,,contributions ,,from   ,,the ,,museum 
,,of ,,history ,,and ,,technology3      
,,paper #ai     ,,elevator ,,systems    
,,of ,,the ,,eiffel ,,tower1 #ahhi      
,robert ,m4 ,vogel     ,,preparatory    
,,work ,,for ,,the ,,tower              
#d    ,,the ,,tower',s ,,structural     
,,rationale           #e    ,,elevator  
,,development ,,before ,,the ,,tower    
#f    ,,the ,,tower',s ,,elevators      
#bj    ,,epilogue                       
#cg     ,,elevator ,,systems of the     
,,eiffel ,,tower1 #ahhi  ,by ,robert ,m4
 ,vogel       ,this article traces the  
evolution of the powered passenger      
elevator      from its initial          
development in the mid-#aith century to 
the      installation of the three      
separate elevator systems in the ,eiffel
      ,tower in #ahhi4 ,the design of   
the ,tower's elevators involved problems
      of capacity1 length of rise1 and  
safety far greater than any             
previously encountered in the field2 and
 the equipment that resulted      was   

the first capable of meeting the        
conditions of vertical                  
transportation found in the just        
emerging skyscraper4       ,,the        
,,author3 ,robert ,m4 ,vogel is         
associate curator of mechanical and     
civil engineering1 ,united ,states      
,national ,museum1 ,smithsonian         
,institution4   ,the #a1jjj-;foot tower 
that formed the focal point and central 
feature of the ,universal ,exposition of
 #ahhi at ,paris has become one of the  
best known of man's works4 ,it was among
 the most outstanding technological     
achievements of an age which was itself 
remarkable for such achievements4       
,second to the interest shown in the    
tower's structural aspects was the      
interest in its mechanical organs4 ,of  
these1 the most exceptional were the    
three separate elevator systems by which
 the upper levels were made accessible  
to the ,exposition visitors4 ,the design
 of these systems involved problems far 
greater than had been encountered in    

previous elevator work anywhere in the  
world4 ,the basis of these difficulties 
was the amplification of the two        
conditions that were the normal         
determinants in elevator                
design--passenger capacity and height of
 rise4 ,in addition1 there was the      
problem1 totally new1 of fitting        
elevator shafts to the curvature of the 
,tower's legs4 ,the study of the various
 solutions to these problems presents a 
concise view of the capabilities of the 
elevator art just prior to the beginning
 of the most recent phase of its        
development1 marked by the entry of     
electricity into the field4  ,the great 
confidence of the ,tower's builder in   
his own engineering ability can be fully
 appreciated1 however1 only when notice 
is taken of one exceptional way in which
 the project differed from works of     
earlier periods as well as from         
contemporary ones4 ,in almost every     
case1 these other works had evolved1 in 
a natural and progressive way1 from a   

fundamental concept firmly based upon   
precedent4 ,this was true of such       
notable structures of the time as the   
,brooklyn ,bridge and1 to a lesser      
extent1 the ,forth ,bridge4 ,for the    
design of his tower1 there was virtually
 no experience in structural history    
from which ,eiffel could draw other than
 a series of high piers that his own    
firm had designed earlier for railway   
bridges4 ,it was these designs that led 
,eiffel to consider the practicality of 
iron structures of extreme height4      
,illustration3 ,figure #a4--,the ,eiffel
 ,tower at the time of the ,universal   
,exposition of #ahhi at ,paris4 7,from  
,la ,nature1 ,june #bi1 #ahhi1 vol4 #ag1
 p4 #gc47  ,illustration3 ,figure       
#b4--;,gustave ,eiffel 7#ahcb-aibc74    
7,from ,gustave ,eiffel1 ,la ,tour de   
,trois ,cents ,mtres1 ,paris1 #aijj1    
frontispiece47   ,there was1 it is true1
 some inspiration to be found in the    
paper projects of several earlier       
designers--themselves inspired by that  

compulsion which throughout history     
seems to have driven men to attempt the 
erection of magnificently high          
structures4  ,one such inspiration was a
 proposal made in #ahcb by the          
celebrated but eccentric ,welsh engineer
 ,richard ,trevithick to erect a        
#a1jjj-;foot1 conical1 cast-iron tower  
7fig4 #c7 to celebrate the passing of   
the ,reform ,bill4 ,of particular       
interest in light of the present        
discussion was ,trevithick's plan to    
raise visitors to the summit on a       
piston1 driven upward within the        
structure's hollow central tube by      
compressed air4 ,it probably is         
fortunate for ,trevithick's reputation  
that his plan died shortly after this   
and the project was forgotten4  ,one    
project of genuine promise was a tower  
proposed by the eminent ,american       
engineering firm of ,clarke1 ,reeves    
,company to be erected at the           
,centennial ,exhibition at ,philadelphia
 in #ahgf4 ,at the time1 this firm was  

perhaps the leading designer and erector
 of iron structures in the ,united      
,states1 having executed such works as  
the ,girard ,avenue ,bridge over the    
,schuylkill at ,fairmount ,park1 and    
most of ,new ,york's early elevated     
railway system4 ,the company's proposal 
7fig4 #d7 for a #a1jjj-;foot shaft of   
wrought-iron columns braced by a        
continuous web of diagonals was based   
upon sound theoretical knowledge and    
practical experience4 ,nevertheless1 the
 natural hesitation that the fair's     
sponsors apparently felt in the face of 
so heroic a scheme could not be         
overcome1 and this project also remained
 a vision4     ,preparatory ,work for   
the ,tower   ,in the year #ahhe1 the    
,eiffel firm1 which also had an         
extensive background of experience in   
structural engineering1 undertook a     
series of investigations of tall        
metallic piers based upon its recent    
experiences with several lofty railway  
viaducts and bridges4 ,the most         

spectacular of these was the famous     
,garabit ,viaduct 7#ahhj-ahhd71 which   
carries a railroad some #djj feet above 
the valley of the ,truyere in southern  
,france4 ,while the #bjj-;foot height of
 the viaduct's two greatest piers was   
not startling even at that period1 the  
studies proved that piers of far greater
 height were entirely feasible in iron  
construction4 ,this led to the design of
 a #cie-;foot pier1 which1 although     
never incorporated into a bridge1 may be
 said to have been the direct basis for 
the ,eiffel ,tower4  ,preliminary       
studies for a #cjj-meter tower were made
 with the #ahhi fair immediately in     
mind4 ,with an assurance born of        
positive knowledge1 ,eiffel in ,june of 
#ahhf approached the ,exposition        
commissioners with the project4 ,there  
can be no doubt that only the singular  
respect with which ,eiffel was regarded 
not only by his profession but by the   
entire nation motivated the ,commission 
to approve a plan which1 in the hands of

 a figure of less stature1 would have   
been considered grossly impractical4    
,between this time and commencement of  
the ,tower's construction at the end of 
,january #ahhg1 there arose one of the  
most persistently annoying of the       
numerous difficulties1 both structural  
and social1 which confronted ,eiffel as 
the project advanced4 ,in the wake of   
the initial enthusiasm--on the part of  
the fair's ,commission inspired by the  
desire to create a monument to ,french  
technological achievement1 and on the   
part of the majority of ,frenchmen by   
the stirring of their imagination at the
 magnitude of the structure--there grew 
a rising movement of disfavor4 ,the     
nucleus was1 not surprisingly1 formed   
mainly of the intelligentsia1 but       
objections were made by prominent       
,frenchmen in all walks of life4 ,the   
most interesting point to be noted in a 
retrospection of this often violent     
opposition was that1 although the       
,tower's every aspect was attacked1     

there was remarkably little criticism of
 its structural feasibility1 either by  
the engineering profession or1 as seems 
traditionally to be the case with bold  
and unprecedented undertakings1 by large
 numbers of the technically uninformed  
laity4 ,true1 there was an undercurrent 
of what might be characterized as unease
 by many property owners in the         
structure's shadow1 but the most        
obstinate element of resistance was that
 which deplored the ,tower as a         
mechanistic intrusion upon the          
architectural and natural beauties of   
,paris4 ,this resistance voiced its fury
 in a flood of special newspaper        
editions1 petitions1 and manifestos     
signed by such lights of the fine and   
literary arts as ,de ,maupassant1       
,gounod1 ,dumas fils1 and others4 ,the  
eloquence of one article1 which appeared
 in several ,paris papers in ,february  
#ahhg1 was typical3       ,we protest in
 the name of ,french taste and the      
national art culture      against the   

erection of a staggering ,tower1 like a 
gigantic kitchen      chimney dominating
 ,paris1 eclipsing by its barbarous mass
 ,notre ,dame1      the                 
,sainte-,chapelle1 the tower of ,st4    
,jacques1 the ,dme des      ,invalides1 
the ,arc de ,triomphe1 humiliating these
 monuments by an act      of madness4#a 
,further1 a prediction was made that the
 entire city would become dishonored by 
the odious shadow of the odious column  
of bolted sheet iron4  ,it is impossible
 to determine what influence these      
outcries might have had on the project  
had they been organized sooner4 ,but    
inasmuch as the ,commission had1 in     
,november #ahhf1 provided #a1ejj1jjj    
francs for its commencement1 the work   
had been fairly launched by the time the
 protestations became loud enough to    
threaten and they were ineffectual4     
,upon completion1 many of the most      
vigorous protestants became as vigorous 
in their praise of the ,tower1 but a    
hard core of critics continued for      

several years to circulate petitions    
advocating its demolition by the        
government4 ,one of these critics1 it   
was said--probably apocryphally--took an
 office on the first platform1 that     
being the only place in ,paris from     
which the ,tower could not be seen4     
,illustration3 ,figure                  
#c4--,trevithick's proposed cast-iron   
tower 7#ahcb7 would have been #a1jjj    
feet high1 #ajj feet in diameter at the 
base1 #ab feet at the top1 and          
surmounted by a colossal statue4 7,from 
,f4 ,dye1 ,popular ,engineering1        
,london1 #ahie1 p4 #bje47     ,the      
,tower's ,structural ,rationale         
,during the previously mentioned studies
 of high piers undertaken by the ,eiffel
 firm1 it was established that as the   
base width of these piers increased in  
proportion to their height1 the diagonal
 bracing connecting the vertical        
members1 necessary for rigidity1 became 
so long as to be subject to high        
flexural stresses from wind and columnar

 loading4 ,to resist these stresses1 the
 bracing required extremely large       
sections which greatly increased the    
surface of the structure exposed to the 
wind1 and was1 moreover1 decidedly      
uneconomical4 ,to overcome this         
difficulty1 the principle which became  
the basic design concept of the ,tower  
was developed4  ,the material which     
would otherwise have been used for the  
continuous lattice of diagonal bracing  
was concentrated in the four corner     
columns of the ,tower1 and these        
verticals were connected only at two    
widely separated points by the deep     
bands of trussing which formed the first
 and second platforms4 ,a slight        
curvature inward was given to the main  
piers to further widen the base and     
increase the stability of the structure4
 ,at a point slightly above the second  
platform1 the four members converged to 
the extent that conventional bracing    
became more economical1 and they were   
joined4   ,illustration3 ,figure        

