,book provided by the ,new ,york        
,university ,library4           includes
 the original more than #ahj            
illustrations4       ,see #agjba-;h4htm 
or #agjba-;h4zip3                       
7https3_/_/www4gutenberg4org_/dirs_/#a_/
g_/j_/b_/agjba_/agjba-;h_/#agjba-;h4htm7
       or                               
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g_/j_/b_/agjba_/agjba-;h4zip7           
,,watch ,,and ,,clock ,,escapements  ,a 
,complete ,study in ,theory and         
,practice of the ,lever1 ,cylinder and  
,chronometer ,escapements1 ,together    
with a ,brief ,account of the ,origin   
and ,evolution of the ,escapement in    
,horology  ,compiled from the well-known
 ,escapement ,serials published in ,the 
,keystone  ,nearly ,two ,hundred        
,original ,illustrations                
,published by ,the ,keystone ,the ,organ
 of the ,jewelry and ,optical ,trades   
#aith  ,brown ,sts41 ,philadelphia1     
,u4,s4,a4  #aijd  ,all ,rights ,reserved
 ,copyright1 #aijd1 ,by ,b4 ,thorpe1    

,publisher of the ,keystone4            
,,preface   ,especially notable among   
the achievements of ,the ,keystone in   
the field of horology were the three    
serials devoted to the lever1 cylinder  
and chronometer escapements4 ,so highly 
valued were these serials when published
 that on the completion of each we were 
importuned to republish it in book form1
 but we deemed it advisable to postpone 
such publication until the completion of
 all three1 in order that the volume    
should be a complete treatise on the    
several escapements in use in horology4 
,the recent completion of the third     
serial gave us the opportunity to       
republish in book form1 and the present 
volume is the result4 ,we present it to 
the trade and students of horology happy
 in the knowledge that its contents have
 already received their approval4 ,an   
interesting addition to the book is the 
illustrated story of the escapements1   
from the first crude conceptions to     
their present perfection4               

,,contents     ,,chapter ,i4    ,,the   
,,detached ,,lever ,,escapement      #i 
,,chapter ,,ii4    ,,the ,,cylinder     
,,escapement          #aaa     ,,chapter
 ,,iii4    ,,the ,,chronometer          
,,escapement       #aca     ,,chapter   
,,iv4    ,,history ,,of ,,escapements   
#aec     ,,chapter ,v4    ,,putting ,,in
 ,a ,,new ,,cylinder        #afi        
,,index                            #agg 
,,watch ,,and ,,clock ,,escapements     
,,chapter ,i4  ,,the ,,detached ,,lever 
,,escapement4   ,in this treatise we do 
not propose to go into the history of   
this escapement and give a long         
dissertation on its origin and          
evolution1 but shall confine ourselves  
strictly to the designing and           
construction as employed in our best    
watches4 ,by designing1 we mean giving  
full instructions for drawing an        
escapement of this kind to the best     
proportions4 ,the workman will need but 
few drawing instruments1 and a          
drawing-board about #ae by #ah will be  

quite large enough4 ,the necessary      
drawing-instruments are a ,t-square with
 #ae blade2 a scale of inches divided   
into decimal parts2 two pairs dividers  
with pen and pencil points--one pair of 
these dividers to be #e and the other   
#f2 one ruling pen4 ,other instruments  
can be added as the workman finds he    
needs them4 ,those enumerated above1    
however1 will be all that are absolutely
 necessary4  ,illustration3 ,fig4 #a    
,we shall1 in addition1 need an arc of  
degrees1 which we can best make for     
ourselves4 ,to construct one1 we procure
 a piece of ,no4 #bd brass1 about #e    
long by #a wide4 ,we show such a piece  
of brass at ,a1 ,fig4 #a4 ,on this piece
 of brass we sweep two arcs with a pair 
of dividers set at precisely #e1 as     
shown 7reduced7 at a a and b b4 ,on     
these arcs we set off the space held in 
our dividers--that is #e--;as shown at  
the short radial lines at each end of   
the two arcs4 ,now it is a well-known   
fact that the space embraced by our     

dividers contains exactly sixty degrees 
of the arcs a a and b b1 or one-sixth of
 the entire circle2 consequently1 we    
divide the arcs a a and b b into sixty  
equal parts1 to represent degrees1 and  
at one end of these arcs we halve five  
spaces so we can get at half degrees4   
,illustration3 ,fig4 #b  ,before we take
 up the details of drawing an escapement
 we will say a few words about degrees1 
as this seems to be something difficult 
to understand by most pupils in horology
 when learning to draw parts of watches 
to scale4 ,at ,fig4 #b we show several  
short arcs of fifteen degrees1 all      
having the common center g4 ,most       
learners seem to have an idea that a    
degree must be a specific space1 like an
 inch or a foot4 ,now the first thing in
 learning to draw an escapement is to   
fix in our minds the fact that the      
extent of a degree depends entirely on  
the radius of the arc we employ4 ,to aid
 in this explanation we refer to ,fig4  
#b4 ,here the arcs c1 d1 e and f are all

 fifteen degrees1 although the linear   
extent of the degree on the arc c is    
twice that of the degree on the arc f4  
,when we speak of a degree in connection
 with a circle we mean the              
one-three-hundred-and-sixtieth part of  
the periphery of such a circle4 ,in     
dividing the arcs a a and b b we first  
divide them into six spaces1 as shown1  
and each of these spaces into ten minor 
spaces1 as is also shown4 ,we halve five
 of the degree spaces1 as shown at h4   
,we should be very careful about making 
the degree arcs shown at ,fig4 #a1 as   
the accuracy of our drawings depends a  
great deal on the perfection of the     
division on the scale ,a4 ,in connection
 with such a fixed scale of degrees as  
is shown at ,fig4 #a1 a pair of small   
dividers1 constantly set to a degree    
space1 is very convenient4   ,,making ,a
 ,,pair ,,of ,,dividers4  ,illustration3
 ,fig4 #c  ,to make such a pair of small
 dividers1 take a piece of hard sheet   
brass about #a_/bj thick1  wide1 #a     

long1 and shape it as shown at ,fig4 #c4
 ,it should be explained1 the part cut  
from the sheet brass is shown below the 
dotted line k1 the portion above 7,c7   
being a round handle turned from hard   
wood or ivory4 ,the slot l is sawn in1  
and two holes drilled in the end to     
insert the needle points i i4 ,in making
 the slot l we arrange to have the      
needle points come a little too close   
together to agree with the degree spaces
 on the arcs a a and b b4 ,we then put  
the small screw j through one of the    
legs ,d''1 and by turning j1 set the    
needle points i i to exactly agree with 
the degree spaces4 ,as soon as the      
points i i are set correctly1 j should  
be soft soldered fast4  ,the degree     
spaces on ,a are set off with these     
dividers and the spaces on ,a very      
carefully marked4 ,the upper and outer  
arc a a should have the spaces cut with 
a graver line1 while the lower one1 b b 
is best permanently marked with a       
carefully-made prick punch4 ,after the  

arc a a is divided1 the brass plate ,a  
is cut back to this arc so the divisions
 we have just made are on the edge4 ,the
 object of having two arcs on the plate 
,a is1 if we desire to get at the number
 of degrees contained in any arc of a #e
 radius we lay the scale ,a so the edge 
agrees with the arc a a1 and read off   
the number of degrees from the scale4   
,in setting dividers we employ the      
dotted spaces on the arc b b4           
,,delineating ,,an ,,escape ,,wheel4    
,illustration3 ,fig4 #d  ,we will now   
proceed to delineate an escape wheel for
 a detached lever4 ,we place a piece of 
good drawing-paper on our drawing-board 
and provide ourselves with a very hard  
7,,hhh7 drawing-pencil and a bottle of  
liquid ,india ink4 ,after placing our   
paper on the board1 we draw1 with the   
aid of our ,t-square1 a line through the
 center of the paper1 as shown at m m1  
,fig4 #d4 ,at #e from the lower margin  
of the paper we establish the point p   
and sweep the circle n n with a radius  

of #e4 ,we have said nothing about      
stretching our paper on the             
drawing-board2 still1                   
carefully-stretched paper is an         
important part of nice and correct      
drawing4 ,we shall subsequently give    
directions for properly stretching      
paper1 but for the present we will      
suppose the paper we are using is nicely
 tacked to the face of the drawing-board
 with the smallest tacks we can procure4
 ,the paper should not come quite to the
 edge of the drawing-board1 so as to    
interfere with the head of the          
,t-square4 ,we are now ready to commence
 delineating our escape wheel and a set 
of pallets to match4  ,the simplest form
 of the detached lever escapement in use
 is the one known as the ratchet-tooth  
lever escapement1 and generally found in
 ,english lever watches4 ,this form of  
escapement gives excellent results when 
well made2 and we can only account for  
it not being in more general use from   
the fact that the escape-wheel teeth are

 not so strong and capable of resisting 
careless usage as the club-tooth escape 
wheel4  ,it will be our aim to convey   
broad ideas and inculcate general       
principles1 rather than to give specific
 instructions for doing one thing one   
way4 ,the ratchet-tooth lever           
escapements of later dates have almost  
invariably been constructed on the      
ten-degree lever-and-pallet-action plan2
 that is1 the fork and pallets were     
intended to act through this arc4 ,some 
of the other specimens of this          
escapement have larger arcs--some as    
high as twelve degrees4                 
,,pallet-,,and-,,fork ,,action4         
,illustration3 ,fig4 #e  ,we illustrate 
at ,fig4 #e what we mean by ten degrees 
of pallet-and-fork action4 ,if we draw a
 line through the center of the pallet  
staff1 and also through the center of   
the fork slot1 as shown at a b1 ,fig4   
#e1 and allow the fork to vibrate five  
degrees each side of said lines a b1 to 
the lines a c and a c'1 the fork has    

what we term ten-degree pallet action4  
,if the fork and pallets vibrate six    
degrees on each side of the line a      
b--that is1 to the lines a d and a      
d'--we have twelve degrees pallet       
action4 ,if we cut the arc down so the  
oscillation is only four and one-quarter
 degrees on each side of a b1 as        
indicated by the lines a s and a s'1 we 
have a pallet-and-fork action of eight  
and one-half degrees2 which1 by the way1
 is a very desirable arc for a          
carefully-constructed escapement4  ,the 
controlling idea which would seem to    
rule in constructing a detached lever   
escapement1 would be to make it so the  
balance is free of the fork2 that is1   
detached1 during as much of the arc of  
the vibration of the balance as         
possible1 and yet have the action       
thoroughly sound and secure4 ,where a   
ratchet-tooth escapement is thoroughly  
well-made of eight and one-half degrees 
of pallet-and-fork action1 ten and      
one-half degrees of escape-wheel action 

can be utilized1 as will be explained   
later on4  ,we will now resume the      
drawing of our escape wheel1 as         
illustrated at ,fig4 #d4 ,in the drawing
 at ,fig4 #f we show the circle n n1    
which represents the periphery of our   
escape wheel2 and in the drawing we are 
supposed to be drawing it ten inches in 
diameter4  ,we produce the vertical line
 m passing through the center p of the  
circle n4 ,from the intersection of the 
circle n with the line m at i we lay off
 thirty degrees on each side1 and       
establish the points e f2 and from the  
center p1 through these points1 draw the
 radial lines p e' and p f'4 ,the points
 f e1 ,fig4 #f1 are1 of course1 just    
sixty degrees apart and represent the   
extent of two and one-half teeth of the 
escape wheel4 ,there are two systems on 
which pallets for lever escapements are 
made1 viz41 equidistant lockings and    
circular pallets4 ,the advantages       
claimed for each system will be         
discussed subsequently4 ,for the first  

and present illustration we will assume 
we are to employ circular pallets and   
one of the teeth of the escape wheel    
resting on the pallet at the point f2   
and the escape wheel turning in the     
direction of the arrow j4 ,if we imagine
 a tooth as indicated at the dotted     
outline at ,d1 ,fig4 #f1 pressing       
against a surface which coincides with  
the radial line p f1 the action would be
 in the direction of the line f h and at
 right angles to p f4 ,if we reason on  
the action of the tooth ,d1 as it       
presses against a pallet placed at f1 we
 see the action is neutral4             
,illustration3 ,fig4 #f   ,,establishing
 ,,the ,,center ,,of ,,pallet ,,staff4  
,illustration3 ,fig4 #g  ,with a        
fifteen-tooth escape wheel each tooth   
occupies twenty-four degrees1 and from  
the point f to e would be two and       
one-half tooth-spaces4 ,we show the     
dotted points of four teeth at ,d ,d'   
,d'',d'''4 ,to establish the center of  
the pallet staff we draw a line at right

 angles to the line p e' from the point 
e so it intersects the line f h at k4   
,for drawing a line at right angles to  
another line1 as we have just done1 a   
hard-rubber triangle1 shaped as shown at
 ,c1 ,fig4 #g1 can be employed4 ,to use 
such a triangle1 we place it so the     
right1 or ninety-degrees angle1 rests at
 e1 as shown at the dotted triangle ,c1 
,fig4 #f1 and the long side coincides   
with the radial line p e'4 ,if the short
 side of the hard-rubber triangle is too
 short1 as indicated1 we place a short  
ruler so it rests against the edge1 as  
shown at the dotted line g e1 ,fig4 #g1 
and while holding it securely down on   
the drawing we remove the triangle1 and 
with a fine-pointed pencil draw the line
 e g1 ,fig4 #f1 by the short rule4 ,let 
us imagine a flat surface placed at e so
 its face was at right angles to the    
line g e1 which would arrest the tooth  
,d'' after the tooth ,d resting on f had
 been released and passed through an arc
 of twelve degrees4 ,a tooth resting on 

a flat surface1 as imagined above1 would
 also rest dead4 ,as stated previously1 
the pallets we are considering have     
equidistant locking faces and correspond
 to the arc l l1 ,fig4 #f4  ,in order to
 realize any power from our escape-wheel
 tooth1 we must provide an impulse face 
to the pallets faced at f e2 and the    
problem before us is to delineate these 
pallets so that the lever will be       
propelled through an arc of eight and   
one-half degrees1 while the escape wheel
 is moving through an arc of ten and    
one-half degrees4 ,we make the arc of   
fork action eight and one-half degrees  
for two reasons--7#a7 because most      
text-books have selected ten degrees of 
fork-and-pallet action2 7#b7 because    
most of the finer lever escapements of  
recent construction have a lever action 
of less than ten degrees4   ,,laying    
,,out ,,escape-,,wheel ,,teeth4  ,to lay
 out or delineate our escape-wheel      
teeth1 we continue our drawing shown at 
,fig4 #f1 and reproduce this cut very   

nearly at ,fig4 #h4 ,with our dividers  
set at five inches1 we sweep the short  
arc a a' from f as a center4 ,it is to  
be borne in mind that at the point f is 
located the extreme point of an         
escape-wheel tooth4 ,on the arc a a we  
lay off from p twenty-four degrees1 and 
establish the point b2 at twelve degrees
 beyond b we establish the point c4     
,from f we draw the lines f b and f c2  
these lines establishing the form and   
thickness of the tooth ,d4 ,to get the  
length of the tooth1 we take in our     
dividers one-half a tooth space1 and on 
the radial line p f establish the point 
d and draw circle d' d'4  ,to facilitate
 the drawing of the other teeth1 we draw
 the circles d' c'1 to which the lines f
 b and f c are tangent1 as shown4 ,we   
divide the circle n n1 representing the 
periphery of our escape wheel1 into     
fifteen spaces1 to represent teeth1     
commencing at f and continued as shown  
at o o until the entire wheel is        
divided4 ,we only show four teeth       

complete1 but the same methods as       
produced these will produce them all4   
,to briefly recapitulate the            
instructions for drawing the teeth for  
the ratchet-tooth lever escapement3 ,we 
draw the face of the teeth at an angle  
of twenty-four degrees to a radial line2
 the back of the tooth at an angle of   
thirty-six degrees to the same radial   
line2 and make teeth half a tooth-space 
deep or long4  ,illustration3 ,fig4 #h  
,we now come to the consideration of the
 pallets and how to delineate them4 ,to 
this we shall add a careful analysis of 
their action4 ,let us1 before proceeding
 further1 think a little over some of   
the factors involved4 ,to aid in this   
thinking or reasoning on the matter1 let
 us draw the heavy arc l extending from 
a little inside of the circle n at f to 
the circle n at e4 ,if now we imagine   
our escape wheel to be pressed forward  
in the direction of the arrow j1 the    
tooth ,d would press on the arc l and be
 held4 ,if1 however1 we should revolve  

the arc l on the center k in the        
direction of the arrow i1 the tooth ,d  
would escape from the edge of l and the 
tooth ,d'' would pass through an arc    
7reckoning from the center p7 of twelve 
degrees1 and be arrested by the inside  
of the arc l at e4 ,if we now should    
reverse the motion and turn the arc l   
backward1 the tooth at e would1 in turn1
 be released and the tooth following    
after ,d 7but not shown7 would engage l 
at f4 ,by supplying motive to revolve   
the escape wheel 7,e7 represented by the
 circle n1 and causing the arc l to     
oscillate back and forth in exact       
intervals of time1 we should have1 in   
effect1 a perfect escapement4 ,to       
accomplish automatically such           
oscillations is the problem we have now 
on hand4   ,,how ,,motion ,,is          
,,obtained4  ,in clocks1 the            
back-and-forth movement1 or oscillating 
motion1 is obtained by employing a      
pendulum2 in a movable timepiece we make
 use of an equally-poised wheel of some 

weight on a pivoted axle1 which device  
we term a balance2 the vibrations or    
oscillations being obtained by applying 
a coiled spring1 which was first called 
a pendulum spring1 then a balance       
spring1 and finally1 from its diminutive
 size and coil form1 a hairspring4 ,we  
are all aware that for the motive power 
for keeping up the oscillations of the  
escaping circle l we must contrive to   
employ power derived from the teeth ,d  
of the escape wheel4 ,about the most    
available means of conveying power from 
the escape wheel to the oscillating arc 
l is to provide the lip of said arc with
 an inclined plane1 along which the     
tooth which is disengaged from l at f to
 slide and move said arc l through--in  
the present instance an arc of eight and
 one-half degrees1 during the time the  
tooth ,d is passing through ten and     
one-half degrees4 ,this angular motion  
of the arc l is represented by the      
radial lines k f' and k r1 ,fig4 #h4 ,we
 desire to impress on the reader's mind 

the idea that each of these angular     
motions is not only required to be made1
 but the motion of one mobile must      
convey power to another mobile4  ,in    
this case the power conveyed from the   
mainspring to the escape wheel is to be 
conveyed to the lever1 and by the lever 
transmitted to the balance4 ,we know it 
is the usual plan adopted by text-books 
to lay down a certain formula for       
drawing an escapement1 leaving the pupil
 to work and reason out the principles  
involved in the action4 ,in the plan we 
have adopted we propose to induct the   
reader into the why and how1 and point  
out to him the rules and methods of     
analysis of the problem1 so that he can1
 if required1 calculate mathematically  
exactly how many grains of force the    
fork exerts on the jewel pin1 and also  
how much 7or1 rather1 what percentage7  
of the motive power is lost in various  
power leaks1 like drop and lost motion4 
,in the present case the mechanical     
result we desire to obtain is to cause  

our lever pivoted at k to vibrate back  
and forth through an arc of eight and   
one-half degrees2 this lever not only to
 vibrate back and forth1 but also to    
lock and hold the escape wheel during a 
certain period of time2 that is1 through
 the period of time the balance is      
performing its excursion and the jewel  
pin free and detached from the fork4    
,we have spoken of paper being employed 
for drawings1 but for very accurate     
delineations we would recommend the     
horological student to make drawings on 
a flat metal plate1 after perfectly     
smoothing the surface and blackening it 
by oxidizing4   ,,pallet-,,and-,,fork   
,,action4  ,by adopting eight and       
one-half degrees pallet-and-fork action 
we can utilize ten and one-half degrees 
of escape-wheel action4 ,we show at ,a  
,a'1 ,fig4 #i1 two teeth of a           
ratchet-tooth escape wheel reduced      
one-half2 that is1 the original drawing 
was made for an escape wheel ten inches 
in diameter4 ,we shall make a radical   

departure from the usual practice in    
making cuts on an enlarged scale1 for   
only such parts as we are talking about4
 ,to explain1 we show at ,fig4 #aj about
 one-half of an escape wheel one eighth 
the size of our large drawing2 and when 
we wish to show some portion of such    
drawing on a larger scale we will       
designate such enlargement by saying    
one-fourth1 one-half or full size4      
,illustration3 ,fig4 #i  ,at ,fig4 #i we
 show at half size that portion of our  
escapement embraced by the dotted lines 
d1 ,fig4 #aj4 ,this plan enables us to  
show very minutely such parts as we have
 under consideration1 and yet occupy but
 little space4 ,the arc a1 ,fig4 #i1    
represents the periphery of the escape  
wheel4 ,on this line1 ten and one-half  
degrees from the point of the tooth ,a1 
we establish the point c and draw the   
radial line c c'4 ,it is to be borne in 
mind that the arc embraced between the  
points b and c represents the duration  
of contact between the tooth ,a and the 

entrance pallet of the lever4 ,the space
 or short arc c n represents the drop of
 the tooth4  ,this arc of one and       
one-half degrees of escape-wheel        
movement is a complete loss of six and  
one-fourth per cent4 of the entire power
 of the mainspring1 as brought down to  
the escapement2 still1 up to the present
 time1 no remedy has been devised to    
overcome it4 ,all the other escapements1
 including the chronometer1 duplex and  
cylinder1 are quite as wasteful of      
power1 if not more so4 ,it is usual to  
construct ratchet-tooth pallets so as to
 utilize but ten degrees of escape-wheel
 action2 but we shall show that half a  
degree more can be utilized by adopting 
the eight and one-half degree fork      
action and employing a double-roller    
safety action to prevent over-banking4  
,illustration3 ,fig4 #aj  ,from the     
point e1 which represents the center of 
the pallet staff1 we draw through b the 
line e f4 ,at one degree below e f we   
draw the line e g1 and seven and        

one-half degrees below the line e g we  
draw the line e h4 ,for delineating the 
lines e g1 etc41 correctly1 we employ a 
degree-arc2 that is1 on the large       
drawing we are making we first draw the 
line e b f1 ,fig4 #aj1 and then1 with   
our dividers set at five inches1 sweep  
the short arc i1 and on this lay off    
first one degree from the intersection  
of f e with the arc i1 and through this 
point draw the line e g4  ,from the     
intersection of the line f e with the   
arc i we lay off eight and one-half     
degrees1 and through this point draw the
 line e h4 ,bear in mind that we are    
drawing the pallet at ,b to represent   
one with eight and one-half degrees     
fork-and-pallet action1 and with        
equidistant lockings4 ,if we reason on  
the matter under consideration1 we will 
see the tooth ,a and the pallet ,b1     
against which it acts1 part or separate 
when the tooth arrives at the point c2  
that is1 after the escape wheel has     
moved through ten and one-half degrees  

