed       

motions in the tones of some voices that
 gave them the element we call quality4 
,all these complex motions are          
communicated by the air to the          
diaphragm1 and the diaphragm sets up    
electric currents in the wire wound on  
the spool1 corresponding exactly in     
number and form1 so that the current is 
molded exactly as the air-waves are4    
,now1 if we connect another telephone in
 the circuit1 and talk to one of them1  
the diaphragm of the other will be      
vibrated by the electric current sent1  
and caused to move in sympathy with it  
and make exactly the same motions       
relatively1 both as to number and       
amplitude4  ,it will be plain that if   
the receiving diaphragm is making the   
same motions as the transmitting        
diaphragm1 it will put the air in the   
same kind of motion that the air is in  
at the transmitting end1 and will       
produce the same sensation when sensed  
by the brain through the ear4 ,if the   
air-motion is that of any spoken word it

 will be the same at both ends of the   
line1 except that it will not be so     
intense at the receiving-end2 it is the 
same relatively4 ,and this is how the   
telephone talks4  ,i have said that the 
permanent magnet had two functions4 ,in 
the case of the transmitter it is the   
medium through which mechanical is      
converted into electrical energy4 ,it   
corresponds to the field-magnet of the  
dynamo1 while the diaphragm corresponds 
to the revolving armature1 and the voice
 is the steam-engine that drives it4 ,in
 the second place1 it puts a tension on 
the diaphragm and also puts the         
molecules of the iron core of the magnet
 in a state of tension or magnetic      
strain1 and in that condition both the  
molecules and the diaphragm are much    
more sensitive to the electric impulses 
sent over the wire from the transmitter4
 ,this fact was experimented upon by the
 writer as far back as #ahgi and        
published in the ,journal of the        
,american ,electrical ,society4 ,at the 

present day this form of telephone is   
used only as a receiver4  ,transmitters 
have been made in a variety of forms1   
but there are only two generic methods  
of transmission4 ,one is the magneto    
method--the one we have described--and  
the other is effected by varying the    
resistance of a battery current4 ,the   
former will work without a battery1 as  
the voice acting on the wire around the 
magnet through the diaphragm creates the
 current2 in the latter the current is  
created by the battery but molded by the
 voice4 ,in the latter method the       
current passes through carbon contacts  
that are moved by the diaphragm4 ,carbon
 is the best substance1 because it will 
bear a wider separation of contact      
without actually breaking the current4  
,when carbon points are separated that  
have an electric current passing through
 them1 there is an arc formed on the    
same principle as the electric          
arc-light4  ,great improvements in      
details have been made in the telephone 

since its first use1 but no new         
principles have been discovered as      
applied to transmission4  ,we have      
spoken in another place regarding the   
various claimants to the invention of   
the telephone1 but here is one that has 
been overlooked4 ,a young man from the  
country was in a telegraph-office at one
 time and was left alone while the      
operator went to dinner4 ,suddenly the  
sounder started up and rattled away at  
such a rate that the countryman thought 
something should be done4 ,he leaned    
down close to the instrument and shouted
 as loudly as possible these words3 ,the
 operator has gone to dinner4 ,from what
 we know now of the operation of the    
telephone ,i have no doubt but that he  
transmitted his voice to some extent    
over the wire4 ,this young man's claims 
have never been put forward before1 and 
we are doing him tardy justice4 ,but his
 claim is quite as good as many others  
set forth by people who think they      
invent1 whenever it occurs to them that 

something new might possibly be done1 if
 only somebody would do it4 ,and when   
that somebody does do it they lay claim 
to it4  ,in the early days of the       
telephone it was not supposed that a    
vocal message could be transmitted to a 
very great distance4 ,however1 as time  
went on and experiments were multiplied 
the distance to which one could converse
 with another through a wire kept on    
increasing4  ,in these days1 as every   
one knows1 it is a daily occurrence that
 business men converse with each other1 
telephonically1 for a distance of #ajjj 
miles or more2 in fact1 it is possible  
to transmit the voice through a single  
circuit about as great a distance as it 
is possible to practically telegraph4   
,this leads us to speak of another      
telegraphic apparatus which we have not 
heretofore mentioned1 and that is the   
telegraphic repeater4 ,it is a common   
notion that messages are sent through a 
single circuit across the continent1 but
 this is not the case1 although the     

circuits are very much longer than they 
were some years ago4 ,the repeater is an
 instrument that repeats a message      
automatically from one circuit to       
another4 ,for instance1 if ,chicago is  
sending a message to ,new ,york through 
two circuits1 the division being in     
,buffalo1 the repeater will be located  
at ,buffalo and under the control of    
both the operator at ,chicago and the   
operator in ,new ,york4 ,when ,chicago  
is sending1 one part of the repeater    
works in unison with the ,chicago key   
and is the key to the ,new ,york        
circuit1 which begins at ,buffalo4 ,when
 ,new ,york is sending the other part of
 the repeater operates1 which becomes a 
key which repeats the message to the    
,chicago line4 ,in this way the         
practical result is the same as though  
the circuit were complete from ,new     
,york to ,chicago4 ,at the present day  
some of the copper wires and perhaps    
some of the larger iron wires are used  
direct from ,chicago to ,new ,york      

without repetition1 but all messages    
between ,new ,york and ,san ,francisco  
are automatically repeated at least     
twice and under certain conditions of   
weather oftener4 ,i can remember that in
 wet weather in the old days1 with such 
wires as they had then 7being ,no4 #i   
iron with bad joints1 which gave the    
circuit a high resistance7 that these   
repeaters would be inserted at ,toledo1 
,cleveland1 ,buffalo and ,albany in     
order to work from ,chicago to ,new     
,york4 ,under such conditions the       
transmission would necessarily be slow1 
because an armature time will be lost at
 each repeater4 ,regarding each repeater
 as a key1 when ,chicago depresses his  
key the armature of the next repeater   
must act1 and then the next             
successively1 and all of this takes     
time1 although only a small fraction of 
a second4  ,the repeater was a very     
delicate instrument and had to be       
handled by a skilled operator4 ,every   
wire must be in its place or the        

instrument would fail to operate4 ,i    
remember on one occasion in ,cleveland  
that along in the middle of the night   
the repeater failed to work4 ,the       
operator knew nothing of the principle  
of its operation1 so that when it failed
 he had to appeal to some of his        
superiors4  ,at this time there was no  
one in the office who knew how to adjust
 it1 so they had to send up to the house
 of the superintendent and arouse him   
from his sleep and bring him down to the
 office4 ,he looked under the table and 
found that one of the wires had loosened
 from its binding-post and was hanging  
down4 ,he said immediately1 ,here's the 
trouble2 ,i should think you could have 
seen it yourself4 ,the operator replied1
 ,i did see that1 but ,i didn't think   
one wire would make any difference4 ,he 
learned the lesson that all electricians
 have had to learn--that even one wire  
makes all the difference in the world4  
,but this operator was no worse in that 
respect than some of his superiors4 ,one

 of the heads of the ,cleveland office  
at one time in the early days wanted to 
give some directions to the office at   
,buffalo4 ,he told the operator at the  
key to tell ,buffalo so and so1 when the
 operator replied3 ,i can't do it2      
,buffalo has his key open4 ,the official
 immediately said with severity3 ,tell  
him to close it4 ,he forgot that it     
would be as difficult for him to tell   
him to close it1 as it would have been  
to have sent the original message4  ,but
 let us go back to the telephone4 ,while
 it is possible to send a message from  
,new ,york to ,san ,francisco by        
telegraph1 it is not possible to        
telephone that distance1 because as yet 
no one has been able to devise a        
repeater that will transfer spoken words
 from one line to another               
satisfactorily4 ,but unless the printer 
and publisher bestir themselves some one
 may accomplish the feat before this    
little book reaches the reader4 ,if this
 proves to be true1 let the writer be   

the first to congratulate the successful
 inventor4     ,,chapter ,,xvii4        
,,submarine ,,cables4   ,the first      
attempts at transmitting messages       
through wires laid in water were made   
about #ahci4 ,these early experiments   
were not very successful1 because the   
art of wire-insulation had not attained 
any degree of perfection at that time4  
,it was not until gutta-percha began to 
be used as an insulator for submarine   
lines that any substantial progress was 
made4  ,the first line1 so history      
states1 that was successfully laid and  
operated was across the ,hudson ,river  
in #ahdh4 ,this line was constructed for
 the use of the ,magnetic ,telegraph    
,company4  ,in the following year       
experiments with gutta-percha insulation
 were successfully made1 and about #ahej
 a cable was laid across the ,english   
,channel between ,dover and ,calais     
7twenty-seven miles71 consisting of a   
single strand of wire having a covering 
of gutta-percha4 ,the insulation was    

destroyed in a day or two1 which        
demonstrated the fact that all submarine
 cables must be protected by some kind  
of armor4 ,in #ahea another cable was   
laid between these two points1          
containing four conductors insulated    
with gutta-percha1 and over all was an  
armor of iron wire4 ,twenty-one years   
later this cable was still working1 and 
for all we know is working now4 ,after  
this successful demonstration other     
cables were laid for longer distances4  
,these short-line cables served to      
demonstrate the relative value of       
different material for insulating       
purposes under water1 and it has been   
found that gutta-percha possesses       
qualities superior to almost every other
 material as an insulator for submarine 
cables1 although there are many better  
materials for air-line insulation4      
,gutta-percha when exposed to air       
becomes hardened and will crack1 but    
under water it seems to be practically  
indestructible4  ,ocean telegraphy      

really dates from the laying of the     
first successful ,atlantic cable4 ,there
 were many problems that had to be      
solved1 which could be done only by the 
very expensive experiment of laying a   
cable across the ,atlantic ,ocean4 ,in  
the first place a survey had to be made 
of the bottom of the ocean between the  
shores of ,america and ,great ,britain4 
,the most available route was discovered
 by ,lieutenant ,maury of the ,united   
,states ,navy1 who made a series of     
deep-sea soundings1 and discovered that1
 from ,newfoundland to the west coast of
 ,ireland the bottom of the ocean was   
comparatively even1 but gradually       
deepening toward the coast of ,ireland  
until it reached a depth of #bjjj       
fathoms4 ,it was not so deep but that   
the cable could be laid on the bottom1  
nor so shallow as to be in danger of the
 waves1 icebergs or large sea-animals4  
,the water below a certain depth is     
always still and not affected by winds  
or ocean currents4 ,at many other points

 in crossing the ocean1 high mountains  
and deep valleys are encountered1       
possessing all the topographical        
features of dry land--as the ocean bed  
is only a great submerged continent4    
,the beginning of the laying of the     
first ,atlantic cable was on ,aug4 #g1  
#aheg4 ,on the morning of ,aug4 #g1     
#aheh1 a year later1 after a series of  
mishaps and adverse circumstances that  
would have discouraged most men1 the    
country was electrified by a dispatch   
from ,cyrus ,w4 ,field of ,new ,york 7to
 whom the final success of the ,atlantic
 cable is mainly due71 that the cable   
had been successfully laid and worked4  
,but this cable worked only from the    
#ajth of ,august to the #ast of         
,september1 having sent in that time    
#bga messages4 ,the insulation became   
impaired at some point1 when an attempt 
to force the current through by means of
 a large battery only increased the     
difficulty4  ,the failure of this first 
cable served to teach manufacturers and 

engineers how to construct cables with  
reference to the conditions under which 
they are to be used4 ,it was found that 
in the deep sea a much smaller and less 
expensive cable could be used than would
 answer at the shore ends1 where the    
water is shallow4 ,the shore ends of an 
ocean cable are made very large1 as     
compared to the deep-sea portions1 so as
 to resist the effect of the waves and  
other interfering obstacles4 ,it was    
further learned that the most successful
 mode of transmitting signals through   
the cable was with a small battery of   
low voltage1 and by the use of very     
delicate instruments for receiving the  
messages4 ,it is not possible to employ 
such instruments on cables as are used  
on land-lines1 while it would not be a  
difficult feat to transmit even twice   
the distance over land-lines strung on  
poles1 using the ordinary ,morse        
telegraph4  ,the water of the ocean is a
 conductor1 as well as the heavy armor  
that surrounds the insulation of the    

cable4 ,when a current is transmitted   
through the conducting wires1 in the    
center of the cable1 they set up a      
countercharge in the armor and the water
 above it1 somewhat as an electrified   
cloud will induce a charge in the earth 
under it1 of an opposite nature4 ,this  
countercharge1 being so close to the    
conducting wire1 has a retarding effect 
upon the current transmitted through it4
 ,an ordinary land-line that is strung  
on poles that are high up from the      
ground has this effect reduced to a     
minimum1 but the greater the number of  
wires clustered together on the same    
poles the more difficult it becomes to  
send rapid signals through any one of   
them4  ,the instrument used for         
receiving cable messages was devised by 
,sir ,william ,thompson1 now ,lord      
,kelvin4 ,one form consists of a very   
short and delicate galvanometer-needle  
carrying a tiny mirror4 ,this mirror is 
so related to a beam of light thrown    
upon it that it reflects it upon a      

graduated screen at some distance away1 
so that its motions are magnified many  
hundred times as it appears upon the    
screen4 ,an operator sits in a dark room
 with his eye on the screen and his hand
 upon the key of an ordinary ,morse     
instrument4 ,he reads the signal at     
sight1 and with his key transmits it to 
a sounder1 which may be in another room1
 where it is read and copied by another 
operator4 ,another form of              
receiving-instrument carries1 instead of
 the mirror1 a delicate capillary glass 
tube that feeds ink from a reservoir1   
and by this means the movements of the  
needle are recorded on a moving strip of
 paper4 ,the symbols 7representing      
letters7 are formed by combinations of  
zigzag lines4 ,this instrument is the   
syphon-recorder4     ,,chapter ,,xviii4 
,,short-,,line ,,telegraphs4   ,early in
 the history of the telegraph short     
lines began to be used for private      
purposes1 and as the ,morse code was    
familiar only to those who had studied  

it and were expert operators on         
commercial lines1 some system had to be 
devised that any one with an ordinary   
,english education could use2 as the    
expense of employing two ,morse         
operators would be too great for all    
ordinary business enterprises4 ,these   
short lines are called private lines1   
and the instruments used upon them were 
called private-line                     
telegraph-instruments4 ,of course they  
are now nearly all superseded by the    
telephone1 but they are a part of       
history4  ,one of the earliest forms of 
short-line instruments was called the   
dial-telegraph4 ,one of the first       
inventors1 if not the first1 of this    
form of instrument was ,professor       
,wheatstone of ,england1 who perfected a
 dial-telegraph-instrument about the    
year #ahci4 ,the receiving-end of this  
instrument consisted of a lettered      
dial-face1 under which was clockwork    
mechanism and an escape-wheel controlled
 by an electromagnet4 ,each time the    