#d4--,the proposed #a1jjj-;foot iron    
tower designed by ,clarke1 ,reeves  ,co4
 for the ,centennial ,exhibition of     
#ahgf at ,philadelphia4 7,from          
,scientific ,american1 ,jan4 #bd1 #ahgd1
 vol4 #cj1 p4 #dg47   ,that this theory 
was successful not only practically1 but
 visually1 is evident from the resulting
 work4 ,the curve of the legs and the   
openings beneath the two lower platforms
 are primarily responsible for the      
,tower's graceful beauty as well as for 
its structural soundness4  ,the design  
of the ,tower was not actually the work 
of ,eiffel himself but of two of his    
chief engineers1 ,emile ,nouguier       
7#ahdj-87 and ,maurice ,koechlin        
7#ahef-aidf7--the men who had conducted 
the high pier studies--and the architect
 ,stphen ,sauvestre 7#ahdg-874  ,in the 
planning of the foundations1 extreme    
care was used to ensure adequate        
footing1 but in spite of the ,tower's   
light weight in proportion to its bulk1 
and the low earth pressure it exerted1  

uneven pier settlement with resultant   
leaning of the ,tower was considered a  
dangerous possibility4#b ,to compensate 
for this eventuality1 a device was used 
whose ingenious directness justifies a  
brief description4 ,in the base of each 
of the #af columns forming the four main
 legs was incorporated an opening into  
which an #hjj-ton hydraulic press could 
be placed1 capable of raising the member
 slightly4 ,a thin steel shim could then
 be inserted to make the necessary      
correction 7fig4 #e74 ,the system was   
used only during construction to        
overcome minor erection discrepancies4  
,in order to appreciate fully the       
problem which confronted the ,tower's   
designers and sponsors when they turned 
to the problem of making its observation
 areas accessible to the fair's         
visitors1 it is first necessary to      
investigate briefly the contemporary    
state of elevator art4     ,elevator    
,development before the ,tower   ,while 
power-driven hoists and elevators in    

many forms had been used since the early
 years of the #aith century1 the        
ever-present possibility of breakage of 
the hoisting rope restricted their use  
almost entirely to the handling of goods
 in mills and warehouses4#c ,not until  
the invention of a device which would   
positively prevent this was there much  
basis for work on other elements of the 
system4 ,the first workable mechanism to
 prevent the car from dropping to the   
bottom of the hoistway in event of rope 
failure was the product of ,elisha ,g4  
,otis 7#ahaa-ahfa71 a mechanic of       
,yonkers1 ,new ,york4 ,the invention was
 made more or less as a matter of course
 along with the other machinery for a   
new mattress factory of which ,otis was 
master mechanic4   ,illustration3       
,figure #e4--;,correcting erection      
discrepancies by raising pier           
member--with hydraulic press and hand   
pump--and inserting shims4 7,from ,la   
,nature1 ,feb4 #ah1 #ahhh1 vol4 #af1 p4 
#ahd47  ,illustration3 ,figure #f4--,the

 promenade beneath the ,eiffel ,tower1  
#ahhi4 7,from ,la ,nature1 ,nov4 #cj1   
#ahhi1 vol4 #ag1 p4 #dbe47              
,illustration3 ,figure #g4--,teagle     
elevator in an ,english mill about      
#ahde4 ,power was taken from the line   
shafting4 7,from ,pictorial ,gallery of 
,arts1 ,volume of ,useful ,arts1        
,london1 n4d4 ca4 #ahde47   ,the        
importance of this invention soon became
 evident to ,otis1 and he introduced his
 device to the public three years later 
during the second season of the ,new    
,york ,crystal ,palace ,exhibition1 in  
#ahed4 ,here he would demonstrate       
dramatically the perfect safety of his  
elevator by cutting the hoisting rope of
 a suspended platform on which he       
himself stood1 uttering the immortal    
words which have come to be inseparably 
associated with the history of the      
elevator--,all safe1 gentlemen6#d  ,the 
invention achieved popularity slowly1   
but did find increasing favor in        
manufactories throughout the eastern    

,united ,states4 ,the significance of   
,otis' early work in this field lay     
strictly in the safety features of his  
elevators rather than in the hoisting   
equipment4 ,his earliest systems were   
operated by machinery similar to that of
 the teagle elevator in which the       
hoisting drum was driven from the mill  
shafting by simple fast and loose       
pulleys with crossed and straight belts 
to raise1 lower1 and stop4 ,this scheme1
 already common at the time1 was itself 
a direct improvement on the ancient     
hand-powered drum hoist4  ,the first    
complete elevator machine in the ,united
 ,states1 constructed in #ahee1 was a   
complex and inefficient contrivance     
built around an oscillating-cylinder    
steam engine4 ,the advantages of an     
elevator system independent of the mill 
drive quickly became apparent1 and by   
#ahfj improved steam elevator machines  
were being produced in some quantity1   
but almost exclusively for freight      
service4 ,it is not clear when the first

 elevator was installed explicitly for  
passenger service1 but it was probably  
in #aheg1 when ,otis placed one in a    
store on ,broadway at ,broome ,street in
 ,new ,york4  ,in the decade following  
the ,civil ,war1 tall buildings had just
 begun to emerge2 and1 although the     
skylines of the world's great cities    
were still dominated by church spires1  
there was increasing activity in the    
development of elevator apparatus       
adapted to the transportation of people 
as well as of merchandise4 ,operators of
 hotels and stores gradually became     
aware of the commercial advantages to be
 gained by elevating their patrons even 
one or two floors above the ground1 by  
machinery4 ,the steam engine formed the 
foundation of the early elevator        
industry1 but as building heights       
increased it was gradually replaced by  
hydraulic1 and ultimately by electrical1
 systems4   ,,the ,,steam ,,elevator    
,the progression from an elevator       
machine powered by the line shafting of 

a mill to one in which the power source 
was independent would appear a simple   
and direct one4 ,nevertheless1 it was   
about #dj years after the introduction  
of the powered elevator before it became
 common to couple elevator machines     
directly to separate engines4 ,the      
multiple belt and pulley transmission   
system was at first retained1 but it    
soon became evident that a more         
satisfactory service resulted from      
stopping and reversing the engine       
itself1 using a single fixed belt to    
connect the engine and winding          
mechanism4 ,interestingly1 the same     
pattern was followed #dj years later    
when the first attempts were made to    
apply the electric motor to elevator    
drive4   ,illustration3 ,figure         
#h4--;,in the typical steam elevator    
machine two vertical cylinders were     
situated either above or below the      
crankshaft1 and a small pulley was keyed
 to the crankshaft4 ,in a light-duty    
machine1 the power was transmitted by   

flatbelt from the small pulley to a     
larger one mounted directly on the drum4
 ,in heavy-duty machines1 spur gearing  
was interposed between the large        
secondary pulley and the winding drum4  
7,photo courtesy of ,otis ,elevator     
,company47  ,illustration3 ,figure      
#i4--,several manufacturers built steam 
machines in which a gear on the drum    
shaft meshed directly with a worm on the
 crankshaft4 ,this arrangement          
eliminated the belt1 and1 since the drum
 could not drive the engine through the 
worm gearing1 no brake was necessary for
 holding the load4 7,courtesy of ,otis  
,elevator ,company47   ,by #ahgj the    
steam elevator machine had attained its 
ultimate form1 which1 except for a      
number of minor refinements1 was to     
remain unchanged until the type became  
completely obsolete toward the end of   
the century4  ,by the last quarter of   
the century1 a continuous series of     
improvements in the valving1 control    
systems1 and safety features of the     

steam machine had made possible an      
elevator able to compete with the       
subsequently appearing hydraulic systems
 for freight and low-rise passenger     
service insofar as smoothness1 control1 
and lifting power were concerned4       
,however1 steam machinery began to fail 
in this competition as the increasing   
height of buildings rapidly extended the
 demands of speed and length of rise4   
,the limitation in rise constituted the 
most serious shortcoming of the steam   
elevator 7figs4 #h-aj71 an inherent     
defect that did not exist in the various
 hydraulic systems4   ,illustration3    
,figure #aj4--;,components of the steam 
passenger elevator at the time of its   
peak development and use 7#ahgf74 7,from
 ,the ,first ,one ,hundred ,years1 ,otis
 ,elevator ,company1 #aiec47   ,since   
the only practical way in which the     
power of a steam engine could be applied
 to the haulage of elevator cables was  
through a rotational system1 the cables 
invariably were wound on a drum4 ,the   

travel or rise of the car was therefore 
limited by the cable capacity of the    
winding drum4 ,as building heights      
increased1 drums became necessarily     
longer and larger until they grew so    
cumbersome as to impose a serious       
limitation upon further upward growth4  
,a drum machine rarely could be used for
 a lift of more than #aej feet4#e       
,another organic difficulty existing in 
drum machines was the dangerous         
possibility of the car--or the          
counterweight1 whose cables often wound 
on the drum--being drawn past the normal
 top limit and into the upper supporting
 works4 ,only safety stops could prevent
 such an occurrence if the operator     
failed to stop the car at the top or    
bottom of the shaft1 and even these were
 not always effective4 ,hydraulic       
machines were not susceptible to this   
danger1 the piston or plunger being     
arrested by the ends of the cylinder at 
the extremes of travel4   ,,the         
,,hydraulic ,,elevator  ,the rope-geared

 hydraulic elevator1 which was          
eventually to become known as the       
standard of the industry1 is generally  
thought to have evolved directly from an
 invention of the ,english engineer ,sir
 ,william ,armstrong 7#ahaj-aijj7 of    
ordnance fame4 ,in #ahdf he developed a 
water-powered crane1 utilizing the      
hydraulic head available from a         
reservoir on a hill #bjj feet above4    
,the system was not basically different 
from the simple hydraulic press so well 
known at the time4 ,water1 admitted to a
 horizontal cylinder1 displaced a piston
 and rod to which a sheave was attached4
 ,around the sheave passed a loop of    
chain1 one end of which was fixed1 the  
other running over guide sheaves and    
terminating at the crane arm with a     
lifting hook4 ,as the piston was pressed
 into the cylinder1 the free end of the 
chain was drawn up at triple the piston 
speed1 raising the load4 ,the effect was
 simply that of a #c-to-#a tackle1 with 
the effort and load elements reversed4  