of angular motion1 the tooth drops from 
the impulse face of the pallet and falls
 through one and one-half degrees of    
arc1 when the tooth ,a''1 ,fig4 #aj1 is 
arrested by the exit pallet4  ,to locate
 the position of the inner angle of the 
pallet ,b1 sweep the short arc l by     
setting the dividers so one point or leg
 rests at the center e and the other at 
the point c4 ,somewhere on this arc l is
 to be located the inner angle of our   
pallet4 ,in delineating this angle1     
,moritz ,grossman1 in his ,prize ,essay 
on the ,detached ,lever ,escapement1    
makes an error1 in ,plate ,,iii of large
 ,english edition1 of more than his     
entire lock1 or about two degrees4 ,we  
make no apologies for calling attention 
to this mistake on the part of an       
authority holding so high a position on 
such matters as ,mr4 ,grossman1 because 
a mistake is a mistake1 no matter who   
makes it4  ,we will say no more of this 
error at present1 but will farther on   
show drawings of ,mr4 ,grossman's faulty

 method1 and also the correct method of 
drawing such a pallet4 ,to delineate the
 locking face of our pallet1 from the   
point formed by the intersection of the 
lines e g b b'1 ,fig4 #i1 as a center1  
we draw the line j at an angle of twelve
 degrees to b b''4 ,in doing this we    
employ the same method of establishing  
the angle as we made use of in drawing  
the lines e g and e h1 ,fig4 #aj4 ,the  
line j establishes the locking face of  
the pallet ,b4 ,setting the locking face
 of the pallet at twelve degrees has    
been found in practice to give a safe   
draw to the pallet and keep the lever   
secure against the bank4 ,it will be    
remembered the face of the escape-wheel 
tooth was drawn at twenty-four degrees  
to a radial line of the escape wheel1   
which1 in this instance1 is the line b  
b'1 ,fig4 #i4 ,it will now be seen that 
the angle of the pallet just halves this
 angle1 and consequently the tooth ,a   
only rests with its point on the locking
 face of the pallet4 ,we do not show the

 outlines of the pallet ,b1 because we  
have not so far pointed out the correct 
method of delineating it4   ,,methods   
,,of ,,making ,,good ,,drawing          
,,instruments4  ,perhaps we cannot do   
our readers a greater favor than to     
digress from the study of the detached  
lever escapement long enough to say a   
few words about drawing instruments and 
tablets or surfaces on which to         
delineate1 with due precision1          
mechanical designs or drawings4         
,ordinary drawing instruments1 even of  
the higher grades1 and costing a good   
deal of money1 are far from being       
satisfactory to a man who has the proper
 idea of accuracy to be rated as a      
first-class mechanic4 ,ordinary         
compasses are obstinate when we try to  
set them to the hundredth of an inch2   
usually the points are dull and         
ill-shapen2 if they make a puncture in  
the paper it is unsightly4  ,watchmakers
 have one advantage1 however1 because   
they can very easily work over a cheap  

set of drawing instruments and make them
 even superior to anything they can buy 
at the art stores4 ,to illustrate1 let  
us take a cheap pair of brass or        
,german-silver five-inch dividers and   
make them over into needle points and   
spring set4 ,to do this the points are  
cut off at the line a a1 ,fig #aa1 and a
 steel tube is gold-soldered on each    
leg4 ,the steel tube is made by taking a
 piece of steel wire which will fit a   
,no4 #af chuck of a ,whitcomb lathe1 and
 drilling a hole in the end about       
one-fourth of an inch deep and about the
 size of a ,no4 #c sewing needle4 ,we   
,show at ,fig4 #ab a view of the point  
,a'1 ,fig4 #aa1 enlarged1 and the steel 
tube we have just drilled out attached  
at ,c4 ,about the best way to attach ,c 
is to solder4 ,after the tube ,c is     
attached a hole is drilled through ,a'  
at d1 and the thumb-screw d inserted4   
,this thumb-screw should be of steel1   
and hardened and tempered4 ,the use of  
this screw is to clamp the needle point4

 ,with such a device as the tube ,c and 
set-screw d1 a ,no4 #c needle is used   
for a point2 but for drawings on paper a
 turned point1 as shown at ,fig #ac1 is 
to be preferred4 ,such points can be    
made from a ,no4 #c needle after        
softening enough to be turned so as to  
form the point c4 ,this point at the    
shoulder f should be about #ab_/ajjj of 
an inch1 or the size of a fourth-wheel  
pivot to an eighteen size movement4     
,illustration3 ,fig4 #aa  ,illustration3
 ,fig4 #ab  ,illustration3 ,fig4 #ac    
,illustration3 ,fig4 #ad  ,the idea is1 
when drawing on paper the point c enters
 the paper4 ,for drawing on metal the   
form of the point is changed to a simple
 cone1 as shown at ,b' c1 ,fig4 #ac4    
such cones can be turned carefully1 then
 hardened and tempered to a straw color2
 and when they become dull1 can be      
ground by placing the points in a wire  
chuck and dressing them up with an emery
 buff or an ,arkansas slip4 ,the        
opposite leg of the dividers is the one 

to which is attached the spring for     
close setting of the points4  ,in making
 this spring1 we take a piece of steel  
about two and one-fourth inches long and
 of the same width as the leg of the    
divider1 and attach it to the inside of 
the leg as shown at ,fig4 #ad1 where ,d 
represents the spring and ,a the leg of 
the dividers4 ,the spring ,d has a short
 steel tube ,c'' and set-screw d'' for a
 fine point like ,b or ,b'4 ,in the     
lower end of the leg ,a1 ,fig4 #ad1 is  
placed the milled-head screw g1 which   
serves to adjust the two points of the  
dividers to very close distances4 ,the  
spring ,d is1 of course1 set so it would
 press close to the leg ,a if the screw 
g did not force it away4   ,,spring     
,,and ,,adjusting ,,screw ,,for         
,,drawing ,,instruments4  ,illustration3
 ,fig4 #ae  ,it will be seen that we can
 apply a spring ,d and adjusting screw  
opposite to the leg which carries the   
pen or pencil point of all our dividers 
if we choose to do so2 but it is for    

metal drawing that such points are of   
the greatest advantage1 as we can secure
 an accuracy very gratifying to a       
workman who believes in precision4 ,for 
drawing circles on metal1 bar compasses 
are much the best1 as they are almost   
entirely free from spring1 which attends
 the jointed compass4 ,to make 7because 
they cannot be bought7 such an          
instrument1 take a piece of flat steel1 
one-eighth by three-eighths of an inch  
and seven inches long1 and after turning
 and smoothing it carefully1 make a     
slide half an inch wide1 as shown at    
,fig4 #ae1 with a set-screw h on top to 
secure it at any point on the bar ,e4   
,in the lower part of the slide ,f is   
placed a steel tube like ,c1 shown in   
,figs4 #ab and #ad1 with set-screw for  
holding points like ,b ,b'1 ,fig4 #ac4  
,at the opposite end of the bar ,e is   
placed a looped spring ,g1 which carries
 a steel tube and point like the spring 
,d1 ,fig4 #ad4 ,above this tube and     
point1 shown at j1 ,fig4 #ae1 is placed 

an adjustment screw k for fine          
adjustment4 ,the inner end of the screw 
k rests against the end of the bar ,e4  
,the tendency of the spring ,g is to    
close upon the end of ,e2 consequently  
if we make use of the screw k to force  
away the lower end of ,g1 we can set the
 fine point in j to the greatest        
exactness4  ,the spring ,g is made of a 
piece of steel one-eighth of an inch    
square1 and secured to the bar ,e with a
 screw and steady pins at m4 ,a pen and 
pencil point attachment can be added to 
the spring ,g2 but in case this is done 
it would be better to make another      
spring like ,g without the point j1 and 
with the adjusting screw placed at l4   
,in fitting pen and pencil points to a  
spring like ,g it would probably be     
economical to make them outright2 that  
is1 make the blades and screw for the   
ruling pen and a spring or clamping tube
 for the pencil point4   ,,consideration
 ,,of ,,detached ,,lever ,,escapement   
,,resumed4  ,we will now1 with our      

improved drawing instruments1 resume the
 consideration of the ratchet-tooth     
lever escapement4 ,we reproduce at ,fig4
 #af a portion of diagram ,,iii1 from   
,moritz ,grossmann's ,prize ,essay on   
the ,detached ,lever ,escapement1 in    
order to point out the error in         
delineating the entrance pallet to which
 we previously called attention4 ,the   
cut1 as we give it1 is not quite        
one-half the size of ,mr4 ,grossmann's  
original plate4  ,in the cut we give the
 letters of reference employed the same 
as on the original engraving1 except    
where we use others in explanation4 ,the
 angular motion of the lever and pallet 
action as shown in the cut is ten       
degrees2 but in our drawing1 where we   
only use eight and one-half degrees1 the
 same mistake would give proportionate  
error if we did not take the means to   
correct it4 ,the error to which we refer
 lies in drawing the impulse face of the
 entrance pallet4 ,the impulse face of  
this pallet as drawn by ,mr4 ,grossmann 

would not1 from the action of the       
engaging tooth1 carry this pallet       
through more than eight degrees of      
angular motion2 consequently1 the tooth 
which should lock on the exit pallet    
would fail to do so1 and strike the     
impulse face4  ,we would here beg to add
 that nothing will so much instruct a   
person desiring to acquire sound ideas  
on escapements as making a large model4 
,the writer calls to mind a wood model  
of a lever escapement made by one of the
 boys in the ,elgin factory about a year
 or two after ,mr4 ,grossmann's prize   
essay was published4 ,it went from hand 
to hand and did much toward establishing
 sound ideas as regards the correct     
action of the lever escapement in that  
notable concern4  ,if a horological     
student should construct a large model  
on the lines laid down in ,mr4          
,grossmann's work1 the entrance pallet  
would be faulty in form and would not   
properly perform its functions4 ,why8   
perhaps says our reader4 ,in reply let  

us analyze the action of the tooth ,b as
 it rests on the pallet ,a4 ,now1 if we 
move this pallet through an angular     
motion of one and one-half degrees on   
the center g 7which also represents the 
center of the pallet staff71 the tooth  
,b is disengaged from the locking face  
and commences to slide along the impulse
 face of the pallet and drops1 that is1 
falls from the pallet1 when the inner   
angle of the pallet is reached4         
,illustration3 ,fig4 #af  ,this inner   
angle1 as located by ,mr4 ,grossmann1 is
 at the intersection of the short arc i 
with the line g n1 which limits the     
ten-degree angular motion of the        
pallets4 ,if we carefully study the     
drawing1 we will see the pallet has only
 to move through eight degrees of       
angular motion of the pallet staff for  
the tooth to escape1 because the tooth  
certainly must be disengaged when the   
inner angle of the pallet reaches the   
peripheral line a4 ,the true way to     
locate the position of the inner angle  

of the pallet1 is to measure down on the
 arc i ten degrees from its intersection
 with the peripheral line a and locate a
 point to which a line is drawn from the
 intersection of the line g m with the  
radial line a c1 thus defining the inner
 angle of the entrance pallet4 ,we will 
name this point the point x4  ,it may   
not be amiss to say the arc i is swept  
from the center g through the point u1  
said point being located ten degrees    
from the intersection of the radial a c 
with the peripheral line a4 ,it will be 
noticed that the inner angle of the     
entrance pallet ,a seems to extend      
inward1 beyond the radial line a j1 that
 is1 toward the pallet center g1 and    
gives the appearance of being much      
thicker than the exit pallet ,a'2 but we
 will see on examination that the       
extreme angle x of the entrance pallet  
must move on the arc i and1             
consequently1 cross the peripheral line 
a at the point u4 ,if we measure the    
impulse faces of the two pallets ,a ,a'1

 we will find them nearly alike in      
linear extent4  ,mr4 ,grossmann1 in     
delineating his exit pallet1 brings the 
extreme angle 7shown at #d7 down to the 
periphery of the escape1 as shown in the
 drawing1 where it extends beyond the   
intersection of the line g f with the   
radial line a #c4 ,the correct form for 
the entrance pallet should be to the    
dotted line z x y4  ,illustration3 ,fig4
 #ag  ,we have spoken of engaging and   
disengaging frictions2 we do not know   
how we can better explain this term than
 by illustrating the idea with a        
grindstone4 ,suppose two men are        
grinding on the same stone2 each has1   
say1 a cold chisel to grind1 as shown at
 ,fig4 #ag1 where ,g represents the     
grindstone and ,n ,n' the cold chisels4 
,the grindstone is supposed to be       
revolving in the direction of the arrow4
 ,the chisels ,n and ,n' are both being 
ground1 but the chisel ,n' is being cut 
much the more rapidly1 as each particle 
of grit of the stone as it catches on   

the steel causes the chisel to hug the  
stone and bite in deeper and deeper2    
while the chisel shown at ,n is thrust  
away by the action of the grit4 ,now1   
friction of any kind is only a sort of  
grinding operation1 and the same        
principles hold good4   ,,the           
,,necessity ,,for ,,good ,,instruments4 
,it is to be hoped the reader who       
intends to profit by this treatise has  
fitted up such a pair of dividers as    
those we have described1 because it is  
only with accurate instruments he can   
hope to produce drawings on which any   
reliance can be placed4 ,the drawing of 
a ratchet-tooth lever escapement of     
eight and one-half degrees pallet action
 will now be resumed4 ,in the drawing at
 ,fig4 #ah is shown a complete          
delineation of such an escapement with  
eight and one-half degrees of pallet    
action and equidistant locking faces4   
,it is1 of course1 understood the escape
 wheel is to be drawn ten inches in     
diameter1 and that the degree arcs shown

 in ,fig4 #a will be used4  ,we commence
 by carefully placing on the            
drawing-board a sheet of paper about    
fifteen inches square1 and then         
vertically through the center draw the  
line a' a''4 ,at some convenient        
position on this line is established the
 point a1 which represents the center of
 the escape wheel4 ,in this drawing it  
is not important that the entire escape 
wheel be shown1 inasmuch as we have     
really to do with but a little over     
sixty degrees of the periphery of the   
escape wheel4 ,with the dividers        
carefully set at five inches1 from a1 as
 a center1 we sweep the arc n n1 and    
from the intersection of the            
perpendicular line a' a'' with the arc n
 we lay off on each side thirty degrees 
from the brass degree arc1 and through  
the points thus established are drawn   
the radial lines a b' and a d'4         
,illustration3 ,fig4 #ah  ,the point on 
the arc n where it intersects with the  
line b' is termed the point b4 ,at the  

intersection of the radial line a d' is 
established the point d4 ,we take ten   
and one-half degrees in the dividers1   
and from the point b establish the point
 c1 which embraces the arc of the escape
 wheel which is utilized by the pallet  
action4 ,through the point b the line h'
 h is drawn at right angles to the line 
a b'4 ,the line j j' is also drawn at   
right angles to the line a d' through   
the point d4 ,we now have an            
intersection of the lines just drawn in 
common with the line a a' at the point  
g1 said point indicating the center of  
the pallet action4  ,the dividers are   
now set to embrace the space between the
 points b and g on the line h' h1 and   
the arc f f is swept2 which1 in proof of
 the accuracy of the work1 intersects   
the arc n at the point d4 ,this arc     
coincides with the locking faces of both
 pallets4 ,to lay out the entrance      
pallet1 the dividers are set to five    
inches1 and from g as a center the short
 arc o o is swept4 ,on this arc one     

degree is laid off below the line h' h1 
and the line g i drawn4 ,the space      
embraced between the lines h and i on   
the arc f represents the locking face of
 the entrance pallet1 and the point     
formed at the intersection of the line g
 i with the arc f is called the point p4
 ,to give the proper lock to the face of
 the pallet1 from the point p as a      
center is swept the short arc r r1 and  
from its intersection with the line a b'
 twelve degrees are laid off and the    
line b s drawn1 which defines the       
locking face of the entrance pallet4    
,from g as a center is swept the arc c' 
c'1 intersecting the arc n n at c4 ,on  
this arc 7c7 is located the inner angle 
of the entrance pallet4 ,the dividers   
are set to embrace the space on the arc 
c' between the lines g h' and g k4 ,with
 this space in the dividers one leg is  
set at the point c1 measuring down on   
the arc c' and establishing the point t4
 ,the points p and t are then connected1
 and thus the impulse face of the       

entrance pallet ,b is defined4 ,from the
 point t is drawn the line t t'1        
parallel to the line b s1 thus defining 
the inner face of the entrance pallet4  
,,delineating ,,the ,,exit ,,pallet4    
,to delineate the exit pallet1 sweep the
 short arc u u 7from g as a center7 with
 the dividers set at five inches1 and   
from the intersection of this arc with  
the line g j' set off eight and one-half
 degrees and draw the line g l4 ,at one 
degree below this line is drawn the line
 g m4 ,the space on the arc f between   
these lines defines the locking face of 
the exit pallet4 ,the point where the   
line g m intersects the arc f is named  
the point x4 ,from the point x is       
erected the line x w1 perpendicular to  
the line g m4 ,from x as a center1 and  
with the dividers set at five inches1   
the short arc y y is swept1 and on this 
arc are laid off twelve degrees1 and the
 line x z is drawn1 which line defines  
the locking face of the exit pallet4    
,next is taken ten and one-half degrees 

from the brass degree-scale1 and from   
the point d on the arc n the space named
 is laid off1 and thus is established   
the point v2 and from g as a center is  
swept the arc v' v' through the point v4
 ,it will be evident on a little        
thought1 that if the tooth ,a' impelled 
the exit pallet to the position shown1  
the outer angle of the pallet must      
extend down to the point v1 on the arc  
v' v'2 consequently1 we define the      
impulse face of this pallet by drawing a
 line from point x to v4 ,to define the 
outer face of the exit pallet1 we draw  
the line v e parallel to the line x z4  
,there are no set rules for drawing the 
general form of the pallet arms1 only to
 be governed by and conforming to about 
what we would deem appropriate1 and to  
accord with a sense of proportion and   
mechanical elegance4 ,ratchet-tooth     
pallets are usually made in what is     
termed close pallets2 that is1 the      
pallet jewel is set in a slot sawed in  
the steel pallet arm1 which is          

undoubtedly the strongest and most      
serviceable form of pallet made4 ,we    
shall next consider the ratchet-tooth   
lever escapement with circular pallets  
and ten degrees of pallet action4       
,,delineating ,,circular ,,pallets4  ,to
 delineate circular pallets for a       
ratchet-tooth lever escapement1 we      
proceed very much as in the former      
drawing1 by locating the point ,a1 which
 represents the center of the escape    
wheel1 at some convenient point1 and    
with the dividers set at five inches1   
sweep the arc m1 to represent the       
periphery of the escape wheel1 and then 
draw the vertical line ,a ,b'1 ,fig4    
#ai4 ,we 7as before7 lay off thirty     
degrees on the arc m each side of the   
intersection of said arc with the line  
,a ,b'1 and thus establish on the arc m 
the points a b1 and from ,a as a center 
draw through the points so established  
the radial lines ,a a' and ,a b'4  ,we  
erect from the point a a perpendicular  
to the line ,a a1 and1 as previously    

explained1 establish the pallet center  
at ,b4 ,inasmuch as we are to employ    
circular pallets1 we lay off to the left
 on the arc m1 from the point a1 five   
degrees1 said five degrees being half of
 the angular motion of the escape wheel 
utilized in the present drawing1 and    
thus establish the point c1 and from ,a 
as a center draw through this point the 
radial line ,a c'4 ,to the right of the 
point a we lay off five degrees and     
establish the point d4 ,to illustrate   
the underlying principle of our circular
 pallets3 with one leg of the dividers  
set at ,b we sweep through the points c 
a d the arcs c'' a'' d''4  ,from ,b as a
 center1 we continue the line ,b a to f1
 and with the dividers set at five      
inches1 sweep the short arc e e4 ,from  
the intersection of this arc with the   
line ,b f we lay off one and a half     
degrees and draw the line ,b g1 which   
establishes the extent of the lock on   
the entrance pallet4 ,it will be noticed
 the linear extent of the locking face  

of the entrance pallet is greater than  
that of the exit1 although both         
represent an angle of one and a half    
degrees4 ,really1 in practice1 this     
discrepancy is of little importance1 as 
the same side-shake in banking would    
secure safety in either case4           
,illustration3 ,fig4 #ai  ,the fault we 
previously pointed out1 of the generally
 accepted method of delineating a       
detached lever escapement1 is not as    
conspicuous here as it is where the     
pallets are drawn with equidistant      
locking faces2 that is1 the inner angle 
of the entrance pallet 7shown at s7 does
 not have to be carried down on the arc 
d' as far to insure a continuous pallet 
action of ten degrees1 as with the      
pallets with equidistant locking faces4 
,still1 even here we have carried the   
angle s down about half a degree on the 
arc d'1 to secure a safe lock on the    
exit pallet4   ,,the ,,amount ,,of      
,,lock4  ,if we study the large drawing1
 where we delineate the escape wheel ten

 inches in diameter1 it will readily be 
seen that although we claim one and a   
half degrees lock1 we really have only  
about one degree1 inasmuch as the curve 
of the peripheral line m diverges from  
the line ,b f1 and1 as a consequence1   
the absolute lock of the tooth ,c on the
 locking face of the entrance pallet ,e 
is but about one degree4 ,under these   
conditions1 if we did not extend the    
outer angle of the exit pallet at t down
 to the peripheral line m1 we would     
scarcely secure one-half a degree of    
lock4 ,this is true of both pallets4 ,we
 must carry the pallet angles at r s n t
 down on the circles c'' d' if we would 
secure the lock and impulse we claim2   
that is1 one and a half degrees lock and
 eight and a half degrees impulse4      
,now1 while the writer is willing to    
admit that a one-degree lock in a sound1
 well-made escapement is ample1 still he
 is not willing to allow of a looseness 
of drawing to incorporate to the extent 
of one degree in any mechanical matter  

demanding such extreme accuracy as the  
parts of a watch4 ,it has been claimed  
that such defects can1 to a great       
extent1 be remedied by setting the      
escapement closer2 that is1 by bringing 
the centers of the pallet staff and     
escape wheel nearer together4 ,we hold  
that such a course is not mechanical    
and1 further1 that there is not the     
slightest necessity for such a policy4  
,,advantage ,,of ,,making ,,large       
,,drawings4  ,by making the drawings    
large1 as we have already suggested and 
insisted upon1 we can secure an accuracy
 closely approximating perfection4 ,as1 
for instance1 if we wish to get a lock  
of one and a half degrees on the locking
 face of the entrance pallet ,e1 we     
measure down on the arc c'' from its    
intersection with the peripheral line m 
one and a half degrees1 and establish   
the point r and thus locate the outer   
angle of the entrance pallet ,e1 so     
there will really be one and a half     
degrees of lock2 and by measuring down  