circuit was opened or closed the wheel  
would move forward one step1 and each   
step represented one of the letters of  
the alphabet1 so that the wheel1 like   
the type-wheel of a printing telegraph1 
had fourteen teeth1 each tooth          
representing two steps4 ,as the         
reciprocating movement of the escapement
 had a pallet or check-piece on each    
side of the wheel1 its movement was     
arrested twenty-eight times in each     
revolution4 ,these twenty-eight steps   
correspond to the twenty-six letters of 
the alphabet1 a dot and a space4 ,on the
 shaft of the escape-wheel is fastened a
 hand or pointer1 which revolves over a 
dial-face having the twenty-six letters 
of the alphabet1 also a dot and space4  
,the pointer was so adjusted that when  
the escape-wheel was arrested by one of 
the pallets it would stop over a letter1
 showing thus1 letter by letter1 the    
message which the sender was spelling   
out4  ,the transmitter consisted of a   
crank with a knob and a pointer on it1  

which was mounted over a dial that was  
lettered in the same way as the face of 
the receiving-instrument4 ,a revolution 
of this crank would break and close the 
circuit twenty-eight times2 that is to  
say1 there were fourteen breaks and     
fourteen closes of the circuit4 ,if now 
the transmitting-pointer and the        
receiving-pointer are unified so that   
they both start from the same point on  
the dial1 and the transmitting-crank is 
rotated from left to right1 the         
receiving-pointer will follow it up to  
the limit of its speed4 ,in transmitting
 a message the sender would turn his    
crank1 or pointer1 to the first letter  
of the word he wished to transmit1      
making a short pause1 and then move on  
to the next letter1 and so on to the end
 of the message1 making a short pause on
 each letter4 ,the end of a word was    
indicated by turning the pointer to the 
space-mark on the dial4 ,the            
receiving-operator would read by the    
pauses of the needle on the various     

letters4 ,this was a system of reading  
by sight4  ,there have been many forms  
of this dial-telegraph worked out by    
different inventors at different times1 
and quite a number of them were used in 
the old days4 ,it was a slow process of 
telegraphing1 but it was suited to the  
age in which it flourished4 ,one of the 
difficulties of a dial-telegraph        
consisted in the readiness with which   
the transmitter and receiver would get  
out of unison with each other2 and when 
this happened of course a message is    
unintelligible1 and you have to stop and
 unify again4  ,about #ahfi the writer  
invented a dial-telegraph to obviate    
this difficulty4 ,in this system a      
transmitter and receiver were combined  
in one instrument1 and instead of a     
crank there were buttons arranged around
 the dial in a circle1 one opposite each
 letter4 ,when not in operation the     
pointers of both instruments at both    
stations stood at zero4 ,in the act of  
transmitting the operator would depress 

the button opposite the letter he wished
 to indicate1 when immediately the      
pointers of both instruments would start
 up and move automatically1 step by     
step1 until the pointer came in contact 
with the stem of the depressed button1  
when it would be arrested1 and at the   
same time cut out the automatic         
transmitting-mechanism and cause both   
needles to remain stationary during the 
time the button was depressed4 ,upon    
releasing the button the pointers both  
fall back to zero at one leap4  ,the    
first private line equipped by this     
instrument was for ,rockefeller1        
,andrews  ,flagler1 which was the firm  
name of the parties who afterward       
organized the ,standard ,oil ,company4  
,this line was built between their      
office on the public square in          
,cleveland and their works over on the  
,cuyahoga flats4  ,it seemed1 however1  
to be the fate of the writer to make new
 inventions that would supersede the old
 ones before they were fairly brought   

into use4 ,very soon after the          
dial-telegraph began to be used1        
printing telegraph instruments for      
private-line purposes superseded them4  
,about #ahfg a printing instrument was  
devised for stock reporting1 which in   
one of its forms is still in use4 ,soon 
after the invention of this form of     
printer a company was organized to      
operate not only these stock-reporting  
lines1 but short lines for all sorts of 
private purposes4 ,following the        
invention of the stock-reporting        
instrument there were several           
adaptations made of the printing        
telegraph for private-line purposes4    
,among others the writer invented one   
known as ,gray's automatic printer1 a   
cut and a description of which may be   
found on page #fhd in ,electricity and  
,electric ,telegraph1 by ,george ,b4    
,prescott1 published in #ahgg4 ,this    
instrument was adopted by the ,gold and 
,stock ,telegraph ,company as their     
standard private-line printer4 ,it was  

first introduced in the year #ahga1 and 
at the time the telephone began to be   
used there were large numbers of these  
printers in operation in all of the     
leading cities and towns in the ,united 
,states4 ,while this has been superseded
 to a large extent by the telephone1    
there are still a few isolated cases    
where it is used4  ,short lines have    
multiplied for all sorts of purposes1   
until to-day the money invested in them 
largely exceeds the amount invested in  
the regular commercial telegraphic      
enterprises4  ,the invention of the     
telephone created such a demand for     
short-line service that some scheme had 
to be devised not only to make room for 
the necessary wires1 but to so cheapen  
the instruments as to bring them within 
reach of the ability of the ordinary man
 of business4  ,this problem has been   
solved 7but not without many            
difficulties7 by the inauguration of    
what is known as the central station4   
,by this system one party simply        

controls a single wire from his office  
or residence to the central station2    
here he can have his line connected with
 any other wire running into this same  
station1 by calling the central operator
 and asking for the required number4 ,it
 is useless to tell the public that very
 often this number is busy1 and here is 
the great drawback to the               
central-station system4 ,this is        
especially true in large cities1 where  
there are a great number of lines4 ,the 
switchboards in large cities are        
necessarily very complicated affairs1   
and it requires a number of operators to
 answer the many calls that are         
constantly coming in4 ,each             
central-station operator presides over a
 certain section of the board1 and as   
this section has to be related in a     
certain way to every other section1 it  
is easy to see wherein arises the       
complication4  ,in large cities the     
central stations themselves have to be  
divided and located in different        

districts1 being connected by a system  
of trunk lines4     ,,chapter ,,xix4    
,,the ,,telautograph4   ,so far we have 
described several methods of electrical 
communication at a distance1 including  
the reading of letters and symbols at   
sight 7as by the dial-telegraph and the 
,morse code embossed on a strip of      
paper72 printed messages and messages   
received by means of arbitrary sounds1  
and culminating in the most wonderful of
 all1 the electrical transmission of    
articulate speech4  ,none of these      
systems1 however1 are able to transmit a
 message that completely identifies the 
sender without confirmation in the form 
of an autograph letter by mail4  ,in    
#ahic there was exhibited in the        
electrical building at the ,world's     
,fair an instrument invented by the     
writer called the ,telautograph4 ,as the
 word implies1 it is a system by which a
 man's own handwriting may be           
transmitted to a distance through a wire
 and reproduced in facsimile at the     

receiving-end4 ,this instrument has been
 so often described in the public prints
 that we will not attempt to do it here1
 for the reason that it would be        
impossible without elaborate drawings   
and specifications4 ,it is unnecessary  
to state that it differs in a           
fundamental way from other facsimile    
systems of telegraphy4 ,suffice it to   
say that as one writes his message in   
one city another pen in another city    
follows the transmitting-pen with       
perfect synchronism2 it is as though a  
man were writing with a pen with two    
points widely separated1 both moving at 
the same time and both making exactly   
the same motions4 ,by this system a man 
may transact business with the same     
accuracy as by the ,united ,states mail1
 and with the same celerity as by the   
electric telegraph4  ,a broker may buy  
or sell with his own signature attached 
to the order1 and do it as quickly as he
 could by any other method of           
telegraphing1 and with absolute         

accuracy1 secrecy and perfect           
identification4  ,in #ahic1 when this   
apparatus was first publicly exhibited1 
it operated by means of four wires      
between stations1 and while the work it 
did was faultless1 the use of four wires
 made it too expensive and too          
cumbersome for commercial purposes2 so  
during all the years since then the     
endeavor has been to reduce the number  
of wires to two1 when it would stand on 
an equality with the telephone in this  
respect4 ,it is only lately that this   
improvement has been satisfactorily     
accomplished1 and1 for reasons above    
stated1 no serious attempt has been made
 to introduce it as yet2 but it has been
 used for a long enough time to         
demonstrate its practicability and      
commercial value4 ,companies have been  
organized both in ,europe and ,america  
for the purpose of putting the          
telautograph into commercial use4  ,by  
means of a switch located in each       
subscriber's office the wires may be    

switched from a telephone to a          
telautograph1 or vice versa1 in a moment
 of time4 ,by this arrangement a man may
 do all the preliminary work of a       
business transaction through the        
telephone1 and when he is ready to put  
it into black and white switch in the   
telautograph and write it down4 ,for    
ordinary exchange work this is          
undoubtedly the true way to use the     
telautograph1 because one system of     
wires and one central-station system    
will answer for both modes of           
communication1 and in this way an       
enormous saving can be made to the      
public4 ,there is no question in the    
mind of any one who is familiar with the
 operation of both the telephone and    
telautograph but that some day they will
 both be used1 either in the same or    
separate systems1 as they each have     
distinctly separate fields of           
usefulness1--the telephone for desultory
 conversation1 the telautograph for     
accurate business transactions4 ,the    

question may arise in the minds of      
experts how the two systems can be      
worked in the same set of cables1 and   
this leads us to discuss the phenomena  
of induction4  ,every one who has       
listened at a telephone has heard a     
jumble of noises more or less           
pronounced1 which is the effect of the  
working of other wires in proximity to  
those of the telephone4 ,if1 when a     
,morse telegraph instrument is in       
operation on one of a number of wires   
strung on the same poles1 we should     
insert a telephone in any one of the    
wires that were strung on the same poles
 or on another set of poles even across 
the street1 we could hear the working of
 this ,morse wire in the telephone1 more
 or less pronounced1 according to the   
distance the wire is from the ,morse    
circuit4 ,this phenomenon is the result 
of induction1 caused by magnetic        
ether-waves that are set up whenever a  
circuit is broken and closed1 as        
explained in ,chapter ,,vi4  ,the       

telephone is perhaps the most sensitive 
of all instruments1 and will detect     
electrical disturbances that are too    
feeble to be felt on almost any other   
instrument1 hence the telephone is      
preyed upon by every other system of    
electrical transmission1 and for this   
reason has to adopt means of            
self-protection4 ,it has been found that
 the surest way to prevent interference 
in the telephone from neighboring wires 
is to use what is called a metallic     
circuit--that is to say1 instead of     
running a single wire from point to     
point and grounding at each end1 as in  
ordinary telegraph systems1 the         
telephone circuit is completed by using 
a second wire instead of the earth4  ,as
 a complete defense against the effects 
of induced currents the wires should be 
exactly alike as to cross-section 7or   
size7 and resistance4 ,they should be   
insulated and laid together with a      
slight twist4 ,this latter is to cause  
the two wires so twisted to average     

always the same distance from any       
contiguous wire4  ,one factor in        
determining the intensity of an induced 
current is the distance the wire in     
which it flows is from the source of    
induction4 ,a telephone put in circuit  
at the end of the two wires that are    
thus laid together will be practically  
free from the effects of induced        
currents that are set up by the working 
of contiguous wires--for this reason3   
,whenever a current is induced in one of
 the slack-twisted wires it is induced  
in both alike2 the two impulses being of
 the same polarity meet in the          
telephone1 where they kill each other4  
,in order to have a perfect result we   
must have perfect conditions1 which are 
never attained absolutely1 but nearly   
enough for all practical purposes4  ,in 
the early days of telephony great       
difficulty was experienced in using a   
single wire grounded at each end in the 
ordinary way1 if it ran near other wires
 that were in active use4 ,as time      

passed on and the electric light and    
electric railroad came into operation   
these difficulties were immensely       
increased1 till now in large cities the 
telephone companies are fast being      
driven to the double-wire system1 which 
will soon become universal for          
telephonic purposes the world over1     
except perhaps in a few country places  
where there is freedom from other       
systems of electrical transmission4 ,to 
successfully work the telephone and     
telautograph through the same cables1   
these protective devices against        
induction must be very carefully        
provided and maintained4     ,,chapter  
,,xx4  ,,some ,,curiosities4   ,until   
within recent years it was never        
supposed that a sunbeam would ever laugh
 except in poetry4 ,but the modern      
scientist has taken it out of the realm 
of poetry and put it into the prosy play
 of every-day life4 ,the ,radiophone1   
invented by ,a4 ,g4 ,bell1 is an        
instrument by which articulate or other 

sounds are transmitted through the      
medium of a ray of light4 ,it has as yet
 no practical application and has never 
gone beyond the experimental stage1 but 
as a bit of scientific information it is
 very interesting4  ,if we introduce    
into an electric circuit a piece of     
selenium1 prepared in a certain way1 its
 resistance as an electric conductor    
undergoes a radical change when a beam  
of sunlight is thrown upon it4 ,for     
instance1 a selenium cell1 so called1   
that in the dark would measure #cjj ohms
 resistance1 would have only about #aej 
ohms when exposed to sunlight4 ,this    
amount of variation in a short circuit  
of low resistance would produce a       
considerable change in the strength of a
 current passing through it from a      
battery of a given voltage4  ,if now we 
connect a selenium cell to one pole of a
 battery1 and thence through a telephone
 and back to the other pole1 we have    
completed an electric circuit1 of which 
the selenium cell is a part1 and any    

variation of resistance in this cell1 if
 made suddenly1 will be heard in the    
telephone4 ,let the diaphragm of a      
telephone transmitter have a very light1
 thin mirror on one side of it1 and a   
beam of sunlight be thrown upon it and  
reflected from that on to the selenium  
cell1 which may be some distance away4  
,then1 if the diaphragm is thrown into  
vibration by an articulate word or other
 sound1 the light-ray is also thrown    
into vibration1 which causes a vibratory
 change of resistance in the selenium   
cell in sympathy with the               
light-vibrations2 and this in turn      
throws the electric current into a      
sympathetic vibratory state which is    
heard in the telephone4 ,so that if a   
person laughs or talks or sings to the  
diaphragm1 the sunbeam laughs1 talks and
 sings and tells its story to the       
electric current1 which impresses itself
 upon the telephone as audible          
sounds--articulate or otherwise4        
,instead of the telephone1 battery and  