,simple valves controlled admission and 
exhaust of the water4 7,see fig4 #aa47  
,illustration3 ,figure                  
#aa4--;,armstrong's hydraulic crane4    
,the main cylinder was inclined1        
permitting gravity to assist in         
overhauling the hook4 ,the small        
cylinder rotated the crane4 7,from ,john
 ,h4 ,jallings1 ,elevators1 ,chicago1   
#aiaf1 p4 #hb47   ,the success of this  
system initiated a sizable industry in  
,england1 and the hydraulic crane1 with 
many modifications1 was in common use   
there for many years4 ,such cranes were 
introduced in the ,united ,states in    
about #ahfg but never became popular2   
they did1 however1 have a profound      
influence on the elevator art1 forming  
the basis of the third generic type to  
achieve widespread use in this country4 
,the ease of translation from the       
,armstrong crane to an elevator system  
could hardly have been more evident1    
only two alterations of consequence     
being necessary in the passage4 ,a      

guided platform or car was substituted  
for the hook2 and the control valves    
were connected to a stationary endless  
rope that was accessible to an operator 
on the car4  ,the rope-geared hydraulic 
system 7fig4 #ac7 appeared in mature    
form in about #ahgf4 ,however1 before it
 had become the standard elevator       
through a process of refinement1 another
 system was introduced which merits     
notice if for no other reason than that 
its popularity for some years seems     
remarkable in view of its preposterously
 unsafe design4 ,patented by ,cyrus ,w4 
,baldwin of ,boston in ,january #ahgj1  
this system was termed the              
,hydro-,atmospheric ,elevator1 but more 
commonly known as the water-balance     
elevator 7fig4 #ab74 ,it employed water 
not under pressure but simply as mass   
under the influence of gravity4 ,the    
elevator car's supporting cables ran    
over sheaves at the top of the shaft to 
a large iron bucket1 which traveled in a
 closed tube or well adjacent to and the

 same length as the shaft4 ,to raise the
 car1 the operator caused a valve to    
open1 filling the bucket with water from
 a roof tank4 ,when the weight of water 
was sufficient to overbalance the loaded
 car1 the bucket descended1 raising the 
car4 ,on its ascent the car was stopped 
at intermediate floors by a strong brake
 that gripped the guides4 ,upon reaching
 the top1 the operator was able to open 
a valve in the bucket1 now at the bottom
 of its travel1 and discharge its       
contents into a basement tank1 to be    
pumped back to the roof4 ,no longer     
counterbalanced1 the car could descend1 
its speed controlled solely by the      
brake4  ,the great popularity of this   
novel system apparently was due to its  
smooth operation1 high speed1           
simplicity1 and economy of operation4   
,managed by a skillful operator1 it was 
capable of speeds far greater than other
 systems could then achieve--up to a    
frightening #a1hjj feet per minute4#f   
,illustration3 ,figure #ab4--;,final    

development of the ,baldwin-,hale water 
balance elevator1 #ahgc4 ,the brake1    
kept applied by powerful springs1 was   
released only by steady pressure on a   
lever4 ,there were two additional       
controls--the continuous rope that      
opened the cistern valve to fill the    
bucket1 and a second lever to open the  
valve of the bucket to empty it4 7,from 
,united ,states ,railroad and ,mining   
,register1 ,apr4 #ab1 #ahgc1 vol4 #ag1  
p4 #c47   ,in addition to the element of
 potential danger from careless         
operation or failure of the brake1 the  
,baldwin system was extremely expensive 
to install as a result of the second    
shaft1 which of course was required to  
be more or less watertight4  ,much of   
the water-balance elevator's development
 and refinement was done by ,william ,e4
 ,hale of ,chicago1 who also made most  
of the installations4 ,the system has1  
therefore1 come to bear his name more   
commonly than ,baldwin's4  ,the         
popularity of the water-balance system  

waned after only a few years1 being     
eclipsed by more rational systems4 ,hale
 eventually abandoned it and became the 
western agent for ,otis--by this time   
prominent in the field--and subsequently
 was influential in development of the  
hydraulic elevator4  ,the rope-geared   
system of hydraulic elevator operation  
was so basically simple that by #ahhj it
 had been embraced by virtually all     
manufacturers4 ,however1 for years most 
builders continued to maintain a line of
 steam and belt driven machines for     
freight service4 ,inspired by the rapid 
increase of taller and taller buildings1
 there was a concentrated effort1       
heightened by severe competition1 to    
refine the basic system4                
,illustration3 ,figure #ac4--,vertical  
cylinder1 rope-geared hydraulic elevator
 with #b3a gear ratio and rope control  
7about #ahhj74 ,for higher rises and    
speeds1 ratios of up to #aj3a were used1
 and the endless rope was replaced by a 
lever4 7,courtesy of ,otis ,elevator    

,company47   ,by the late #ahhj's a vast
 number of improvements in detail had   
appeared1 and this form of elevator was 
considered to be almost without defect4 
,it was safe4 ,absence of a drum enabled
 the car to be carried by a number of   
cables rather than by one or two1 and   
rendered overtravel impossible4 ,it was 
fast4 ,control devices had received     
probably the most attention by engineers
 and were as perfect and sensitive as   
was possible with mechanical means4     
,cars with lever control could be run at
 the high speeds required for high      
buildings1 yet they could be stopped    
with a smoothness and precision         
unattainable earlier with systems in    
which the valves were controlled by an  
endless rope1 worked by the operator4   
,it was almost completely silent1 and   
when the cylinder was placed vertically 
in a well near the shaft1 practically no
 valuable floor space was occupied4 ,but
 most important1 the length of rise was 
unlimited because no drum was used4 ,as 

greater rises were required1 the        
multiplication of the ropes and sheaves 
was simply increased1 raising the       
piston-car travel ratio and permitting  
the cylinder to remain of manageable    
length4 ,the ratio was often as high as 
#aj or #ab to #a1 the car moving #aj or 
#ab feet to the piston's #a4  ,in       
addition to its principal advantages1   
the hydraulic elevator could be operated
 directly from municipal water mains in 
the many cities where there was         
sufficient pressure1 thus eliminating a 
large investment in tanks1 pumps and    
boilers 7fig4 #ad74  ,by far the        
greatest development in this specialized
 branch of mechanical engineering       
occurred in the ,united ,states4 ,the   
comparative position of ,american       
practice1 which will be demonstrated    
farther on1 is indicated by the fact    
that ,otis ,brothers and other large    
elevator concerns in the ,united ,states
 were able to establish offices in many 
of the major cities of ,europe and      

compete very successfully with local    
firms in spite of the higher costs due  
to shipment4 ,this also demonstrates the
 extent of error in the oft-heard       
statement that the skyscraper was the   
direct result of the elevator's         
invention4 ,there is no question that   
continued elevator improvement was an   
essential factor in the rapid increase  
of building heights4 ,however1          
consideration of the situation in       
,european cities1 where buildings of    
over #aj stories were 7and still are7   
rare in spite of the availability of    
similar elevator techniques1 points to  
the fundamental matter of tradition4    
,the ,european city simply did not      
develop with the lack of judicial       
restraint which characterized           
metropolitan growth in the ,united      
,states4 ,the ,american tendency to     
confine mercantile activity to the      
smallest possible area resulted in      
excessive land values1 which drove      
buildings skyward4 ,the elevator        

followed1 or1 at most1 kept pace with1  
the development of higher buildings4    
,illustration3 ,figure #ad4--;,in the   
various hydraulic systems1 a pump was   
required if pressure from water mains   
was insufficient to operate the elevator
 directly4 ,there was either a gravity  
tank on the roof or a pressure tank in  
the basement4 7,from ,thomas ,e4 ,brown1
 ,jr41 ,the ,american ,passenger        
,elevator1 ,engineering ,magazine 7,new 
,york71 ,june #ahic1 vol4 #e1 p4 #cdj47 
,european elevator                      
development--notwithstanding the number 
of ,american rope-geared hydraulic      
machines sold in ,europe in the #aj     
years or so preceding the ,paris fair of
 #ahhi--was confined mainly to          
variations on the direct plunger type1  
which was first used in ,english        
factories in the #ahcj's4 ,the plunger  
elevator 7fig4 #af71 an even closer     
derivative of the hydraulic press than  
,armstrong's crane1 was nothing more    
than a platform on the upper end of a   

vertical plunger that rose from a       
cylinder as water was forced in4  ,there
 were two reasons for this ,european    
practice4 ,the first and most apparent  
was the rarity of tall buildings4 ,the  
drilling of a well to receive the       
cylinder was thus a matter of little    
difficulty4 ,this well had to be        
equivalent in depth to the elevator     
rise4 ,the second reason was an innate  
,european distrust of cable-hung        
elevator systems in any form1 an        
attitude that will be discussed more    
fully farther on4   ,,the ,,electric    
,,elevator  ,at the time the ,eiffel    
,tower elevators were under             
consideration1 water under pressure was1
 from a practical standpoint1 the only  
agent capable of fulfilling the power   
and control requirements of this        
particularly severe service4 ,steam1 as 
previously mentioned1 had already been  
found wanting in several respects4      
,electricity1 on the other hand1 seemed 
to hold promise for almost every field  

of human endeavor4 ,by #ahhh the        
electric motor had behind it a #aj- or  
#ae-year history of active development4 
,frank ,j4 ,sprague had already placed  
in successful operation a sizable       
electric trolley-car system1 and was    
manufacturing motors of up to #bj       
horsepower in commercial quantity4      
,lighting generators were being produced
 in sizes far greater4 ,there were1     
nevertheless1 many obstacles preventing 
the translation of this progress into   
machinery capable of hauling large      
groups of people a vertical distance of 
#a1jjj feet with unquestionable         
dependability4  ,the first application  
of electricity to elevator propulsion   
was an experiment of the distinguished  
,german electrician ,werner von         
,siemens1 who1 in #ahhj1 constructed a  
car that successfully climbed a rack by 
means of a motor and worm gearing       
beneath its deck 7figs4 #ag1            
#ah7--;again1 the characteristic        
,european distrust of cable suspension4 