on the arc d' ten degrees from its      
intersection with the peripheral line m1
 we locate the point s1 which determines
 the position of the inner angle of the 
entrance pallet1 and we know for a      
certainty that when this inner angle is 
freed from the tooth it will be after   
the pallet 7and1 of course1 the lever7  
has passed through exactly ten degrees  
of angular motion4  ,for locating the   
inner angle of the exit pallet1 we      
measure on the arc d'1 from its         
intersection with the peripheral line m1
 eight and a half degrees1 and establish
 the point n1 which locates the position
 of this inner angle2 and1 of course1   
one and a half degrees added on the arc 
d' indicates the extent of the lock on  
this pallet4 ,such drawings not only    
enable us to theorize to extreme        
exactness1 but also give us             
proportionate measurements1 which can be
 carried into actual construction4      
,,the ,,club-,,tooth ,,lever            
,,escapement4  ,we will now take up the 

club-tooth form of the lever escapement4
 ,this form of tooth has in the ,united 
,states and in ,switzerland almost      
entirely superceded the ratchet tooth4  
,the principal reason for its finding so
 much favor is1 we think1 chiefly owing 
to the fact that this form of tooth is  
better able to stand the manipulations  
of the able-bodied watchmaker1 who      
possesses more strength than skill4 ,we 
will not pause now1 however1 to consider
 the comparative merits of the ratchet  
and club-tooth forms of the lever       
escapement1 but leave this part of the  
theme for discussion after we have given
 full instructions for delineating both 
forms4  ,with the ratchet-tooth lever   
escapement all of the impulse must be   
derived from the pallets1 but in the    
club-tooth escapement we can divide the 
impulse planes between the pallets and  
the teeth to suit our fancy2 or perhaps 
it would be better to say carry out     
theories1 because we have it in our     
power1 in this form of the lever        

escapement1 to indulge ourselves in many
 changes of the relations of the several
 parts4 ,with the ratchet tooth the     
principal changes we could make would be
 from pallets with equidistant lockings 
to circular pallets4 ,the club-tooth    
escape wheel not only allows of circular
 pallets and equidistant lockings1 but  
we can divide the impulse between the   
pallets and the teeth in such a way as  
will carry out many theoretical         
advantages which1 after a full knowledge
 of the escapement action is acquired1  
will naturally suggest themselves4 ,in  
the escapement shown at ,fig4 #bj we    
have selected1 as a very excellent      
example of this form of tooth1 circular 
pallets of ten degrees fork action and  
ten and a half degrees of escape-wheel  
action4  ,it will be noticed that the   
pallets here are comparatively thin to  
those in general use2 this condition is 
accomplished by deriving the principal  
part of the impulse from driving planes 
placed on the teeth4 ,as relates to the 

escape-wheel action of the ten and      
one-half degrees1 which gives impulse to
 the escapement1 five and one-half      
degrees are utilized by the driving     
planes on the teeth and five by the     
impulse face of the pallet4 ,of the ten 
degrees of fork action1 four and a half 
degrees relate to the impulse face of   
the teeth1 one and a half degrees to    
lock1 and four degrees to the driving   
plane of the pallets4  ,in delineating  
such a club-tooth escapement1 we        
commence1 as in former examples1 by     
first assuming the center of the escape 
wheel at ,a1 and with the dividers set  
at five inches sweeping the arc a a4    
,through ,a we draw the vertical line ,a
 ,b'4 ,on the arc a a1 and each side of 
its intersection with the line ,a ,b'1  
we lay off thirty degrees1 as in former 
drawings1 and through the points so     
established on the arc a a we draw the  
radial lines ,a b and ,a c4 ,from the   
intersection of the radial line ,a b    
with the arc a we draw the line h h at  

right angles to ,a b4 ,where the line h 
intersects the radial lines ,a ,b' is   
located the center of the pallet staff1 
as shown at ,b4 ,inasmuch as we decided 
to let the pallet utilize five degrees  
of escape-wheel action1 we take a space 
of two and a half degrees in the        
dividers1 and on the arc a a lay off the
 said two and a half degrees to the left
 of this intersection1 and through the  
point so established draw the radial    
line ,a g4 ,from ,b as a center we sweep
 the arc d d so it passes through the   
point of intersection of the arc a with 
the line ,a g4  ,illustration3 ,fig4 #bj
  ,we again lay off two and a half      
degrees from the intersection of the    
line ,a b with the arc a1 but this time 
to the right of said intersection1 and  
through the point so established1 and   
from ,b as a center1 we sweep the arc e4
 ,from the intersection of the radial   
line ,a g with the arc a we lay off to  
the left five and a half degrees on said
 arc1 and through the point so          

established draw the radial line ,a f4  
,with the dividers set at five inches we
 sweep the short arc m from ,b as a     
center4 ,from the intersection of the   
line h ,b h' with the arc m we lay off  
on said arc and above the line h' four  
and a half degrees1 and through the     
point so established draw the line ,b j4
  ,we next set the dividers so they     
embrace the space on the radial line ,a 
b between its intersection with the line
 ,b j and the center ,a1 and from ,a as 
a center sweep the arc i1 said arc      
defining the addendum of the            
escape-wheel teeth4 ,we draw a line from
 the intersection of the radial line ,a 
f with the arc i to the intersection of 
the radial line ,a g with the arc a1 and
 thus define the impulse face of the    
escape-wheel tooth ,d4 ,for defining the
 locking face of the tooth we draw a    
line at an angle of twenty-four degrees 
to the line ,a g1 as previously         
described4 ,the back of the tooth is    
defined with a curve swept from some    

point on the addendum circle i1 such as 
our judgment will dictate4  ,in the     
drawing shown at ,fig4 #bj the radius of
 this curve was obtained by taking      
eleven and a half degrees from the      
degree arc of #e radius in the dividers1
 and setting one leg at the intersection
 of the radial line ,a f with the arc i1
 and placing the other on the line i1   
and allowing the point so established to
 serve as a center1 the arc was swept   
for the back of the tooth1 the small    
circle at n denoting one of the centers 
just described4 ,the length for the face
 of the tooth was obtained by taking    
eleven degrees from the degree arc just 
referred to and laying that space off on
 the line p1 which defined the face of  
the tooth4 ,the line ,b k is laid off   
one and a half degrees below ,b h on the
 arc m4 ,the extent of this arc on the  
arc d defines the locking face of the   
entrance pallet4 ,we set off four       
degrees on the arc m below the line ,b  
k1 and through the point so established 

draw the line ,b l4 ,we draw a line from
 the intersection of the line ,a g with 
the line c h to the intersection of the 
arc e with the line c l1 and define the 
impulse face of the entrance pallet4    
,,relations ,,of ,,the ,,several        
,,parts4  ,before we proceed to         
delineate the exit pallet of our        
escapement1 let us reason on the        
relations of the several parts4  ,the   
club-tooth lever escapement is really   
the most complicated escapement made4   
,we mean by this that there are more    
factors involved in the problem of      
designing it correctly than in any other
 known escapement4 ,most--we had better 
say all1 for there are no exceptions    
which occur to us--writers on the lever 
escapement lay down certain empirical   
rules for delineating the several parts1
 without giving reasons for this or that
 course4 ,for illustration1 it is an    
established practice among escapement   
makers to employ tangential lockings1 as
 we explained and illustrated in ,fig4  

#af4  ,now1 when we adopt circular      
pallets and carry the locking face of   
the entrance pallet around to the left  
two and a half degrees1 the true center 
for the pallet staff1 if we employ      
tangent lockings1 would be located on a 
line drawn tangent to the circle a a    
from its intersection with the radial   
line ,a k1 ,fig4 #ba4 ,such a tangent is
 depicted at the line s l'4 ,if we      
reason on the situation1 we will see    
that the line ,a k is not at right      
angles to the line s l2 and1            
consequently1 the locking face of the   
entrance pallet ,e has not really the   
twelve-degree lock we are taught to     
believe it has4  ,illustration3 ,fig4   
#ba  ,we will not discuss these minor   
points further at present1 but leave    
them for subsequent consideration4 ,we  
will say1 however1 that we could locate 
the center of the pallet action at the  
small circle ,b' above the center ,b1   
which we have selected as our           
fork-and-pallet action1 and secure a    

perfectly sound escapement1 with several
 claimed advantages4  ,let us now take  
up the delineation of the exit pallet4  
,it is very easy to locate the outer    
angle of this pallet1 as this must be   
situated at the intersection of the     
addendum circle i and the arc g1 and    
located at o4 ,it is also self-evident  
that the inner or locking angle must be 
situated at some point on the arc h4 ,to
 determine this location we draw the    
line ,b c from ,b 7the pallet center7   
through the intersection of the arc h   
with the pitch circle a4  ,again1 it    
follows as a self-evident fact1 if the  
pallet we are dealing with was locked1  
that is1 engaged with the tooth ,d''1   
the inner angle n of the exit pallet    
would be one and a half degrees inside  
the pitch circle a4 ,with the dividers  
set at #e1 we sweep the short arc b b1  
and from the intersection of this arc   
with the line ,b c we lay off ten       
degrees1 and through the point so       
established1 from ,b1 we draw the line  

,b d4 ,below the point of intersection  
of the line ,b d with the short arc b b 
we lay off one and a half degrees1 and  
through the point thus established we   
draw the line ,b e4   ,,locating ,,the  
,,inner ,,angle ,,of ,,the ,,exit       
,,pallet4  ,the intersection of the line
 ,b e with the arc h1 which we will term
 the point n1 represents the location of
 the inner angle of the exit pallet4 ,we
 have already explained how we located  
the position of the outer angle at o4   
,we draw the line n o and define the    
impulse face of the exit pallet4 ,if we 
mentally analyze the problem in hand1 we
 will see that as the exit pallet       
vibrates through its ten degrees of arc 
the line ,b d and ,b c change places1   
and the tooth ,d'' locks one and a half 
degrees4 ,to delineate the locking face 
of the exit pallet1 we erect a          
perpendicular to the line ,b e from the 
point n1 as shown by the line n p4      
,from n as a center we sweep the short  
arc t t1 and from its intersection with 

the line n p we lay off twelve degrees1 
and through the point so established we 
draw the line n u1 which defines the    
locking face of the exit pallet4 ,we    
draw the line o o' parallel with n u and
 define the outer face of said pallet4  
,in ,fig4 #ba we have not made any      
attempt to show the full outline of the 
pallets1 as they are delineated in      
precisely the same manner as those      
previously shown4  ,we shall next       
describe the delineation of a club-tooth
 escapement with pallets having         
equidistant locking faces2 and in ,fig4 
#bb we shall show pallets with much     
wider arms1 because1 in this instance1  
we shall derive more of the impulse from
 the pallets than from the teeth4 ,we do
 this to show the horological student   
the facility with which the club-tooth  
lever escapement can be manipulated4 ,we
 wish also to impress on his mind the   
facts that the employment of thick      
pallet arms and thin pallet arms depends
 on the teeth of the escape wheel for   

its efficiency1 and that he must have   
knowledge enough of the principles of   
action to tell at a glance on what lines
 the escapement was constructed4        
,suppose1 for illustration1 we get hold 
of a watch which has thin pallet arms1  
or stones1 if they are exposed pallets1 
and the escape was designed for pallets 
with thick arms4 ,there is no sort of   
tinkering we can do to give such a watch
 a good motion1 except to change either 
the escape wheel or the pallets4 ,if we 
know enough of the lever escapement to  
set about it with skill and judgment1   
the matter is soon put to rights2 but   
otherwise we can look and squint1 open  
and close the bankings1 and tinker about
 till doomsday1 and the watch be none   
the better4   ,,club-,,tooth ,,lever    
,,with ,,equidistant ,,locking ,,faces4 
,in drawing a club-tooth lever          
escapement with equidistant locking1 we 
commence1 as on former occasions1 by    
producing the vertical line ,a k1 ,fig4 
#bb1 and establishing the center of the 

escape wheel at ,a1 and with the        
dividers set at #e sweep the pitch      
circle a4 ,on each side of the          
intersection of the vertical line ,a k  
with the arc a we set off thirty degrees
 on said arc1 and through the points so 
established draw the radial lines ,a b  
and ,a c4  ,from the intersection of the
 radial line ,a b with the arc a lay off
 three and a half degrees to the left of
 said intersection on the arc a1 and    
through the point so established draw   
the radial line ,a e4 ,from the         
intersection of the radial line ,a b    
with the arc a erect the perpendicular  
line f1 and at the crossing or          
intersection of said line with the      
vertical line ,a k establish the center 
of the pallet staff1 as indicated by the
 small circle ,b4 ,from ,b as a center  
sweep the short arc l with a #e radius2 
and from the intersection of the radial 
line ,a b with the arc a continue the   
line f until it crosses the short arc l1
 as shown at f'4 ,lay off one and a half

 degrees on the arc l below its         
intersection with the line f'1 and from 
,b as a center draw the line ,b i       
through said intersection4 ,from ,b as a
 center1 through the intersection of the
 radial line ,a b and the arc a1 sweep  
the arc g4  ,the space between the lines
 ,b f' and ,b i on the arc g defines the
 extent of the locking face of the      
entrance pallet ,c4 ,the intersection of
 the line ,b f' with the arc g we       
denominate the point o1 and from this   
point as a center sweep the short arc p 
with a #e radius2 and on this arc1 from 
its intersection with the radial line ,a
 b1 lay off twelve degrees1 and through 
the point so established1 from o as a   
center1 draw the radial line o m1 said  
line defining the locking face of the   
entrance pallet ,c4  ,illustration3     
,fig4 #bb  ,it will be seen that this   
gives a positive draw of twelve degrees 
to the entrance pallet2 that is1        
counting to the line ,b f'4 ,in this    
escapement as delineated there is       

perfect tangential locking4 ,if the     
locking face of the entrance-pallet     
stone at ,c was made to conform to the  
radial line ,a b1 the lock of the tooth 
,d at o would be dead2 that is1         
absolutely neutral4 ,the tooth ,d would 
press the pallet ,c in the direction of 
the arrow x1 toward the center of the   
pallet staff ,b1 with no tendency on the
 part of the pallet to turn on its axis 
,b4 ,theoretically1 the pallet with the 
locking face cut to coincide with the   
line ,a b would resist movement on the  
center ,b in either direction indicated 
by the double-headed arrow y4  ,a pallet
 at ,c with a circular locking face made
 to conform to the arc g1 would permit  
movement in the direction of the        
double-headed arrow y with only         
mechanical effort enough to overcome    
friction4 ,but it is evident on         
inspection that a locking face on the   
line ,a b would cause a retrograde      
motion of the escape wheel1 and         
consequent resistance1 if said pallet   

was moved in either direction indicated 
by the double-headed arrow y4 ,precisely
 the same conditions obtain at the point
 u1 which holds the same relations to   
the exit pallet as the point o does to  
the entrance pallet ,c4   ,,angular     
,,motion ,,of ,,escape ,,wheel          
,,determined4  ,the arc 7three and a    
half degrees7 of the circle a embraced  
between the radial lines ,a b and ,a e  
determines the angular motion of the    
escape wheel utilized by the            
escape-wheel tooth4 ,to establish and   
define the extent of angular motion of  
the escape wheel utilized by the pallet1
 we lay off seven degrees on the arc a  
from the point o and establish the point
 n1 and through the point n1 from ,b as 
a center1 we sweep the short arc n'4    
,now somewhere on this arc n' will be   
located the inner angle of the entrance 
pallet4 ,with a carefully-made drawing1 
having the escape wheel #aj in diameter1
 it will be seen that the arc a         
separates considerably from the line1 ,b

 f' where it crosses the arc n'4  ,it   
will be remembered that when drawing the
 ratchet-tooth lever escapement a       
measurement of eight and a half degrees 
was made on the arc n' down from its    
intersection with the pitch circle1 and 
thus the inner angle of the pallet was  
located4 ,in the present instance the   
addendum line w becomes the controlling 
arc1 and it will be further noticed on  
the large drawing that the line ,b h at 
its intersection with the arc n'        
approaches nearer to the arc w than does
 the line ,b f' to the pitch circle a2  
consequently1 the inner angle of the    
pallet should not in this instance be   
carried down on the arc n' so far to    
correct the error as in the ratchet     
tooth4  ,reason tells us that if we     
measure ten degrees down on the arc n'  
from its intersection with the addendum 
circle w we must define the position of 
the inner angle of the entrance pallet4 
,we name the point so established the   
point r4 ,the outer angle of this pallet

 is located at the intersection of the  
radial line ,a b with the line ,b i2    
said intersection we name the point v4  
,draw a line from the point v to the    
point r1 and we define the impulse face 
of the entrance pallet2 and the angular 
motion obtained from it as relates to   
the pallet staff embraces six degrees4  
,measured on the arc l1 the entire ten  
degrees of angular motion is as follows3
 ,two and a half degrees from the       
impulse face of the tooth1 and indicated
 between the lines ,b h and ,b f2 one   
and a half degrees lock between the     
lines ,b f' and ,b i2 six degrees       
impulse from pallet face1 entrance      
between the lines ,b i and ,b j4   ,a   
,,departure ,,from ,,former ,,practices4
  ,grossmann and ,britten1 in all their 
delineations of the club-tooth          
escapement1 show the exit pallet as     
disengaged4 ,to vary from this beaten   
track we will draw our exit pallet as   
locked4 ,there are other reasons which  
prompt us to do this1 one of which is1  

pupils are apt to fall into a rut and   
only learn to do things a certain way1  
and that way just as they are           
instructed4  ,to illustrate1 the writer 
has met several students of the lever   
escapement who could make drawings of   
either club or ratchet-tooth escapement 
with the lock on the entrance pallet2   
but when required to draw a pallet as   
illustrated at ,fig4 #bc1 could not do  
it correctly4 ,occasionally one could do
 it1 but the instances were rare4 ,a    
still greater poser was to request them 
to delineate a pallet and tooth when the
 action of escaping was one-half or     
one-third performed2 and it is easy to  
understand that only by such studies the
 master workman can thoroughly          
comprehend the complications involved in
 the club-tooth lever escapement4   ,,an
 ,,apt ,,illustration4  ,as an          
illustration3 ,two draughtsmen1 employed
 by two competing watch factories1 each 
designs a club-tooth escapement4 ,we    
will further suppose the trains and     

mainspring power used by each concern to
 be precisely alike4 ,but in practice   
the escapement of the watches made by   
one factory would set1 that is1 if you  
stopped the balance dead still1 with the
 pin in the fork1 the watch would not   
start of itself2 while the escapement   
designed by the other draughtsman would 
not set--stop the balance dead as often 
as you choose1 the watch would start of 
itself4 ,yet even to experienced workmen
 the escape wheels and pallets looked   
exactly alike4 ,of course1 there was a  
difference1 and still none of the       
text-books make mention of it4  ,for the
 present we will go on with delineating 
our exit pallet4 ,the preliminaries are 
the same as with former drawings1 the   
instructions for which we need not      
repeat4 ,previous to drawing the exit   
pallet1 let us reason on the matter4    
,the point r in ,fig4 #bc is located at 
the intersection of pitch circle a and  
the radial line ,a c2 and this will also
 be the point at which the tooth ,c will

 engage the locking face of the exit    
pallet4  ,this point likewise represents
 the advance angle of the engaging      
tooth4 ,now if we measure on the arc k  
7which represents the locking faces of  
both pallets7 downward one and a half   
degrees1 we establish the lock of the   
pallet ,e4 ,to get this one and a half  
degrees defined on the arc k1 we set the
 dividers at #e1 and from ,b as a center
 sweep the short arc i1 and from the    
intersection of the arc i with the line 
,b e we lay off on said arc i one and a 
half degrees1 and through the point so  
established draw the line ,b f4  ,now   
the space on the arc k between the lines
 ,b e and ,b f defines the angular      
extent of the locking face4 ,with the   
dividers set at #e and one leg resting  
at the point r1 we sweep the short arc  
t1 and from the intersection of said arc
 with the line ,a c we draw the line n  
p2 but in doing so we extend it 7the    
line7 so that it intersects the line ,b 
f1 and at said intersection is located  

the inner angle of the exit pallet4     
,this intersection we will name the     
point n4  ,illustration3 ,fig4 #bc      
,from the intersection of the line ,b e 
with the arc i we lay off two and a half
 degrees on said arc1 and through the   
point so established we draw the line ,b
 g4 ,the intersection of this line with 
the arc k we name the point z4 ,with one
 leg of our dividers set at ,a we sweep 
the arc l so it passes through the point
 z4 ,this last arc defines the addendum 
of the escape-wheel teeth4 ,from the    
point r on the arc a we lay off three   
and a half degrees1 and through the     
point so established draw the line ,a j4
   ,,locating ,,the ,,outer ,,angle ,,of
 ,,the ,,impulse ,,planes4  ,the        
intersection of this line with the      
addendum arc l locates the outer angle  
of the impulse planes of the teeth1 and 
we name it the point x4 ,from the point 
r we lay off on the arc a seven degrees 
and establish the point v1 which defines
 the extent of the angular motion of the

 escape wheel utilized by pallet4       
,through the point v1 from ,b as a      
center1 we sweep the short arc m4 ,it   
will be evident on a moment's reflection
 that this arc m must represent the path
 of movement of the outer angle of the  
exit pallet1 and if we measure down ten 
degrees from the intersection of the arc
 l with the arc m1 the point so         
established 7which we name the point s7 
must be the exact position of the outer 
angle of the pallet during locking4 ,we 
have a measure of ten degrees on the arc
 m1 between the lines ,b g and ,b h1 and
 by taking this space in the dividers   
and setting one leg at the intersection 
of the arc l with the arc m1 and        
measuring down on m1 we establish the   
point s4 ,drawing a line from point n to
 point s we define the impulse face of  
the pallet4   ,,making ,,an ,,escapement
 ,,model4  ,illustration3 ,fig4 #bd  ,it
 is next proposed we apply the theories 
we have been considering and make an    
enlarged model of an escapement1 as     

shown at ,figs4 #bd and #be4 ,this model
 is supposed to have an escape wheel    
one-fifth the size of the #aj one we    
have been drawing4 ,in the accompanying 
cuts are shown only the main plate and  
bridges in full lines1 while the        
positions of the escape wheel and       
balance are indicated by the dotted     
circles ,i ,b4 ,the cuts are to no      
precise scale1 but were reduced from a  
full-size drawing for convenience in    
printing4 ,we shall give exact          
dimensions1 however1 so there will be no
 difficulty in carrying out our         
instructions in construction4           
,illustration3 ,fig4 #be  ,perhaps it   
would be as well to give a general      
description of the model before taking  
up the details4 ,a reduced side view of 
the complete model is given at ,fig4    
#bf4 ,in this cut the escapement model  
shown at ,figs4 #bd and #be is sketched 
in a rough way at ,r1 while ,n shows a  
glass cover1 and ,m a wooden base of    
polished oak or walnut4 ,this base is   