selenium cell1 a block of vulcanite or  
certain other substances may be used as 
a receiver2 as a light-ray thrown into  
vibration has the power to produce sound
 or sympathetic vibration in certain    
substances4  ,another curious           
application of the selenium cell has    
been attempted1 but has scarcely gone   
beyond the domain of theory4 ,this      
apparatus1 if perfected1 might be called
 a ,telephote4 ,it is an apparatus by   
which an illuminated picture at one end 
of a line of many wires is reproduced   
upon a screen at the other end4 ,the    
light is not actually transmitted1 but  
only its effects4 ,suppose a picture is 
laid off into small squares and there is
 a selenium cell corresponding to each  
square and for each selenium cell there 
is a wire that runs to a distant station
 in which circuit there is a battery4   
,at the distant station there are little
 shutters1 one for each wire1 that are  
controlled by the electric current and  
so adjusted that when the cell at the   

transmitting-end is in the dark the     
shutter will be closed4 ,now if a strong
 light be thrown upon the picture at the
 transmitting-end1 and each square of   
the picture reflects the light upon its 
corresponding selenium cell1 the high   
lights of the picture will reflect      
stronger light than the shadows1 and    
therefore the wires corresponding to the
 high-light squares will have a stronger
 current of electricity flowing through 
them1 because the resistance of the     
circuit is less than the ones connected 
with the darker shadows4 ,so that the   
degree of current-strength in the       
various wires will correspond to the    
intensity of light reflected by the     
different sections of the picture4 ,the 
shutters are so adjusted that the amount
 of opening depends upon the strength of
 current4 ,the shutters corresponding to
 the high lights of the picture will    
open the widest and throw the strongest 
light upon the screen1 from a source of 
light that is placed behind the         

shutters4 ,the shutters that open the   
least will be those that are operated   
upon by the shadows of the picture4     
,inasmuch as a picture thrown on a      
screen from a source of light is wholly 
made up of lights and shadows1 the      
theory is that this apparatus perfectly 
constructed would transmit any picture  
to a distance1 through telegraph-wires4 
,it must not be understood that the rays
 of light are transmitted through the   
wires as sound-vibrations are4 ,light1  
per se1 can be transmitted only through 
the luminiferous ether1 as we have seen 
in the chapter on light in ,volume ,,ii4
  ,while we are talking about these     
curious methods of telegraphic          
transmission1 ,i wish to refer to an    
apparatus constructed by the writer in  
#ahgd-e1 for the purpose of receiving   
musical tones or compositions           
transmitted from a distance through a   
wire by electricity4 7,a cut of this    
apparatus is shown on page #hge of      
,electricity and ,electric ,telegraph1  

by ,prescott1 issued in #ahgg47 ,it     
consists of a disk of metal rotated by a
 crank mounted on a suitable stand4 ,the
 electric circuit passes through the    
disk to the hand of the operator in     
contact with it1 thence running through 
the line-wire to the distant station4   
,now1 if a tune is played at that       
station1 upon an electrical key-board1  
as described in a previous chapter1 and 
the disk rotated with the fingers in    
contact with it1 the tune or other      
sounds will be reproduced at the ends of
 the fingers4 ,after the telephone was  
invented and put into use ,i used this  
revolving disk as a receiver for speech 
as well as music1 and by this means     
persons may carry on an oral            
conversation through the ends of their  
fingers4 ,this apparatus has been       
confounded in the minds of some people  
with ,edison's electromotograph4 ,the   
phenomena of the electromotograph were  
produced by chemical effects1 while that
 of the apparatus just described is     

electrostatic in its action4 ,the       
electrostatic disk was made in the      
winter of #ahgc-d1 while ,edison's      
electrochemical discovery was made some 
time later4     ,,chapter ,,xxi4        
,,wireless ,,telegraphy4   ,broadly     
speaking1 ,wireless ,telegraphy is any  
method of transmitting intelligible     
signals to a distance without wires2 and
 this includes the old ,semaphore       
systems of visual signals1 such as flags
 and long arms of wood by day1 and      
lights by night2 also the ,heliograph   
7an apparatus for flashing sunlight71   
and ,sound ,signals1 made either through
 the air or water4 ,electrical          
conduction1 either through rarefied air 
or the earth1 also comes under this     
heading4  ,the name ,wireless           
,telegraphy1 however1 is specifically   
applied to a system of signaling by     
means of ether-waves induced by         
electrical discharges of very high      
voltage4 ,ether-waves of a greater or   
less degree are always set up whenever  

there are sudden electrical             
disturbances1 however slight4           
,ether-waves1 electrically induced1 are 
probably as old as the universe4 ,when  
there were thunders and lightnings from 
the cloud that hovered over ,mount      
,sinai in the time of ,moses1           
ether-waves of great power were sent out
 through the camp of ,israel4 ,but the  
people of those days had no coherer or  
telephone or any other means of         
converting these waves into visual or   
audible signals4 ,thousands of years had
 to elapse before the intellect of man  
could grasp the meaning of these natural
 phenomena sufficiently to harness them 
and make them subservient to his will4  
,many people have been powerfully       
shocked--some even killed--by the impact
 of ether-waves set up by powerful      
discharges of lightning between the     
clouds and the earth--when they were not
 in the direct path of the              
lightning-stroke4  ,the history of      
,electro-,wireless ,telegraphy1 like    

that of all inventions1 is one of       
successive stages1 and all the work was 
not done by one man4 ,the one who gets  
the most credit is usually the one who  
puts on the finishing touches and brings
 it out before the public4 ,he may have 
done much toward its development or he  
may have done but little4  ,in the year 
#ahdb ,morse transmitted a battery      
current through the water of a canal    
eighty feet wide so as to affect a      
galvanometer on the opposite side from  
the battery4 ,this was wireless         
telegraphy by conduction through water4 
,in #ahce ,joseph ,henry produced an    
effect on a galvanometer by ether-waves 
through a distance of twenty feet by an 
arrangement of batteries and circuits   
like that shown in ,fig4 #a1 ,chapter   
,,vi4 ,this was called induction1 and is
 still so called when electrical effects
 are produced from one wire to another  
through the ether for short distances4  
,all induction-coils and transformers   
7see ,chapter ,,xxiv7 are operated by   

effects produced through the ether from 
the primary to the secondary coil--but  
through very short distances4  ,in #ahhj
 ,professor ,trowbridge transmitted an  
electrical current through the earth for
 one mile so as to produce signals in a 
telephone4 ,in #ahha-b ,professor       
,dolbear used for a short distance      
7fifty feet7 substantially the same     
arrangement as ,marconi now uses1 except
 that the former used a telephone as a  
receiver4 ,he used an induction-coil    
having one end of the secondary wire    
connected with the earth1 while the     
other was attached to a wire running up 
into the air4 ,at the receiving-end a   
wire starting from the earth extended   
into the air1 passing through a         
telephone1 which acted as a receiver4   
,in #ahhf he used a kite to elevate the 
wire1 through which electrical          
discharges of high voltage were made    
into the air to produce ether-waves--the
 receiver being #bjjj feet away4        
,dolbear's experiments were public      

fourteen years ago1 but at that time    
there was no interest in such matters1  
so that his work received little or no  
attention4 ,in #ahhg ,dr4 ,hertz of     
,germany made some experiments in       
producing and detecting ether-waves1 and
 he did a great deal to awaken an       
interest in the subject1 so that others 
began investigations that have led to   
its present use as a means of           
telegraphing to a distance of many      
miles4  ,in #ahia ,professor ,branly of 
,paris invented the coherer4 ,in #ahid  
it was improved by ,lodge and by him    
used as a detector of ether-waves4 ,in  
#ahif1 ten years after ,dolbear had used
 it with the kite at the                
transmitting-end and telephone at the   
receiving-end1 ,marconi1 an ,italian1   
substituted the coherer of ,branly for  
the telephone of ,dolbear4 ,this coherer
 is constructed and operated as follows3
  ,it consists of a glass tube1 of      
comparatively small diameter1 loosely   
filled with metal filings of a certain  

grade4 ,this body of metal-dust is made 
a part of a local battery circuit in    
which is placed an ordinary electric    
bell or telegraphic sounder4 ,the       
resistance of this body of filings is so
 great that current enough will not pass
 through it to ring the bell or actuate 
the sounder until an ether-wave strikes 
it and the wire attached to it1 when the
 metal particles are made to cohere to  
such an extent that the conductivity of 
the mass is greatly increased2 so that a
 current of sufficient volume will now  
pass through the bell-magnet to ring it4
 ,before the next signal comes the      
filings must be made to de-cohere2 and  
to accomplish this a little tapper1 that
 works automatically between the        
signals1 strikes the glass tube with a  
succession of light blows4  ,briefly    
stated1 the wireless system of ,marconi1
 in its essentials1 consists of a       
powerful induction-coil with one end of 
the secondary wire connected with the   
earth1 while the other extends into the 

air a greater or less distance according
 to the distance it is desired to send  
signals4 ,the greater the distance the  
higher the wire should extend into the  
air4 ,at the receiving-end a wire of    
corresponding height is erected1 also   
connected with the earth4 ,in this      
wire--as a part of its circuit--is      
placed the coherer4 ,in a local circuit 
that is connected to the upright wire in
 parallel with the coherer is placed a  
battery1 a sounder1 or a bell1 that is  
rung when the filings cohere4  ,when an 
ether-wave is set up by a discharge of  
electricity into the air it strikes the 
perpendicular wire of the receiver1 and 
that portion of the wave that strikes is
 converted into electricity1 which is   
called an induced current4 ,it is this  
current1 as it discharges through the   
coherer to the earth1 that causes the   
filings to unite so as to close the     
local circuit and operate the sounder4  
,to send a message it is only necessary 
to make the discharges into the air1 at 

the sending-end1 correspond to the      
,morse alphabet4  ,while ,marconi has   
done more than any other man to improve 
and popularize wireless telegraphy1     
history shows that he invented none of  
the essential elements so far as the    
system has been made public4  ,what he  
seems to have really done was to        
substitute the coherer of ,branly and   
,lodge1 with its adjuncts1 for the      
telephone of ,dolbear4 ,there is no     
doubt but that ,marconi has done much to
 improve and enlarge the capacity of the
 apparatus and to demonstrate to the    
world some of its possibilities4 ,he has
 been an indefatigable worker and       
deserves great credit2 but without the  
work of those who preceded him he could 
not have succeeded3 the honors should be
 divided4  ,this system has been used at
 various times for reporting            
yacht-races1 and between ships4 ,it is  
said also to have been used to some     
extent in the ,south ,african ,war4     
,there is much to be done yet1 however1 

before it can be made entirely reliable 
for defensive work in time of war4 ,as  
it is now1 all an enemy would have to do
 to destroy its usefulness would be to  
set an ether-wave-producer to work      
automatically anywhere within the sphere
 of influence of the system--to speak   
diplomatically--when it would render    
unintelligible any message that should  
be sent4 ,to make the system of the     
greatest value some sort of selective   
receiver must be invented that will     
select signals sent from a transmitter  
that is designed to work with it4       
,there is no doubt but that wireless    
telegraphy will some time play an       
important part in many spheres of       
usefulness4  ,there is another mode     
7already referred to7 for transmitting  
signals electrically without wires      
through the earth instead of through the
 air1 but in this case it is not through
 the medium of induction1 but           
conduction4 ,it has been explained in   
former chapters that earth-currents are 

constantly flowing from one point to    
another where the potentials are        
unequal4 ,sometimes these inequalities  
of potential are caused by heat and     
sometimes by electricity1 as in the case
 of a thunder-storm4 ,if a cloud is     
heavily charged with positive           
electricity1 say1 the earth underneath  
will have an equal charge of negative   
electricity4 ,let us illustrate it by   
the tides4 ,as the moon passes over the 
ocean it attracts the water toward it   
and tends to pile up1 as it were1 at the
 nearest point between the earth and the
 moon4 ,suppose that 7while the water is
 thus piled up at a point under the     
moon7 we could suddenly suspend the     
attraction between the earth and the    
moon--the water would begin immediately 
to flow off by the force of gravitation 
until it had found a common level4      
,suppose in the place of the moon we    
have a cloud containing a static charge 
of positive electricity--it attracts a  
negative charge to a point on the earth 

nearest the cloud4 ,if now a discharge  
takes place between the earth and cloud 
the potential between the two will      
suddenly become equalized and the static
 charge that was accumulated in the     
earth is released and it dissipates in  
every direction1 seeking an equilibrium1
 following the analogy of the water2 the
 difference being that in one case the  
movement is very slow1 while in the     
other it is as quick as lightning4      
,about eighteen years ago ,i had a short
 telephone-line between my house and    
that of one of my neighbors4 ,this line 
was equipped with what was known in     
those days as magneto-transmitters1 such
 as we have described in a previous     
chapter on the subject of telephony4    
,when a line is equipped in this way no 
batteries are needed1 as the voice      
generates the current1 on the principle 
employed in the dynamo-electric machine4
 ,often on summer evenings1 when the sky
 appears to be cloudless1 we can see    
faint flashes of lightning on the       

horizon1 an appearance which is commonly
 called heat-lightning4 ,as a matter of 
fact1 ,i do not suppose there is any    
such thing as heat-lightning1 but what  
we see is the effect of very distant    
storm-clouds4 ,often at such times ,i   
have held the telephone receiver to my  
ear and could hear simultaneously with  
each flash a slight sound in the        
telephone4 ,this effect could be        
produced in the earth by a simple       
discharge between two or more clouds1   
which would distribute the electrical   
discharge over a greater area4 ,and     
because my line had connection with the 
earth it could have been disturbed      
electrically by conduction instead of   
induction2 or it may have been the      
effect of ether-waves set up by the     
lightning discharges4 ,there is no doubt
 in my mind but that both of these      
effects 7ether-waves and conduction     
through earth7 may be felt when a       
discharge takes place between a cloud   
and the earth4  ,if we could1 by        

operating an ordinary telegraphic key1  
cause the lightning to discharge from   
cloud to earth1 and some one was        
listening at a telephone in a circuit   
that was grounded at both ends #ajj     
miles or more distant from the cloud1   
the man who controlled the discharges by
 the key could transmit the ,morse code 
through the earth to the man who was    
listening at the telephone4 ,thousands  
of people might be listening at         
telephones in every direction from the  
transmitting-station1 and they would all
 get the same message4 ,if the          
receiving-station is near to the point  
where there is a heavy discharge from   
the clouds to the earth the             
earth-current is very strong--flowing   
out in every direction4 ,for some years 
,i had an underground line between my   
house and laboratory1 and no part of the
 line between the two stations was above
 ground4 ,many and many times during the
 prevalence of a thunder-storm have the 
telephone-bells been made to ring at    