,however1 the effect of this success on 
subsequent development was negligible4  
,significant use of electricity in this 
field occurred somewhat later1 and in a 
manner parallel to that by which steam  
was first applied to the elevator--the  
driving of mechanical 7belt driven7     
elevator machines by individual motors4 
,slightly later came another application
 of the conversion type4 ,this was the  
simple substitution of electrically     
driven pumps 7fig4 #ba7 for steam pumps 
in hydraulic installations4 ,it will be 
recalled that pumps were necessary in   
cases where water main pressure was     
insufficient to operate the elevator    
directly4  ,in both of these cases the  
operational demands on the motor were of
 course identical to those on the prime 
movers which they replaced2 no reversal 
of direction was necessary1 the speed   
was constant1 and the load was nearly   
constant4 ,furthermore1 the load could  
be applied to the motor gradually       
through automatic relief valves on the  

pump and in the mechanical machines by  
slippage as the belt was shifted from   
the loose to the fast pulleys4 ,the     
ultimate simplicity in control resulted 
from permitting the motor to run        
continuously1 drawing current only in   
proportion to its loading4 ,the         
direct-current motor of the #ahhj's was 
easily capable of such service1 and it  
was widely used in this way4            
,illustration3 ,figure                  
#ae4--,rope-geared hydraulic freight    
elevator using a horizontal cylinder    
7about #ahhc74 7,from a ,lane  ,bodley  
illustrated catalog of hydraulic        
elevators1 ,cincinnati1 n4d47           
,illustration3 ,figure #af4--;,english  
direct plunger hydraulic elevator 7about
 #ahie74 7,from ,f4 ,dye1 ,popular      
,engineering1 ,london1 #ahie1 p4 #bhj47 
,adaptation of the motor to the direct  
drive of an elevator machine was quite  
another matter1 the difficulties being  
largely those of control4 ,at this time 
the only practical means of starting a  

motor under load was by introducing     
resistance into the circuit and cutting 
it out in a series of steps as the speed
 picked up2 precisely the method used to
 start traction motors4 ,in the early   
attempts to couple the motor directly to
 the winding drum through worm gearing1 
this notching up was transmitted to the 
car as a jerking motion1 disagreeable to
 passengers and hard on machinery4      
,furthermore1 the controller contacts   
had a short life because of the arcing  
which resulted from heavy starting      
currents4 ,in all1 such systems were    
unsatisfactory and generally unreliable1
 and were held in disfavor by both      
elevator experts and owners4            
,illustration3 ,figure #ag4--,siemens'  
electric rack-climbing elevator of      
#ahhj4 7,from ,werner von ,siemens1     
,gesammelte ,abhandlungen und ,vortrge1 
,berlin1 #ahha1 pl4 #e47   ,there was1  
moreover1 little inducement to overcome 
the problem of control and other minor  
problems because of a more serious      

difficulty which had persisted since the
 days of steam4 ,this was the matter of 
the drum and its attendant limitations4 
,the motor's action being rotatory1 the 
winding drum was the only practical way 
in which to apply its motive power to   
hoisting4 ,this single fact shut        
electricity almost completely out of any
 large-scale elevator business until    
after the turn of the century4 ,true1   
there was a certain amount of           
development1 after about #ahhg1 of the  
electric worm-drive drum machine for    
slow-speed1 low-rise service 7fig4 #ai74
 ,but the first installation of this    
type that was considered practically    
successful--in that it was in continuous
 use for a long period--was not made    
until #ahhi1g the year in which the     
,eiffel ,tower was completed4           
,pertinent is the one nearly successful 
attempt which was made to approach the  
high-rise problem electrically4 ,in     
#ahhh1 ,charles ,r4 ,pratt1 an elevator 
engineer of ,montclair1 ,new ,jersey1   

invented a machine based on the         
horizontal cylinder rope-geared         
hydraulic elevator1 in which the two    
sets of sheaves were drawn apart by a   
screw and traveling nut4 ,the screw was 
revolved directly by a ,sprague motor1  
the system being known as the           
,sprague-,pratt4 ,while a number of     
installations were made1 the machine was
 subject to several serious mechanical  
faults and passed out of use around     
#aijj4 ,generally1 electricity as a     
practical workable power for elevators  
seemed to hold little promise in #ahhh4h
   ,illustration3 ,figure #ah4--,motor  
and drive mechanism of ,siemens'        
elevator4 7,from ,alfred ,r4            
,urbanitzky1 ,electricity in the        
,service of ,man1 ,london1 #ahhf1 p4    
#fdf47  ,illustration3    ,morse1       
,williams  ,co41    ,,builders ,,of     
,,passenger   ,,and   ,,freight         
,,elevators4    ,,electric ,,elevator4  
,write us for ,circulars and ,prices4   
,main ,office and ,works1 #aaje         

,frankford ,avenue1   ,,philadelphia4   
,new ,york ,office1      #ajh ,liberty  
,street4   ,new ,haven            #hb   
,church ,street4   ,pittsburg           
#dac ,fourth ,avenue4   ,boston ,office 
#ai ,pearl ,street4   ,baltimore        
,builders' ,exchange4   ,scranton       
#dbe ,spruce ,street4  ,figure          
#ai4--,the electric elevator in its     
earliest commercial form 7#ahia71 with  
the motor connected directly to the     
load4 ,by this time1 incandescent       
lighting circuits in large cities were  
sufficiently extensive to make such     
installations practical4 ,however1      
capacity and lift were severely limited 
by weaknesses of the control system and 
the necessity of using a drum4 7,from   
,electrical ,world1 ,jan4 #b1 #ahig1    
vol4 #bj1 p4 xcvii47  ,illustration3    
,,miller',s ,,patent   ,,life ,,and     
,,labor-,,saving   ,,screw ,,hoisting   
,,machine1   ,,for ,,the ,,use ,,of     
,stores1 ,hotels1 ,warehouses1          
,factories1 ,sugar ,refineries1         

,packing ,houses1 ,mills1 ,docks1       
,mines1 c4   ,,manufactured ,,by        
,,campbell1 ,,whittier  ,,co41          
,,roxbury1 ,,mass4   ,sole ,agents for  
the ,new ,england ,states4  ,the above  
,engraving illustrates a very superior  
,hoisting ,machine1 designed for ,store 
and ,warehouse ,hoisting4 ,it is very   
simple in its construction1 compact1    
durable1 and not liable to get out of   
order4 ,an examination of the ,engraving
 will convince any one who has any      
knowledge of ,machinery1 that the screw 
is the only safe principle on which to  
construct a ,hoisting ,machine or       
,elevator4  ,figure                     
#bj4--;,advertisement for the ,miller   
screw-hoisting machine1 about #ahfg 7see
 p4 #bc74 ,from flyer in the ,united    
,states ,national ,museum4              
,illustration3 ,figure #ba4--,the first 
widespread use of electricity in the    
elevator field was to drive belt-type   
mechanical machines and the pumps of    
hydraulic systems 7see p4 #ad7 as shown 

here4 7,from ,electrical ,world1 ,jan4  
#d1 #ahij1 vol4 #ae1 p4 #d47     ,the   
,tower's ,elevators   ,a great part of  
the ,eiffel ,tower's worth and its      
raison d'tre lay in the overwhelming    
visual power by which it was to         
symbolize to a world audience the       
scientific1 artistic1 and1 above all1   
the technical achievements of the       
,french ,republic4 ,another             
consideration1 in ,eiffel's opinion1 was
 its great potential value as a         
scientific observatory4 ,at its summit  
grand experiments and observations would
 be possible in such fields as          
meteorology and astronomy4 ,in this     
respect it was welcomed as a tremendous 
improvement over the balloon and steam  
winch that had been featured in this    
service at the #ahgh ,paris exposition4 
,experiments were also to be conducted  
on the electrical illumination of cities
 from great heights4 ,the great         
strategic value of the ,tower as an     
observation post also was recognized4   

,but from the beginning1 sight was never
 lost of the structure's great value as 
an unprecedented public attraction1 and 
its systematic exploitation in this     
manner played a part in its planning1   
second perhaps only to the basic design4
  ,the conveyance of multitudes of      
visitors to the ,tower's first or main  
platform and a somewhat lesser number to
 the summit was a technical problem     
whose seriousness ,eiffel must certainly
 have been aware of at the project's    
onset4 ,while a few visitors could be   
expected to walk to the first or        
possibly second stage1 #cgg feet above  
the ground1 the main means of transport 
obviously had to be elevators4 ,indeed1 
the two aspects of the ,tower with which
 the ,exposition commissioners were most
 deeply concerned were the adequate     
grounding of lightning and the provision
 of a reliable system of elevators1     
which they insisted be unconditionally  
safe4  ,to study the elevator problem1  
,eiffel retained a man named ,backmann  

who was considered an expert on the     
subject4 ,apparently ,backmann          
originally was to design the complete   
system1 but he was to prove inadequate  
to the task4 ,as his few schemes are    
studied it becomes increasingly         
difficult to imagine by what            
qualifications he was regarded as either
 an elevator expert or designer by      
,eiffel and the ,commission4 ,his       
proposals appear1 with one exception1 to
 have been decidedly retrogressive1 and1
 further1 to incorporate the most       
undesirable features of those earlier   
systems he chose to borrow from4        
,nothing has been discovered regarding  
his work1 if any1 on elevators for the  
lower section of the ,tower4 ,realizing 
the difficulty of this aspect of the    
problem1 he may not have attempted its  
solution1 and confined his work to the  
upper half where the structure permitted
 a straight1 vertical run4              
,illustration3 ,figure #bb4--,various   
levels of the ,eiffel ,tower4 7,adapted 

from ,gustave ,eiffel1 ,la ,tour de     
,trois ,cents ,mtres1 ,paris1 #aijj1 pl4
 #a47   ,the ,backmann design for the   
upper elevators was based upon a        
principle which had been attractive to  
many inventors in the mid-#aith century 
period of elevator development--that of 
screwing the car up by means of a       
threaded element and a nut1 either of   
which might be rotated and the other    
remain stationary4 ,the analogy to a nut
 and bolt made the scheme an obvious one
 at that early time1 but its inherent   
complexity soon became equally evident  
and it never achieved practical success4
 ,backmann projected two cylindrical    
cars that traveled in parallel shafts   
and balanced one another from opposite  
ends of common cables that passed over a
 sheave in the upperworks4 ,around the  
inside of each shaft extended a spiral  
track upon which ran rollers attached to
 revolving frames underneath the cars4  
,when the frames were made to revolve1  
the rollers1 running around the track1  

would raise or lower one car1 the other 
traveling in the opposite direction     
7fig4 #bc74   ,illustration3 ,figure    
#bc4--;,backmann's proposed helicoidal  
elevator for the upper section of the   
,eiffel ,tower4 ,the cars were to be    
self-powered by electric motors4 ,note  
similarity to the ,miller system 7fig4  
#bj74 7,adapted from ,the ,engineer     
7,london71 ,aug4 #c1 #ahhh1 vol4 #ff1 p4
 #aja47   ,in the plan as first         
presented1 a ground-based steam engine  
drove the frames and rollers through an 
endless fly rope--traveling at high     
speed presumably to permit it to be of  
small diameter and still transmit a     
reasonable amount of power--which       
engaged pulleys on the cars4 ,the design
 was remarkably similar to that of the  
,miller ,patent ,screw ,hoisting        
,machine1 which had had a brief life in 
the ,united ,states around #ahfe4 ,the  
,miller system 7see p4 #ai7 used a flat 
belt rather than a rope 7fig4 #bj74     
,this plan was quickly rejected1        

probably because of anticipated         
difficulties with the rope              
transmission4#i  ,backmann's second     
proposal1 actually approved by the      
,commission1 incorporated the           
only--although highly                   
significant--innovation evident in his  
designs4 ,for the rope transmission1    
electric motors were substituted1 one in
 each car to drive the roller frame     
directly4 ,with this modification1 the  
plan does not seem quite as             
unreasonable1 and would probably have   
worked4 ,however1 it would certainly    
have lacked the necessary durability and
 would have been extremely expensive4   
,the ,commission discarded the whole    
scheme about the middle of #ahhh1 giving
 two reasons for its action3 7#a7 the   
novelty of the system and the attendant 
possibility of stoppages which might    
seriously interrupt the exploitation of 
the ,tower1 and 7#b7 fear that the      
rollers running around the tracks would 
cause excessive noise and vibration4    