recessed on the lower side to receive an
 eight-day spring clock movement1 which 
supplies the motive power for the model4
 ,this base is recessed on top to       
receive the main plate ,a1 ,fig4 #bd1   
and also to hold the glass shade ,n in  
position4 ,the base ,m is #b high and #h
 diameter4 ,the glass cover ,n can have 
either a high and spherical top1 as     
shown1 or1 as most people prefer1 a     
flattened oval4  ,illustration3 ,fig4   
#bf  ,the main plate ,a is of hard      
spring brass1 #a_/aj thick and #f in    
diameter2 in fact1 a simple disk of the 
size named1 with slightly rounded edges4
 ,the top plate1 shown at ,c1 ,figs4 #bd
 and #be1 is #a_/h thick and shaped as  
shown4 ,this plate 7,c7 is supported on 
two pillars  in diameter and #a high4   
,fig4 #be is a side view of ,fig4 #bd   
seen in the direction of the arrow p4   
,the cock ,d is also of #a_/h spring    
brass shaped as shown1 and attached by  
the screw f and steady pins s s to the  
top plate ,c4 ,the bridge ,f ,g carries 

the top pivots of escape wheel and      
pallet staff1 and is shaped as shown at 
the full outline4 ,this bridge is       
supported on two pillars  high and  in  
diameter1 one of which is shown at ,e1  
,fig4 #be1 and both at the dotted       
circles ,e ,e'1 ,fig4 #bd4  ,to lay out 
the lower plate we draw the line a a so 
it passes through the center of ,a at m4
 ,at #a4c from one edge of ,a we        
establish on the line a the point d1    
which locates the center of the escape  
wheel4 ,on the same line a at #a4ae from
 d we establish the point b1 which      
represents the center of the pallet     
staff4 ,at the distance of #a4af from b 
we establish the point c1 which         
represents the center of the balance    
staff4 ,to locate the pillars ,h1 which 
support the top plate ,c1 we set the    
dividers at #b4eh1 and from the center m
 sweep the arc n4  ,from the            
intersection of this arc with the line a
 7at r7 we lay off on said arc n #b4a   
and establish the points g g'1 which    

locate the center of the pillars ,h ,h4 
,with the dividers set so one leg rests 
at the center m and the other leg at the
 point d1 we sweep the arc t4 ,with the 
dividers set at #a4cc we establish on   
the arc t1 from the point d1 the points 
e e'1 which locate the position of the  
pillars ,e ,e'4 ,the outside diameter of
 the balance ,b is #c-e_/h with the rim 
#c_/af wide and #e_/af deep1 with screws
 in the rim in imitation of the ordinary
 compensation balance4  ,speaking of a  
balance of this kind suggests to the    
writer the trouble he experienced in    
procuring material for a model of this  
kind--for the balance1 a pattern had to 
be made1 then a casting made1 then a    
machinist turned the casting up1 as it  
was too large for an ,american lathe4 ,a
 hairspring had to be specially made1   
inasmuch as a mainspring was too short1 
the coils too open and1 more            
particularly1 did not look well4 ,pallet
 jewels had to be made1 and lapidists   
have usually poor ideas of close        

measurements4 ,present-day conditions1  
however1 will1 no doubt1 enable the     
workman to follow our instructions much 
more readily4   ,,making ,,the          
,,bridges4  ,in case the reader makes   
the bridges ,c and ,f1 as shown in ,fig4
 #bg1 he should locate small circles on 
them to indicate the position of the    
screws for securing these bridges to the
 pillars which support them1 and also   
other small circles to indicate the     
position of the pivot holes d b for the 
escape wheel and pallet staff4 ,in      
practice it will be well to draw the    
line a a through the center of the main 
plate ,a1 as previously directed1 and   
also establish the point d as therein   
directed4  ,the pivot hole d' for the   
escape wheel1 and also the holes at e e 
and b1 are now drilled in the bridge ,f4
 ,these holes should be about #a_/af in 
diameter4 ,the same sized hole is also  
drilled in the main plate ,a at d4 ,we  
now place a nicely-fitting steel pin in 
the hole d' in the bridge ,f and let it 

extend into the hole d in the main      
plate4 ,we clamp the bridge ,f to ,a so 
the hole b comes central on the line a1 
and using the holes e e in ,f as guides1
 drill or mark the corresponding holes  
e' e' and b in the main plate for the   
pillars ,e ,e' and the pallet staff4    
,illustration3 ,fig4 #bg  ,this plan    
will insure the escape wheel and pallet 
staff being perfectly upright4 ,the same
 course pursued with the plate ,c will  
insure the balance being upright4 ,the  
pillars which support the bridges are   
shaped as shown at ,fig4 #bh1 which     
shows a side view of one of the pillars 
which support the top plate or bridge   
,c4 ,the ends are turned to  in diameter
 and extend half through the plate1     
where they are held by screws1 the same 
as in ,american movements4              
,illustration3 ,fig4 #bh  ,the pillars  
7like ,h7 can be riveted in the lower   
plate ,a1 but we think most workmen will
 find it more satisfactory to employ    
screws1 as shown at ,fig4 #bi4 ,the     

heads of such screws should be about    
#c_/h in diameter and nicely rounded1   
polished and blued4 ,we would not advise
 jeweling the pivot holes1 because there
 is but slight friction1 except to the  
foot of the balance pivot1 which should 
be jeweled with a plano-convex garnet4  
,illustration3 ,fig4 #bi  ,,imitation   
,,rubies ,,for ,,capping ,,the ,,top    
,,pivots4  ,the top pivots to the escape
 wheel should be capped with imitation  
rubies for appearance sake only1 letting
 the cap settings be red gold1 or brass 
red gilded4 ,if real twelve-karat gold  
is employed the cost will not be much1  
as the settings are only about #c_/h    
across and can be turned very thin1 so  
they will really contain but very little
 gold4 ,the reason why we recommend     
imitation ruby cap jewels for the upper 
holes1 is that such jewels are much more
 brilliant than any real stone we can   
get for a moderate cost4 ,besides1 there
 is no wear on them4  ,the pallet jewels
 are also best made of glass1 as garnet 

or any red stone will look almost black 
in such large pieces4 ,red carnelian has
 a sort of brick-red color1 which has a 
cheap appearance4 ,there is a new       
phosphorus glass used by optical        
instrument makers which is intensely    
hard1 and if colored ruby-red makes a   
beautiful pallet jewel1 which will      
afford as much service as if real stones
 were used2 they are no cheaper than    
carnelian pallets1 but much richer      
looking4 ,the prettiest cap for the     
balance is one of those foilback stones 
in imitation of a rose-cut diamond4     
,illustration3 ,fig4 #cj  ,illustration3
 ,fig4 #ca  ,in turning the staffs it is
 the best plan to use double centers1   
but a piece of ,stubs steel wire that   
will go into a ,no4 #dj wire chuck1 will
 answer2 in case such wire is used1 a   
brass collet must be provided4 ,this    
will be understood by inspecting ,fig4  
#cj1 where ,l represents the ,stubs wire
 and ,b ,n the brass collet1 with the   
balance seat shown at k4 ,the           

escape-wheel arbor and pallet staff can 
be made in the same way4 ,the lower end 
of the escape wheel pivot is made about 
long1 so that a short piece of brass    
wire can be screwed upon it1 as shown in
 ,fig4 #ca1 where h represents the      
pivot1 ,a the lower plate1 and the      
dotted line at p the brass piece screwed
 on the end of the pivot4 ,this piece p 
is simply a short bit of brass wire with
 a female screw tapped into the end1    
which screws on to the pivot4 ,an arm is
 attached to p1 as shown at ,t4 ,the    
idea is1 the pieces ,t p act like a     
lathe dog to convey the power from one  
of the pivots of an old eight-day spring
 clock movement1 which is secured by    
screws to the lower side of the main    
plate ,a4 ,the plan is illustrated at   
,fig4 #cb1 where l represents pivot of  
the eight-day clock employed to run the 
model4 ,counting the escape-wheel pivot 
of the clock as one1 we take the third  
pivot from this in the clock train1     
placing the movement so this point comes

 opposite the escape-wheel pivot of the 
model1 and screw the clock movement fast
 to the lower side of the plate ,a4 ,the
 parts ,t1 ,fig4 #cc1 are alike on both 
pivots4  ,illustration3 ,fig4 #cb       
,illustration3 ,fig4 #cc   ,,profitable 
,,for ,,explaining ,,to ,a ,,customer4  
,to fully appreciate such a large       
escapement model as we have been        
describing1 a person must see it with   
its great balance1 nearly #d across1    
flashing and sparkling in the show      
window in the evening1 and the brilliant
 imitation ruby pallets dipping in and  
out of the escape wheel4 ,a model of    
this kind is far more attractive than if
 the entire train were shown1 the       
mystery of ,what makes it go8 being one 
of the attractions4 ,such a model is1   
further1 of great value in explaining to
 a customer what you mean when you say  
the escapement of his watch is out of   
order4 ,any practical workman can easily
 make an even #ajj extra in a year by   
making use of such a model4  ,for       

explaining to customers an extra balance
 cock can be used to show how the jewels
 7hole and cap7 are arranged4 ,where the
 parts are as large as they are in the  
model1 the customer can see and         
understand for himself what is necessary
 to be done4  ,it is not to be          
understood that our advice to purchase  
the jewels for an extra balance cock    
conflicts with our recommending the     
reader not to jewel the holes of his    
model4 ,the extra cock is to be shown1  
not for use1 and is employed solely for 
explaining to a customer what is        
required when a pivot or jewel is found 
to be broken4   ,,how ,,large ,,screws  
,,are ,,made4  ,the screws which hold   
the plates in place should have heads   
about #c_/h in diameter1 to be in       
proportion to the scale on which the    
balance and escape wheel are gotten up4 
,there is much in the manner in which   
the screw heads are finished as regards 
the elegance of such a model4 ,a        
perfectly flat head1 no matter how      

highly polished1 does not look well1    
neither does a flattened conehead1 like 
,fig4 #ce4 ,the best head for this      
purpose is a cupped head with chamfered 
edges1 as shown at ,fig4 #cd in vertical
 section4 ,the center b is ground and   
polished into a perfect concave by means
 of a metal ball4 ,the face1 between the
 lines a a1 is polished dead flat1 and  
the chamfered edge a c finished a trifle
 convex4 ,the flat surface at a is      
bright1 but the concave b and chamfer at
 c are beautifully blued4 ,for a        
gilt-edged1 double extra head1 the      
chamfer at c can be snailed1 that is1   
ground with a suitable lap before       
bluing1 like the stem-wind wheels on    
some watches4  ,illustration3 ,fig4 #cd 
,illustration3 ,fig4 #ce   ,,fancy      
,,screwheads4  ,there are two easy      
methods of removing the blue from the   
flat part of the screwhead at a4 7#a7   
,make a special holder for the screw in 
the end of a cement brass1 as shown at  
,e1 ,fig4 #cf1 and while it is slowly   

revolving in the lathe touch the flat   
surface a with a sharpened pegwood wet  
with muriatic acid1 which dissolves the 
blue coating of oxide of iron4 7#b7 ,the
 surface of the screwhead is coated with
 a very thin coating of shellac         
dissolved in alcohol and thoroughly     
dried1 or a thin coating of collodion1  
which is also dried4 ,the screw is      
placed in the ordinary polishing        
triangle and the flat face at a polished
 on a tin lap with diamantine and oil4  
,in polishing such surfaces the thinnest
 possible coating of diamantine and oil 
is smeared on the lap--in fact1 only    
enough to dim the surface of the tin4   
,it is1 of course1 understood that it is
 necessary to move only next to nothing 
of the material to restore the polish of
 the steel4 ,the polishing of the other 
steel parts is done precisely like any  
other steel work4  ,illustration3 ,fig4 
#cf  ,the regulator is of the ,howard   
pattern4 ,the hairspring stud is set in 
the cock like the ,elgin                

three-quarter-plate movement4 ,the      
richest finish for such a model is      
frosted plates and bridges4 ,the        
frosting should not be a fine mat1 like 
a watch movement1 but coarse-grained--in
 fact1 the grain of the frosting should 
be proportionate to the size of the     
movement4 ,the edges of the bridges and 
balance cock can be left smooth4 ,the   
best process for frosting is by acid4   
,details for doing the work will now be 
given4  ,illustration3 ,fig4 #cg        
,illustration3 ,fig4 #ch  ,to do this   
frosting by acid nicely1 make a sieve by
 tacking and gluing four pieces of thin 
wood together1 to make a rectangular box
 without a bottom4 ,four pieces of      
cigar-box wood1 #h long by #a wide1     
answer first rate4 ,we show at ,a ,a ,a 
,a1 ,fig4 #cg1 such a box as if seen    
from above2 with a side view1 as if seen
 in the direction of the arrow a1 at    
,fig4 #ch4 ,a piece of ,india muslin is 
glued across the bottom1 as shown at the
 dotted lines b b4 ,by turning up the   

edges on the outside of the box1 the    
muslin bottom can be drawn as tight as a
 drum head4   ,,how ,,to ,,do ,,acid    
,,frosting4  ,to do acid frosting1 we   
procure two ounces of gum mastic and    
place in the square sieve1 shown at     
,fig4 #cg4 ,usually more than half the  
weight of gum mastic is in fine dust1   
and if not1 that is1 if the gum is in   
the shape of small round pellets called 
mastic tears1 crush these into dust and 
place the dust in ,a4 ,let us next      
suppose we wish to frost the cock on the
 balance1 shown at ,fig4 #ci4 ,before we
 commence to frost1 the cock should be  
perfectly finished1 with all the holes  
made1 the regulator cap in position1 the
 screw hole made for the ,howard        
regulator and the index arc engraved    
with the letters ,s and ,f4             
,illustration3 ,fig4 #ci  ,it is not    
necessary the brass should be polished1 
but every file mark and scratch should  
be stoned out with a ,scotch stone2 in  
fact1 be in the condition known as in   

the gray4 ,it is not necessary to frost 
any portion of the cock ,c1 except the  
upper surface4 ,to protect the portion  
of the cock not to be frosted1 like the 
edges and the back1 we stop out by      
painting over with shellac dissolved in 
alcohol1 to which a little lampblack is 
added4 ,it is not necessary the coating 
of shellac should be very thick1 but it 
is important it should be well dried4   
,,how ,,to ,,prepare ,,the ,,surface4   
,for illustration1 let us suppose the   
back and edges of the cock at ,fig4 #ci 
are coated with shellac and it is laid  
flat on a piece of paper about a foot   
square to catch the excess of mastic4   
,holes should be made in this paper and 
also in the board on which the paper    
rests to receive the steady pins of the 
cock4 ,we hold the sieve containing the 
mastic over the cock and1 gently tapping
 the box ,a with a piece of wood like a 
medium-sized file handle1 shake down a  
little snowstorm of mastic dust over the
 face of the cock ,c4  ,exactly how much

 mastic dust is required to produce a   
nice frosting is only to be determined  
by practice4 ,the way to obtain the     
knack is to frost a few scraps to get   
your hand in4 ,nitric acid of full      
strength is used1 dipping the piece into
 a shallow dish for a few seconds4 ,a   
good-sized soup plate would answer very 
nicely for frosting the bottom plate1   
which1 it will be remembered1 is #f in  
diameter4   ,,how ,,to ,,etch ,,the     
,,surface4  ,after the mastic is sifted 
on1 the cock should be heated up to     
about #bej ,f41 to cause the particles  
of mastic to adhere to the surface4 ,the
 philosophy of the process is1 the      
nitric acid eats or dissolves the brass1
 leaving a little brass island the size 
of the particle of mastic which was     
attached to the surface4 ,after heating 
to attach the particles of mastic1 the  
dipping in nitric acid is done as just  
described4 ,common commercial nitric    
acid is used1 it not being necessary to 
employ chemically pure acid4 ,for that  

matter1 for such purposes the commercial
 acid is the best4  ,after the acid has 
acted for fifteen or twenty seconds the 
brass is rinsed in pure water to remove 
the acid1 and dried by patting with an  
old soft towel1 and further dried by    
waving through the air4 ,a little       
turpentine on a rag will remove the     
mastic1 but turpentine will not touch   
the shellac coating4 ,the surface of the
 brass will be found irregularly acted  
upon1 producing a sort of mottled look4 
,to obtain a nice frosting the process  
of applying the mastic and etching must 
be repeated three or four times1 when a 
beautiful coarse-grain mat or frosting  
will be produced4  ,the shellac         
protection will not need much patching  
up during the three or four bitings of  
acid1 as the turpentine used to wash off
 the mastic does not much affect the    
shellac coating4 ,all the screw holes   
like s s and d1 also the steady pins on 
the back1 are protected by varnishing   
with shellac4 ,the edges of the cocks   

and bridges should be polished by       
rubbing lengthwise with willow charcoal 
or a bit of chamois skin saturated with 
oil and a little hard rouge scattered   
upon it4 ,the frosting needs thorough   
scratch-brushing4  ,illustration3 ,fig4 
#dj  ,at ,fig4 #dj we show the balance  
cock of our model with modified form of 
,howard regulator4 ,the regulator bar ,a
 and spring ,b should be ground smooth  
on one side and deeply outlined to      
perfect form4 ,the regulator cap ,c is  
cut out to the correct size4 ,these     
parts are of decarbonized cast steel1   
annealed until almost as soft as sheet  
brass4 ,it is not so much work to finish
 these parts as one might imagine4 ,let 
us take the regulator bar for an example
 and carry it through the process of    
making4 ,the strip of soft sheet steel  
on which the regulator bar is outlined  
is represented by the dotted outline b1 
,fig4 #da4  ,illustration3 ,fig4 #da    
,to cut out sheet steel rapidly we take 
a piece of smooth clock mainspring about

  and #aj long and double it together1  
softening the bending point with the    
lamp until the piece of mainspring      
assumes the form shown at ,fig4 #db1    
where c represents the piece of spring  
and ,h ,h the bench-vise jaws4 ,the     
piece of soft steel is placed between   
the limbs of c c' of the old mainspring 
up to the line a1 ,fig4 #da1 and clamped
 in the vise jaws4 ,the superfluous     
steel is cut away with a sharp and      
rather thin cold chisel4  ,illustration3
 ,fig4 #db  ,the chisel is presented as 
shown at ,g1 ,fig4 #dc 7which is an end 
view of the vise jaws ,h ,h and         
regulator bar71 and held to cut         
obliquely and with a sort of shearing   
action1 as illustrated in ,fig4 #db1    
where ,a'' represents the soft steel and
 ,g the cold chisel4 ,we might add that 
,fig4 #db is a view of ,fig4 #dc seen in
 the direction of the arrow f4 ,it is   
well to cut in from the edge b on the   
line d1 ,fig4 #da1 with a saw1 in order 
to readily break out the surplus steel  

and not bend the regulator bar4 ,by     
setting the pieces of steel obliquely in
 the vise1 or so the line e comes even  
with the vise jaws1 we can cut to more  
nearly conform to the circular loop ,a''
 of the regulator ,a4  ,illustration3   
,fig4 #dc  ,the smooth steel surface of 
the bent mainspring c prevents the vise 
jaws from marking the soft steel of the 
regulator bar4 ,a person who has not    
tried this method of cutting out soft   
steel would not believe with what       
facility pieces can be shaped4 ,any     
workman who has a universal face plate  
to his lathe can turn out the center of 
the regulator bar to receive the disk   
,c1 and also turn out the center of the 
regulator spring ,b4 ,what we have said 
about the regulator bar applies also to 
the regulator spring ,b4 ,this spring is
 attached to the cock ,d by means of two
 small screws at n4  ,the micrometer    
screw ,f is tapped through ,b'' as in   
the ordinary ,howard regulator1 and the 
screw should be about ,no4 #f of a      

,swiss screw-plate4 ,the wire from which
 such screw is made should be #a_/aj in 
diameter4 ,the steel cap ,c is fitted   
like the finer forms of ,swiss watches4 
,the hairspring stud ,e is of steel1    
shaped as shown1 and comes outlined with
 the other parts4   ,,to ,,temper ,,and 
,,polish ,,steel4  ,the regulator bar   
should be hardened by being placed in a 
folded piece of sheet iron and heated   
red hot1 and thrown into cold water4    
,the regulator bar ,a ,a' is about #c   
long2 and for holding it for hardening1 
cut a piece of thin sheet iron #b by #c 
and fold it through the middle          
lengthwise1 as indicated by the dotted  
line g1 ,fig4 #dd4 ,the sheet iron when 
folded will appear as shown at ,fig4    
#de4 ,a piece of flat sheet metal of the
 same thickness as the regulator bar    
should be placed between the iron leaves
 ,i ,i1 and the leaves beaten down with 
a hammer1 that the iron may serve as a  
support for the regulator during heating
 and hardening4 ,a paste made of castile

 soap and water applied to the regulator
 bar in the iron envelope will protect  
it from oxidizing much during the       
heating4 ,the portions of the regulator 
bar marked h are intended to be rounded1
 while the parts marked m are intended  
to be dead flat4 ,the rounding is       
carefully done1 first with a file and   
finished with emery paper4 ,the outer   
edge of the loop ,a'' is a little       
rounded1 also the inner edge next the   
cap ,c4 ,this will be understood by     
inspecting ,fig4 #df1 where we show a   
magnified vertical section of the       
regulator on line l1 ,fig4 #dj4 ,the    
curvature should embrace that portion of
 ,a'' between the radial lines o o'1 and
 should1 on the model1 not measure more 
than #a_/dj4 ,it will be seen that the  
curved surface of the regulator is sunk 
so it meets only the vertical edge of   
the loop ,a''4 ,for the average workman1
 polishing the flat parts m is the most 
difficult to do1 and for this reason we 
will give entire details4 ,it is to be  

expected that the regulator bar will    
spring a little in hardening1 but if    
only a little we need pay no attention  
to it4  ,illustration3 ,fig4 #dd        
,illustration3 ,fig4 #de  ,illustration3
 ,fig4 #df   ,,how ,,flat ,,steel       
,,polishing ,,is ,,done4  ,polishing a  
regulator bar for a large model1 such as
 we are building1 is only a heavy job of
 flat steel work1 a little larger but no
 more difficult than to polish a        
regulator for a sixteen-size watch4 ,we 
would ask permission here to say that   
really nice flat steel work is something
 which only a comparatively few workmen 
can do1 and1 still1 the process is quite
 simple and the accessories few and     
inexpensive4 ,first1 ground-glass slab  
#f by #f by 2 second1 flat zinc piece #c
 by #c by 2 third1 a piece of thick     
sheet brass #c by #b by #a_/h2 and a    
bottle of ,vienna lime4 ,the glass slab 
is only a piece of plate glass cut to   
the size given above4 ,the zinc slab is 
pure zinc planed dead flat1 and the     

glass ground to a dead surface with     
another piece of plate glass and some   
medium fine emery and water1 the whole  
surface being gone over with emery and  
water until completely depolished4 ,the 
regulator bar1 after careful filing and 
dressing up on the edges with an        
oilstone slip or a narrow emery buff1 is
 finished as previously described4 ,we  
would add to the details already given a
 few words on polishing the edges4      
,illustration3 ,fig4 #dg  ,it is not    
necessary that the edges of steelwork1  
like the regulator bar ,b1 ,fig4 #dg1   
should be polished to a flat surface2   
indeed1 they look better to be nicely   
rounded4 ,perhaps we can convey the idea
 better by referring to certain parts3  
say1 spring to the regulator1 shown at  
,d1 ,fig4 #dj1 and also the hairspring  
stud ,e4 ,the edges of these parts look 
best beveled in a rounded manner4       
,illustration3 ,fig4 #dh  ,illustration3
 ,fig4 #di  ,it is a little difficult to
 convey in words what is meant by       

rounded manner4 ,to aid in understanding
 our meaning1 we refer to ,figs4 #dh and
 #di1 which are transverse sections of  
,d1 ,fig4 #ej1 on the line f4 ,the edges
 of ,d1 in ,fig4 #dh1 are simply        
rounded4 ,there are no rules for such   
rounding--only good judgment and an eye 
for what looks well4 ,the edges of ,d as
 shown in ,fig4 #di are more on the     
beveled order4 ,in smoothing and        
polishing such edges1 an ordinary       
jeweler's steel burnish can be used4    
,illustration3 ,fig4 #ej   ,,smoothing  
,,and ,,polishing4  ,the idea in        
smoothing and polishing such edges is to
 get a fair gloss without much attention
 to perfect form1 inasmuch as it is the 
flat surface d on top which produces the
 impression of fine finish4 ,if this is 
flat and brilliant1 the rounded edges1  
like g c can really have quite an       
inferior polish and still look well4    
,for producing the flat polish on the   
upper surface of the regulator bar ,b   
and spring ,d1 the flat surface d1      