both ends of the line by a discharge    
from the cloud to the earth1 and in some
 cases the discharge was several miles  
away4 ,the wires could not have been    
affected so powerfully in any other way 
than through the earth4  ,it will be    
seen by the foregoing statements that it
 is possible to transmit messages       
through the earth for long distances1   
but the difficulty in the way of its    
becoming a general system is twofold4   
,first1 we cannot always have a         
thunder-cloud at hand from which to     
transmit our signals1 and1 secondly1 the
 signals would be received alike at     
every station simultaneously4           
,,chapter ,,xxii4  ,,niagara ,,falls    
,,power--,,introduction4   ,as our      
readers know1 ,niagara ,falls is        
situated upon the ,niagara ,river1 which
 is the connecting-link between ,lake   
,erie and ,lake ,ontario4 ,the surface  
of ,lake ,erie lies #ccj feet above that
 of ,lake ,ontario4 ,the high level upon
 which ,lake ,erie is situated abruptly 

terminates at ,queenstown1 which is near
 the point where the ,niagara ,river    
empties into ,lake ,ontario4 ,from ,lake
 ,erie to the falls the level of the    
river is gradually lowered a little less
 than #ajj feet1 and most of this       
7making the rapids7 occurs in the last  
mile above the point where it takes a   
perpendicular plunge of #afe feet into a
 narrow gorge extending for seven miles1
 through which the river runs1 gradually
 falling also #ajj feet in that         
distance4 ,the river above the falls is 
broad1 varying from one to three miles  
in width1 but below that point it is    
suddenly narrowed up to a distance of   
from #bjj to #djj yards4  ,it is        
supposed that at one time the fall was  
situated at the bluff overlooking       
,queenstown1 near ,lake ,ontario1 and at
 that time was very much higher than it 
is at present4 ,through long ages of    
time the water has gradually eaten away 
the rock1 thus forming the gorge4 ,it is
 estimated by different geologists that 

the time required to wear away the rock 
back to the present position of the fall
 has required from #ae1jjj to #ce1jjj   
years4 ,some authorities place the rate 
of wear at three feet per annum and     
others not more than one4 ,it is well   
known1 however1 that this erosion is    
constantly going on1 and if nothing is  
done to check it the time will come when
 the gorge will extend up to ,lake ,erie
 and drain it1 practically1 to the      
bottom4 ,this is a matter1 however1 that
 the people of this and those of several
 succeeding generations need not worry  
about4  ,in the early days1 before the  
country was settled and the banks of the
 river were lined with trees1 and no    
houses1 hotels or horse-cars were to be 
seen2 when the puffing of the locomotive
 was not heard echoing from shore to    
shore2 when no bridges spanned the river
 to mar its beauty1 and when nature was 
the only architect and beautifier1      
,niagara ,falls must have been one of   
the most attractive spots on the earth2 

at least it is the place of all places  
where the mighty energies of nature are 
gathered together in one grand          
exhibition of sublime power4 ,here for  
ages this same grand exhibition had been
 going on1 and although there was no    
human eye to see it1 those of us who    
believe that nature is not a thing of   
chance1 but that it was planned by an   
intelligence infinitely superior to that
 of any man1 can easily imagine that the
 ,great ,architect and beautifier of    
this same nature1 not only plans but    
enjoys the work of ,his own hand4 ,why  
not8 ,for ages the same sun1 in his     
daily round1 has reflected that         
beautifully colored rainbow1 here the   
product of sunshine and mist4 ,the same 
water1 through these successive ages1   
has been lifted to the clouds by the    
power of the sun's rays1 and has been   
carried back to the fountain-heads on   
the wings of the wind1 and there has    
been condensed into raindrops1 that have
 fallen on land1 lake and river1 and in 

turn has been carried over this same    
waterfall in its onward course toward   
the sea1 only again to be caught up into
 the clouds2 and thus through an eternal
 round it has been kept moving by that  
mighty engine of nature1 the sun4 ,it is
 said that the mill will never grind    
with the water that has passed4 ,this is
 true only in poetry4 ,as a matter of   
fact1 the water that has passed may     
often return to help the mill to grind  
again4  ,water-powers have been utilized
 in a small way for many years for the  
purpose of generating electricity       
through the medium of the dynamo1 but   
nowhere in the world has the application
 of the force been made for this purpose
 on such a grand scale as at ,niagara   
,falls4 ,when one stands on the bank of 
the river and sees the great waterfall  
as it plunges over the precipice1       
exerting a force of from five to ten    
million horse-power1 one is overwhelmed 
in contemplation of its possibilities as
 a source of energy that may be         

converted into work1 mechanical and     
chemical1 through the medium of         
electricity4  ,the genius of man has    
devised a way by which some of this     
constantly wasting energy may be        
converted into electricity and          
distributed to different points to      
perform various kinds of work4 ,but the 
amount utilized as yet is scarcely a    
drop when compared with that which might
 be if the whole torrent could be set to
 work in the same manner as a very small
 portion of it now is4     ,,chapter    
,,xxiii4  ,,niagara ,,falls             
,,power--,,appliances4   ,some years ago
 a company was formed for the purpose of
 utilizing1 to some extent1 this        
greatest of all water-powers4 ,a tunnel 
of large capacity was run from a point a
 short distance below the falls on a    
level a little above the river at that  
point4 ,the general direction of this   
tunnel is up the river2 it is about a   
mile and one-half in length1 terminating
 at a point near the bank of the river a

 mile or more above the falls4 ,above   
the end of this tunnel an upright pit   
comes to the surface1 where a           
power-house of large dimensions has been
 constructed of solid masonry4 ,it is   
long enough at present to contain ten   
dynamos of mammoth size4 ,along the side
 of this power-house a deep broad canal 
is cut1 which communicates with the     
river at that point1 and through which  
flows the water that is to furnish the  
power4 ,of course the water level of    
this canal is the same as that of the   
river4  ,the foundations of the         
power-house extend to the bottom of the 
tunnel1 which at that point is #ahj feet
 below the surface of the ground4 ,to   
put it in other words1 the cellar or pit
 under the power-house is #ahj feet deep
 and communicates with the great tunnel1
 which has its outlet below the falls4  
,each of the ten dynamos is driven by a 
turbine water-wheel situated near the   
bottom of the pit heretofore described4 
,the turbine-wheel is on the lower end  

of a continuous shaft1 which reaches    
from a point near the bottom of the     
tunnel to a point ten or fifteen feet   
above the floor of the power-house      
7which is about on a level with the     
surface of the ground74  ,this shaft is 
incased in a water-tight cylinder of    
such diameter as will admit a sufficient
 amount of water1 and connects with the 
turbine wheel at the bottom in the      
ordinary way4 ,the water is admitted    
into the top of this cylinder from the  
canal1 so that the wheel is under the   
pressure of a falling column of water   
over #adj feet high4 ,the water1 forcing
 its way out at the bottom through the  
turbine1 revolves it and its long1      
upward-reaching shaft with great power1 
and enables it to work the dynamos in   
the power-house above1 as will be       
described4 ,the water discharges through
 the wheel in such a manner as to lift  
the whole shaft1 thus taking away the   
tremendous end-thrust downward that     
would otherwise interfere greatly with  

the running of the machine through      
friction4 ,after the water has done its 
work it flows off through the tunnel    
into the river below the falls4  ,to the
 upper end of the power-shaft is        
attached a great revolving              
umbrella-shaped hood2 to the periphery  
7circumference7 of this hood is attached
 a forged steel ring1 #e inches in      
thickness1 about #ab feet in diameter   
and from #d to #e feet in width4 ,the   
whole of the revolving                  
portion--including the ring upon which  
are mounted the field-magnets1 the hood1
 and the shaft running to the bottom of 
the pit1 where the turbine wheel is     
attached--weighs about thirty-five tons4
  ,the dynamos belong to the alternating
 type1 and are comparatively simple in  
construction4 ,in a previous chapter    
upon the dynamo it was stated that the  
fundamental feature was the relation    
that the field-magnet and the armature  
sustained to each other1 and that in    
some cases the field-magnet revolves    

while the part that is technically      
called the armature remains stationary4 
,in other cases the armature revolves   
and the field-magnets are stationary4   
,in the latter case brushes and         
commutators are used1 to catch and      
transfer the generated electricity1     
while in the former these are not       
needed1 which simplifies the            
construction of the machine4  ,as we    
have stated1 the dynamos used at        
,niagara are constructed with revolving 
field-magnets that are bolted on to the 
inner surface of the steel ring that is 
carried by the hood1 so that there are  
no brushes connected with the machine   
except the small ones used to carry the 
current to the field-magnets4  ,the     
current for power purposes is generated 
in a large stationary armature about ten
 feet in diameter and of the same depth 
as the revolving ring4 ,the revolutions 
of the ring send out currents of        
alternating polarity1 and each of the   
ten machines will furnish electrical    

energy equal to #ejjj horse-power1 so   
that when the work that is now under way
 is completed #ej1jjj horse-power can be
 furnished in the form of electricity4  
,about #ce1jjj horse-power is now       
actually delivered to the various       
industrial enterprises4 ,the dynamos are
 set horizontally1 since the shaft which
 connects them with the turbine wheel   
stands in a perpendicular position4     
,not all of the energy that is developed
 by the water-wheel is converted into   
electricity1 but some of it appears as  
heat4 ,in order to prevent the heat from
 becoming so great as to be dangerous to
 the machine it must be constructed in  
such a way as to admit of sufficient    
ventilation for cooling purposes4 ,the  
armature is so constructed that there   
are air-passages running all through it1
 and on top of the revolving hood are   
two bonnet-shaped air-tubes set in such 
a way as to force the air down through  
the armature1 which carries off the heat
 and warms the power-house1 on the      

principle of a hot-air furnace4 ,this   
great machine--which1 in a way1 is so   
simple in its construction--when in     
action conveys to the mind of the       
beholder a sense of wonderful power4 ,it
 is only when we stand in the presence  
of such exhibitions as may be seen in   
this power-house1 devised and executed  
by the genius of man1 and in that       
greater presence1 the mighty ,falls of  
,niagara1 that we get something of a    
conception of the power of the silent   
yet potent energy of the great king of  
daylight1 the sun4  ,there are very many
 interesting details that work in       
connection with this great power-plant1 
some of which we will describe1 in a    
general way4  ,standing within a few    
feet of each one of the great dynamos is
 a very beautifully constructed piece of
 machinery called the governor4 ,the    
governor regulates the speed of the     
dynamos by partially opening and closing
 the water-gates that regulate the flow 
of water into the turbines4 ,the        

question may be asked1 why is there any 
regulation needed1 if there is always an
 even head of water8 ,there are two     
reasons--one because the load on the    
dynamo is constantly changing1 and      
another that the head of water changes1 
although this latter fluctuation is in  
long periods4 ,if the circuit leading   
out from the dynamo is broken1 the      
rotating part of the dynamo will move   
with great ease and little power1 as    
compared with what is required when the 
circuit is closed1 and the current is   
going out and doing work4 ,the increased
 amount of energy that will be required 
to keep the dynamo moving at a certain  
rate of speed when the load is on--in   
other words1 when the circuit is        
closed--will depend upon the amount of  
current that is going out from the      
dynamo to perform work at other points4 
,as the amount of current used outside  
for the various purposes is constantly  
changing1 it follows that the load on   
the dynamo is constantly changing also4 

,as the load changes1 the speed will    
change1 unless the amount of water that 
is flowing into the turbine is changed  
in a like proportion2 hence the         
necessity for a governor that will      
perform this work4 ,you can easily      
imagine that it will require a great    
amount of power to move the gate up or  
down with such a pressure of water      
behind it4 ,it is not possible here to  
explain the operation of the governor in
 detail1 as that could not be done      
without elaborate drawings2 suffice it  
to say that the whole thing is          
controlled by a small ball governor such
 as we see used in ordinary             
steam-engines for regulating            
steam-pressure4  ,the rising or falling 
of the balls of this governor to only a 
very slight extent will bring into      
action a power that is driven by the    
turbine itself1 which is able to move   
the water-gate in either direction      
according as the balls rise or fall4    
,for instance1 if the balls rise beyond 

their normal position1 it shows that the
 dynamo is increasing in speed1 and     
immediately machinery is brought into   
action that shuts the water off in a    
small degree1 just enough to bring the  
speed back to normal4 ,if the balls drop
 to any extent1 it shows that the load  
is too great for the amount of water1   
and that the dynamo is decreasing in    
speed2 immediately the power is brought 
into action1 now in the opposite        
direction1 and the water-gate is opened 
wider4 ,these slight variations of speed
 are constantly going on1 and the       
constant opening and closing of the gate
 follows with them4 ,it is a beautiful  
piece of machinery1 and is beautifully  
adapted to the work it has to perform4  
,it is continually standing guard over  
this greater piece of machinery that is 
exerting an energy of #ejjj horse-power 
and prevents it from going wrong1 both  
in doing that which it should not do and
 leaving undone that which it should do4
 ,it is a machine that1 when in action1 

points a moral to every thinking person 
who beholds it4 ,every man has such a   
governor if he only has the inclination 
to use it4  ,i have said further back   
that the water-head varies1 but usually 
at long periods4 ,this variation is     
chiefly caused by changes of wind1 and  
it is very much greater than one would  
suppose without studying the causes4    
,lake ,erie lies in an easterly and     
westerly direction1 and when the wind   
blows constantly for a time from the    
west1 with considerable force1 the water
 piles up at the eastern end of the     
lake1 which causes the level of the     
,niagara ,river to rise to a very       
sensible extent4 ,it is not so          
noticeable above the falls as below1    
because of the great difference in the  
width of the river at these two points4 
,sometimes the river below the falls1 as
 it flows through the narrow gorge1 will
 vary in height from twenty to forty    
feet4 ,when the wind stops blowing from 
the west and suddenly changes and blows 

from the east1 it carries the water of  
the lake away from the east toward the  
west end1 which will produce a          
corresponding depression in the ,niagara
 ,river4 ,no doubt there is an effect   
produced by the difference of annual    
rainfall1 but the effect from this cause
 is not so marked as that from the      
changing winds4  ,another appliance used
 in the power-house1 chiefly for        
handling heavy loads and transferring   
them from one point to another1 is      
called the electric crane4 ,it is       
mounted upon tracks located on each side
 of the power-house4 ,the crane spans   
the whole distance1 and runs on this    
track by means of trucks from one end of
 the power-house to the other4 ,running 
across this crane is another track which
 carries the lifting-machinery1         
consisting of block and tackle1 able to 
sustain a weight of fifty tons4         
,situated at one end of the crane are   
one or more electric motors1 which are  
able1 under the control of the engineer1