,both reasons seem quite incredible when
 the ,backmann system is compared to one
 of those actually used--the ,roux1     
described below--which obviously must   
have been subject to identical failings1
 and on a far greater scale4 ,more      
likely there existed an unspoken        
distrust of electric propulsion4  ,that 
the ,backmann system should have been   
given serious consideration at all      
reflects the uncertainty surrounding the
 entire matter of providing elevator    
service of such unusual nature4 ,had the
 ,eiffel ,tower been erected only #ae   
years later1 the situation would have   
been simply one of selection4 ,as it    
was1 ,eiffel and the commissioners were 
governed not by what they wanted but    
largely by what was available4   ,,the  
,,otis ,,system  ,the curvature of the  
,tower's legs imposed a problem unique  
in elevator design1 and it caused great 
annoyance to ,eiffel1 the fair's        
,commission1 and all others concerned4  
,since a vertical shaftway anywhere     

within the open area beneath the first  
platform was esthetically unthinkable1  
the elevators could be placed only in   
the inclined legs4 ,the problem of      
reaching the first platform was not     
serious4 ,the legs were wide enough and 
their curvature so slight in this lower 
portion as to permit them to contain a  
straight run of track1 and the service  
could have been designed along the lines
 of an ordinary inclined railway4 ,it   
was estimated that the great majority of
 visitors would go only to this level1  
attracted by the several international  
restaurants1 bars and other features    
located there4 ,two elevators to operate
 only that far were contracted for with 
no difficulty--one to be placed in the  
east leg and one in the west4  ,to      
transport people to the second platform 
was an altogether different problem4    
,since there was to be a single run from
 the ground1 it would have been         
necessary to form the elevator guides   
either with a constant curvature1       

approximating that of the legs1 or with 
a series of straight chords connected by
 short segmental curves of small radius4
 ,eiffel planned initially to use the   
first method1 but the second was adopted
 ultimately1 probably as being the      
simpler because only two straight       
lengths of run were found to be         
necessary4  ,bids were invited for two  
elevators on this basis--one each for   
the north and south legs4 ,here the     
unprecedented character of the matter   
became evident--there was not a firm in 
,france willing to undertake the work4  
,the ,american ,elevator ,company1 the  
,european branch of ,otis ,brothers     
,company1 did submit a proposal through 
its ,paris office1 ,otis ,ascenseur     
,cie41 but the ,commission was compelled
 to reject it because a clause in the   
fair's charter prohibited the use of any
 foreign material in the construction of
 the ,tower4 ,furthermore1 there was a  
strong prejudice against foreign        
contractors1 which1 because of the      

general background of disfavor          
surrounding the project during its early
 stages1 was an element worth serious   
consideration by the ,commission4 ,the  
bidding time was extended1 and many     
attempts were made to attract a native  
design but none was forthcoming4  ,as   
time grew short1 it became imperative to
 resolve the matter1 and the            
,commission1 in desperation1 awarded the
 contract to ,otis in ,july #ahhg for   
the amount of #bb1ejj4aj ,a curious     
footnote to the affair appeared much    
later in the form of a published        
interview#aa with ,w4 ,frank ,hall1     
,otis' ,paris representative3           
,yes1 said ,mr4 ,hall1 this is the first
 elevator of its kind4 ,our      people 
for thirty-eight years have been doing  
this work1 and have      constructed    
thousands of elevators vertically1 and  
many on an      incline1 but never one  
to strike a radius of #afj feet for a   
distance      of over #ej feet4 ,it has 
required a great amount of preparatory  

study      and we have worked on it for 
three years4       ,that was before you 
got the contract8       ,quite so1 but  
we knew that1 although the ,french      
authorities were      very reluctant to 
give away this piece of work1 they would
 be bound      to come to us1 and so we 
were preparing for them4  ,such supreme 
confidence must have rapidly evaporated 
as events progressed4 ,despite the      
invaluable advertising to be derived    
from an installation of such            
distinction1 the ,otises would probably 
have defaulted had they foreseen the    
difficulties which preceded completion  
of the work4   ,illustration3 ,figure   
#bd4--;,general arrangement of ,otis    
elevator system in ,eiffel ,tower4      
7,from ,the ,engineer 7,london71 ,july  
#ai1 #ahhi1 vol4 #fh1 p4 #eh47   ,the   
proposed system 7fig4 #bd7 was based    
fundamentally upon ,otis' standard      
hydraulic elevator1 but it was          
recognizable only in basic operating    
principle 7fig4 #be74 ,tracks of regular

 rail section replaced the guides       
because of the incline1 and the         
double-decked cabin 7fig4 #bi7 ran on   
small flanged wheels4 ,this much of the 
apparatus was really not unlike that of 
an ordinary inclined railway4 ,motive   
power was provided by the customary     
hydraulic cylinder 7fig4 #bf71 set on an
 angle roughly equal to the incline of  
the lower section of run4 ,balancing the
 cabin's dead weight was a counterpoise 
carriage 7fig4 #bg7 loaded with pig iron
 that traveled on a second set of rails 
beneath the main track4 ,like the       
driving system1 the counterweight was   
rope-geared1 #c to #a1 so that its      
travel was about #abe feet to the       
cabin's #cgg feet4   ,illustration3     
,figure #be4--,schematic diagram of the 
rigging of the ,otis system4 7,adapted  
from ,gustave ,eiffel1 ,la ,tour de     
,trois ,cents ,mtres1 ,paris1 #aijj1 p4 
#abg47   ,everything about the system   
was on a scale far heavier than found in
 the normal elevator of the type4 ,the  

cylinder1 of #ch-;inch bore1 was #cf    
feet long4 ,rather than a simple nest of
 pulleys1 the piston rods pulled a large
 guided carriage or chariot bearing six 
movable sheaves 7fig4 #bh74             
,corresponding were five stationary     
sheaves1 the whole reeved to form an    
immense #ab-purchase tackle4 ,the car1  
attached to the free ends of the cables1
 was hauled up as the piston drew the   
two sheave assemblies apart4  ,in       
examining the system1 it is difficult to
 determine what single element in its   
design might have caused such a problem 
as to have been beyond the engineering  
ability of a ,french firm1 and to have  
caused such concern to a large1         
well-established ,american organization 
of ,otis' wide elevator and inclined    
railway experience4 ,indeed1 when the   
,french system--which served the first  
platform from the east and west legs--is
 examined1 it appears curious that a    
national technology capable of producing
 a machine at such a level of complexity

 should have been unable to deal easily 
with the entire matter4 ,this can be    
plausibly explained only on the basis of
 ,europe's previously mentioned lack of 
experience with rope-geared and other   
cable-hung elevator systems4 ,the       
difficulty attending ,otis' work1       
usually true in the case of all         
innovations1 lay unquestionably in the  
multitudes of details--many of them1 of 
course1 invisible when only the         
successfully working end product is     
observed4  ,more than a matter of detail
 was the ,commission's demand for       
perfect safety1 which precipitated a    
situation typical of many confronting   
,otis during the entire work4 ,otis had 
wished to coordinate the entire design  
process through ,mr4 ,hall1 with        
technical matters handled by mail4      
,nevertheless1 at ,eiffel's insistence1 
and with some inconvenience1 in #ahhh   
the company dispatched the project's    
engineer1 ,thomas ,e4 ,brown1 ,jr41 to  
,paris for a direct consultation4 ,mild 

conflict over minor details ensued1 but 
a gross difference of opinion arose     
ultimately between the ,american and    
,french engineers over the safety of the
 system4 ,the disagreement threatened to
 halt the entire project4 ,in common    
with all elevators in which the car     
hangs by cables1 the prime consideration
 here was a means of arresting the cabin
 should the cables fail4 ,as originally 
presented to ,eiffel1 the plans         
indicated an elaborate modification of  
the standard ,otis safety device--itself
 a direct derivative of ,e4 ,g4 ,otis'  
original4  ,if any one of the six       
hoisting cables broke or stretched      
unduly1 or if their tension slackened   
for any reason1 powerful leaf springs   
were released causing brake shoes to    
grip the rails4 ,the essential feature  
of the design was the car's arrest by   
friction between its grippers and the   
rails so that the stopping action was   
gradual1 not sudden as in the elevator  
safety4 ,during proof trials of the     

safety1 made prior to the fair's opening
 by cutting away a set of temporary     
hoisting cables1 the cabin would fall   
about #aj feet before being halted4     
,illustration3 ,figure #bf4--,section   
through the ,otis power cylinder4       
7,adapted from ,gustave ,eiffel1 ,la    
,tour de ,trois ,cents ,mtres1 ,paris1  
#aijj1 pl4 #bb47  ,illustration3 ,figure
 #bg4--;,details of the counterweight   
carriage in the ,otis system4 7,from    
,gustave ,eiffel1 ,la ,tour de ,trois   
,cents ,mtres1 ,paris1 #aijj1 pl4 #bbd47
   ,although highly efficient and of    
unquestionable security1 this safety    
device was considered an insufficient   
safeguard by ,eiffel1 who1 speaking in  
the name of the ,commission1 demanded   
the application of a device known as the
 rack and pinion safety that was used to
 some extent on ,european cog railways4 
,the commissioners not only considered  
this system more reliable but felt that 
one of its features was a necessity3 a  
device that permitted the car to be     

lowered by hand1 even after failure of  
all the hoisting cables4 ,the serious   
shortcomings of the rack and pinion were
 its great noisiness and the limitation 
it imposed on hoisting speed4 ,both     
disadvantages were due to the constant  
engagement of a pinion on the car with a
 continuous rack set between the rails4 
,the meeting ended in an impasse1 with  
,brown unwilling to approve the         
objectionable apparatus and able only to
 return to ,new ,york and lay the matter
 before his company4  ,while ,eiffel's  
attitude in the matter may appear highly
 unreasonable1 it must be said that     
during a subsequent meeting between     
,brown and ,koechlin1 the ,french       
engineer implied that a mutual          
antagonism had arisen between the       
,tower's creator and the ,commission4   
,thus1 since his own judgment must have 
had little influence with the           
commissioners at that time1 ,eiffel was 
compelled to specify what he well knew  
were excessive safety provisions4  ,this