,figs4 #dh1 #di1 #ea and #eb1 we must   
attach the regulator bar to a plate of  
heavy brass1 as shown at ,fig4 #dg1     
where ,a represents the brass plate1 and
 ,b the regulator bar1 arranged for     
grinding and polishing flat4            
,illustration3 ,fig4 #ea  ,illustration3
 ,fig4 #eb  ,for attaching the regulator
 bar ,b to the brass plate ,a1 a good   
plan is to cement it fast with lathe    
wax2 but a better plan is to make the   
plate ,a of heavy sheet iron1 something 
about #a_/h thick1 and secure the two   
together with three or four little      
catches of soft solder4 ,it is to be    
understood the edges of the regulator   
bar or the regulator spring are         
polished1 and all that remains to be    
done is to grind and polish the flat    
face4  ,two pieces a a of the same      
thickness as the regulator bar are      
placed as shown and attached to ,a to   
prevent rocking4 ,after ,b is securely  
attached to ,a1 the regulator should be 
coated with shellac dissolved in alcohol

 and well dried4 ,the object of this    
shellac coating is to keep the angles   
formed at the meeting of the face and   
side clean in the process of grinding   
with oilstone dust and oil4 ,the face of
 the regulator is now placed on the     
ground glass after smearing it with oil 
and oilstone dust4 ,it requires but a   
very slight coating to do the work4     
,the grinding is continued until the    
required surface is dead flat1 after    
which the work is washed with soap and  
water and the shellac dissolved away    
with alcohol4 ,the final polish is      
obtained on the zinc lap with ,vienna   
lime and alcohol4 ,where lathe cement is
 used for securing the regulator to the 
plate ,a1 the alcohol used with the     
,vienna lime dissolves the cement and   
smears the steel4 ,diamantine and oil   
are the best materials for polishing    
when the regulator bar is cemented to   
the plate ,a4   ,,knowledge ,,that ,,is 
,,most ,,essential4  ,the knowledge most
 important for a practical working      

watchmaker to possess is how to get the 
watches he has to repair in a shape to  
give satisfaction to his customers4 ,no 
one will dispute the truth of the above 
italicised statement4 ,it is only when  
we seek to have limits set1 and define  
what such knowledge should consist of1  
that disagreement occurs4  ,one workman 
who has read ,grossmann or ,saunier1 or 
both1 would insist on all watches being 
made to a certain standard1 and1        
according to their ideas1 all such lever
 watches as we are now dealing with     
should have club-tooth escapements with 
equidistant lockings1 ten degrees lever 
and pallet action1 with one and one-half
 degrees lock and one and one-half      
degrees drop4 ,another workman would    
insist on circular pallets1 his judgment
 being based chiefly on what he had read
 as stated by some author4 ,now the     
facts of the situation are that lever   
escapements vary as made by different   
manufacturers1 one concern using        
circular pallets and another using      

pallets with equidistant lockings4      
,,what ,a ,,workman ,,should ,,know ,,to
 ,,repair ,a ,,watch4  ,one escapement  
maker will divide the impulse equally   
between the tooth and pallet2 another   
will give an excess to the tooth4 ,now  
while these matters demand our attention
 in the highest degree in a theoretical 
sense1 still1 for such know hows as     
count in a workshop1 they are of but    
trivial importance in practice4  ,we    
propose to deal in detail with the      
theoretical consideration of thick and  
thin pallets1 and dwell exhaustively on 
circular pallets and those with         
equidistant locking faces2 but before we
 do so we wish to impress on our readers
 the importance of being able to free   
themselves of the idea that all lever   
escapements should conform to the rigid 
rules of any dictum4   ,,educate ,,the  
,,eye ,,to ,,judge ,,of ,,angular ,,as  
,,well ,,as ,,linear ,,extent4  ,for    
illustration3 ,it would be easy to      
design a lever escapement that would    

have locking faces which were based on  
the idea of employing neither system1   
but a compromise between the two1 and   
still give a good1 sound action4 ,all   
workmen should learn to estimate        
accurately the extent of angular motion1
 so as to be able to judge correctly of 
escapement actions4 ,it is not only     
necessary to know that a club-tooth     
escapement should have one and one-half 
degrees drop1 but the eye should be     
educated1 so to speak1 as to be able to 
judge of angular as well as linear      
extent4  ,illustration3 ,fig4 #ec  ,most
 mechanics will estimate the size of any
 object measured in inches or parts of  
inches very closely2 but as regards     
angular extent1 except in a few         
instances1 we will find mechanics but   
indifferent judges4 ,to illustrate1 let 
us refer to ,fig4 #ec4 ,here we have the
 base line ,a ,a' and the perpendicular 
line a ,b4 ,now almost any person would 
be able to see if the angle ,a a ,b was 
equal to ,b a ,a'2 but not five in one  

hundred practical mechanics would be    
able to estimate with even tolerable    
accuracy the measure the angles made to 
the base by the lines b c d2 and still  
watchmakers are required in the daily   
practice of their craft to work to      
angular motions and movements almost as 
important as to results as diameters4   
,what is the use of our knowing that in 
theory an escape-wheel tooth should have
 one and one-half degrees drop1 when in 
reality it has three degrees8 ,it is    
only by educating the eye from          
carefully-made drawings2 or1 what is    
better1 constructing a model on a large 
scale1 that we can learn to judge of    
proper proportion and relation of parts1
 especially as we have no convenient    
tool for measuring the angular motion of
 the fork or escape wheel4 ,nor is it   
important that we should have1 if the   
workman is thoroughly booked up in the  
principles involved4  ,as we explained  
early in this treatise1 there is no     
imperative necessity compelling us to   

have the pallets and fork move through  
ten degrees any more than nine and      
one-half degrees1 except that experience
 has proven that ten degrees is about   
the right thing for good results4 ,in   
this day1 when such a large percentage  
of lever escapements have exposed       
pallets1 we can very readily manipulate 
the pallets to match the fork and roller
 action4 ,for that matter1 in many      
instances1 with a faulty lever          
escapement1 the best way to go about    
putting it to rights is to first set the
 fork and roller so they act correctly1 
and then bring the pallets to conform to
 the angular motion of the fork so      
adjusted4   ,,fork ,,and ,,roller       
,,action4  ,although we could say a good
 deal more about pallets and pallet     
action1 still we think it advisable to  
drop for the present this particular    
part of the lever escapement and take up
 fork and roller action1 because1 as we 
have stated1 frequently the fork and    
roller are principally at fault4 ,in    

considering the action and relation of  
the parts of the fork and roller1 we    
will first define what is considered    
necessary to constitute a good1 sound   
construction where the fork vibrates    
through ten degrees of angular motion   
and is supposed to be engaged with the  
roller by means of the jewel pin for    
thirty degrees of angular motion of the 
balance4  ,there is no special reason   
why thirty degrees of roller action     
should be employed1 except that         
experience in practical construction has
 come to admit this as about the right  
arc for watches of ordinary good1 sound 
construction4 ,manufacturers have made  
departures from this standard1 but in   
almost every instance have finally come 
back to pretty near these proportions4  
,in deciding on the length of fork and  
size of roller1 we first decide on the  
distance apart at which to place the    
center of the balance and the center of 
the pallet staff4 ,these two points     
established1 we have the length of the  

fork and diameter of the roller defined 
at once4   ,,how ,,to ,,find ,,the      
,,roller ,,diameter ,,from ,,the        
,,length ,,of ,,the ,,fork4  ,to        
illustrate1 let us imagine the small    
circles ,a ,b1 ,fig4 #ed1 to represent  
the center of a pallet staff and balance
 staff in the order named4 ,we divide   
this space into four equal parts1 as    
shown1 and the third space will         
represent the point at which the pitch  
circles of the fork and roller will     
intersect1 as shown by the arc a and    
circle b4 ,now if the length of the     
radii of these circles stand to each    
other as three to one1 and the fork     
vibrates through an arc of ten degrees1 
the jewel pin engaging such fork must   
remain in contact with said fork for    
thirty degrees of angular motion of the 
balance4  ,illustration3 ,fig4 #ed  ,or1
 in other words1 the ratio of angular   
motion of two mobiles acting on each    
must be in the same ratio as the length 
of their radii at the point of contact4 

,if we desire to give the jewel pin1 or1
 in ordinary horological phraseology1   
have a greater arc of roller action1 we 
would extend the length of fork 7say7 to
 the point c1 which would be one-fifth  
of the space between ,a and ,b1 and the 
ratio of fork to roller action would be 
four to one1 and ten degrees of fork    
action would give forty degrees of      
angular motion to the roller--and such  
escapements have been constructed4      
,,why ,,thirty ,,degrees ,,of ,,roller  
,,action ,,is ,,about ,,right4  ,now we 
have two sound reasons why we should not
 extend the arc of vibration of the     
balance3 7a7 ,if there is an advantage  
to be derived from a detached           
escapement1 it would surely be policy to
 have the arc of contact1 that is1 for  
the jewel pin to engage the fork1 as    
short an arc as is compatible with a    
sound action4 7b7 ,it will be evident to
 any thinking mechanic that the acting  
force of a fork which would carry the   
jewel pin against the force exerted by  

the balance spring through an arc of    
fifteen degrees1 or half of an arc of   
thirty degrees1 would fail to do so     
through an arc of twenty degrees1 which 
is the condition imposed when we adopt  
forty degrees of roller action4  ,for   
the present we will accept thirty       
degrees of roller action as the         
standard4 ,before we proceed to         
delineate our fork and roller we will   
devote a brief consideration to the size
 and shape of a jewel pin to perform    
well4 ,in this matter there has been a  
broad field gone over1 both             
theoretically and in practical          
construction4 ,wide jewel pins1 round   
jewel pins1 oval jewel pins have been   
employed1 but practical construction has
 now pretty well settled on a round     
jewel pin with about two-fifths cut     
away4 ,and as regards size1 if we adopt 
the linear extent of four degrees of    
fork or twelve degrees of roller action1
 we will find it about right4   ,,how   
,,to ,,set ,a ,,fork ,,and ,,roller     

,,action ,,right4  ,as previously       
stated1 frequently the true place to    
begin to set a lever escapement right is
 with the roller and fork4 ,but to do   
this properly we should know when such  
fork and roller action is right and safe
 in all respects4 ,we will see on       
analysis of the actions involved that   
there are three important actions in the
 fork and roller functions3 7a7 ,the    
fork imparting perfect impulse through  
the jewel pin to the balance4 7b7       
,proper unlocking action4 7c7 ,safety   
action4 ,the last function is in most   
instances sadly neglected and1 we regret
 to add1 by a large majority of even    
practical workmen it is very imperfectly
 understood4 ,in most ,american watches 
we have ample opportunity afforded to   
inspect the pallet action1 but the fork 
and roller action is placed so that     
rigid inspection is next to impossible4 
,the ,vacheron concern of ,swiss        
manufacturers were acute enough to see  
the importance of such inspection1 and  

proceeded to cut a circular opening in  
the lower plate1 which permitted1 on the
 removal of the dial1 a careful scrutiny
 of the action of the roller and fork4  
,while writing on this topic we would   
suggest the importance not only of      
knowing how to draw a correct fork and  
roller action1 but letting the workman  
who desires to be au fait in escapements
 delineate and study the action of a    
faulty fork and roller action--say one  
in which the fork1 although of the      
proper form1 is too short1 or what at   
first glance would appear to amount to  
the same thing1 a roller too small4     
,drawings help wonderfully in reasoning 
out not only correct actions1 but also  
faulty ones1 and our readers are        
earnestly advised to make such faulty   
drawings in several stages of action4   
,by this course they will educate the   
eye to discriminate not only as to      
correct actions1 but also to detect     
those which are imperfect1 and we       
believe most watchmakers will admit that

 in many instances it takes much longer 
to locate a fault than to remedy it     
after it has been found4  ,illustration3
 ,fig4 #ee  ,let us now proceed to      
delineate a fork and roller4 ,it is not 
imperative that we should draw the parts
 to any scale1 but it is a rule among   
,english makers to let the distance     
between the center of the pallet staff  
and the center of the balance staff     
equal in length the chord of ninety-six 
degrees of the pitch circle of the      
escape wheel1 which1 in case we employ a
 pitch circle of #e radius1 would make  
the distance between ,a and ,b1 ,fig4   
#ee1 approximately #g1 which is a very  
fair scale for study drawings4   ,,how  
,,to ,,delineate ,a ,,fork ,,and        
,,roller4  ,to arrive at the proper     
proportions of the several parts1 we    
divide the space ,a ,b into four equal  
parts1 as previously directed1 and draw 
the circle a and short arc b4 ,with our 
dividers set at #e1 from ,b as a center 
we sweep the short arc c4 ,from our arc 

of sixty degrees1 with a #e radius1 we  
take five degrees1 and from the         
intersection of the right line ,a ,b    
with the arc c we lay off on each side  
five degrees and establish the points d 
e2 and from ,b as a center1 through     
these points draw the lines ,b d' and ,b
 e'4 ,now the arc embraced between these
 lines represents the angular extent of 
our fork action4  ,from ,a as a center  
and with our dividers set at #e1 we     
sweep the arc f4 ,from the scale of     
degrees we just used we lay off fifteen 
degrees on each side of the line ,a ,b  
on the arc f1 and establish the points g
 h4 ,from ,a as a center1 through the   
points just established we draw the     
radial lines ,a g' and ,a h'4 ,the      
angular extent between these lines      
defines the limit of our roller action4 
,now if we lay off on the arc f six     
degrees each side of its intersection   
with the line ,a ,b1 we define the      
extent of the jewel pin2 that is1 on the
 arc f we establish the points l m at   

six degrees from the line ,a ,b1 and    
through the points l m draw1 from ,a as 
a center1 the radial lines ,a l' and ,a 
m'4 ,the extent of the space between the
 lines ,a l' and ,a m' on the circle a  
defines the size of our jewel pin4      
,,to ,,determine ,,the ,,size ,,of ,a   
,,jewel ,,pin4  ,illustration3 ,fig4 #ef
  ,to make the situation better         
understood1 we make an enlarged drawing 
of the lines defining the jewel pin at  
,fig4 #ef4 ,at the intersection of the  
line ,a ,b with the arc a we locate the 
point k1 and from it as a center we     
sweep the circle i so it passes through 
the intersection of the lines ,a l' and 
,a m' with the arc a4 ,we divide the    
radius of the circle i on the line ,a ,b
 into five equal parts1 as shown by the 
vertical lines j4 ,of these five spaces 
we assume three as the extent of the    
jewel pin1 cutting away that portion to 
the right of the heavy vertical line at 
k4  ,illustration3 ,fig4 #eg  ,we will  
now proceed to delineate a fork and     

roller as the parts are related on first
 contact of jewel pin with fork and     
initial with the commencing of the act  
of unlocking a pallet4 ,the position and
 relations are also the same as at the  
close of the act of impulse4 ,we        
commence the drawing at ,fig4 #eg1 as   
before1 by drawing the line ,a ,b and   
the arcs a and b to represent the pitch 
circles4 ,we also sweep the arc f to    
enable us to delineate the line ,a g'4  
,next in order we draw our jewel pin as 
shown at ,d4 ,in drawing the jewel pin  
we proceed as at ,fig4 #ef1 except we   
let the line ,a g'1 ,fig4 #eg1 assume   
the same relations to the jewel pin as  
,a ,b in ,fig4 #ef2 that is1 we         
delineate the jewel pin as if extending 
on the arc a six degrees on each side of
 the line ,a g'1 ,fig4 #eg4   ,,the     
,,theory ,,of ,,the ,,fork ,,action4    
,to aid us in reasoning1 we establish   
the point m1 as in ,fig4 #ee1 at m1     
,fig4 #eg1 and proceed to delineate     
another and imaginary jewel pin at ,d'  

7as we show in dotted outline74 ,a brief
 reasoning will show that in allowing   
thirty degrees of contact of the fork   
with the jewel pin1 the center of the   
jewel pin will pass through an arc of   
thirty degrees1 as shown on the arcs a  
and f4 ,now here is an excellent        
opportunity to impress on our minds the 
true value of angular motion1 inasmuch  
as thirty degrees on the arc f is of    
more than twice the linear extent as on 
the arc a4  ,before we commence to draw 
the horn of the fork engaging the jewel 
pin ,d1 shown at full line in ,fig4 #eg1
 we will come to perfectly understand   
what mechanical relations are required4 
,as previously stated1 we assume the    
jewel pin1 as shown at ,d1 ,fig4 #eg1 is
 in the act of encountering the inner   
face of the horn of the fork for the end
 or purpose of unlocking the engaged    
pallet4 ,now if the inner face of the   
horn of the fork was on a radial line1  
such radial line would be p ,b1 ,fig4   
#eg4 ,we repeat this line at p1 ,fig4   

#ef1 where the parts are drawn on a     
larger scale4  ,to delineate a fork at  
the instant the last effort of impulse  
has been imparted to the jewel pin1 and 
said jewel pin is in the act of         
separating from the inner face of the   
prong of the fork--we would also call   
attention to the fact that relations of 
parts are precisely the same as if the  
jewel pin had just returned from an     
excursion of vibration and was in the   
act of encountering the inner face of   
the prong of the fork in the act of     
unlocking the escapement4  ,we mentioned
 this matter previously1 but venture on 
the repetition to make everything clear 
and easily understood4 ,we commence by  
drawing the line ,a ,b and dividing it  
in four equal parts1 as on previous     
occasions1 and from ,a and ,b as centers
 draw the pitch circles c d4 ,by methods
 previously described1 we draw the lines
 ,a a and ,a a'1 also ,b b and ,b b' to 
represent the angular motion of the two 
mobiles1 viz41 fork and roller action4  

,as already shown1 the roller occupies  
twelve degrees of angular extent4 ,to   
get at this conveniently1 we lay off on 
the arc by which we located the lines ,a
 a and ,a a' six degrees above the line 
,a a and draw the line ,a h4  ,now the  
angular extent on the arc c between the 
lines ,a a and ,a h represents the      
radius of the circle defining the jewel 
pin4 ,from the intersection of the line 
,a a with the arc c as a center1 and    
with the radius just named1 we sweep the
 small circle ,d1 ,fig4 #eh1 which      
represents our jewel pin2 we afterward  
cut away two-fifths and draw the full   
line ,d1 as shown4 ,we show at ,fig4 #ei
 a portion of ,fig4 #eh1 enlarged four  
times1 to show certain portions of our  
delineations more distinctly4 ,if we    
give the subject a moment's             
consideration we will see that the      
length of the prong ,e of the lever fork
 is limited to such a length as will    
allow the jewel pin ,d to pass it4      
,,how ,,to ,,delineate ,,the ,,prongs   