 to produce a motion in any direction1  
which is the resultant of a compound    
motion of the two cars acting crosswise 
to each other together with the         
perpendicular motion of the lifting-rope
 connected with the block and tackle4   
,it seems like a thing endowed with     
human reason1 when we see it move off to
 a distant part of the building1 reach  
down and pick up a piece of metal       
weighing several tons1 carry it to some 
other portion of the building and lower 
it into place1 to the fraction of an    
inch4 ,while the machine itself does not
 reason1 there is a reasoning being at  
the helm1 who controls it and makes it  
subservient to his will4 ,the machine is
 to the engineer who manipulates it what
 a man's brain is to the man himself4   
,the brain is the instrument through    
which the unseen man expresses his will 
and impresses his work upon men and     
things in the visible world4            
,,chapter ,,xxiv4  ,,niagara ,,falls    
,,power--,,appliances4   ,in the last   

chapter ,i described some of the        
appliances used in connection with the  
power-house4 ,there are many things that
 are commonplace as electrical          
appliances when used with currents of   
low voltage and small quantity1 that    
become extremely interesting when       
constructed for the purpose of handling 
such currents as are developed by the   
dynamos used at ,niagara4 ,for instance1
 it is a very commonplace and simple    
thing to break and close a circuit      
carrying such a current as is used for  
ordinary telegraphic purposes1 but it   
requires quite a complicated and        
scientifically constructed device to    
handle currents of large volume and     
great pressure4 ,if such a current as is
 generated by a dynamo giving out #ejjj 
horse-power under a pressure of #bbjj   
volts should be broken at a single point
 in a conductor1 there would be a flash 
and a report1 attended with such a      
degree of heat and such power for       
disintegration that it would destroy the

 instrument4  ,the circuit-breakers used
 at ,niagara are constructed with a very
 large number of contacts made of metal 
sleeves1 or tubes1 say one inch in      
diameter1 so constructed that one will  
slide within the other2 the sleeves     
being slotted so as to give them a      
little spring that secures a firm       
contact4 ,these are all connected       
together electrically1 on each half of  
the switch1 as one conductor1 so that   
when the switch is closed the current is
 divided into as many parts as there are
 points of contact in the switch4       
,suppose there are #ajj of these        
contact-points1 a one-hundredth part of 
the current would be flowing through    
each one of them4 ,if1 now1 these points
 are so arranged that they can be all   
simultaneously separated1 the spark that
 will occur at each break will be very  
small as compared with what it would be 
if the whole current were flowing       
through a single point1 and it would be 
so small that there would be no danger  

attending the opening of the switch4    
,these switches are carefully guarded1  
being boxed in and under the control of 
a single individual4  ,there is another 
apparatus that is a necessary part of   
every manufacturing or other kind of    
plant that uses electricity from this   
power-house1 and this is called the     
transformer4 ,many of you are familiar  
with the box-shaped apparatus that is   
used in connection with electric        
lighting when the alternating current is
 used4 ,where simply heating effects are
 required1 such as in electric lighting1
 for instance1 the alternating current  
can be used to greater advantage than   
the direct current when it has to be    
carried to some distance1 owing to the  
fact that it may be a current of high   
voltage4 ,a greater amount can be       
carried through a small conductor2 thus 
greatly reducing the cost of an         
electrical plant that distributes power 
to a distance4 ,a transformer is an     
apparatus that changes the current from 

one voltage to another4  ,in the        
ordinary electric-light plant1 such as  
is used in a small town or village1 the 
current that is sent out from the       
power-station has a pressure of from    
#ajjj to #aejj volts1 according to the  
distance to which it is sent4 ,it would 
not do1 however1 for the current to     
enter a dwelling at this high pressure1 
because it is dangerous to handle1 and  
the liability to fires originating from 
the current would be greatly increased4 
,at some point1 therefore1 outside of   
the building1 and not a great distance  
from it1 a transformer is inserted which
 changes the voltage1 say1 from #ajjj   
down to #ej or #ajj1 according to the   
kind of lamps used4 ,some lamps are     
constructed to be used with a current of
 fifty volts and others for #ajj or     
more4 ,the lamp must always be adapted  
to the current or the current to the    
lamp1 as you choose4 ,the human body may
 be placed in a circuit where such low  
voltage is used without danger1 but it  

would be exceedingly dangerous to be put
 in contact with a pressure of #ajjj or 
more volts1 such as is used for lighting
 purposes4  ,in principle the           
transformer is nothing more or less than
 an induction-coil on a very large      
scale4 ,the ordinary induction-coil1    
such as is used for medical purposes1 is
 ordinarily constructed by winding a    
coarse wire around an iron core4 ,this  
core is usually made of a bundle of soft
 iron wires1 because the wires more     
readily magnetize and demagnetize than a
 solid iron core would4 ,around this    
coil of coarse wire1 which we call the  
primary coil1 is wound a secondary coil 
of finer wire4 ,if now a battery is     
connected with the primary coil1 which  
is made of the coarse wire1 and the     
circuit is interrupted by some sort of  
mechanical circuit-breaker1 each time   
the primary or battery circuit is opened
 there will be a momentary impulse in   
the secondary circuit of a much higher  
voltage2 and at the moment the primary  

circuit is closed there will be another 
impulse in this secondary circuit in the
 opposite direction4 ,the latter impulse
 is called the initial and the former   
the terminal impulse4 ,a current created
 in this manner is called an induced    
current4 ,the initial current is not so 
strong as the terminal in this          
particular arrangement4  ,if we should  
take hold of the two wires connected    
with the two poles of the battery and   
bring them together so as to close the  
circuit1 and then separate them so as to
 break it we should scarcely feel any   
sensation--if there were only one or two
 cells1 such as are ordinarily used with
 such coils4 ,but if we connect these   
wires to the coils of the induction     
apparatus and then take hold of the two 
ends of the secondary coil and break and
 close the primary circuit we should    
feel a painful shock at each break and  
close1 although the actual amount of    
current flowing through the secondary   
wire is not as great as that which flows

 through the primary2 but the voltage   
7or electromotive force7 is higher1 and 
thus is able to drive what current there
 is through a conductor of higher       
resistance1 such as the human body4 ,for
 this reason there is more current      
forced through the body1 which is a poor
 conductor1 than can be by a direct     
battery current which has a lower       
voltage4 ,if now we should take a       
battery of a number of cells1 so as to  
get a voltage equal to that given off by
 the secondary coil1 and connect it with
 the fine-wire coil instead of the      
coarse-wire coil--thus making what was  
before the secondary coil the           
primary--by breaking and closing the    
battery circuit as before we shall get a
 secondary or induced current in the    
coarse-wire coil1 but it will be a      
current of low voltage1 and will not    
produce the painful sensation that the  
secondary coil did4  ,we have now       
described the principle of a transformer
 as it is worked out in an ordinary     

induction-coil4 ,as has been stated1 at 
,niagara ,falls the current comes from  
the dynamos with an electromotive force 
or pressure of #bbjj volts4 ,for some   
purposes this voltage is not high       
enough1 and for other purposes it is too
 high2 therefore it has to be           
transformed before it is used6 ,for some
 purposes this transformation takes     
place in the power-house1 and for others
 it takes place at the establishment    
where it is used4 ,for instance1 take   
the current that is sent to ,buffalo1 a 
distance of from twenty to thirty miles4
 ,the current first runs to a           
transformer connected with the          
power-house1 where it is stepped-up 7to 
use the parlance of the craft7 from a   
voltage of #bbjj to #aj1jjj4 ,it is     
carried to ,buffalo through wire        
conductors that are strung on poles1 and
 is there stepped-down again through    
another transformer to the voltage      
required for use at that place4 ,the    
object of raising the voltage from #bbjj

 to #aj1jjj in this case is to save     
money in the construction of the line of
 conductors between the two points4 ,if 
the voltage were left at #bbjj--the     
conductors remaining the same as they   
are now--the loss in transmission would 
be very great1 owing to the resistance  
which these wires would offer to a      
current of such comparatively low       
voltage as #bbjj4 ,to overcome this     
difficulty--if the voltage is not       
increased--it would be necessary to use 
conductors that are very much larger in 
cross-section 7thicker7 than the present
 ones are4 ,and as these conductors are 
made of copper the expense would be too 
great to admit of any profit to the     
company4  ,if we go back to an          
illustration we used in one of the early
 chapters on electricity we can better  
explain what takes place by increasing  
the voltage4 ,if we have a column of    
water kept at a level say of ten feet   
above a hole where it discharges1 that  
is one inch in diameter1 a certain      

definite amount of water will discharge 
there each minute4 ,if now we substitute
 for the hole that is one inch in       
diameter one that is only one-half inch 
in diameter a very much smaller amount  
of water will discharge each minute1 if 
the head is kept at the same            
point--namely1 ten feet4 ,but if now we 
raise the column of water we shall in   
time reach a height which will produce a
 pressure that will cause as much water 
to discharge per minute through the     
one-half-inch hole as before discharged 
through the one-inch hole with only the 
pressure of a ten-foot column4 ,this is 
exactly what takes place when the       
voltage is stepped-up1 which is         
equivalent to an increase of pressure4  
,it will be seen from the foregoing that
 these transformers have to be made with
 reference to the use the current is to 
be put to4 ,in general shape they are   
alike in appearance1 the difference     
being chiefly in the relation the       
primary sustains to the secondary coils4

 ,there is another kind of transformer  
that is used when it is necessary to    
have the current always running in the  
same direction4 ,this transformer1 as   
heretofore explained1 does not change   
the voltage of the current1 but simply  
transforms what was an alternating into 
a direct current4 ,by alternating       
current we mean one that is made up of  
impulses of alternating polarity--first 
a positive and then a negative4 ,the    
direct current is one whose impulses are
 all of one polarity4 ,the direct       
current is required for all purposes    
where electrolysis 7chemical            
decomposition by electricity1 as of     
silver for silver-plating1 etc47 is a   
part of the process4 ,the alternating   
current may be used without             
transformation in all processes where   
heat is the chief factor4 ,for motive   
power either current may be used1 only  
the electromotors have to be constructed
 with reference to the kind of current  
that is used4  ,the rotary transformer1 

which may be driven by any power1       
consists of a wheel carrying a rotating 
commutator so arranged with reference to
 brushes that deliver the current to the
 commutator and carry it away from the  
same1 that the brushes leading out from 
the transformer will always have        
impulses of the same polarity delivered 
to them4 ,in the parlance of the craft1 
the transformers that are used to change
 the voltage from high to low1 or vice  
versa1 are called static transformers1  
simply because they are stationary1 we  
suppose4 ,the others are called rotary1 
or moving transformers1 to distinguish  
them from the other forms4 ,the         
operation of the latter is purely       
mechanical1 while the former is         
electrical4 ,in some instances where the
 static transformers are very large they
 develop a great amount of heat1 so much
 that it is necessary to devise means   
for dissipating it as fast as created4  
,in some instances this is done by      
air-currents forced through them1 but in

 others1 where they are very large1 oil 
is kept circulating through the         
transformer from a tank that is elevated
 above it1 the oil being pumped back by 
a rotary pump into the tank where it is 
cooled by a coil of pipe located in the 
oil1 through which cold water is        
continually circulating4 ,by this means 
cold oil is constantly flowing down     
through the transformer1 where it       
absorbs the heat1 which in turn is      
pumped back into the tank1 where it is  
cooled4  ,having now traced the energy  
from the water-wheel through the various
 transformations and having described in
 a very general way the apparatus both  
for generating electricity and for      
transforming it to the right voltage    
necessary for the various uses to which 
it is put1 we will proceed in our next  
chapter to follow it out to the points  
where it is delivered1 and trace it     
through its processes1 and the part it  
plays in creating the products of these 
various commercial establishments4      

,,chapter ,,xxv4  ,,electrical          
,,products--,,carborundum4   ,the       
production of electricity in such       
enormous quantities as are generated at 
,niagara ,falls has led to many         
discoveries and will lead to many more4 
,products that at one time existed only 
in the chemical laboratory for          
experimental purposes1 have been so     
cheapened by utilizing electrical energy
 in their manufacture1 as to bring them 
into the play of every-day life4 ,still 
other products have only been discovered
 since the advent of heavy electrical   
currents4 ,a substance called           
carborundum1 which was discovered as    
late as #ahia1 has now become the basis 
of an industry of no small importance4  
,it is a substance not unlike a diamond 
in hardness1 and not very unlike it in  
its composition4 ,the chief use to which
 it is put is for grinding metals and   
all sorts of abrasive work4 ,it is      
manufactured into wheels1 in structure  
like the emery-wheel1 and serves the    

same purpose4 ,it is much more expensive
 than the emery-wheel1 but it is claimed
 that it will do enough more and better 
work to make it fully as economical4    
,it was my pleasure and privilege to    
visit the factory at ,niagara ,falls1   
and through the courtesy of ,mr4        
,fitzgerald1 the chemist in charge of   
the works1 ,i learned much of the       
manufacture and use of carborundum4 ,the
 crude materials used in the manufacture
 of carborundum are1 sand1 coke1 sawdust
 and salt2 the compound is a combination
 of coke and sand4 ,it combines at a    
very high heat1 such as can be had only 
from electricity4 ,when cooled down the 
product forms into beautiful crystals   
with iridescent colors4 ,the            
predominating colors are blue and green1
 and yet when subjected to sunlight it  
shows all the colors of the solar       
spectrum to a greater or less degree4   
,the crystals form into hexagonal       
shapes1 and sometimes they are quite    
large1 from a quarter to a half inch on 

a side4 ,the salt does not enter into   
the product as a part of the compound1  
neither does the sawdust4 ,the salt acts
 as a flux to facilitate the union of   
the silica and carbon4 ,the sawdust is  
put into the mixture to render it porous
 so that the gases that are formed by   
the enormous heat can readily pass off1 
thus preventing a dangerous explosion   
that might otherwise occur4 ,in fact1   
these explosions have occurred1 which   
led to the necessity of devising some   
means for the ready escape of the gases4
  ,the process of manufacture as it is  
carried on at ,niagara is interesting4  
,the visitor is first taken into the    
rooms where are stored the crude        
material1 the sand1 coke1 sawdust and   
salt4 ,the sand is of the finest quality
 and very white4 ,the coke is first     
crushed and screened1 the part which is 
reduced to sufficient fineness is mixed 
by machinery with the right proportion  
of sand1 salt and sawdust4 ,the coarser 
pieces of coke are used for what is     