 decision placed ,otis ,brothers in a   
decidedly uncomfortable position1 at the
 mercy of the ,commission4 ,w4 ,e4      
,hale1 promoter of the water balance    
elevator--who by then had a strong voice
 in ,otis' affairs--expressed the       
seriousness of the matter in a letter to
 the company's president1 ,charles ,r4  
,otis1 following receipt of ,brown's    
report on the ,paris conference4        
,referring to the controversial         
cogwheel1 ,hale wrote       444 if this 
must be arranged so that the car is     
effected sic in its      operation by   
constant contact with the rack and      
pinion 444 so as to      communicate the
 noise and jar1 and unpleasant motion   
which such an      arrangement always   
produces1 ,i should favor giving up the 
whole      matter rather than allying   
ourselves with any such abortion4444 we 
would be the laughing stock of the      
world1 for putting up such a            
contrivance4  ,this difficult situation 
apparently was the product of a somewhat

 general contract phrased in terms of   
service to be provided rather than of   
specific equipment to be used4 ,this is 
not unusual1 but it did leave open to   
later dispute such ambiguous clauses as 
adequate safety devices are to be       
provided4  ,although faced with the loss
 not only of all previously expended    
design work but also of an advertisement
 of international consequence1 the      
company apparently concurred with ,hale 
and so advised ,paris4 ,unfortunately1  
there are no ,otis records to reveal the
 subsequent transactions1 but we may    
assume that ,otis' threat of withdrawal 
prevailed1 coupled as it was with       
,eiffel's confidence in the ,american   
equipment4 ,the system went into        
operation as originally designed1 free  
of the odious rack and pinion4  ,that1  
unfortunately1 was not the final        
disagreement4 ,before the fair's opening
 in ,may #ahhi1 the relationship was    
strained so drastically that a mutually 
satisfactory conclusion to the project  

must indeed have seemed hopeless4 ,the  
numerous minor structural modifications 
of the ,tower legs found necessary as   
construction progressed had necessitated
 certain equivalent alteration to the   
,otis design insofar as its dependency  
upon the framework was affected4        
,consequently1 work on the machinery was
 set back by some months4 ,eiffel was   
informed that although everything was   
guaranteed to be in full operation by   
opening day on ,may #a1 the contractual 
deadline of ,january #a could not       
possibly be met4 ,eiffel1 now           
unquestionably acting on his own        
volition1 responded by cable1 refusing  
all payment4 ,charles ,otis' reply1 a   
classic of indignation1 disclosed to    
,eiffel the jeopardy in which his       
impetuosity had placed the success of   
the entire project3       ,after all    
else we have borne and suffered and     
achieved in your      behalf1 we regard 
this as a trifle too much2 and we do not
 hesitate      to declare1 in the       

strongest terms possible to the ,english
 language1      that we will not put up 
with it 444 and1 if there is to be ,war1
 under      the existing circumstances1 
propose that at least part of it shall  
be      fought on ,american ground4 ,if 
,mr4 ,eiffel shall1 on the contrary1    
treat us as we believe we are entitled  
to be treated1 under the                
circumstances1 and his confidence in our
 integrity to serve him well      shall 
be restored in season to admit of the   
completion of this work      at the time
 wanted1 well and good2 but it must be  
done at once 444      otherwise we shall
 ship no more work from this side1 and  
,mr4 ,eiffel      must charge to himself
 the consequences of his own acts4      
,this message apparently had the desired
 effect and the matter was somehow      
resolved1 as the machinery was in full  
operation when the ,exposition opened4  
,the installation must have had immense 
promotional value for ,otis ,brothers1  
particularly in its contrast to the     

somewhat anomalous ,french system4 ,this
 contrast evidently was visible to the  
technically unsophisticated as well as  
to visiting engineers4 ,several         
newspapers reported that the ,otis      
elevators were one of the best ,american
 exhibits at the fair4  ,in spite of    
their large over-all scale and the      
complication of the basic pattern       
imposed by the unique situation1 the    
,otis elevators performed well and      
justified the original judgment and     
confidence which had prompted ,eiffel to
 fight for their installation4 ,aside   
from the obvious advantage of simplicity
 when compared to the ,french machines1 
their operation was relatively quiet1   
and fast4  ,the double car1 traveling at
 #djj feet per minute1 carried #dj      
persons1 all seated because of the      
change of inclination4 ,the main valve  
or distributor that controlled the flow 
of water to and from the driving        
cylinder was operated from the car by   
cables4 ,the hydraulic head necessary to

 produce pressure within the cylinder   
was obtained from a large open reservoir
 on the second platform4 ,after being   
exhausted from the cylinder1 the water  
was pumped back up by two ,girard pumps 
7fig4 #ca7 in the engine room at the    
base of the ,tower's south leg4   ,,the 
,,system ,,of ,,roux1 ,,combaluzier     
,,and ,,lepape  ,there can be little    
doubt that the ,french elevators placed 
in the east and west piers to carry     
visitors to the first stage of the      
,tower had the important secondary      
function of saving face4 ,that an       
engineer of ,eiffel's mechanical        
perception would have permitted their   
use1 unless compelled to do so by the   
,exposition ,commission1 is unthinkable4
 ,whatever the attitudes of the         
commissioners may have been1 it must be 
said--recalling the ,backmann           
system--that they did not fear          
innovation4 ,the machinery installed by 
the firm of ,roux1 ,combaluzier and     
,lepape was novel in every respect1 but 

it was a product of misguided ingenuity 
and set no precedent4 ,the system1 never
 duplicated1 was conceived1 born1 lived 
a brief and not overly creditable life1 
and died1 entirely within the ,tower4   
,basis of the ,french system was an     
endless chain of short1 rigid1          
articulated links 7fig4 #ce71 to one    
point of which the car was attached4 ,as
 the chain moved1 the car was raised or 
lowered4 ,recalling the ,european       
distrust of suspended elevators1 it is  
interesting to note that the car was    
pushed up by the links below1 not drawn 
by those above1 thus the active links   
were in compression4 ,to prevent        
buckling of the column1 the chain was   
enclosed in a conduit 7fig4 #cf74       
,excessive friction was prevented by a  
pair of small rollers at each of the    
knuckle joints between the links4 ,the  
system was1 in fact1 a duplicate one1   
with a chain on either side of the car4 
,at the bottom of the run the chains    
passed around huge sprocket wheels1     

#ab4hj feet in diameter1 with pockets on
 their peripheries to engage the joints4
 ,smaller wheels at the top guided the  
chains4  ,if by some motive force the   
wheel 7fig4 #cc7 were turned            
counterclockwise1 the lower half of the 
chain would be driven upward1 carrying  
the car with it4 ,slots on the inside   
faces of the lower guide trunks         
permitted passage of the connection     
between the car and chain4 ,lead weights
 on certain links of the chains' upper  
or return sections counterbalanced most 
of the car's dead weight4               
,illustration3 ,figure #bh4--,plan and  
section of the ,otis system's movable   
pulley assembly1 or chariot4 ,piston    
rods are at left4 7,adapted from ,the   
,engineer 7,london71 ,july #ai1 #ahhi1  
vol4 #fh1 p4 #eh47   ,two horizontal    
cylinders rotated the driving sprockets 
through a mechanism whose effect was    
similar to the rope-gearing of the      
standard hydraulic elevator1 but which  
might be described as chain gearing4    

,the cylinders were of the pushing      
rather than the pulling type used in the
 ,otis system2 that is1 the pressure was
 introduced behind the plungers1 driving
 them out4 ,to the ends of the plungers 
were fixed smooth-faced sheaves1 over   
which were looped heavy quadruple-link  
pitch chains1 one end of each being     
solidly attached to the machine base4   
,the free ends ran under the cylinder   
and made another half-wrap around small 
sprockets keyed to the main drive shaft4
 ,as the plungers were forced outward1  
the free ends of the chain moved in the 
opposite direction1 at twice the        
velocity and linear displacement of the 
plungers4 ,the drive sprockets were     
thereby revolved1 driving up the car4   
,descent was made simply by permitting  
the cylinders to exhaust1 the car       
dropping of its own weight4 ,the        
over-all gear or ratio of the system was
 the multiplication due to the double   
purchase of the plunger sheaves times   
the ratio of the chain and drive        

sprocket diameters3 #b7ab4hj_/a4ig7 or  
about #ac3a4 ,to drive the car #bah feet
 to the first platform of the ,tower the
 plungers traveled only about #af4e     
feet4  ,to penetrate the inventive      
rationale behind this strange machine is
 not difficult4 ,aware of the           
fundamental dictum of absolute safety   
before all else1 the ,roux engineers    
turned logically to the safest known    
elevator type--the direct plunger4 ,this
 type of elevator1 being well suited to 
low rises1 formed the main body of      
,european practice at the time1 and in  
this fact lay the further attraction of 
a system firmly based on tradition4     
,since the piers between the ground and 
first platform could accommodate a      
straight1 although inclined run1 the    
solution might obviously have been to   
use an inclined1 direct plunger4 ,the   
only difficulty would have been that of 
drilling a #bbj-;foot1 inclined well for
 the cylinder4 ,while a difficult       
problem1 it would not have been         

insurmountable4 ,what then was the      
reason for using a design vastly more   
complex8 ,the only reasonable answer    
that presents itself is that the        
designers1 working in a period before   
the ,otis bid had been accepted1 were   
attempting to evolve an apparatus       
capable of the complete service to the  
second platform4 ,the use of a rigid    
direct plunger thus precluded1 it became
 necessary to transpose the basic idea  
in order to adapt it to the curvature of
 the ,tower leg1 and at the same time   
retain its inherent quality of safety4  
,continuing the conceptual sequence1 the
 idea of a plunger made in some manner  
flexible apparently suggested itself1   
becoming the heart of the ,roux         
machines4   ,illustration3 ,figure      
#bi4--,section through cabin of the     
,otis elevator4 ,note the pivoted       
floor-sections4 ,as the car traveled1   
these floor-sections were leveled by the
 operator to compensate for the change  
of inclination2 however1 they were soon 

removed because they interfered with the
 loading and unloading of passengers4   
7,from ,la ,nature1 ,may #d1 #ahhi1 vol4
 #ag1 p4 #cfj47   ,here then was a      
design exhibiting strange contrast4 ,it 
was on the one hand completely novel1   
devised expressly for this trying       
service2 yet on the other hand it was   
derived from and fundamentally based on 
a thoroughly traditional system4 ,if    
nothing else1 it was safe beyond        
question4 ,in ,eiffel's own words1 the  
,roux lifts not only were safe1 but     
appeared safe2 a most desirable feature 
in lifts traveling to such heights and  
carrying the general public4#ab  ,the   
system's shortcomings could hardly be   
more evident4 ,friction resulting from  
the more than #cbj joints in the        
flexible pistons1 each carrying two     
rollers1 plus that from the pitch chains
 must have been immense4 ,the noise     
created by such multiplicity of parts   
can only be imagined4 ,capacity was     
equivalent to that of the ,otis system4 