,,of ,a ,,lever ,,fork4  ,illustration3 
,fig4 #eh  ,illustration3 ,fig4 #ei  ,to
 delineate this length1 from ,b as a    
center we sweep the short arc f so it   
passes through the outer angle n1 ,fig4 
#ei1 of the jewel pin4 ,this arc1       
carried across the jewel pin ,d1 limits 
the length of the opposite prong of the 
fork4 ,the outer face of the prong of   
the fork can be drawn as a line tangent 
to a circle drawn from ,a as a center   
through the angle n of the jewel pin4   
,such a circle or arc is shown at o1    
,figs4 #eh and #ei4 ,there has been a   
good deal said as to whether the outer  
edge of the prong of a fork should be   
straight or curved4  ,to the writer's   
mind1 a straight-faced prong1 like from 
s to m1 is what is required for a fork  
with a single roller1 while a fork with 
a curved prong will be best adapted for 
a double roller4 ,this subject will be  
taken up again when we consider         
double-roller action4 ,the extent or    
length of the outer face of the prong is

 also an open subject1 but as there is  
but one factor of the problem of lever  
escapement construction depending on it1
 when we name this and see this         
requirement satisfied we have made an   
end of this question4 ,the function     
performed by the outer face of the prong
 of a fork is to prevent the engaged    
pallet from unlocking while the guard   
pin is opposite to the passing hollow4  
,the inner angle s of the horn of the   
fork must be so shaped and located that 
the jewel pin will just clear it as it  
passes out of the fork1 or when it      
passes into the fork in the act of      
unlocking the escapement4 ,in           
escapements with solid bankings a trifle
 is allowed1 that is1 the fork is made  
enough shorter than the absolute        
theoretical length to allow for safety  
in this respect4   ,,the ,,proper       
,,length ,,of ,a ,,lever4  ,we will now 
see how long a lever must be to perform 
its functions perfectly4 ,now let us    
determine at what point on the inner    

face of the prong ,e' the jewel pin     
parts from the fork1 or engages on its  
return4 ,to do this we draw a line from 
the center r 7,fig4 #ei7 of the jewel   
pin1 so as to meet the line e at right  
angles1 and the point t so established  
on the line e is where contact will take
 place between the jewel pin and fork4  
,it will be seen this point 7t7 of      
contact is some distance back of the    
angle u which terminates the inner face 
of the prong ,e'2 consequently1 it will 
be seen the prongs ,e ,e' of the fork   
can with safety be shortened enough to  
afford a safe ingress or egress to the  
jewel pin to the slot in the fork4 ,as  
regards the length of the outer face of 
the prong of the fork1 a good rule is to
 make it one and a half times the       
diameter of the jewel pin4 ,the depth of
 the slot need be no more than to free  
the jewel in its passage across the ten 
degrees of fork action4 ,a convenient   
rule as to the depth of the slot in a   
fork is to draw the line k1 which1 it   

will be seen1 coincides with the circle 
which defines the jewel pin4   ,,how    
,,to ,,delineate ,,the ,,safety         
,,action4  ,illustration3 ,fig4 #fj  ,we
 will next consider a safety action of  
the single roller type4 ,the active or  
necessary parts of such safety action   
consist of a roller or disk of metal1   
usually steel1 shaped as shown in plan  
at ,a1 ,fig4 #fj4 ,in the edge of this  
disk is cut in front of the jewel pin a 
circular recess shown at a called the   
passing hollow4 ,the remaining part of  
the safety action is the guard pin shown
 at ,n ,figs4 #fa and #fb1 which is     
placed in the lever4 ,now it is to be   
understood that the sole function       
performed by the guard pin is to strike 
the edge of the roller ,a at any time   
when the fork starts to unlock the      
engaged pallet1 except when the jewel   
pin is in the slot of the fork4 ,to     
avoid extreme care in fitting up the    
passing hollow1 the horns of the fork   
are arranged to strike the jewel pin and

 prevent unlocking in case the passing  
hollow is made too wide4 ,to delineate  
the safety action we first draw the fork
 and jewel pin as previously directed   
and as shown at ,fig4 #fc4 ,the position
 of the guard pin should be as close to 
the bottom of the slot of the fork as   
possible and be safe4 ,as to the size of
 the guard pin1 it is usual to make it  
about one-third or half the diameter of 
the jewel pin4 ,the size and position of
 the guard pin decided on and the small 
circle ,n drawn1 to define the size and 
position of the roller we set our       
dividers so that a circle drawn from the
 center ,a will just touch the edge of  
the small circle ,n1 and thus define the
 outer boundary of our roller1 or roller
 table1 as it is frequently called4     
,illustration3 ,fig4 #fa  ,illustration3
 ,fig4 #fb  ,for deciding the angular   
extent of the passing hollow we have no 
fixed rule1 but if we make it to occupy 
about half more angular extent on the   
circle y than will coincide with the    

angular extent of the jewel pin1 it will
 be perfectly safe and effectual4 ,we   
previously stated that the jewel pin    
should occupy about twelve degrees of   
angular extent on the circle c1 and if  
we make the passing hollow occupy       
eighteen degrees 7which is one and a    
half the angular extent of the jewel    
pin7 it will do nicely4 ,but if we      
should extend the width of the passing  
hollow to twenty-four degrees it would  
do no harm1 as the jewel pin would be   
well inside the horn of the fork before 
the guard pin could enter the passing   
hollow4  ,illustration3 ,fig4 #fc  ,we  
show in ,fig4 #fa the fork as separated 
from the roller1 but in ,fig4 #fb1 which
 is a side view1 we show the fork and   
jewel pin as engaged4 ,when drawing a   
fork and roller action it is safe to    
show the guard pin as if in actual      
contact with the roller4 ,then in actual
 construction1 if the parts are made to 
measure and agree with the drawing in   
the gray1 that is1 before polishing1 the

 process of polishing will reduce the   
convex edge of the roller enough to free
 it4  ,it is evident if thought is given
 to the matter1 that if the guard pin is
 entirely free and does not touch the   
roller in any position1 a condition and 
relation of parts exist which is all we 
can desire4 ,we are aware that it is    
usual to give a considerable latitude in
 this respect even by makers1 and allow 
a good bit of side shake to the lever1  
but our judgment would condemn the      
practice1 especially in high-grade      
watches4   ,,restrict ,,the ,,frictional
 ,,surfaces4  ,grossmann1 in his essay  
on the detached lever escapement1 adopts
 one and a half degrees lock4 ,now1 we  
think that one degree is ample2 and we  
are sure that every workman experienced 
in the construction of the finer watches
 will agree with us in the assertion    
that we should in all instances seek to 
reduce the extent of all frictional     
surfaces1 no matter how well jeweled4   
,acting under such advice1 if we can    

reduce the surface friction on the lock 
from one and a half degrees to one      
degree or1 better1 to three-fourths of a
 degree1 it is surely wise policy to do 
so4 ,and as regards the extent of       
angular motion of the lever1 if we      
reduce this to six degrees1 exclusive of
 the lock1 we would undoubtedly obtain  
better results in timing4  ,we shall    
next consider the effects of opening the
 bankings too wide1 and follow with     
various conditions which are sure to    
come in the experience of the practical 
watch repairer4 ,it is to be supposed in
 this problem that the fork and roller  
action is all right4 ,the reader may say
 to this1 why not close the banking8 ,in
 reply we would offer the supposition   
that some workman had bent the guard pin
 forward or set a pallet stone too far  
out4  ,we have now instructed our       
readers how to draw and construct a     
lever escapement complete1 of the       
correct proportions1 and will next take 
up defective construction and consider  

faults existing to a lesser or greater  
degree in almost every watch4 ,faults   
may also be those arising from repairs  
by some workman not fully posted in the 
correct form and relation of the several
 parts which go to make up a lever      
escapement4 ,it makes no difference to  
the artisan called upon to put a watch  
in perfect order as to whom he is to    
attribute the imperfection1 maker or    
former repairer2 all the workman having 
the job in hand has to do is to know    
positively that such a fault actually   
exists1 and that it devolves upon him to
 correct it properly4   ,,be ,,fearless 
,,in ,,repairs1 ,,if ,,sure ,,you ,,are 
,,right4  ,hence the importance of the  
workman being perfectly posted on such  
matters and1 knowing that he is right1  
can go ahead and make the watch as it   
should be4 ,the writer had an experience
 of this kind years ago in ,chicago4 ,a 
,jules ,jurgensen watch had been in the 
hands of several good workmen in that   
city1 but it would stop4 ,it was then   

brought to him with a statement of facts
 given above4 ,he knew there must be a  
fault somewhere and searched for it1 and
 found it in the exit pallet--a certain 
tooth of the escape wheel under the     
right conditions would sometimes not    
escape4 ,it might go through a great    
many thousand times and yet it might1   
and did sometimes1 hold enough to stop  
the watch4  ,now probably most of my    
fellow-workmen in this instance would   
have been afraid to alter a ,jurgensen1 
or even hint to the owner that such a   
thing could exist as a fault in         
construction in a watch of this         
justly-celebrated maker4 ,the writer    
removed the stone1 ground a little from 
the base of the offending pallet stone1 
replaced it1 and all trouble ended--no  
stops from that on4   ,,study ,,of ,,an 
,,escapement ,,error4  ,illustration3   
,fig4 #fd  ,now let us suppose a case1  
and imagine a full-plate ,american      
movement in which the ingress or        
entrance pallet extends out too far1 and

 in order to have it escape1 the banking
 on that side is opened too wide4 ,we   
show at ,fig4 #fd a drawing of the parts
 in their proper relations under the    
conditions named4 ,it will be seen by   
careful inspection that the jewel pin ,d
 will not enter the fork1 which is      
absolutely necessary4 ,this condition   
very frequently exists in watches where 
a new pallet stone has been put in by an
 inexperienced workman4 ,now this is one
 of the instances in which workmen      
complain of hearing a scraping sound    
when the watch is placed to the ear4    
,the remedy1 of course1 lies in warming 
up the pallet arms and pushing the stone
 in a trifle1 ,but how much8 say some of
 our readers4 ,there is no definite     
rule1 but we will tell such querists how
 they can test the matter4  ,remove the 
hairspring1 and after putting the train 
in place and securing the plates        
together1 give the winding arbor a turn 
or two to put power on the train2 close 
the bankings well in so the watch cannot

 escape on either pallet4 ,put the      
balance in place and screw down the     
cock4 ,carefully turn back the banking  
on one side so the jewel pin will just  
pass out of the slot in the fork4       
,repeat this process with the opposite  
banking2 the jewel pin will now pass out
 on each side4 ,be sure the guard pin   
does not interfere with the fork action 
in any way4 ,the fork is now in position
 to conform to the conditions required4 
,,how ,,to ,,adjust ,,the ,,pallets ,,to
 ,,match ,,the ,,fork4  ,if the         
escapement is all right1 the teeth will 
have one and a half degrees lock and    
escape correctly2 but in the instance we
 are considering1 the stone will not    
permit the teeth to pass1 and must be   
pushed in until they will4 ,it is not a 
very difficult matter after we have     
placed the parts together so we can see 
exactly how much the pallet protrudes   
beyond what is necessary1 to judge how  
far to push it back when we have it out 
and heated4 ,there is still an if in the

 problem we are considering1 which lies 
in the fact that the fork we are        
experimenting with may be too short for 
the jewel pin to engage it for ten      
degrees of angular motion4  ,this       
condition a man of large experience will
 be able to judge of very closely1 but  
the better plan for the workman is to   
make for himself a test gage for the    
angular movement of the fork4 ,of course
 it will be understood that with a fork 
which engages the roller for eight      
degrees of fork action1 such fork will  
not give good results with pallets      
ground for ten degrees of pallet action2
 still1 in many instances1 a compromise 
can be effected which will give results 
that will satisfy the owner of a watch  
of moderate cost1 and from a financial  
point of view it stands the repairer in 
hand to do no more work than is         
absolutely necessary to keep him well   
pleased4  ,we have just made mention of 
a device for testing the angular motion 
of the lever4 ,before we take up this   

matter1 however1 we will devote a little
 time and attention to the subject of   
jewel pins and how to set them4 ,we have
 heretofore only considered jewel pins  
of one form1 that is1 a round jewel pin 
with two-fifths cut away4 ,we assumed   
this form from the fact that experience 
has demonstrated that it is the most    
practicable and efficient form so far   
devised or applied4 ,subsequently we    
shall take up the subject of jewel pins 
of different shapes4   ,,how ,,to ,,set 
,a ,,jewel ,,pin ,,as ,,it ,,should     
,,be4  ,many workmen have a mortal      
terror of setting a jewel pin and seem  
to fancy that they must have a          
specially-devised instrument for        
accomplishing this end4 ,most ,american 
watches have the hole for the jewel pin 
a world too wide for it1 and we have    
heard repeated complaints from this     
cause4 ,probably the original object of 
this accommodating sort of hole was to  
favor or obviate faults of pallet       
action4 ,let us suppose1 for            

illustration1 that we have a roller with
 the usual style of hole for a jewel pin
 which will take almost anything from   
the size of a ,no4 #ab sewing needle up 
to a round ,french clock pallet4        
,illustration3 ,fig4 #fe  ,we are       
restricted as regards the proper size of
 jewel pin by the width of the slot in  
the fork4 ,selecting a jewel which just 
fits the fork1 we can set it as regards 
its relation to the staff so it will    
cause the pitch circle of the jewel pin 
to coincide with either of dotted       
circles a or a'1 ,fig4 #fe4 ,this will  
perhaps be better understood by         
referring to ,fig4 #ff1 which is a view 
of ,fig4 #fe seen in the direction of   
the arrow c4 ,here we see the roller    
jewel at ,d1 and if we bring it forward 
as far as the hole in the roller will   
permit1 it will occupy the position     
indicated at the dotted lines2 and if we
 set it in 7toward the staff7 as far as 
the hole will allow1 it will occupy the 
position indicated by the full outline4 

,illustration3 ,fig4 #ff  ,now such     
other condition might very easily exist1
 that bringing the jewel pin forward to 
the position indicated by the dotted    
lines at ,d1 ,fig4 #ff1 would remedy the
 defect described and illustrated at    
,fig4 #fd without any other change being
 necessary4 ,we do not assert1          
understand1 that a hole too large for   
the jewel pin is either necessary or    
desirable--what we wish to convey to the
 reader is the necessary knowledge so   
that he can profit by such a state if   
necessary4 ,a hole which just fits the  
jewel pin so the merest film of cement  
will hold it in place is the way it     
should be2 but we think it will be some 
time before such rollers are made1      
inasmuch as economy appears to be a     
chief consideration4   ,,about          
,,jewel-,,pin ,,setters4  ,to make a    
jewel-pin setter which will set a jewel 
pin straight is easy enough1 but to     
devise any such instrument which will   
set a jewel so as to perfectly accord   

with the fork action is probably not    
practicable4 ,what the workman needs is 
to know from examination when the jewel 
pin is in the proper position to perform
 its functions correctly1 and he can    
only arrive at this knowledge by careful
 study and thought on the matter4 ,if we
 make up our minds on examining a watch 
that a jewel pin is set too wide1 that  
is1 so it carries the fork over too far 
and increases the lock to an undue      
degree1 take out the balance1 remove the
 hairspring1 warm the roller with a     
small alcohol lamp1 and then with the   
tweezers move the jewel pin in toward   
the staff4  ,illustration3 ,fig4 #fg    
,illustration3 ,fig4 #fh  ,illustration3
 ,fig4 #fi  ,illustration3 ,fig4 #gj    
,no attempt should be made to move a    
jewel pin unless the cement which holds 
the jewel is soft1 so that when the     
parts cool off the jewel is as rigid as 
ever4 ,a very little practice will      
enable any workman who has the necessary
 delicacy of touch requisite to ever    

become a good watchmaker1 to manipulate 
a jewel pin to his entire satisfaction  
with no other setter than a pair of     
tweezers and his eye1 with a proper     
knowledge of what he wants to           
accomplish4 ,to properly heat a roller  
for truing up the jewel pin1 leave it on
 the staff1 and after removing the      
hairspring hold the balance by the rim  
in a pair of tweezers1 flashing it back 
and forth through the flame of a rather 
small alcohol lamp until the rim of the 
balance is so hot it can just be held   
between the thumb and finger1 and while 
at this temperature the jewel pin can be
 pressed forward or backward1 as        
illustrated in ,fig4 #ff1 and then a    
touch or two will set the pin straight  
or parallel with the staff4 ,figs4 #fh  
and #fi are self-explanatory4 ,for      
cementing in a jewel pin a very         
convenient tool is shown at ,figs4 #fg  
and #gj4 ,it is made of a piece of      
copper wire about #a_/af in diameter1   
bent to the form shown at ,fig4 #fg4    

,the ends b b of the copper wire are    
flattened a little and recessed on their
 inner faces1 as shown in ,fig4 #gj1 to 
grasp the edges of the roller ,a4 ,the  
heat of an alcohol lamp is applied to   
the loop of the wire at g until the     
small bit of shellac placed in the hole 
h melts4 ,the necessary small pieces of 
shellac are made by warming a bit of the
 gum to near the melting point and then 
drawing the softened gum into a filament
 the size of horse hair4 ,a bit of this 
broken off and placed in the hole h     
supplies the cement necessary to fasten 
the jewel pin4 ,figs4 #fh and #fi will1 
no doubt1 assist in a clear             
understanding of the matter4   ,,how    
,,to ,,make ,,an ,,angle-,,measuring    
,,device4  ,we will now resume the      
consideration of the device for         
measuring the extent of the angular     
motion of the fork and pallets4 ,now1   
before we take this matter up in detail 
we wish to say1 or rather repeat what we
 have said before1 which is to the      

effect that ten degrees of fork and     
lever action is not imperative1 as we   
can get just as sound an action and     
precisely as good results with nine and 
a half or even nine degrees as with ten1
 if other acting parts are in unison    
with such an arc of angular motion4 ,the
 chief use of such an angle-measuring   
device is to aid in comparing the       
relative action of the several parts    
with a known standard4  ,illustration3  
,fig4 #ga  ,for use with full-plate     
movements about the best plan is a      
spring clip or clasp to embrace the     
pallet staff below the pallets4 ,we show
 at ,fig4 #ga such a device4 ,to make   
it1 take a rather large size of sewing  
needle--the kind known as a milliner's  
needle is about the best4 ,the diameter 
of the needle should be about ,no4 #b1  
so that at b we can drill and put in a  
small screw4 ,it is important that the  
whole affair should be very light4 ,the 
length of the needle should be about    
#a-e_/h1 in order that from the notch a 

to the end of the needle ,a' should be  
#a4 ,the needle should be annealed and  
flattened a little1 to give a pretty    
good grasp to the notch a on the pallet 
staff4  ,good judgment is important in  
making this clamp1 as it is nearly      
impossible to give exact measurements4  
,about #a_/dj in width when seen in the 
direction of the arrow j will be found  
to be about the right width4 ,the spring
 ,b can be made of a bit of mainspring1 
annealed and filed down to agree in     
width with the part ,a4 ,in connection  
with the device shown at ,fig4 #ga we   
need a movement-holder to hold the      
movement as nearly a constant height as 
possible above the bench4 ,the idea is1 
when the clamp ,a ,b is slipped on the  
pallet staff the index hand ,a' will    
extend outward1 as shown in ,fig4 #gb1  
where the circle ,c is supposed to      
represent the top plate of a watch1 and 
,a' the index hand4   ,,how ,,the       
,,angular ,,motion ,,is ,,measured4     
,illustration3 ,fig4 #gb  ,fig4 #gb is  

supposed to be seen from above4 ,it is  
evident that if we remove the balance   
from the movement shown at ,c1 leaving  
power on the train1 and with an oiling  
tool or hair broach move the lever back 
and forth1 the index hand ,a' will show 
in a magnified manner the angular motion
 of the lever4 ,now if we provide an    
index arc1 as shown at ,d1 we can       
measure the extent of such motion from  
bank to bank4  ,illustration3 ,fig4 #gc 
,illustration3 ,fig4 #gd  ,to get up    
such an index arc we first make a stand 
as shown at ,e ,f1 ,fig4 #gc4 ,the arc  
,d is made to #a radius1 to agree with  
the index hand ,a'1 and is divided into 
twelve degree spaces1 six each side of a
 zero1 as shown at ,fig4 #gd1 which is  
an enlarged view of the index ,d in     
,fig4 #gb4 ,the index arc is attached to
 a short bit of wire extending down into
 the support ,e1 and made adjustable as 
to height by the set-screw l4 ,let us   
suppose the index arc is adjusted to the
 index hand ,a'1 and we move the fork as

 suggested2 you see the hand would show 
exactly the arc passed through from bank
 to bank1 and by moving the stand ,e ,f 
we can arrange so the zero mark on the  
scale stands in the center of such arc4 
,this1 of course1 gives the angular     
motion from bank to bank4 ,as an        
experiment1 let us close the bankings so
 they arrest the fork at the instant the
 tooth drops from each pallet4 ,if this 
arc is ten degrees1 the pallet action is
 as it should be with the majority of   
modern watches4   ,,testing ,,lock ,,and
 ,,drop ,,with ,,our ,,new ,,device4    
,let us try another experiment3 ,we     
carefully move the fork away from the   
bank1 and if after the index hand has   
passed through one and a half degrees   
the fork flies over1 we know the lock is
 right4 ,we repeat the experiment from  
the opposite bank1 and in the same      
manner determine if the lock is right on
 the other pallets4 ,you see we have now
 the means of measuring not only the    
angular motion of the lever1 but the    

angular extent of the lock4 ,at first   
glance one would say that if now we     
bring the roller and fork action to     
coincide and act in unison with the     
pallet action1 we would be all right2   
and so we would1 but frequently this    
bringing of the roller and fork to agree
 is not so easily accomplished4  ,it is 
chiefly toward this end the ,waltham    
fork is made adjustable1 so it can be   
moved to or from the roller1 and also   
that we can allow the pallet arms to be 
moved1 as we will try and explain4 ,as  
we set the bankings the pallets are all 
right2 but to test matters1 let us      
remove the hairspring and put the       
balance in place4 ,now1 if the jewel pin
 passes in and out of the fork1 it is to
 be supposed the fork and roller action 
is all right4 ,to test the fork and     
roller action we close the banking a    
little on one side4 ,if the fork and    
jewel pin are related to each other as  
they should be1 the jewel pin will not  
pass out of the fork1 nor will the      

engaged tooth drop from that pallet4    
,this condition should obtain on both   
pallets1 that is1 if the jewel pin will 
not pass out of the fork on a given bank
 the tooth engaged on its pallet should 
not drop4  ,we have now come to the most
 intricate and important problems which 
relate to the lever escapement4         
,however1 we promise our readers that if
 they will take the pains to follow     
closely our elucidations1 to make these 
puzzles plain4 ,but we warn them that   
they are no easy problems to solve1 but 
require good1 hard thinking4 ,the       
readiest way to master this matter is by
 means of such a model escapement as we 
have described4 ,with such a model1 and 
the pallets made to clamp with small    
set-screws1 and roller constructed so   
the jewel pin could be set to or from   
the staff1 this matter can be reduced to
 object lessons4 ,but study of the due  
relation of the parts in good drawings  
will also master the situation4   ,a    
,,few ,,experiments ,,with ,,our        

,,angle-,,measuring ,,device4  ,in using
 the little instrument for determining  
angular motion that we have just        
described1 care must be taken that the  
spring clamp which embraces the pallet  
staff does not slip4 ,in order to       
thoroughly understand the methods of    
using this angle-measuring device1 let  
us take a further lesson or two4  ,we   
considered measuring the amount of lock 
on each pallet1 and advised the removal 
of the balance1 because if we left the  
balance in we could not readily tell    
exactly when the tooth passed on to the 
impulse plane2 but if we touch the fork 
lightly with an oiling tool or a hair   
broach1 moving it 7the fork7 carefully  
away from the bank and watching the arc 
indicated by the hand ,a1 ,fig4 #gb1 we 
can determine with great exactness the  
angular extent of lock4 ,the diagram at 
,fig4 #ge illustrates how this          
experiment is conducted4 ,we apply the  
hair broach to the end of the fork ,m1  
as shown at ,l1 and gently move the fork

 in the direction of the arrow i1       
watching the hand ,a and note the number
 of degrees1 or parts of degrees1       
indicated by the hand as passed over    
before the tooth is unlocked and passes 
on to the impulse plane and the fork    
flies forward to the opposite bank4     
,now1 the quick movement of the pallet  
and fork may make the hand mark more or 
less of an arc on the index than one of 
ten degrees1 as the grasp may slip on   
the pallet staff2 but the arc indicated 
by the slow movement in unlocking will  
be correct4  ,illustration3 ,fig4 #ge   
,by taking a piece of sharpened pegwood 
and placing the point in the slot of the
 fork1 we can test the fork to see if   
the drop takes place much before the    
lever rests against the opposite bank4  
,as we have previously stated1 the drop 
from the pallet should not take place   
until the lever almost rests on the     
banking pin4 ,what the reader should    
impress on his mind is that the lever   
should pass through about one and a half

 degrees arc to unlock1 and the         
remainder 7eight and a half degrees7 of 
the ten degrees are to be devoted to    
impulse4 ,but1 understand1 if the       
impulse angle is only seven and a half  
degrees1 and the jewel pin acts in      
accordance with the rules previously    
given1 do not alter the pallet until you
 know for certain you will gain by it4  
,an observant workman will1 after a     
little practice1 be able to determine   
this matter4  ,we will next take up the 
double roller and fork action1 and also 
consider in many ways the effect of less
 angles of action than ten degrees4     
,this matter now seems of more          
importance1 from the fact that we are   
desirous to impress on our readers that 
there is no valid reason for adopting   
ten degrees of fork and roller action   
with the table roller1 except that about
 this number of degrees of action are   
required to secure a reliable safety    
action4 ,with the double roller1 as low 
as six degrees fork and pallet action   

can be safely employed4 ,in fork and    
pallet actions below six degrees of     
angular motion1 side-shake in pivot     
holes becomes a dangerous factor1 as    
will be explained further on4 ,it is    
perfectly comprehending the action of   
the lever escapement and then being able
 to remedy defects1 that constitute the 
master workman4   ,,how ,,to ,,measure  
,,the ,,angular ,,motion ,,of ,,an      
,,escape ,,wheel4  ,illustration3 ,fig4 
#gf  ,we can also make use of our       
angle-testing device for measuring our  
escape-wheel action1 by letting the     
clasp embrace the arbor of the escape   
wheel1 instead of the pallet staff4 ,we 
set the index arc as in our former      
experiments1 except we place the movable
 index ,d1 ,fig4 #gf1 so that when the  
engaged tooth rests on the locking face 
of a pallet1 the index hand stands at   
the extreme end of our arc of twelve    
degrees4 ,we next1 with our pointed     
pegwood1 start to move the fork away    
from the bank1 as before1 we look sharp 

and see the index hand move backward a  
little1 indicating the draw on the      
locking face4 ,as soon as the pallet    
reaches the impulse face1 the hand ,a   
moves rapidly forward1 and if the       
escapement is of the club-tooth order   
and closely matched1 the hand ,a will   
pass over ten and a half degrees of     
angular motion before the drop takes    
place4  ,illustration3 ,fig4 #gg  ,we   
will warn our readers in advance1 that  
if they make such a testing device they 
will be astonished at the inaccuracy    
which they will find in the escapements 
of so-called fine watches4 ,the lock1 in
 many instances1 instead of being one   
and a half degrees1 will oftener be     
found to be from two to four degrees1   
and the impulse derived from the escape 
wheel1 as illustrated at ,fig4 #gf1 will
 often fall below eight degrees4 ,such  
watches will have a poor motion and tick
 loud enough to keep a policeman awake4 
,trials with actual watches1 with such a
 device as we have just described1 in   

conjunction with a careful study of the 
acting parts1 especially if aided by a  
large model1 such as we have described1 
will soon bring the student to a degree 
of skill unknown to the old-style       
workman1 who1 if a poor escapement      
bothered him1 would bend back the       
banking pins or widen the slot in the   
fork4  ,we hold that educating our      
repair workmen up to a high knowledge of
 what is required to constitute a       
high-grade escapement1 will have a      
beneficial effect on manufacturers4     
,when we wish to apply our device to the
 measurement of the escapement of       
three-quarter-plate watches1 we will    
require another index hand1 with the    
grasping end bent downward1 as shown at 
,fig4 #gg4 ,the idea with this form of  
index hand is1 the bent-down jaws ,b'1  
,fig4 #gg1 grasp the fork as close to   
the pallet staff as possible1 making an 
allowance for the acting center by so   
placing the index arc that the hand ,a  
will read correctly on the index ,d4    