called the core of the furnace1 which   
will be described later on4  ,this      
mixture is carried to the furnace-room1 
which has a capacity for ten furnaces1  
but not all of these will be found in   
operation at one time4 ,here the workmen
 will be taking the manufactured        
material from a furnace that has been   
completed1 and there another furnace is 
in process of construction1 while a     
third is under full heat1 so that one   
sees the whole process at a glance4     
,these furnaces are built of brick1     
about sixteen feet in length and about  
five feet in width and depth4 ,the ends 
and bed of the furnace are built of     
brick1 and might be called stationary   
structures4 ,the sides are also built of
 brick laid up loosely without mortar2  
each time the material is placed in the 
furnace1 and each time the furnace is   
emptied1 the side-walls are taken down4 
,a furnace is made ready for firing by  
placing a mass of the mixture on the    
bottom1 and building the sides up about 

four feet high 7or half the height when 
it shall be completed74 ,a trough1 about
 twenty or twenty-one inches wide and   
half as deep1 is scooped out the whole  
length of the pulverized stuff1 and in  
this is placed what has before been     
referred to as the core of the furnace1 
namely1 pure coke broken into small     
pieces1 but not pulverized1 as in the   
case of the other mixture4 ,the amount  
used is carefully weighed1 so as to have
 the core the proper size that          
experiment has proved to give the best  
results4 ,the core is filled in and     
rounded over till it is in circular     
form1 being about twenty-one inches in  
diameter4 ,at each end of the furnace   
the core connects with a number of      
carbon rods--about sixty in all--that   
are thirty inches long and three inches 
in diameter4 ,these carbon rods are     
connected with a solid iron frame that  
stands flush with the outer end of the  
furnace4 ,on the inside the spaces      
between the rods are packed full of     

graphite1 which is simply carbon or coke
 with all the impurities driven out1 so 
as to make good electrical connections  
with the core4 ,this core corresponds1  
electrically speaking1 to the filament  
in an ordinary incandescent lamp1 only  
it is fourteen feet long and twenty-one 
inches in diameter4 ,the mixed material 
is now piled up over this core1 and the 
walls at the sides are built up until   
the whole structure stands about eight  
feet from the floor--a mass of the fine 
pulverized mixture1 with a core of      
broken coke electrically connected at   
the ends4 ,it is now ready for the      
application of electricity1 which       
completes the work4  ,let us go back to 
the transformer-room and examine the    
electrical appliances that bring the    
current down to a proper voltage to     
produce the heat necessary to cause a   
union between the silica of the sand and
 the carbon of the coke1 which results  
in the beautiful carborundum crystals   
that we have heretofore described4  ,the

 current is delivered from the ,niagara 
,power ,company under a pressure of     
#bbjj volts4 ,the conductors run first  
into the transformer-room1 which adjoins
 the furnace-room1 and is there         
transformed down from #bbjj volts to an 
average of about #bjj volts4 ,the       
transformers at these works have a      
capacity of about #aajj horse-power4    
,about #d per cent of this power is     
converted into heat in the process of   
transformation1 making a loss in        
electrical energy of a little over #dj  
horse-power4 ,this heat would be        
sufficient to destroy the transformer if
 some arrangement were not provided to  
carry it off4 ,we have already described
 how this is done through the medium of 
a circulation of oil4 ,because of the   
low voltage and enormous quantity of the
 current passing from the transformer to
 the furnace very large conductors are  
required4 ,the two conductors running to
 the furnace have a cross-section of    
eight square inches1 and this enormous  

current1 representing over #ajjj        
horse-power1 is passed through the core 
of the furnace1 and is kept running     
through it constantly for a period of   
twenty-four to thirty-six hours4  ,let  
us consider for a moment what #ajjj     
horse-power means2 as this will give us 
some conception of the enormous energy  
expended in producing carborundum4 ,a   
horse-power is supposed to be the force 
that one horse can exert in pulling a   
load1 and this is the unit of power4    
,however1 a horse-power as arbitrarily  
fixed is about one-quarter greater than 
the average real horse-power4 ,if #ajjj 
horses were hitched up in series1 one in
 front of the other1 and each horse     
should occupy the space of twelve feet1 
say1 it would make a line of horses     
#ab1jjj feet long1 which would be       
something over two miles4 ,imagine the  
load that a string of horses two miles  
long could draw1 if all were pulling    
together1 and you will get something of 
an idea of the energy expended during   

the burning of one of these carborundum 
furnaces4  ,within a half hour after the
 current is turned on a gas begins to be
 emitted from the sides and top of the  
furnace1 and when a match is applied to 
it1 it lights and burns with a bluish   
flame during the whole process4 ,it is  
estimated that over five and one-half   
tons of this gas is thrown off during   
the burning of a single furnace4 ,this  
gas is called carbon monoxide1 and is   
caused by the carbon of the coke uniting
 with the oxygen of the sand4 ,when we  
consider the vast amount of material    
that comes away from the furnace in the 
form of gas it is easy to see why it is 
necessary to introduce sawdust or some  
equivalent material into the mixture1 in
 order to give the whole bulk porosity1 
so that the gas can readily escape4 ,we 
should also expect that after five and  
one-half tons had been taken away from  
the whole bulk that it would shrink in  
size4 ,this is found to be the case4    
,the top of the mass of material sinks  

down to a considerable extent by the end
 of the time it has been exposed to this
 intense heat4 ,gradually1 after the    
current has been turned on1 the core    
becomes heated1 first to a red1 and     
afterwards to an intense white heat4    
,this heat is communicated to the       
material surrounding the core1 producing
 various effects in the different       
strata1 owing to the fact that it is not
 possible to keep a uniform heat        
throughout the whole bulk of material4  
,some of it will be overdone and some of
 it underdone4 ,the material which lies 
immediately in contact with the core    
will be overheated1 and that1 which at  
one stage was carborundum1 has become   
disintegrated by overheating4  ,the     
silica of the compound has been driven  
off1 leaving a shell of graphitic       
substance formed from the coke4  ,after 
the current is shut off and the furnace 
has cooled down1 a cross-section through
 the whole mass becomes a very          
interesting study4 ,the core itself1    

owing to the intense heat it has been   
subjected to1 has had the impurities    
driven out of the coke1 leaving a       
substance like black lead1 that will    
make a mark like a lead-pencil1 and is  
really the same substance1 known as     
plumbago1 in one of its forms4 ,it is   
the carbon left after the impurities    
have been driven out of the coke4       
,surrounding the core for a distance of 
ten or twelve inches1 radiating in every
 direction1 beautifully colored crystals
 of carborundum are found1 so that a    
single furnace will yield over #djjj    
pounds of this material4 ,beyond this   
point the heat has not been great enough
 to cause the union between the carbon  
and silica1 which leaves a stratum of   
partly-formed carborundum2 outside of   
that the mixture is found to be         
unchanged4  ,these carborundum crystals 
are next crushed under rollers of       
enormous weight1 after which the crushed
 material is separated into various     
grades for use in making grinding-wheels

 of different degrees of fineness4 ,this
 crushed material is now mixed with     
certain kinds of clay1 to hold it       
together1 and then pressed into wheels  
of various sizes in a hydraulic press1  
and afterward carried into kilns and    
burned the same as ordinary pottery or  
porcelain4 ,these wheels vary in size   
from one to sixteen inches4 ,the        
substances used as a bond in            
manufacturing wheels are kaolin1 a kind 
of clay1 and feldspar4  ,while          
carborundum has already a large place as
 a commercial product1 there is no doubt
 but that the uses to which it will be  
put will vastly increase as time goes   
on4 ,this product may be called an      
artificial one1 and never would have    
been known had it not been for the      
intense heating effects that are        
obtained from the use of electricity4   
,it certainly never could have been     
brought into play as one of the useful  
agencies in manufacturing and the arts4 
,it is not known to exist as a natural  

product1 which at first thought would   
seem a little strange in view of the    
evidences of intense heat that at one   
time existed in the earth4 ,its absence 
in nature is explained by ,mr4          
,fitzgerald by the fact that the        
temperatures of formation and of        
decomposition lie very close together4  
,,chapter ,,xxvi4  ,,electrical         
,,products--,,bleaching-,,powder4       
,another industry that has assumed large
 proportions at ,niagara ,falls1 owing  
to the vast quantity of electricity     
produced there1 is the manufacture of a 
commercial product called               
bleaching-powder1 or chloride of lime4  
,every one knows that chloride of sodium
 is simply common salt1 so extensively  
used wherever people and animals exist4 
,simple and harmless as it is1 while it 
exists as a compound of the original    
elements1 when separated into those     
elements they are each very unpleasant  
and even dangerous substances to handle4
 ,salt is one of the most common        

substances in nature4 ,it is found in   
many parts of the world in solid beds1  
and is one of the prominent constituents
 of sea-water4  ,salt is a compound of  
chlorine and a metal called sodium4     
,sodium in its pure state has a strong  
affinity for oxygen1 so much so that    
when a lump of it is thrown into water  
it takes fire and burns violently with a
 yellow flame4 ,chlorine1 the substance 
with which it unites to form common     
salt1 is a greenish-colored gas1 the    
fumes of which are very offensive and   
very dangerous even to breathe1 if the  
quantity is very considerable4  ,it is a
 curious fact in nature that two such   
substances as chlorine and sodium1 both 
of them so difficult and dangerous to   
handle1 should unite together to form   
such a useful and harmless compound as  
common salt4 ,the important element in  
bleaching-powder is the chlorine which  
it contains4 ,it is extensively used in 
the manufacture of paper and in all     
other materials where bleaching is      

required4 ,the object of combining it   
with lime1 forming a chloride of lime1  
is simply to have a convenient method of
 holding the chlorine in a safe and     
convenient manner until it is needed for
 use4  ,the chemical works at ,niagara  
,falls manufacture bleaching-powder on a
 very large scale4 ,the part that       
electricity plays is to separate the    
chlorine from the sodium as it exists in
 common salt4 ,at the works ,i was first
 taken into a room where a large        
quantity of salt was stored4 ,a belt    
with little carrier-buckets on it picked
 up this salt and carried it into       
another room1 where it was thrown into a
 vast mixing-vat containing water4 ,the 
salt was mixed with water until a       
saturated solution was obtained4 ,in a  
large room1 covering one-half acre or   
more of ground1 were assembled a great  
number of shallow vessels1 about #d by  
#e feet square and #a foot deep4 ,these 
vessels were sealed up so that they were
 gas-tight4 ,communicating with all of  

these vessels were pipes connecting with
 the great tank containing the saturated
 solution of salt4  ,from the top or    
cover of each vessel is a pipe running  
to a main pipe that carries off the     
chlorine gas into another room as fast  
as it is formed4 ,through each one of   
these vessels a current of electricity  
passes2 the whole system consuming about
 #bjjj horse-power4 ,the electric       
current1 as it passes through the brine1
 separates the chlorine from the sodium1
 the chlorine passing in the form of gas
 up through the pipes1 before mentioned1
 into the main pipe1 where it is carried
 into another large room and discharged 
into a system of gas-tight chambers4    
,upon the floor of these chambers is    
spread a coating of unslacked lime      
ground into a fine powder4 ,the lime has
 a strong affinity for the chlorine gas 
and rapidly absorbs it1 forming chloride
 of lime4 ,when the lime is fully       
saturated with the chlorine the gas is  
turned off from that chamber1 which is  

then opened up and the chloride taken   
out for shipment4 ,a new coating of lime
 is now spread in the chamber and the   
gas is turned on and the process        
repeated4  ,there are a number of these 
chambers1 so that the operation in all  
of its phases is going on continuously4 
,the room where the chlorine gas is     
formed is thoroughly ventilated1 a      
precaution which is very necessary in   
case any one of the vats should spring a
 leak1 as they sometimes do4  ,in each  
one of these vats where the electrolytic
 process is going on there are two      
products constantly passing off2 one1 as
 before mentioned1 is chlorine gas1 and 
the other caustic soda in solution4 ,the
 solution in the vat is constantly being
 renewed by the saturated solution of   
salt from the reservoir before          
mentioned4 ,there is one stream         
continuously coming into the vat and two
 going out1 caused by the decomposing   
power of the electric current4 ,the     
solution of caustic soda is carried to  

large evaporating-pans1 where the water 
is driven out of it1 leaving the caustic
 soda in dry1 white sticks of           
crystalline formation4 ,in this process 
the electric current1 which comes from  
the power-house with an energy of #bjjj 
horse-power1 has to be transformed      
twice2 first1 to bring it to the proper 
voltage for the work of decomposition1  
and1 secondly1 to change it from an     
alternating to a direct current1 by     
which all electrolytic processes are    
carried on4  ,you will notice that the  
electrical energy expended in this      
establishment is double that used in the
 manufacture of carborundum4  ,the      
caustic soda1 which is one of the       
products from the decomposition of salt1
 is taken to another establishment1     
where1 by still another electrical      
process1 metallic sodium is             
manufactured4 ,the process here being a 
secret one1 the writer did not have the 
privilege of examining the details4     
,,chapter ,,xxvii  ,,electrical         