,about #ajj people could be carried in  
the double-deck cabin1 some standing4   
,the speed1 however1 was only #bjj feet 
per minute1 understandably low4  ,if it 
had been the initial intention of the   
designers to operate their cars to the  
second platform1 they must shortly have 
become aware of the impracticability of 
this plan1 caused by an inherent        
characteristic of the apparatus4 ,as    
long as the compressive force acted     
along the longitudinal axis of the      
links1 there was no lateral resultant   
and the only load on the small rollers  
was that due to the dead weight of the  
link itself4 ,however1 if a curve had   
been introduced in the guide channels to
 increase the incline of the upper run1 
as done by ,otis1 the force on those    
links traversing the bend would have    
been eccentric--assuming the car to be  
in the upper section1 above the bend4   
,the difference between the two sections
 7based upon the ,otis system7 was #ghi'
 minus #edce'1 or #bccd'1 the tangent of

 which equals #j4dcf4 ,forty-three      
percent of the unbalanced weight of the 
car and load would then have borne upon 
the1 say1 #ab sets of rollers on the    
curve4 ,the immense frictional load thus
 added to the entire system would       
certainly have made it dismally         
inefficient1 if not actually unworkable4
  ,in spite of ,eiffel's public remarks 
regarding the safety of the ,roux       
machinery1 in private he did not trouble
 to conceal his doubts4 ,otis'          
representative1 ,hall1 discussing this  
toward the end of ,brown's previously   
mentioned report1 probably presented a  
fairly accurate picture of the          
situation4 ,his comments were based on  
conversations with ,eiffel and          
,koechlin3       ,mr4 ,gibson1 ,mr4     
,hanning who were other ,otis employees 
and myself      came to the unanimous   
conclusion that ,mr4 ,eiffel had been   
forced to      order those other        
machines1 from outside parties1 against 
his own      judgment3 and that he was  

very much in doubt as to their being a  
practical success--and was1 therefore1  
all the more anxious to put in      our 
machines 7which he did have faith in7   
444 and if the others ate      up coal  
in proportions greatly in excess of     
ours1 he would have it to      say 444  
,gentlemen1 these are my choice of      
elevators1 those are yours      c4      
,there was a published interview 444 in 
which ,eiffel stated 444      that he   
was to meet some ,american gentlemen the
 following day1 who      were to provide
 him with elevators--grand elevators1 ,i
 think he      said4444   ,illustration3
 ,figure #cj4--,upperworks and passenger
 platforms of the ,otis system at second
 level4 7,from ,la ,nature1 ,aug4 #aj1  
#ahhi1 vol4 #ag1 p4 #afi47   ,the ,roux 
and the ,otis systems both drew their   
water supply from the same tanks2 also1 
each system used similar distributing   
valves 7fig4 #cb7 operated from the     
cars4 ,although no reports have been    
found of actual controlled tests        

comparing the efficiencies of the ,otis 
and ,roux systems1 a general            
quantitative comparison may be made from
 the balance figures given for each 7p4 
#dj71 where it is seen that #b1ffe      
pounds of excess tractive effort were   
allowed to overcome the friction of the 
,otis machinery against #ac1hef pounds  
for the ,roux4   ,,the ,,edoux ,,system 
,the section of the ,tower presenting   
the least difficulty to elevator        
installation was that above the juncture
 of the four legs--from the second      
platform to the third1 or observation1  
enclosure4 ,there was no question that  
,french equipment could perform this    
service4 ,the run being perfectly       
straight and vertical1 the only unusual 
demand upon contemporary elevator       
technology was the length of rise--#ebe 
feet4  ,the system ultimately selected  
7fig4 #cg7 appealed to the ,commission  
largely because of a similar one that   
had been installed in one tower of the  
famous ,trocadero#ac and which had been 

operating successfully for #aj years4   
,it was the direct plunger system of    
,leon ,edoux1 and was1 for the time1 far
 more rationally contrived than         
,backmann's helicoidal system4 ,edoux1  
an old schoolmate of ,eiffel's1 had     
built thousands of elevators in ,france 
and was possibly the country's most     
successful inventor and manufacturer in 
the field4 ,it is likely that he did not
 attempt to obtain the contract for the 
elevator equipment in the ,tower legs1  
as his experience was based almost      
entirely on plunger systems1 a type1 as 
we have seen1 not readily adaptable to  
that situation4 ,what is puzzling was   
the failure of the ,commission's members
 to recognize sooner ,edoux's obvious   
ability to provide equipment for the    
upper run4 ,it may have been due to     
their inexplicable confidence in        
,backmann4   ,illustration3 ,figure     
#ca4--,the ,french ,girard pumps that   
supplied the ,otis and ,roux systems4   
7,from ,la ,nature1 ,oct4 #e1 #ahhi1    

vol4 #ag1 p4 #bib47   ,the direct       
plunger elevator was the only type in   
which ,european practice was in advance 
of ,american practice at this time4 ,not
 until the beginning of the #bjth       
century1 when hydraulic systems were    
forced into competition with electrical 
systems1 was the direct plunger elevator
 improved in ,america to the extent of  
being practically capable of high rises 
and speeds4 ,another reason for its     
early disfavor in the ,united ,states   
was the necessity for drilling an       
expensive plunger well equal in length  
to the rise4#ad  ,as mentioned1 the most
 serious problem confronting ,edoux was 
the extremely high rise of #ebe feet4   
,the ,trocadero elevator1 then the      
highest plunger machine in the world1   
traveled only about #bcj feet4 ,a       
secondary difficulty was the esthetic   
undesirability of permitting a plunger  
cylinder to project downward a distance 
equal to such a rise1 which would have  
carried it directly into the center of  

the open area beneath the first platform
 7fig4 #f74 ,both problems were met by  
an ingenious modification of the basic  
system4 ,the run was divided into two   
equal sections1 each of #bfb feet1 and  
two cars were used4 ,one operated from  
the bottom of the run at the second     
platform level to an intermediate       
platform half-way up1 while the other   
operated from this point to the         
observation platform near the top of the
 ,tower4 ,the two sections were of      
course parallel1 but offset4 ,a central 
guide1 on the ,tower's center-line1     
running the entire #ebe feet served both
 cars1 with shorter guides on either    
side--one for the upper and one for the 
lower run4 ,thus1 each car traveled only
 half the total distance4 ,the two cars 
were connected1 as in the ,backmann     
system1 by steel cables running over    
sheaves at the top1 balancing each other
 and eliminating the need for           
counterweights4 ,two driving rams were  
used4 ,by being placed beneath the upper

 car1 their cylinders extended downward 
only the #bfb feet to the second        
platform and so did not project beyond  
the confines of the system itself4#ae   
,in making the upward or downward trip1 
the passengers had to change from one   
car to the other at the intermediate    
platform1 where the two met and parted  
7fig4 #ci74 ,this transfer was the only 
undesirable feature of what was1 on the 
whole1 a thoroughly efficient and well  
designed work of elevator engineering4  
,illustration3 ,figure #cb4--,the ,otis 
distributor1 with valves shown in       
motionless1 neutral position4 ,since the
 main valve at all times was subjected  
to the full operating pressure1 it was  
necessary to drive this valve with a    
servo piston4 ,the control cable        
operated only the servo piston's valve4 
7,adapted from ,gustave ,eiffel1 ,la    
,tour de ,trois ,cents ,mtres1 ,paris1  
#aijj1 p4 #acj47  ,illustration3 ,figure
 #cc4--;,general arrangement of the     
,roux ,combaluzier and ,lepape elevator4

  ,illustration3 ,figure #cd4--,roux1   
,combaluzier and ,lepape machinery and  
cabin at the ,tower's base4 7,from ,la  
,nature1 ,aug4 #aj1 #ahhi1 vol4 #ag1 p4 
#afh47   ,in operation1 water was       
admitted to the two cylinders from a    
tank on the third platform4 ,the        
resultant hydraulic head was sufficient 
to force out the rams and raise the     
upper car4 ,as the rams and car rose1   
the rising water level in the cylinders 
caused a progressive reduction of the   
available head4 ,this negative effect   
was further heightened by the fact that1
 as the rams moved upward1 less and less
 of their length was buoyed by the water
 within the cylinders1 increasing their 
effective weight4 ,these two factors    
were1 however1 exactly compensated for  
by the lengthening of the cables on the 
other side of the pulleys as the lower  
car descended4 ,perfect balance of the  
system's dead load for any position of  
the cabins was1 therefore1 a quality    
inherent in its design4 ,however1 there 

were two extreme conditions of live     
loading which required consideration3   
the lower car full and the upper empty1 
or vice versa4 ,to permit the upper car 
to descend under the first condition1   
the plungers were made sufficiently     
heavy1 by the addition of cast iron at  
their lower ends1 to overbalance the    
weight of a capacity load in the lower  
car4 ,the second condition demanded     
simply that the system be powerful      
enough to lift the unbalanced weight of 
the plungers plus the weight of         
passengers in the upper car4  ,as in the
 other systems1 safety was a matter of  
prime importance4 ,in this case1 the    
element of risk lay in the possibility  
of the suspended car falling4 ,the upper
 car1 resting on the rams1 was virtually
 free of such danger4 ,here again the   
influence of ,backmann was felt--a brake
 of his design was applied 7fig4 #ch74  
,it was1 true to form1 a throwback1     
similar safety devices having proven    
unsuccessful much earlier4 ,attached to 

the lower car were two helically        
threaded vertical rollers1 working      
within the hollow guides4 ,corresponding
 helical ribs in the guides rotated the 
rollers as the car moved4 ,if the car   
speed exceeded a set limit1 the         
increased resistance offered by the     
apparatus drove the rollers up into     
friction cups1 slowing or stopping the  
car4   ,illustration3 ,figure           
#ce4--;,detail of links in the ,roux    
system4 7,from ,gustave ,eiffel1 ,la    
,tour de ,trois ,cents ,mtres1 ,paris1  
#aijj1 p4 #aef47  ,illustration3 ,figure
 #cf4--,section of guide trunks in the  
,roux system4 7,from ,gustave ,eiffel1  
,la ,tour de ,trois ,cents ,mtres1      
,paris1 #aijj1 p4 #aef47   ,the device  
was considered ineffectual by ,edoux and
 ,eiffel1 who were aware that the       
ultimate safety of the system resulted  
from the use of supporting cables far   
heavier than necessary4 ,there were four
 such cables1 with a total sectional    
area of #ae4e square inches4 ,the total 

maximum load to which the cables might  
be subjected was about #dg1jjj pounds1  
producing a stress of about #c1jjj      
pounds per square inch compared to a    
breaking stress of #adj1jjj pounds per  
square inch--a safety factor of #df6af  
,illustration3 ,figure #cg4--,schematic 
diagram of the ,edoux system4 7,adapted 
from ,gustave ,eiffel1 ,la ,tour de     
,trois ,cents ,mtres1 ,paris1 #aijj1 p4 
#age47  ,illustration3 ,figure          
#ch4--,vertical section through lower   
7suspended7 ,edoux car1 showing         
,backmann helicoidal safety brake4      
7,adapted from ,gustave ,eiffel1 ,la    
,tour ,eiffel en #aijj1 ,paris1 #aijb1  
p4 #ab47   ,a curiosity in connection   
with the ,edoux system was the use of   
,worthington 7,american7 pumps 7fig4    
#dj7 to carry the water exhausted from  
the cylinders back to the supply tanks4 
,no record has been found that might    
explain why this particular exception   
was made to the foreign materials       
stipulation4 ,this exception is even    

more strange in view of ,otis' futile   
request for the same pumps and the fact 
that any number of native machines must 
have been available4 ,it is possible    
that ,edoux's personal influence was    
sufficient to overcome the authority of 
the regulation4   ,illustration3 ,figure
 #ci4--,passengers changing cars on     
,edoux elevator at intermediate         
platform4 7,from ,la ,nature1 ,may #d1  
#ahhi1 vol4 #ag1 p4 #cfa47              
,illustration3 ,figure                  
#dj4--,worthington tandem compound steam
 pumps1 at base of the ,tower's south   
pier1 supplied water for the ,edoux     
system4 ,the tank was at #hif feet1 but 
suction was taken from the top of the   
cylinders at #fdc feet2 therefore1 the  
pumps worked against a head of only     
about #bej feet4 7,from ,la ,nature1    
,oct4 #e1 #ahhi1 vol4 #ag1 p4 #bic47    
,illustration3 ,figure #da4--,recent    
view of lower car of the ,edoux system1 
showing slotted cylindrical guides that 
enclose the cables4     ,epilogue   ,in 