,suppose1 for instance1 we place the    
jaws ,b' inside the pallet staff1 we    
then place the index arc so the hand    
reads to the arc indicated by the dotted
 arc m1 ,fig4 #gh1 and if set outside of
 the pallet staff1 read by the arc o4   
,illustration3 ,fig4 #gh   ,,how ,a     
,,balance ,,controls ,,the ,,timekeeping
 ,,of ,a ,,watch4  ,we think a majority 
of the fine lever escapements made      
abroad in this day have what is termed  
double-roller safety action4 ,the chief 
gains to be derived from this form of   
safety action are3 7#a7 ,reducing the   
arc of fork and roller action2 7#b7     
reducing the friction of the guard point
 to a minimum4 ,while it is entirely    
practicable to use a table roller for   
holding the jewel pin with a            
double-roller action1 still a departure 
from that form is desirable1 both for   
looks and because as much of the        
aggregate weight of a balance should be 
kept as far from the axis of rotation as
 possible4  ,we might as well consider  

here as elsewhere1 the relation the     
balance bears to the train as a         
controlling power4 ,strictly speaking1  
the balance and hairspring are the time 
measurers1 the train serving only two   
purposes3 7a7 ,to keep the balance in   
motion2 7b7 to classify and record the  
number of vibrations of the balance4    
,hence1 it is of paramount importance   
that the vibrations of the balance      
should be as untrammeled as possible2   
this is why we urge reducing the arc of 
connection between the balance and fork 
to one as brief as is consistent with   
sound results4 ,with a double-roller    
safety action we can easily reduce the  
fork action to eight degrees and the    
roller action to twenty-four degrees4   
,inasmuch as satisfactory results in    
adjustment depend very much on the      
perfection of construction1 we shall now
 dwell to some extent on the necessity  
of the several parts being made on      
correct principles4 ,for instance1 by   
reducing the arc of engagement between  

the fork and roller1 we lessen the      
duration of any disturbing influence of 
escapement action4  ,to resume the      
explanation of why it is desirable to   
make the staff and all parts near the   
axis of the balance as light as         
possible1 we would say it is the moving 
portion of the balance which controls   
the regularity of the intervals of      
vibration4 ,to illustrate1 suppose we   
have a balance only #c_/h in diameter1  
but of the same weight as one in an     
ordinary eighteen-size movement4 ,we can
 readily see that such a balance would  
require but a very light hairspring to  
cause it to give the usual #ah1jjj      
vibrations to the hour4 ,we can also    
understand1 after a little thought1 that
 such a balance would exert as much     
breaking force on its pivots as a       
balance of the same weight1 but  in     
diameter acting against a very much     
stronger hairspring4 ,there is another  
factor in the balance problem which     
deserves our attention1 which factor is 

atmospheric resistance4 ,this increases 
rapidly in proportion to the velocity4  
,,how ,,barometric ,,pressure ,,affects 
,a ,,watch4  ,the most careful          
investigators in horological mechanics  
have decided that a balance much above  
#ge_/ajj in diameter1 making #ah1jjj    
vibrations per hour1 is not desirable1  
because of the varying atmospheric      
disturbances as indicated by barometric 
pressure4 ,a balance with all of its    
weight as near the periphery as is      
consistent with strength1 is what is to 
be desired for best results4 ,it is the 
moving matter composing the balance1    
pitted against the elastic force of the 
hairspring1 which we have to depend upon
 for the regularity of the timekeeping  
of a watch1 and if we can take two      
grains' weight of matter from our roller
 table and place them in the rim or     
screws of the balance1 so as to act to  
better advantage against the hairspring1
 we have disposed of these two grains so
 as to increase the efficiency of the   

controlling power and not increase the  
stress on the pivots4  ,illustration3   
,fig4 #gi  ,we have deduced from the    
facts set forth1 two axioms3 7a7 ,that  
we should keep the weight of our balance
 as much in the periphery as possible1  
consistent with due strength2 7b7 avoid 
excessive size from the disturbing      
effect of the air4 ,we show at ,a1 ,fig4
 #gi1 the shape of the piece which      
carries the jewel pin4 ,as shown1 it    
consists of three parts3 7#a7 ,the      
socket ,a1 which receives the jewel pin 
a2 7#b7 the part ,a'' and hole b1 which 
goes on the balance staff2 7#c7 the     
counterpoise ,a'''1 which makes up for  
the weight of the jewel socket ,a1 neck 
,a' and jewel pin4 ,this counterpoise   
also makes up for the passing hollow ,c 
in the guard roller ,b1 ,fig4 #hj4 ,as  
the piece ,a is always in the same      
relation to the roller ,b1 the poise of 
the balance must always remain the same1
 no matter how the roller action is     
placed on the staff4 ,we once saw a     

double roller of nearly the shape shown 
at ,fig4 #gi1 which had a small gold    
screw placed at d1 evidently for the    
purpose of poising the double rollers2  
but1 to our thinking1 it was a sort of  
hairsplitting hardly worth the extra    
trouble4 ,rollers for very fine watches 
should be poised on the staff before the
 balance is placed upon it4             
,illustration3 ,fig4 #hj  ,we shall next
 give detailed instructions for drawing 
such a double roller as will be adapted 
for the large model previously          
described1 which1 as the reader will    
remember1 was for ten degrees of roller 
action4 ,we will also point out the     
necessary changes required to make it   
adapted for eight degrees of fork       
action4 ,we would beg to urge again the 
advantages to be derived from           
constructing such a model1 even for     
workmen who have had a long experience  
in escapements1 our word for it they    
will discover a great many new wrinkles 
they never dreamed of previously4  ,it  

is important that every practical       
watchmaker should thoroughly master the 
theory of the lever escapement and be   
able to comprehend and understand at    
sight the faults and errors in such     
escapements1 which1 in the every-day    
practice of his profession1 come to his 
notice4 ,in no place is such knowledge  
more required than in fork and roller   
action4 ,we are led to say the above    
chiefly for the benefit of a class of   
workmen who think there is a certain set
 of rules which1 if they could be       
obtained1 would enable them to set to   
rights any and all escapements4 ,it is  
well to understand that no such system  
exists and that1 practically1 we must   
make one error balance another2 and it  
is the know how to make such faults and 
errors counteract each other that       
enables one workman to earn more for    
himself or his employer in two days than
 another workman1 who can file and drill
 as well as he can1 will earn in a week4
   ,,proportions ,,of ,,the             

,,double-,,roller ,,escapement4  ,the   
proportion in size between the two      
rollers in a double-roller escapement is
 an open question1 or1 at least1 makers 
seldom agree on it4 ,grossmann shows1 in
 his work on the lever escapement1 two  
sizes3 7#a7 ,half the diameter of the   
acting roller2 7#b7 two-thirds of the   
size of the acting roller4 ,the chief   
fault urged against a smaller safety    
roller is1 that it necessitates longer  
horns to the fork to carry out the      
safety action4 ,longer horns mean more  
metal in the lever1 and it is the       
conceded policy of all recent makers to 
have the fork and pallets as light as   
possible4 ,another fault pertaining to  
long horns is1 when the horn does have  
to act as safety action1 a greater      
friction ensues4  ,in all               
soundly-constructed lever escapements   
the safety action is only called into   
use in exceptional cases1 and if the    
watch was lying still would             
theoretically never be required4 ,where 

fork and pallets are poised on their    
arbor1 pocket motion 7except torsional7 
should but very little affect the fork  
and pallet action of a watch1 and       
torsional motion is something seldom    
brought to act on a watch to an extent  
to make it worthy of much consideration4
 ,in the double-roller action which we  
shall consider1 we shall adopt          
three-fifths of the pitch diameter of   
the jewel-pin action as the proper size4
 ,not but what the proportions given by 
,grossmann will do good service2 but we 
adopt the proportions named because it  
enables us to use a light fork1 and     
still the friction of the guard point on
 the roller is but little more than     
where a guard roller of half the        
diameter of the acting roller is        
employed4  ,the fork action we shall    
consider at present is ten degrees1 but 
subsequently we shall consider a        
double-roller action in which the fork  
and pallet action is reduced to eight   
degrees4 ,we shall conceive the play    

between the guard point and the safety  
roller as one degree1 which will leave  
half a degree of lock remaining in      
action on the engaged pallet4           
,,theoretical ,,action ,,of ,,double    
,,roller ,,considered4  ,in the drawing 
at ,fig4 #ha we show a diagram of the   
action of the double-roller escapement4 
,the small circle at ,a represents the  
center of the pallet staff1 and the one 
at ,b the center of the balance staff4  
,the radial lines ,a d and ,a d'        
represent the arc of angular motion of  
fork action4 ,the circle b b represents 
the pitch circle of the jewel pin1 and  
the circle at c c the periphery of the  
guard or safety roller4 ,the points     
established on the circle c c by        
intersection of the radial lines ,a d   
and ,a d' we will denominate the points 
h and h'4 ,it is at these points the end
 of the guard point of the fork will    
terminate4 ,in construction1 or in      
delineating for construction1 we show   
the guard enough short of the points h  

h' to allow the fork an angular motion  
of one degree1 from ,a as a center1     
before said point would come in contact 
with the safety roller4  ,illustration3 
,fig4 #ha  ,we draw through the points h
 h'1 from ,b as a center1 the radial    
lines ,b g and ,b g'4 ,we measure this  
angle by sweeping the short arc i with  
any of the radii we have used for arc   
measurement in former delineations1 and 
find it to be a trifle over sixty       
degrees4 ,to give ourselves a practical 
object lesson1 let us imagine that a    
real guard point rests on the circle c  
at h4 ,suppose we make a notch in the   
guard roller represented by the circle  
c1 to admit such imaginary guard point1 
and then commence to revolve the circle 
c in the direction of the arrow j1      
letting the guard point rest constantly 
in such notch4 ,when the notch n in c   
has been carried through thirty degrees 
of arc1 counting from ,b as a center1   
the guard point1 as relates to ,a as a  
center1 would only have passed through  

an arc of five degrees4 ,we show such a 
guard point and notch at o n4 ,in fact1 
if a jewel pin was set to engage the    
fork on the pitch circle b a1 the       
escapement would lock4 ,to obviate such 
lock we widen the notch n to the extent 
indicated by the dotted lines n'1       
allowing the guard point to fall back1  
so to speak1 into the notch n1 which    
really represents the passing hollow4   
,it is not to be understood that the    
extended notch at n is correctly drawn  
as regards position1 because when the   
guard point was on the line ,a f the    
point o would be in the center of the   
extended notch1 or passing hollow4 ,we  
shall next give the details of drawing  
the double roller1 but before doing so  
we deemed it important to explain the   
action of such guard points more fully  
than has been done heretofore4   ,,how  
,,to ,,design ,a ,,double-,,roller      
,,escapement4  ,we have already given   
very desirable forms for the parts of a 
double-roller escapement1 consequently  

we shall now deal chiefly with acting   
principles as regards the rollers1 but  
will give1 at ,fig4 #hb1 a very well    
proportioned and practical form of fork4
 ,the pitch circle of the jewel pin is  
indicated by the dotted circle a1 and   
the jewel pin of the usual cylindrical  
form1 with two-fifths cut away4 ,the    
safety roller is three-fifths of the    
diameter of the pitch diameter of the   
jewel-pin action1 as indicated by the   
dotted circle a4  ,the safety roller is 
shown in full outline at ,b'1 and the   
passing hollow at ,e4 ,it will be seen  
that the arc of intersection embraced   
between the radial lines ,b c and ,b d  
is about sixty-one and a half degrees   
for the roller1 but the angular extent  
of the passing hollow is only a little  
over thirty-two degrees4 ,the passing   
hollow ,e is located and defined by     
drawing the radial line ,b c from the   
center ,b through the intersection of   
radial line ,a i with the dotted arc b1 
which represents the pitch circle of the

 safety roller4 ,we will name this      
intersection the point l4 ,now the end  
of the guard point ,c terminates at the 
point l1 and the passing hollow ,e      
extends on b sixteen degrees on each    
side of the radial line ,b c4           
,illustration3 ,fig4 #hb  ,the roller   
action is supposed to continue through  
thirty degrees of angular motion of the 
balance staff1 and is embraced on the   
circle a between the radial line ,b k   
and ,b o4 ,to delineate the inner face  
of the horn p of the fork ,f we draw the
 short arc g1 from ,a as a center1 and  
on said arc locate at two degrees from  
the center at ,b the point f4 ,we will  
designate the upper angle of the outer  
face of the jewel pin ,d as the point s 
and1 from ,a as a center1 sweep through 
this point s the short arc n n4         
,parallel with the line ,a i and at the 
distance of half the diameter of the    
jewel pin ,d1 we draw the short lines t 
t'1 which define the inner faces of the 
fork4  ,the intersection of the short   

line t with the arc n we will designate 
the point r4 ,with our dividers set to  
embrace the space between the point r   
and the point f1 we sweep the arc which 
defines the inner face of the prong of  
the fork4 ,the space we just made use of
 is practically the same as the radius  
of the circle a1 and consequently of the
 same curvature4 ,practically1 the      
length of the guard point ,c' is made as
 long as will1 with certainty1 clear the
 safety roller ,b in all positions4     
,while we set the point f at two degrees
 from the center ,b1 still1 in a        
well-constructed escapement1 one and a  
half degrees should be sufficient1 but  
the extra half degree will do no harm4  
,if the roller ,b' is accurately made   
and the guard point ,c' properly fitted1
 the fork will not have half a degree of
 play4  ,the reader will remember that  
in the escapement model we described we 
cut down the drop to one degree1 being  
less by half a degree than advised by   
,grossmann and ,saunier4 ,we also       

advised only one degree of lock4 ,in the
 perfected lever escapement1 which we   
shall describe and give working drawings
 for the construction of1 we shall      
describe a detached lever escapement    
with only eight degrees fork and pallet 
action1 with only three-fourths of a    
degree drop and three-fourths of a      
degree lock1 which we can assure our    
readers is easily within the limits of  
practical construction by modern        
machinery4   ,,how ,,the ,,guard ,,point
 ,,is ,,made4  ,illustration3 ,fig4 #hc 
,the guard point ,c'1 as shown at ,fig4 
#hb1 is of extremely simple             
construction4 ,back of the slot of the  
fork1 which is three-fifths of the      
diameter of the jewel pin in depth1 is  
made a square hole1 as shown at u1 and  
the back end of the guard point ,c is   
fitted to this hole so that it is rigid 
in position4 ,this manner of fastening  
the guard point is equally efficient as 
that of attaching it with a screw1 and  
much lighter--a matter of the highest   

importance in escapement construction1  
as we have already urged4 ,about the    
best material for such guard points is  
either aluminum or phosphor bronze1 as  
such material is lighter than gold and  
very rigid and strong4 ,at ,fig4 #hc we 
show a side view of the essential parts 
depicted in ,fig4 #hb1 as if seen in the
 direction of the arrow v1 but we have  
added the piece which holds the jewel   
pin ,d4 ,a careful study of the cut     
shown at ,fig4 #hb will soon give the   
horological student an excellent idea of
 the double-roller action4  ,we will now
 take up and consider at length why     
,saunier draws his entrance pallet with 
fifteen degrees draw and his exit pallet
 with only twelve degrees draw4 ,to make
 ourselves more conversant with         
,saunier's method of delineating the    
lever escapement1 we reproduce the      
essential features of his drawing1 ,fig4
 #a1 plate ,,viii1 of his ,modern       
,horology1 in which he makes the draw of
 the locking face of the entrance pallet

 fifteen degrees and his exit pallet    
twelve degrees4 ,in the cut shown at    
,fig4 #hd we use the same letters of    
reference as he employs4 ,we do not     
quote his description or directions for 
delineation because he refers to so much
 matter which he has previously given in
 the book just referred to4 ,besides we 
cannot entirely endorse his methods of  
delineations for many reasons1 one of   
which appears in the drawing at ,fig4   
#hd4  ,illustration3 ,fig4 #hd   ,,more 
,,about ,,tangential ,,lockings4  ,most 
writers endorse the idea of tangential  
lockings1 and ,saunier speaks of the    
escapement as shown at ,fig4 #hd as     
having such tangential lockings1 which  
is not the case4 ,he defines the        
position of the pallet staff from the   
circle t1 which represents the extreme  
length of the teeth2 drawing the radial 
lines ,a ,d and ,a ,e to embrace an arc 
of sixty degrees1 and establishing the  
center of his pallet staff ,c at the    
intersection of the lines ,d ,c and ,e  

,c1 which are drawn at right angles to  
the radial lines ,a ,d and ,a ,e1 and   
tangential to the circle t4  ,here is an
 error2 the lines defining the center of
 the pallet staff should have been drawn
 tangent to the circle s1 which         
represents the locking angle of the     
teeth4 ,this would have placed the      
center of the pallet staff farther in1  
or closer to the wheel4 ,any person can 
see at a glance that the pallets as     
delineated are not tangential in a true 
sense4  ,illustration3 ,fig4 #he  ,we   
have previously considered engaging     
friction and also repeatedly have spoken
 of tangential lockings1 but will repeat
 the idea of tangential lockings at     
,fig4 #he4 ,a tangential locking is     
neutral1 or nearly so1 as regards       
engaging friction4 ,for illustration we 
refer to ,fig4 #he1 where ,a represents 
the center of an escape wheel4 ,we draw 
the radial lines ,a y and ,a z so that  
they embrace sixty degrees of the arcs s
 or t1 which correspond to similar      

circles in ,fig4 #hd1 and represent the 
extreme extent of the teeth and likewise
 the locking angle of such teeth4 ,in   
fact1 with the club-tooth escapement all
 that part of a tooth which extends     
beyond the line s should be considered  
the same as the addendum in gear wheels4
 ,consequently1 a tangential locking    
made to coincide with the center of the 
impulse plane1 as recommended by        
,saunier1 would require the pallet staff
 to be located at ,c' instead of ,c1 as 
he draws it4 ,if the angle k' of the    
tooth k in ,fig4 #hd was extended       
outward from the center ,a so it would  
engage or rest on the locking face of   
the entrance pallet as shown at ,fig4   
#hd1 then the draw of the locking angle 
would not be quite fifteen degrees2 but 
it is evident no lock can take place    
until the angle a of the entrance pallet
 has passed inside the circle s4 ,we    
would say here that we have added the   
letters s and t to the original         
drawings1 as we have frequently to refer

 to these circles1 and without letters  
had no means of designation4 ,before the
 locking angle k' of the tooth can      
engage the pallet1 as shown in ,fig4    
#hd1 the pallet must turn on the center 
,c through an angular movement of at    
least four degrees4 ,we show the        
situation in the diagram at ,fig4 #hf1  
using the same letters of reference for 
similar parts as in ,fig4 #hd4          
,illustration3 ,fig4 #hf  ,as drawn in  
,fig4 #hd the angle of draft ,g a ,i is 
equal to fifteen degrees1 but when      
brought in a position to act as shown at
 ,g a' ,i'1 ,fig4 #hf1 the draw is less 
even than twelve degrees4 ,the angle ,c 
a ,i remains constant1 as shown at ,c a'
 ,i'1 but the relation to the radial ,a 
,g changes when the pallet moves through
 the angle w ,c w'1 as it must when     
locked4 ,a tangential locking in the    
true sense of the meaning of the phrase 
is a locking set so that a pallet with  
its face coinciding with a radial line  
like ,a ,g would be neutral1 and the    

thrust of the tooth would be tangent to 
the circle described by the locking     
angle of the tooth4 ,thus the center ,c1
 ,fig4 #hf1 is placed on the line w'    
which is tangent to the circle s2 said  
line w' also being at right angles to   
the radial line ,a ,g4  ,the facts are1 
the problems relating to the club-tooth 
lever escapement are very intricate and 
require very careful analysis1 and      
without such care the horological       
student can very readily be misled4     
,faulty drawings1 when studying such    
problems1 lead to no end of errors1 and 
practical men who make imperfect        
drawings lead to the popular phrase1    
,oh1 such a matter may be all right in  
theory1 but will not work in practice4  
,we should always bear in mind that     
theory1 if right1 must lead practice4   
,,correct ,,drawing ,,required4  ,if we 
delineate our entrance pallet to have a 
draw of twelve degrees when in actual   
contact with the tooth1 and then        
construct in exact conformity with such 