,,products--,,aluminum4   ,another      
comparatively new article of manufacture
 now produced in large quantities at    
,niagara ,falls is aluminum4 ,until     
within the last few years this metal was
 not used to any extent by              
manufacturers1 because of the great     
expense attending its production4 ,now1 
however1 it is produced in such         
quantities as to make it about as cheap 
as brass1 bulk for bulk4 ,aluminum is a 
very light metal1 with a color somewhat 
lighter than silver2 its specific       
gravity being about one-third that of   
iron4 ,aluminum is found in one of its  
compounds in great quantities in nature1
 especially in certain kinds of clay and
 in a state of silicate1 as in feldspar 
and its associated minerals4 ,it is     
found in great quantities in southern   
,georgia1 where it is mixed with the red
 oxide of iron that abounds in that     
region4 ,here1 it exists as alumina1    
which is an oxide of aluminum4 ,before  
it is taken to the reduction-works the  

alumina is separated from all other     
substances4 ,it is a white powder1      
tasteless1 and not easily acted upon by 
acids4  ,electricity is the chief agent 
in the production of metallic aluminum4 
,the reduction company buys this        
alumina1 which has been separated from  
the clay or ores where it is mined4 ,in 
a large room there are located a great  
number of iron vats or crucibles1 lined 
with carbon1 about two or two and       
one-half feet deep1 five or six feet    
long and four feet wide4  ,immediately  
over each vat is constructed a metal    
framework1 through which are inserted a 
large number of carbon rods about       
eighteen or twenty inches long and from 
two to two and one-half inches in       
diameter4 ,this framework is            
electrically insulated from the iron    
crucibles4 ,the framework and the       
carbons are connected with the positive 
conductor of the electric current1 and  
the vat or crucible with the negative4  
,these conductors are very large1       

something like a foot in width and an   
inch in thickness1 and made of some good
 conductor of electricity4 ,they have to
 be very large because they carry a     
current equal to #cjej horse-power4 ,the
 current is one of great volume1 but    
very low voltage2 the electromotive     
force at each vat or crucible being only
 about seven volts4 ,as the process is  
electrolytic1 and not simply a heating  
process1 the direct current must be     
used1 and therefore the current coming  
from the power-house must be transformed
 twice2 first to bring it to a proper   
voltage and secondly to change it from  
an alternating to a direct current4     
,these iron vats or crucibles are       
connected up in series1 electrically1   
and then they are filled with the       
alumina and certain other materials1    
which act either as a flux or as a means
 of increasing the conductivity of the  
mixture2 just what this substance is1 is
 probably one of the secrets of the     
process4 ,when all of the crucibles are 

filled with the mixture the current is  
turned on and is kept on continuously   
night and day seven days in the week4   
,all of the material in the different   
crucibles is heated to redness1 when the
 process of separation takes place4 ,the
 oxygen of the alumina is thrown off as 
a gas1 and other residuum floats to the 
top of the crucible and is skimmed off4 
,metallic aluminum in a melted state    
sinks to the bottom of the crucible1    
where it is dipped out from time to time
 with large iron ladles and poured into 
sand and molded into blocks similar to  
that of pig iron4 ,from time to time1 as
 the metal is dipped out1 fresh alumina 
with the other substances are thrown in 
on top of the crucible1 so that the     
process is continually going on1 day and
 night1 week in and week out4 ,the heat 
in the process of reducing alumina1 as  
we have before seen1 is not the chief   
factor2 it simply serves to reduce the  
compound to a fluid state so that the   
electrolytic action can readily take    

place4  ,therefore it is not necessary  
to be brought to a white heat1 as it is 
in the case of the production of        
carborundum1 described elsewhere4  ,it  
was extremely interesting to observe the
 wonderful magnetic effects that were   
produced in iron when brought into      
proximity with these enormous electrical
 conductors4 ,the voltage was so low    
that one could handle them with         
impunity4 ,the iron crucibles became so 
magnetic that a heavy bar of iron seven 
or eight feet long would cling to their 
sides1 so that it would be held in an   
upright position4 ,bars of iron would   
cling to the conductor at any point     
along its length1 and1 although these   
conductors were carrying an energy of   
over #cjjj horse-power1 they produced no
 perceptible effect upon the human body4
 ,the reason for this lies in the fact1 
first1 that the body is not made of     
magnetic material1 and1 secondly1 the   
pressure is so low that the body--being 
a poor conductor--would not easily allow

 the low-pressure current to pass       
through it4  ,aluminum is fast becoming 
an important article of commerce1 and it
 is destined to become more and more so 
on account of its extreme lightness as  
compared to other metals4  ,it is found 
to be valuable also when used as an     
alloy with many of the other metals4    
,one of the great drawbacks to its more 
extensive use lies in the fact that as  
yet no satisfactory method has been     
devised for soldering it4 ,undoubtedly  
in time this difficulty will be solved1 
when its use will be greatly increased4 
,it is estimated that in its various    
compounds aluminum forms about          
one-twelfth of the crust of the earth4  
,,chapter ,,xxviii4  ,,electrical       
,,products--,,calcium ,,carbide4        
,another important use to which         
electricity is put at ,niagara ,falls is
 the manufacture of a new product1      
called calcium carbide4 ,like           
carborundum and aluminum1 this product  
could not have been produced in         

commercial quantities in advance of a   
means for producing electricity in      
enormous volume4  ,calcium carbide is a 
compound of calcium and carbon4 ,calcium
 is a white metal not found in the      
natural state1 but exists chiefly as a  
carbonate of lime1 which is ordinary    
limestone1 including the various forms  
of marble4 ,as a pure metal it is hard  
to obtain and very hard to maintain1 as 
it readily oxidizes when in contact with
 the air4 ,the symbol for calcium       
carbide is ,ca,c#b1 which means that a  
molecule of this carbide is compounded  
of one atom of calcium and two atoms of 
carbon4 ,ca stands for calcium and ,c   
for carbon4 ,when the symbol has no     
figure following it1 it means that one  
atom only enters into the compound2 but 
if a figure follows1 it means that as   
many atoms enter in as the figure       
represents4  ,the process of            
manufacturing calcium carbide is as     
follows3 ,ordinary lime before it is    
slacked is ground to a fine powder2 then

 it is mixed with powdered coke or      
carbon in the proper quantities1 so that
 when a chemical union takes place the  
proportion will be as before stated1 one
 atom of calcium to two of carbon4 ,as  
is well known1 lime is procured by      
exposing ordinary limestone to a red    
heat for some hours together4 ,the heat 
disengages the carbon dioxide1 leaving  
only a combination of calcium and       
oxygen1 which is common lime4  ,the     
mixture of ground lime and coke is put  
into a crucible that surrounds the arc  
of an electric light of enormous        
dimensions2 the carbon conductors       
amounting to an area of one square foot 
or more4 ,in order to cause the carbon  
to unite with the calcium a very intense
 heat is required1 such a heat as can be
 obtained only in the arc of an electric
 light4 ,when the enormous current is   
turned on 7amounting to over #cjjj      
horse-power7 the mixture is melted1 and 
after an exposure to this intense heat  
for a given length of time the oxygen of

 the unslacked lime is thrown off and   
the carbon unites with the calcium1     
which remains in the proportions of one 
atom of calcium to two of carbon1 as    
before stated4 ,this1 it will be noted1 
is purely a heat process1 and an intense
 one at that4 ,no electrolytic action   
being required1 the alternating current 
is used without transformation to the   
direct current1 as is necessary in the  
manufacture of bleaching-powder and     
aluminum1 both of which are electrolytic
 processes4  ,when the operation is     
completed the current is turned off and 
the compound allowed to cool4 ,in       
cooling it assumes a slate color1 which 
is slightly iridescent when exposed to  
light4 ,it also crystallizes to a       
certain extent4  ,the value of this new 
product consists in its ability to      
evolve ,acetylene gas in large          
quantities4 ,a molecule of acetylene gas
 is composed of two atoms of carbon to  
two of hydrogen4 ,to evolve the gas it  
is necessary only to pour water upon the

 calcium carbide1 when a union takes    
place between the carbon of the carbide 
and the hydrogen of the water in the    
proportions above stated4 ,if there is  
water enough the whole of the carbon    
will pass off with the gas1 leaving a   
residuum of slacked lime4  ,the value of
 acetylene gas lies in its very intense 
illuminating power4 ,this is due to the 
fact that the gas is very rich in carbon
 as compared with other illuminating    
gases4 ,it burns with a pure white light
 when properly mixed with air or oxygen1
 but if there is a lack of air it burns 
with a smoky flame4 ,in this case the   
carbon is not all consumed and escapes  
into the air in the form of soot or     
smoke1 but when burned with the proper  
mixture of oxygen or common air it      
becomes one of the most brilliant of    
illuminants4 ,acetylene1 like most other
 gases1 becomes explosive when mixed    
with air in certain proportions4        
,whether it is more dangerous to handle 
than ordinary illuminating gases the    

writer is not prepared to say1 as he has
 not had the opportunity to make a      
thorough comparison between it and other
 gases from an experimental standpoint4 
,experiment1 after all1 is the only sure
 road to absolute knowledge4 ,theories  
are beautiful in books and lectures1 but
 they often fail in the laboratory4     
,acetylene is now being introduced as an
 illuminating gas for domestic and other
 purposes4 ,several methods of handling 
it have been proposed4 ,one is to       
condense it into strong metal cylinders 
and deliver it in that form2 another is 
to erect generators at convenient places
 and generate the gas as it is used4 ,a 
very ingenious contrivance has been     
invented for regulating the generation  
of the gas4 ,a certain amount of the    
calcium carbide is placed in a gas-tight
 vessel containing water4 ,as soon as   
the water comes in contact with the     
carbide the evolution of the gas begins4
 ,when the pressure on the inside of the
 vessel has reached a certain degree it 

is made1 through mechanical             
contrivances1 to lift the carbide out of
 the water and thus stop the evolution  
of the gas4 ,when the pressure is       
relieved through the consumption of the 
gas at the burners it allows the carbide
 to drop into the water1 when the       
evolution of the gas begins again4  ,of 
course there is the same objection to   
this mode of lighting that attends all  
open burners2 it is constantly          
discharging into the air the products of
 combustion1 chiefly carbon dioxide1    
which is poisonous to animal life4 ,as  
has been explained in some of the       
chapters on heat1 in ,volume ,,ii1 the  
illuminating property of any gas is     
determined by the number of carbon      
particles that are contained in it1     
which become heated to incandescence as 
soon as they come in contact with the   
oxygen of the air1 and remain so1 for a 
brief period1 during their passage      
between the two extremes of the flame4  
,while acetylene equals electricity in  

its illuminating properties1 the latter 
still stands without a rival when       
considered from a sanitary standpoint1  
as the use of electricity does not in   
any degree vitiate the air in a room    
where it is used4  ,we have now given   
somewhat in detail the following        
processes that are carried on at        
,niagara ,falls through the agency of   
electricity1 viz43 ,the reduction of    
aluminum from its oxide alumina2 the    
production of the new and useful        
compound called carborundum2 the        
formation of calcium carbide used for   
the production of acetylene gas1 and a  
large chemical works1 where             
bleaching-powder is made4 ,in addition  
to these works1 there is an             
establishment for the production of     
sodium from caustic potash1 which is one
 of the products arising from the       
decomposition of salt in the            
bleaching-powder works4 ,there is also  
another establishment for the production
 of phosphorus made from the bones and  

shells obtained from the phosphate beds 
that abound in some of the southern     
states1 on the coast of the ,atlantic   
,ocean4 ,there is in process of         
construction a plant for the purpose of 
manufacturing chlorate of potash by an  
electrical process4 ,in addition to     
these establishments mentioned1 the     
electricity is furnished for power      
purposes to the ,niagara ,electric      
,light ,company2 to the electric railway
 between ,niagara and ,buffalo2 to the  
,niagara ,falls ,railway1 on the        
opposite side of the river2 to the      
,niagara ,power and ,conduit ,company of
 ,buffalo1 and the ,niagara ,development
 ,company4 ,this is only a small        
beginning of the uses to which          
electricity will be put as an agent for 
the development of heat1 light and power
 as well as for the production of all   
substances where electrolysis is the    
chief factor4 ,sixteen companies or more
 are now using electricity from the     
,niagara power-house1--the whole        

amounting to about #ce1jjj horse-power4 
,,chapter ,,xxix4  ,,the ,,new ,,era4   
,when we consider the number of new     
products for whose existence we are     
indebted to electricity1 and the number 
of old products that have heretofore    
existed experimentally1 in the          
laboratory of the chemist only1 that    
have now been brought into play as      
useful agents in the various arts and   
industries1 we begin to realize that    
this is truly an electrical age and the 
dawning of a new era4 ,how many1 many   
things there are1 familiar to the       
children of to-day1 that were not even  
imagined by the children of twenty-five 
to fifty years ago4 ,fifty years ago the
 only useful purpose to which           
electricity was put was that of         
transmitting news from city to city by  
the ,morse telegraphic code4 ,it will be
 fifty-seven years the first of ,april1 
#aija1 since the first telegraph-line   
was thrown open to the public4 ,less    
than thirty years ago but little advance

 had been made in the use of electrical 
appliances beyond the perfection of     
certain private-line instruments1 and a 
means for multiple transmission4 ,about 
twenty years ago there were evidences of
 the beginning of a new era in          
electrical development4 ,at no time in  
the history of the world has wonder     
succeeded wonder with such rapidity1    
producing such astounding results that  
have revolutionized all our modes of    
doing business and all of the operations
 of commercial and domestic life1 as    
during the last two decades4 ,we set our
 watches by time furnished by           
electricity from one central point of   
observation4 ,we read the tape from hour
 to hour1 upon which is recorded the    
commercial pulse of the world1 as it    
throbs in the marts of trade1 by means  
of this same speedy messenger4 ,we enter
 a street-car that is lighted and       
heated1 and at the same time propelled  
by the same wonderful agent4 ,in our    
homes and on our streets night is turned

 into day by a light that outrivals all 
other illuminants4  ,when we wish to    
speak to a friend who may be a mile or a
 thousand miles away we step to the end 
of a wire that comes within the walls of
 our dwelling and we talk to him as     
though face to face1 and means are at   
hand by which we may write a letter to  
that same friend and deliver it to him  
in our own handwriting and over our own 
signatures1 so quickly that it will     
appear before him in full form and      
completeness as soon as the last period 
is made at the end of the last line4    
,one sees1 and hears1 and lives more in 
a single day in this age of electricity 
and steam than he did in twelve months  
sixty years ago4 ,and yet there are     
those who cry out against modern        
inventions and modern civilization1 and 
are constantly quoting the days of their
 grandfathers and great-grandfathers    
when life was simple and there was time 
to rest4 ,why are we tormented with this
 thought-stimulating age8 they say4 ,why

 are our emotions called into action by 
modern music and modern art8 ,why are we
 called upon to help the downtrodden and
 oppressed1 and to help to elevate      
mankind to a higher level8 ,why cannot  
we be left alone in peace and quiet1 to 
live in the easiest way8  ,if this be   
good philosophy1 then the swine1 if he  
were a reasoning being1 ought to be     
ranked among the greatest of            
philosophers--when he seeks a wallow in 
the sunshine and sleeps away his useless
 existence4 ,if he is useful it is      
because some other being of a higher    
order uses him to help along his own    
existence4 ,the man in these days who   
does not keep up with the procession is 
soon trodden under foot and some other  
man uses him as a stepping-stone to     
elevate himself4  ,yet this is a selfish
 motive1 after all4 ,the world is now   
rapidly advancing in light1 in          
knowledge1 in power to use the infinite 
gifts that the ,creator has hidden in   
nature2 but hidden only to stimulate and

 reward our seeking4 ,every man can help
 in this grand progress1--if not by     
research and positive thought-power1 at 
least by grateful acceptance and        
realization of what is gained4 ,look    
forward6 ,as ,emerson puts it3 ,to make 
habitually a new estimate--that is      
elevation4     ,,index4     ,acetylene  
gas at ,niagara1 #bcj4    ,alexandria1  
temple with loadstone1 #bj4             
,amber--elektron1 #f4    ,ampere1 theory
 of magnetism1 #be4     unit of         
electrical current1 #he4                
galvanometer1 #ic4    ,aluminum at      
,niagara1 #bbc4    ,arabians1 magnetic  
needle1 #ba4    ,arago1 germ of         
electromagnet1 #ic4    ,aristotle       
mentions torpedo1 #f4     refers to     
magnet1 #bj4    ,atmospheric            
electricity1 ,ch4 ,,viii1 #gg4    ,atoms
 and molecules1 #ci4     of substances  
differ in weight1 #db4     relations to 
heat1 #db4    ,aurora ,borealis1 #ce4   
,bain chemical telegraph register1 #aja4
    ,barlow on galvanism in telegraphy1 