#aijj1 after the customary #aa-year     
period1 ,paris again prepared for an    
international exposition1 about #e years
 too early to take advantage of the     
great progress made by the electric     
elevator4 ,when the ,roux machines1 the 
weakest element in the ,eiffel ,tower   
system1 were replaced at this time1 it  
was by other hydraulics4 ,built by the  
well known ,french engineering          
organization of ,fives-,lilles1 the new 
machines were the ultimate in power1    
control1 and general excellence of      
operation4 ,as in the ,otis system1 the 
cars ran all the way to the second      
platform4  ,the ,fives-,lilles equipment
 reflected the advance of ,european     
elevator engineering in this short time4
 ,the machines were rope-geared and     
incorporated the elegant feature of     
self-leveling cabins which compensated  
for the varying track inclination4 ,for 
the #aijj fair1 the ,otis elevator in   
the south pier was also removed and a   
wide stairway to the first platform     

built in its place4 ,in #aiab1 #be years
 after ,backmann's startling proposal to
 use electricity for his system1 the    
remaining ,otis elevator was replaced by
 a small electric one4 ,this innovation 
was reluctantly introduced solely for   
the purpose of accommodating visitors in
 the winter when the hydraulic systems  
were shut down due to freezing weather4 
,the electric elevator had a short life1
 being removed in #aibb when the number 
of winter visitors increased far beyond 
its capacity4 ,however1 the two         
hydraulic systems were modified to      
operate in freezing                     
temperatures--presumably by the simple  
expedient of adding an antifreezing     
chemical to the water--and operation was
 placed on a year-round basis4  ,today  
the two ,fives-,lilles hydraulic systems
 remain in full use2 and visitors reach 
the ,tower's summit by ,edoux's elevator
 7fig4 #da71 which is all that remains  
of the original installation4           
,,balance ,,of ,,the ,,three ,,elevator 

,,systems  ,the ,otis ,system  ,negative
 effect    ,weight of cabin3 #bc1ijj lb4
  sin #ghi' 7incline of upper run7      
#bc1cij lb4   ,live load3 #dj persons   
#aej lb4  #f1jjj  sin #ghi'             
#e1hgb                                  
------  -- #bi1bfb lb4  ,positive effect
    ,counterweight3 #ee1jjj  sin #edce' 
7incline of lower run7                  
----------------------------------------
--                             #c 7rope 
gear ratio7                  #ad1idj lb4
    ,weight of piston and chariot3      
#cc1jfj  sin #edce'                     
------------------                      
#ab 7ratio7                   #b1bde    
,power3 #aef p4s4i4  #a1acd sq4 in4     
7piston area7                           
----------------------------------------
                      #ab 7ratio7       
#ad1gdb     #ca1ibg lb4  ,excess to     
overcome friction                       
#b1ffe lb4   ,the ,roux1 ,combaluzier   
and ,lepape ,system  ,negative effect   
,weight of cabin3 #ad1ajj  sin #edce'   

#aa1ejj lb4   ,live load3 #ajj persons  
#aej lb4  #ae1jjj  sin #edce'           
#ab1bbj                                 
------  -- #bc1gbj lb4  ,positive effect
    ,counterweight3 #f1fjj  sin #edce'  
#e1chj    ,power3 #aef p4s4i4  #b       
7pistons7  #a1cda4e sq4 in4 7piston     
area7                                   
----------------------------------------
--                          #ac 7ratio7 
#cb1aif     #cg1egf lb4                 
------     ---------- ,excess to        
overcome friction                       
#ac1hef lb4   ,the ,edoux ,system       
,negative effect    ,unbalanced weight  
of plungers 7necessary to raise full    
lower car and weight of cables on lower 
side7                #db1ccj lb4        
,live load3 #fj persons #aej lb4        
#i1jjj                                  
------  -- #ea1ccj lb4   ,positive      
effect    ,power3 #bbg4e p4s4i4  #b     
7plungers7  #abd sq4 in4 7plunger area7 
#ef1dbj lb4                             
----------   ,excess to overcome        

friction                                
#e1jij lb4     ,footnotes3  #a          
,translated from ,jean ,a4 ,keim1 ,la   
,tour ,eiffel1 ,paris1 #aiej4  #b ,the  
foundation footings exerted a pressure  
on the earth of about #bjj pounds per   
square foot1 roughly one-sixth that of  
the ,washington ,monument1 then the     
highest structure in the world4  #c ,a  
type of elevator known as the teagle was
 in use in some multistory ,english     
factories by about #ahce4 ,from its     
description1 this elevator appears to   
have been primarily for the use of      
passengers1 but it unquestionably       
carried freight as well4 ,the machine   
shown in figure #g had1 with the        
exception of a car safety1 all the      
features of later systems driven from   
line shafting--counterweight1 control   
from the car1 and reversal by straight  
and crossed belts4  #d ,the ,otis       
safety1 of which a modified form is     
still used1 consisted essentially of a  
leaf wagon spring1 on the car frame1    

kept strained by the tension of the     
hoisting cables4 ,if these gave way1 the
 spring1 released1 drove dogs into      
continuous racks on the vertical guides1
 holding the car or platform in place4  
#e ,a notable exception was the elevator
 in the ,washington ,monument4          
,installed in #ahhj for raising         
materials during the structure's final  
period of erection and afterwards       
converted to passenger service1 it was  
for many years the highest-rise elevator
 in the world 7about #ejj feet71 and was
 certainly among the slowest1 having a  
speed of #ej feet per minute4  #f       
,today1 although not limited by the     
machinery1 speeds are set at a maximum  
of about #a1djj feet per minute4 ,if    
higher speeds were used1 an             
impractically long express run would be 
necessary for starting and stopping in  
order to prevent an acceleration so     
rapid as to be uncomfortable to         
passengers and a strain on the          
equipment4  #g ,two machines1 by ,otis1 

in the ,demarest ,building1 ,fifth      
,avenue and #cc;d ,street1 ,new ,york4  
,they were in use for over #cj years4   
#h ,although the eventually successful  
application of electric power to the    
elevator did not occur until #aijd1 and 
therefore goes beyond the chronological 
scope of this discussion1 it was of such
 importance insofar as current practice 
is concerned as to be worthy of brief   
mention4 ,in that year the first        
gearless traction machine was installed 
by ,otis in a ,chicago theatre4 ,as the 
name implies1 the cables were not       
wrapped on a drum but passed1 from the  
car1 over a grooved sheave directly on  
the motor shaft1 the other ends being   
attached to the counterweights4 ,the    
result was a system of beautiful        
simplicity1 capable of any rise and     
speed with no proportionate increase in 
the number or size of its parts1 and    
free from any possibility of car or     
weights being drawn into the machinery4 
,this system is still the only one used 

for rises of over #ajj feet or so4 ,by  
the time of its introduction1 motor     
controls had been improved to the point 
of complete practicability4  #i         
,mechanical transmission of power by    
wire rope was a well developed practice 
at this time1 involving in many         
instances high powers and distances up  
to a mile4 ,to attempt this system in   
the ,eiffel ,tower1 crowded with        
structural work1 machinery and people1  
was another matter4  #aj ,according to  
,otis ,elevator ,company1 the final     
price1 because of extras1 was #cj1jjj4  
#aa ,in ,pall ,mall ,gazette1 as quoted 
in ,the ,engineering and ,building      
,record and the ,sanitary ,engineer1    
,may #be1 #ahhi1 vol4 #ai1 p4 #cde4  #ab
 ,from speech at annual summer meeting  
of ,institution of ,mechanical          
,engineers1 ,paris1 #ahhi4 ,quoted in   
,engineering1 ,july #e1 #ahhi1 vol4 #dh1
 p4 #ah4  #ac ,located near the ,tower1 
built for the ,paris fair of #ahgh4  #ad
 ,improved oil-well drilling techniques 

were influential in the intense but     
short burst of popularity enjoyed by    
direct plunger systems in the ,united   
,states between #ahii and #aiaj4 ,in    
,new ,york1 many such systems of        
#bjj-;foot rise1 and one of #chj feet1  
were installed4  #ae ,an obvious        
question arises here3 ,what prevents a  
plunger #bjj or #cjj feet long and no   
more than #af inches in diameter from   
buckling under its compressive loading8 
,the answer is simply that most of this 
length is not in compression but in     
tension4 ,the ,edoux rams1 when fully   
extended1 virtually hung from the upper 
car1 sustained by the weight of #ejj    
feet of cable on the other side of the  
sheaves4 ,as the upper car descended    
this effect diminished1 but as the rams 
moved back into the cylinders their     
unsupported length was correspondingly  
reduced4  #af ,m4 ,a4 ,ansaloni1 ,the   
,lifts in the ,eiffel ,tower1 quoted in 
,engineering1 ,july #e1 #ahhi1 vol4 #dh1
 p4 #bc4 ,the strength of steel when    

drawn into wire is increased            
tremendously4 ,breaking stresses of     
#adj1jjj p4s4i4 were not particularly   
high at the time4 ,special cables with  
breaking stresses of up to #cgj1jjj     
p4s4i4 were available4                  
,transcriber's ,notes3  ,passages in    
italics are indicated by underscore4    
,the original was printed in two columns
 per page4  ,illustrations have been    
moved to the nearest paragraph break4   
,the following misprints have been      
corrected3   ,trevethick's corrected to 
,trevithick's 7page #e7   then corrected
 to than 7page #ad7   smiliar corrected 
to similar 7page #ca7