#ic4    ,bell1 ,alexander ,graham1      
radiophone1 #aga4    ,bleaching-powder  
at ,niagara1 #bah4    ,branly invents   
the coherer1 #agi4     ,cables1         
submarine4 ,see ,submarine ,cables4     
,calcium-carbide at ,niagara1 #bbh4     
,capacity of a circuit1 #aah1 #aai4     
,caustic soda1 #bba4    ,chinese1       
magnetic needle1 #ba4    ,chlorine and  
sodium1 #bai4    ,circuit-breaker at    
,niagara1 #aii4    ,closed circuit and  
current1 #abb4    ,coherer 7wireless    
telegraphy71 #agi4    ,columbus1 compass
 variations1 #bb1 #cd4    ,condenser in 
resistance-coil1 #aah4     in ,morse    
relays1 #aca4    ,conductors and        
non-conductors of electricity1 #dg4     
relation to electric light1 #ej4        
different resistances1 #gd1 #hc4        
,cooke1 needle telegraph1 #ajh4         
,crookes1 ,prof41 ,x-ray1 #aba4         
,cuneus and the ,leyden jar1 #h4        
,curiosities1 ,ch4 ,,xx1 #aga4          
,daniell battery1 #he4    ,differential 
magnet1 #aae4    ,dinocares and the     

loadstone1 #bj4    ,dolbear1 ,amos ,e41 
wireless telegraphy1 #agh4    ,dupay    
discovers positive and negative         
electricity1 #h4    ,duplex telegraphy1 
#aad4    ,dynamo-electric machines1 #fg4
     invented by ,faraday1 #ad1 #fi4    
usual construction1 #gj4     at         
,niagara1 #aib4    ,double transmission1
 #aae4     ,earth electric currents1 in 
telegraphy1 #ii1 #aaf1 #ahb4    ,earth  
magnetism1 #cb4     effects of1 on iron1
 #ce4             ,aurora1 #ce4         
telegraph-lines1 #cf4     from sun's    
heat1 #ge4    ,edison1 ,thomas1 railway 
telegraphy1 #aca4     electromotograph1 
#age4    ,electric currents1 ,ch4 ,,vi1 
#di4     not currents but atomic motion1
 #ed4     induction of1 #ef4            
guarded against1 #afi4     at ,niagara1 
#aic4    ,electric generators1 ,ch4     
,,vii1 #fb4     frictional1 #di4        
galvanic batteries1 #fb4                
storage-batteries1 #fd4     dynamos1    
#fg1 #aib4     metal heating1 #gd4      
,electricity1 science of1 #f4           

achievements of1 #af4     eras in       
science of1 #ah4     theory of1 ,ch4 ,v1
 #ci4     not a fluid1 a form of energy1
 #dj4     static and dynamic1 #df4      
measurement of1 ,ch4 ,,ix1 #hc4         
,electric light1 cause of1 #ej4         
,electric machines1 #di4     frictional1
 #ea4     galvanic or chemical1 #ea4    
mechanical1 #gj4    ,electromagnet      
invented by ,faraday1 #ad4              
commercial value1 #bc4     theory of    
7soft iron71 #bf4     permanent 7steel71
 #bh4     condition of use1 #cj4     the
 earth a1 #cb4     germ of1 #ic4        
differential1 #aae4                     
,electromotograph1 #age4    ,ellsworth1 
,miss1 sends first telegraphic message1 
#if4    ,ether1 lines of force1 #ca4    
nature of1 #dj4    ,ether1 impressed by 
atomic motion1 #ef4     inducing        
electric action1 #ef4     ,farad1 unit  
of capacity1 #aah4    ,faraday1         
,michael1 #ad4    ,farmer1 ,moses ,g41  
double transmission1 #aad4    ,field1   
,cyrus ,w41 lays first ,atlantic cable1 

#aef4    ,field of a magnet1 #ca4       
,fitzgerald1 ,niagara ,falls chemist1   
#baj4    ,franklin catches the          
lightning1 #h4     identity of lightning
 and electricity1 #aj4     kite         
experiment1 #aa4     electric           
firing-telegraph1 #hh4    ,frode1       
history of ,iceland1 #ba4               
,gadenhalen uses magnetic needle #hfh   
,a4,d41 #ba4    ,galileo's seed-thought1
 #hi4    ,galvani1 ,luigi1 and          
galvanism1 #ab4    ,galvanic batteries1 
#fb4     author's experience1 #fe4      
,galvanometer1 #ge1 #ic4    ,gilbert1   
,dr41 frictional electricity1 #g4       
,gintl1 double transmission1 #aad4      
,gray1 ,elisha1 constructs voltaic pile1
 #fe4     electrically transmits music1 
#ia4     experiments on transmission of 
music1 articulate speech1               
and multiple messages1 #abc4     files  
telephone caveat1 #ace4     musical     
experiments1 #acf4     speech receivers1
 #aci4     boys' telephone1 #ada4       
first telephone specification on record1

 #adc4     dial-telegraph1 #afa4        
automatic-printing telegraph1 #afc4     
telautograph1 #afe4     electric musical
 receiver1 #age4    ,gray1 ,stephen1    
electrician1 #h4    ,grier1 ,john ,a41  
quoted1 #fg4    ,guyot of ,provence     
mentions mariner's compass1 #ba4        
,halske1 double transmission1 #aad4     
,harmonic telegraphy1 #abj4             
receivers1 #abe4     relay1 #acj4       
,hawksbee1 ,francis1 electrician1 #g4   
,heat1 a mode of motion1 #dj4           
related to atoms1 #db4     begins and   
ends in matter1 #dd4     electrical and 
mechanical energy the same1 #df4        
,henry1 ,joseph1 first practical        
telegrapher1 #ij4     constructs        
long-distance line1 #id4     produces   
induction1 #agg4    ,heraclea and the   
loadstone1 #bj4    ,hertz experiments in
 ether-waves1 #agh4    ,homer refers to 
loadstone1 #bj4    ,horse-power1 #bad4  
,house1 ,royal ,e41 printing telegraph1 
#ajh1 #aaj4    ,hughes1 ,david ,e41     
printing telegraph1 #ajh1 #aab4         

,induction1 #ef4     guarded against1   
#afi4     produced by ,henry1 #agg4     
,keeper of a magnet1 #ca4    ,kelvin1   
,lord 7,sir ,w4 ,thompson71 cable       
message receiver1 #aeh4    ,kick1 in    
telegraphy1 #aae1 #aah4    ,kleist and  
the ,leyden jar1 #h4     ,let her buzz1 
#c4    ,leyden jar invented1 #h4        
,lightning1 electricity2 ,franklin1 #h4 
restoration of equilibrium1 #gh4        
,lightning-rods1 #hj4     dangerous     
conductors1 #ha4    ,loadstone1 #bj1    
#ba4     ,maury1 ,lieut41 deep-sea      
soundings1 #aee4    ,magnes1 ,magnesia1 
#bj4    ,magnet1 electro4 ,see          
,electromagnet4    ,magnetic earth      
poles1 #bc1 #cb4    ,magnetic lines of  
force1 #ca1 #cd1 #fj4    ,magnetic      
needle1 #ba4     variation of1 #bb4     
dip of1 #bb4     action of1 #cc4        
,magnetism1 history of1 #bj4     and    
electricity mutually dependent1 #bd4    
theories of1 #bd4     in iron and steel1
 #be4     in the earth1 #cb1 #cf4       
and sun-spots1 #cg4    ,magnetization1  

limit of1 #ca4    ,marconi1 wireless    
telegraphy1 #agh-ahj4    ,measurement of
 electricity1 #hc4     ampere1 unit of1 
#he4     method of1 #hf4    ,mercury    
luminous by shaking1 #g4                
,micro-farad1 unit of capacity1 #aai4   
,molecules of iron and steel natural    
magnets1 #be4     and atoms1 #ci4       
,morse1 ,s4 ,f4 ,b41 devises code of    
telegraphic signals1 #ie4     induces   
,congress to construct line1 #if4       
transmits battery current through water1
 #agg4    ,motion universal1 #ch4       
causes sound1 heat1 light1 and          
electricity1 #ci4    ,multiple          
transmission1 ,ch4 ,,xiii1 #aad4        
duplex1 #aaf4     quadruplex1 #aah4     
,multiple transmission1 musical1 #abj4  
,musical message receivers1 #abe1 #aci4 
,musical tones transmitted1 #ia1 #ib1   
#abj1 #acf4    ,muschenbroeck1 ,prof41  
and the ,leyden jar1 #h4    ,newton1    
,sir ,isaac1 electrician1 #h4           
,niagara ,falls ,power1 ,chs4 ,,xxii to 
,,xxviii1 #ahf to #bcc4                 

,introduction--rock1 water1 power1 #ahf4
     ,appliances3       tunnel1         
power-house1 #aij4       shaft1 dynamos1
 #aib4       current1 #aic4             
governor1 #aid4       water-head1 #aie4 
crane1 #aif4       circuit-breaker1     
#aii4       transformer1 #bjj4          
electromotive force1 #bjd4              
,electrical ,products--,carborundum1    
#bji4       materials1 #baj4            
furnaces1 #baa4       electric current1 
#bac4       horse-power1 #bad4          
method of work1 #bae4                   
,bleaching-powder1 #bah4       chlorine 
and sodium1 #bai4       method of work1 
#bbj4       caustic soda1 #bba4         
,aluminum1 #bbc4       crucibles and    
methods1 #bbd4       magnetic effects1  
#bbf4     ,calcium carbide1 #bbh4       
process1 #bbi4       acetylene gas1     
#bcj4     ,other products1 #bcb4        
,oersted1 galvanic current on magnetic  
needle1 #ic4    ,ohm1 ,g4 ,s41          
resistance unit1 #gd4                   
,patents--,caveat and application1 #ace4

    ,plante1 storage-battery plates1    
#fd4    ,pliny mentions electrical      
properties of amber1 #fg4     loadstone1
 #bj4    ,preece1 double transmission1  
#aad4    ,prescott1 ,geo4 ,b41 quoted1  
#ajd1 #ajf1 #afc1 #agd4    ,ptolemy     
,philadelphus and loadstones1 #bj4      
,pythagoras refers to natural magnets1  
#bj4     ,radiophone1 #aga4    ,railway 
train telegraphy1 #aca4    ,richman1    
,prof41 killed1 #ab4    ,reiss1 metallic
 telephone transmitters1 #abb4          
,resistance1 unit of1 #gd4     -coil1   
#aah4     ,siemens1 double transmission1
 #aad4    ,selenium in radiophone1 #agb4
    ,shephard1 ,charles ,s41            
induction-coil1 #abb4    ,stager1 ,gen4 
,anson1 telegrapher1 #aaj4    ,stearns1 
,joseph ,b41 cures the kick in double   
transmission1 #aae4    ,storage-battery1
 #bd4    ,strada1 loadstone telegraph1  
#hh4    ,submarine cables1 ,ch4 ,,xvii1 
#aed4     first lines1 #aed-e4          
,maury's deep-sea soundings1 #aee4      
first ,atlantic1 #aef4     retardations1

 #aeg4     receiver1 #aeh4    ,sun-spots
 and magnetic storms1 #cg4              
,telautograph1 ,ch4 ,,xix1 #afe4        
,telegraph3     heliostat1 #fh4         
semaphore1 #fh4     loadstone1 #hh4     
,franklin's electric firing1 #hh4       
electrically dropped balls1 #hh4        
electric transmission of musical tones1 
#ia4       of signals1 #id4     ,morse  
register1 #ie4     first line1 #ig4     
description1 #ih4     reading by various
 senses1 #ajj4     ,bain1 chemical      
recorder1 #aja4     ,cooke needle1 #ajh4
     ,wheatstone needle1 #ajh4          
,house printing1 #ajh1 #aaj4     ,hughes
 printing1 #ajh1 #aab4     automatic    
systems1 #aji1 #aab4     multiple       
transmission1 #aad4     musical         
transmission1 #abj4     musical         
receivers1 #abe4     ,way duplex1 #abi4 
from moving railway trains1 #aca4       
repeater1 #aej4     short-line dials1   
#aei4     printing1 #afc4     wireless1 
,ch4 ,,xxi1 #agf4    ,telegraphic       
messages1 receiving1 #ajc4              

,telephone1 ,chs4 ,,xv1 ,,xvi1 #acd1    
#ade4     author's first experiment1    
#ia4     experiments1 #abc4     caveat1 
#ace4     speech receivers1 #aci4       
boys' telephone1 #ada4     first        
specification of1 on record1 #adc4      
how telephone talks1 #ade4     simple   
construction1 #adf4     two methods of  
transmission3 magneto and varied        
resistance1 #adb1 #adi4     limit of    
transmission1 #aec4     central station1
 #afd4     affected by heat-lightning1  
#ahc4    ,telephote1 #agc4    ,thales of
 ,miletus first described electrical    
properties of amber1 #f4                
,theophrastus mentions amber1 #f4       
,thermo-electric pile1 #ge4    ,torpedo1
 the1 #f4    ,transformers at ,niagara1 
#bjj4    ,transmission1 multiple1 ,ch4  
,,xiii1 #aad4    ,trowbridge1 ,prof41   
telephones through the earth1 #ahh4     
,tunnel at ,niagara1 #aij4    ,tyndall1 
and ,gray's experiments1 #ib4           
,unrest of the universe1 #ch4     ,volt1
 unit of electrical pressure1 #he4      

,volta1 ,alessandro1 and the voltaic    
pile1 #ac4     ,watt1 ,james1 #hf4      
unit of electrical power1 #hf4    ,way  
duplex system1 ,ch4 ,,xiv1 #abi4        
,wheatstone transmits musical tones     
mechanically1 #ib4     needle telegraph1
 #ajh4     dial-telegraph1 #aei4        
,wireless telegraphy1 ,ch4 ,,xxi1 #agf4 
signaling by ether-waves1 #agf4         
,morse and ,henry1 #agg4                
,trowbridge1 ,dolbear1 ,hertz1 #agh4    
,branly1 ,marconi1 #agi4     ,marconi's 
system1 #ahj4     by earth-currents1    
#ahb4    ,wolimer1 ,king of ,goths1 a   
natural battery1 #g4