drawings1 we will find our lever to hug 
the banks in every instance4 ,it is     
inattention to such details which       
produces the errors of makers complained
 of by ,saunier in section #fif of his  
,modern ,horology1 and which he attempts
 to correct by drawing the locking face 
at fifteen degrees draw4  ,we shall show
 that neither ,c nor ,c'1 ,fig4 #he1 is 
the theoretically correct position for  
the pallet center for a tangential      
locking4  ,we will now take up the      
consideration of a club-tooth lever     
escapement with circular pallets and    
tangential lockings2 but previous to    
making the drawings we must decide      
several points1 among which are the     
thickness of the pallet arms1 which     
establishes the angular motion of the   
escape wheel utilized by such pallet    
arms1 and also the angular motion       
imparted to the pallets by the impulse  
faces of the teeth4 ,we will1 for the   
present1 accept the thickness of the    
arms as being equivalent to five degrees

 of angular extent of the pitch circle  
of the escape wheel4  ,illustration3    
,fig4 #hg  ,illustration3 ,fig4 #hh  ,in
 making our drawings we commence1 as on 
former occasions1 by establishing the   
center of our escape wheel at ,a1 ,fig4 
#hg1 and sweeping the arc a a to        
represent the pitch circle of such      
wheel4 ,through the center ,a we draw   
the vertical line ,a ,b1 which is       
supposed to also pass through the center
 of the pallet staff4 ,the intersection 
of the line ,a ,b with the arc a we term
 the point d1 and from this point we lay
 off on said arc a thirty degrees each  
side of said intersection1 and thus     
establish the points c b4 ,from ,a1     
through the point c1 we draw the line ,a
 c c'4 ,on the arc a a and two and a    
half degrees to the left of the point c 
we establish the point f1 which space   
represents half of the thickness of the 
entrance pallet4 ,from ,a we draw       
through the point f the line ,a f f'4   
,from f1 and at right angles to said    

line ,a f1 we draw the line f e until it
 crosses the line ,a ,b4  ,now this line
 f e is tangent to the arc a from the   
point f1 and consequently a locking     
placed at the point f is a true         
tangential locking2 and if the resting  
or locking face of a pallet was made to 
coincide with the line ,a f'1 such      
locking face would be strictly dead or  
neutral4 ,the intersection of the line f
 e with the line ,a ,b we call the point
 ,c1 and locate at this point the center
 of our pallet staff4 ,according to the 
method of delineating the lever         
escapement by ,moritz ,grossmann the    
tangent line for locating the center of 
the pallet staff is drawn from the point
 c1 which would locate the center of the
 pallet staff at the point h on the line
 ,a ,b4  ,grossmann1 in delineating his 
locking face for the draw1 shows such   
face at an angle of twelve degrees to   
the radial line ,a f'1 when he should   
have drawn it twelve degrees to an      
imaginary line shown at f i1 which is at

 right angles to the line f h4 ,to the  
writer's mind this is not just as it    
should be1 and may lead to              
misunderstanding and bad construction4  
,we should always bear in mind the fact 
that the basis of a locking face is a   
neutral plane placed at right angles to 
the line of thrust1 and the draw comes  
from a locking face placed at an angle  
to such neutral plane4 ,a careful study 
of the diagram at ,fig4 #hh will give   
the reader correct ideas4 ,if a tooth   
locks at the point c1 the tangential    
thrust would be on the line c h'1 and a 
neutral locking face would be on the    
line ,a c4   ,,neutral ,,lockings4  ,to 
aid in explanation1 let us remove the   
pallet center to ,d2 then the line of   
thrust would be c ,d and a neutral      
locking face would coincide with the    
line m m1 which is at right angles to   
the line c ,d4 ,if we should now make a 
locking face with a draw and at an angle
 to the line c ,d1 say1 for             
illustration1 to correspond to the line 

c c' 7leaving the pallet center at ,d71 
we would have a strong draw and also a  
cruel engaging friction4  ,if1 however1 
we removed the engaging tooth1 which we 
have just conceived to be at c1 to the  
point k on the arc a' a'1 ,fig4 #hh1 the
 pallet center ,d would then represent a
 tangential locking1 and a neutral      
pallet face would coincide with the     
radial line ,a k'2 and a locking face   
with twelve degrees draw would coincide 
nearly with the line l4 ,let us next    
analyze what the effect would be if we  
changed the pallet center to h'1 ,fig4  
#hh1 leaving the engaging tooth still at
 k4 ,in this instance the line l l would
 then coincide with a neutral locking   
face1 and to obtain the proper draw we  
should delineate the locking face to    
correspond to the line k n1 which we    
assume to be twelve degrees from k l4   
,it is not to be understood that we     
insist on precisely twelve degrees draw 
from a neutral plane for locking faces  
for lever pallets4 ,what we do insist   

upon1 however1 is a safe and sure draw  
for a lever pallet which will hold a    
fork to the banks and will also return  
it to such banks if by accident the fork
 is moved away4 ,we are well aware that 
it takes lots of patient1 hard study to 
master the complications of the         
club-tooth lever escapement1 but it is  
every watchmaker's duty to conquer the  
problem4 ,the definition of lock1 in the
 detached lever escapement1 is the      
stoppage or arrest of the escape wheel  
of a watch while the balance is left    
free or detached to perform the greater 
portion of its arc of vibration4 ,draw  
is a function of the locking parts to   
preserve the fork in the proper position
 to receive and act on the jewel pin of 
the balance4  ,it should be borne in    
mind in connection with lock and draw1  
that the line of thrust as projected    
from the locked tooth of the escape     
wheel should be as near tangential as   
practicable4 ,this maxim applies        
particularly to the entrance pallet4 ,we

 would beg to add that practically it   
will make but little odds whether we    
plant the center of our pallet staff at 
,c or h1 ,fig4 #hg1 provided we modify  
the locking and impulse angles of our   
pallets to conform to such pallet       
center4 ,but it will not do to arrange  
the parts for one center and then change
 to another4   ,,practical ,,hints ,,for
 ,,lever ,,escapements4  ,apparently    
there seems to be a belief with very    
many watchmakers that there is a set of 
shorthand rules for setting an          
escapement1 especially in ,american     
watches1 which1 if once acquired1       
conquers all imperfections4 ,now we wish
 to disabuse the minds of our readers of
 any such notions4 ,although the lever  
escapement1 as adopted by our ,american 
factories1 is constructed on certain    
lines1 still these lines are subject to 
modifications1 such as may be demanded  
for certain defects of construction4 ,if
 we could duplicate every part of a     
watch movement perfectly1 then we could 

have certain rules to go by1 and fixed  
templets could be used for setting      
pallet stones and correcting other      
escapement faults4  ,let us now make an 
analysis of the action of a lever       
escapement4 ,we show at ,fig4 #hi an    
ordinary eighteen-size full-plate lever 
with fork and pallets4 ,the dotted lines
 a b are supposed to represent an       
angular movement of ten degrees4 ,now1  
it is the function of the fork to carry 
the power of the train to the balance4  
,how well the fork performs its office  
we will consider subsequently2 for the  
present we are dealing with the power as
 conveyed to the fork by the pallets as 
shown at ,fig4 #hi4  ,illustration3     
,fig4 #hi  ,the angular motion between  
the lines a c 7which represents the     
lock7 is not only absolutely            
lost--wasted--but during this movement  
the train has to retrograde2 that is1   
the dynamic force stored in the momentum
 of the balance has to actually turn the
 train backward and against the force of

 the mainspring4 ,true1 it is only      
through a very short arc1 but the       
necessary force to effect this has to be
 discounted from the power stored in the
 balance from a former impulse4 ,for    
this reason we should make the angular  
motion of unlocking as brief as         
possible4 ,grossmann1 in his essay1     
endorses one and a half degrees as the  
proper lock4  ,in the description which 
we employed in describing the large     
model for illustrating the action of the
 detached lever escapement1 we cut the  
lock to one degree1 and in the          
description of the up-to-date lever     
escapement1 which we shall hereafter    
give1 we shall cut the lock down to     
three-quarters of a degree1 a perfection
 easily to be attained by modern tools  
and appliances4 ,we shall also cut the  
drop down to three-quarters of a degree4
 ,by these two economies we more than   
make up for the power lost in unlocking4
 ,with highly polished ruby or sapphire 
pallets ten degrees of draw is ample4   

,but such draw must positively be ten   
degrees from a neutral locking face1 not
 an escapement drawn on paper and called
 ten degrees1 but when actually measured
 would only show eight and a half or    
nine degrees4   ,,the ,,perfected       
,,lever ,,escapement4  ,with ten degrees
 angular motion of the lever and one and
 a half degrees lock1 we should have    
eight and a half degrees impulse4 ,the  
pith of the problem1 as regards pallet  
action1 for the practical workman can be
 embodied in the following question3    
,what proportion of the power derived   
from the twelve degrees of angular      
motion of the escape wheel is really    
conveyed to the fork8 ,the great leak of
 power as transmitted by the lever      
escapement to the balance is to be found
 in the pallet action1 and we shall     
devote special attention to finding and 
stopping such leaks4   ,,when ,,power   
,,is ,,lost ,,in ,,the ,,lever          
,,escapement4  ,if we use a             
ratchet-tooth escape wheel we must allow

 at least one and a half degrees drop to
 free the back of the tooth2 but with a 
club-tooth escape wheel made as can be  
constructed by proper skill and care1   
the drop can be cut down to             
three-quarters of a degree1 or one-half 
of the loss with the ratchet tooth4 ,we 
do not wish our readers to imagine that 
such a condition exists in most of the  
so-called fine watches1 because if we   
take the trouble to measure the actual  
drop with one of the little instruments 
we have described1 it will be found that
 the drop is seldom less than two1 or   
even three degrees4  ,if we measure the 
angular movement of the fork while      
locked1 it will seldom be found less    
than two or three degrees4 ,now1 we can 
all understand that the friction of the 
locking surface has to be counted as    
well as the recoil of the draw4 ,locking
 friction is seldom looked after as     
carefully as the situation demands4 ,our
 factories make the impulse face of the 
pallets rounded1 but leave the locking  

face flat4 ,we are aware this condition 
is1 in a degree1 necessary from the use 
of exposed pallets4 ,in many of the     
,english lever watches with ratchet     
teeth1 the locking faces are made       
cylindrical1 but with such watches the  
pallet stones1 as far as the writer has 
seen1 are set close2 that is1 with steel
 pallet arms extending above and below  
the stone4  ,there is another feature of
 the club-tooth lever escapement that   
next demands our attention which we have
 never seen discussed4 ,we refer to     
arranging and disposing of the impulse  
of the escape wheel to meet the         
resistance of the hairspring4 ,let us   
imagine the dotted line ,a d1 ,fig4 #hi1
 to represent the center of action of   
the fork4 ,we can readily see that the  
fork in a state of rest would stand half
 way between the two banks from the     
action of the hairspring1 and in the    
pallet action the force of the escape   
wheel1 one tooth of which rests on the  
impulse face of a pallet1 would be      

exerted against the elastic force of the
 hairspring4 ,if the force of the       
mainspring1 as represented by the       
escape-wheel tooth1 is superior to the  
power of the hairspring1 the watch      
starts itself4 ,the phases of this      
important part of the detached lever    
escapement will be fully discussed4     
,,about ,,the ,,club-,,tooth            
,,escapement4  ,we will now take up a   
study of the detached lever escapement  
as relates to pallet action1 with the   
point specially in view of constructing 
an escapement which cannot set in the   
pocket1 or1 in other words1 an          
escapement which will start after       
winding 7if run down7 without shaking or
 any force other than that supplied by  
the train as impelled by the mainspring4
 ,in the drawing at ,fig4 #ij we propose
 to utilize eleven degrees of           
escape-wheel action1 against ten and a  
half1 as laid down by ,grossmann4 ,of   
this eleven degrees we propose to divide
 the impulse arc of the escape wheel in 

six and five degrees1 six to be derived 
from the impulse face of the club tooth 
and five from the impulse plane of the  
pallet4  ,the pallet action we divide   
into five and four1 with one degree of  
lock4 ,five degrees of pallet action is 
derived from the impulse face of the    
tooth and four from the impulse face of 
the pallet4 ,the reader will please bear
 in mind that we do not give these      
proportions as imperative1 because we   
propose to give the fullest evidence    
into the reader's hands and enable him  
to judge for himself1 as we do not      
believe in laying down imperious laws   
that the reader must accept on our      
assertion as being correct4 ,our idea is
 rather to furnish the proper facts and 
put him in a situation to know for      
himself4  ,the reader is urged to make  
the drawings for himself on a large     
scale1 say1 an escape wheel #aj pitch   
diameter4 ,such drawings will enable him
 to realize small errors which have been
 tolerated too much in drawings of this 

kind4 ,the drawings1 as they appear in  
the cut1 are one-fourth the size        
recommended1 and many of the lines fail 
to show points we desire to call        
attention to4 ,as for instance1 the     
pallet center at ,b is tangential to the
 pitch circle a from the point of tooth 
contact at f4 ,to establish this point  
we draw the radial lines ,a c and ,a d  
from the escape-wheel center ,a1 as     
shown1 by laying off thirty degrees on  
each side of the intersection of the    
vertical line i 7passing through the    
centers ,a ,b7 with the arc a1 and then 
laying off two and a half degrees on a  
and establishing the point f1 and       
through f from the center ,a draw the   
radial line ,a f'4 ,through the point f 
we draw the tangent line b' b b''1 and  
at the intersection of the line b with i
 we establish the center of our pallet  
staff at ,b4 ,at two and a half degrees 
from the point c we lay off two and a   
half degrees to the right of said point 
and establish the point n1 and draw the 

radial line ,a n n'1 which establishes  
the extent of the arc of angular motion 
of the escape wheel utilized by the     
pallet arm4  ,illustration3 ,fig4 #ij   
,we have now come to the point where we 
must exercise our reasoning powers a    
little4 ,we know the locking angle of   
the escape-wheel tooth passes on the arc
 a1 and if we utilize the impulse face  
of the tooth for five degrees of pallet 
or lever motion we must shape it to this
 end4 ,we draw the short arc k through  
the point n1 knowing that the inner     
angle of the pallet stone must rest on  
this arc wherever it is situated4 ,as1  
for instance1 when the locking face of  
the pallet is engaged1 the inner angle  
of the pallet stone must rest somewhere 
on this arc 7k7 inside of a1 and the    
extreme outer angle of the impulse face 
of the tooth must part with the pallet  
on this arc k4   ,,how ,,to ,,locate    
,,the ,,pallet ,,action4  ,with the     
parts related to each other as shown in 
the cut1 to establish where the inner   

angle of the pallet stone is located in 
the drawing1 we measure down on the arc 
k five degrees from its intersection    
with a1 and establish the point s4 ,the 
line ,b b1 ,fig4 #ij1 as the reader will
 see1 does not coincide with the        
intersection of the arcs a and k1 and to
 conveniently get at the proper location
 for the inner angle of our pallet      
stone1 we draw the line ,b b'1 which    
passes through the point n located at   
the intersection of the arc a with the  
arc k4 ,from ,b as a center we sweep the
 short arc j with any convenient radius 
of which we have a sixty-degree scale1  
and from the intersection of ,b b' with 
j we lay off five degrees and draw the  
line ,b s'1 which establishes the point 
s on the arc k4 ,as stated above1 we    
allow one degree for lock1 which we     
establish on the arc o by laying off one
 degree on the arc j below its          
intersection with the line ,b b4 ,we do 
not show this line in the drawing1 from 
the fact that it comes so near to ,b b' 

that it would confuse the reader4 ,above
 the arc a on the arc k at five degrees 
from the point n we establish the point 
l1 by laying off five degrees on the arc
 j above the intersection of the line ,b
 b with j4  ,the point l1 ,fig4 #ij1    
establishes where the outer angle of the
 tooth will pass the arc k to give five 
degrees of angular motion to the lever4 
,from ,a as a center we sweep the arc m1
 passing through the point l4 ,the      
intersection of the arc m with the line 
,a h we call the point r1 and by drawing
 the right line r f we delineate the    
impulse face of the tooth4 ,on the arc o
 and one degree below its intersection  
with the line ,b b we establish the     
point t1 and by drawing a right line    
from t to s we delineate the impulse    
face of our entrance pallet4   ,,action 
,,drawings4  ,one great fault with most 
of our text books on horology lies in   
the fact that when dealing with the     
detached lever escapement the drawings  
show only the position of the pallets   

when locked1 and many of the conditions 
assumed are arrived at by mental        
processes1 without making the proper    
drawings to show the actual relation of 
the parts at the time such conditions   
exist4 ,for illustration1 it is often   
urged that there is a time in the action
 of the club-tooth lever escapement     
action when the incline on the tooth and
 the incline on the pallet present      
parallel surfaces1 and consequently     
endure excessive friction1 especially if
 the oil is a little thickened4  ,we    
propose to make drawings to show the    
exact position and relation of the      
entrance pallet and tooth at three      
intervals viz3 7#a7 ,locked2 7#b7 the   
position of the parts when the lever has
 performed one-half of its angular      
motion2 7#c7 when half of the impulse   
face of the tooth has passed the pallet4
 ,the position of the entrance pallet   
when locked is sufficiently well shown  
in ,fig4 #ij to give a correct idea of  
the relations with the entrance pallet2 

and to conform to statement 7#b71 as    
above4 ,we will now delineate the       
entrance pallet1 not in actual contact1 
however1 with the pallet1 because if we 
did so the lines we employed would      
become confused4 ,the methods we use are
 such that we can delineate with        
absolute correctness either a pallet or 
tooth at any point in its angular       
motion4  ,we have previously given      
instructions for drawing the pallet     
locked2 and to delineate the pallet     
after five degrees of angular motion1 we
 have only to conceive that we          
substitute the line s' for the line b'4 
,all angular motions and measurements   
for pallet actions are from the center  
of the pallet staff at ,b4 ,as we desire
 to now delineate the entrance pallet1  
it has passed through five degrees of   
angular motion and the inner angle s now
 lies on the pitch circle of the escape 
wheel1 the angular space between the    
lines b' s' being five degrees1 the line
 b'' reducing the impulse face to four  

degrees4   ,,drawing ,,an ,,escapement  
,,to ,,show ,,angular ,,motion4  ,to    
delineate our locking face we draw a    
line at right angles to the line ,b b'' 
from the point t1 said point being      
located at the intersection of the arc o
 with the line ,b b''4 ,to draw a line  
perpendicular to ,b b'' from the point  
t1 we take a convenient space in our    
dividers and establish on the line ,b   
b'' the points x x' at equal distances  
from the point t4 ,we open the dividers 
a little 7no special distance7 and sweep
 the short arcs x'' x'''1 as shown at   
,fig4 #ia4 ,through the intersection of 
the short arcs x'' x''' and to the point
 t we draw the line t y4 ,the reader    
will see from our former explanations   
that the line t y represents the neutral
 plane of the locking face1 and that to 
have the proper draw we must delineate  
the locking face of our pallet at twelve
 degrees4 ,to do this we draw the line t
 x' at twelve degrees to the line t y1  
and proceed to outline our pallet faces 

as shown4 ,we can now understand1 after 
a moment's thought1 that we can         
delineate the impulse face of a tooth at
 any point or place we choose by laying 
off six degrees on the arc m1 and       
drawing radial lines from ,a to embrace 
such arc4 ,to illustrate1 suppose we    
draw the radial lines w' w'' to embrace 
six degrees on the arc a4 ,we make these
 lines contiguous to the entrance pallet
 ,c for convenience only4 ,to delineate 
the impulse face of the tooth1 we draw a
 line extending from the intersection of
 the radial line ,a' w' with the arc m  
to the intersection of the arc a with   
the radial line ,a w''4  ,illustration3 
,fig4 #ia  ,we next desire to know where
 contact will take place between the    
wheel-tooth ,d and pallet ,c4 ,to       
determine this we sweep1 with our       
dividers set so one leg rests at the    
escape-wheel center ,a and the other at 
the outer angle t of the entrance       
pallet1 the short arc t' w4 ,where this 
arc intersects the line w 7which        

represents the impulse face of the      
tooth7 is where the outer angle t of the
 entrance pallet ,c will touch the      
impulse face of the tooth4 ,to prove    
this we draw the radial line ,a v       
through the point where the short arc t 
t' passes through the impulse face w of 
the tooth ,d4 ,then we continue the line
 w to n1 to represent the impulse face  
of the tooth1 and then measure the angle
 ,a w n between the lines w n and v ,a1 
and find it to be approximately         
sixty-four degrees4 ,we then1 by a      
similar process1 measure the angle ,a t 
s' and find it to be approximately      
sixty-six degrees4 ,when contact ensues 
between the tooth ,d and pallet ,c the  
tooth ,d will attack the pallet at the  
point where the radial line ,a v crosses
 the tooth face4 ,we have now explained 
how we can delineate a tooth or pallet  
at any point of its angular motion1 and 
will next explain how to apply this     
knowledge in actual practice4           
,,practical ,,problems ,,in ,,the       

,,lever ,,escapement4  ,to delineate our
 entrance pallet after one-half of the  
engaged tooth has passed the inner angle
 of the entrance pallet1 we proceed1 as 
in former illustrations1 to establish   
the escape-wheel center at ,a1 and from 
it sweep the arc b1 to represent the    
pitch circle4 ,we next sweep the short  
arcs p s1 to represent the arcs through 
which the inner and outer angles of the 
entrance pallet move4 ,now1 to comply   
with our statement as above1 we must    
draw the tooth as if half of it has     
passed the arc s4  ,to do this we draw  
from ,a as a center the radial line ,a  
j1 passing through the point s1 said    
point s being located at the            
intersection of the arcs s and b4 ,the  
tooth ,d is to be shown as if one half  
of it has passed the point s2 and1      
consequently1 if we lay off three       
degrees on each side of the point s and 
establish the points d m1 we have       
located on the arc b the angular extent 
of the tooth to be drawn4 ,to aid in our

 delineations we draw from the center ,a
 the radial lines ,a d' and ,a m'1      
passing through the points d m4 ,the arc
 a is next drawn as in former           
instructions and establishes the length 
of the addendum of the escape-wheel     
teeth1 the outer angle of our           
escape-wheel tooth being located at the 
intersection of the arc a with the      
radial line ,a d'4  ,as shown in ,fig4  
#ib1 the impulse planes of the tooth ,d 
and pallet ,c are in contact and1       
consequently1 in parallel planes1 as    
mentioned on page #ia4 ,it is not an    
easy matter to determine at exactly what
 degree of angular motion of the escape 
wheel such condition takes place2       
because to determine such relation      
mathematically requires a knowledge of  
higher mathematics1 which would require 
more study than most practical men would
 care to bestow1 especially as they     
would have but very little use for such 
knowledge except for this problem and a 
few others in dealing with epicycloidal 

curves for the teeth of wheels4  ,for   
all practical purposes it will make no  
difference whether such parallelism     
takes place after eight or nine degrees 
of angular motion of the escape wheel   
subsequent to the locking action4 ,the  
great point1 as far as practical results
 go1 is to determine if it takes place  
at or near the time the escape wheel    
meets the greatest resistance from the  
hairspring4 ,we find by analysis of our 
drawing that parallelism takes place    
about the time when the tooth has three 
degrees of angular motion to make1 and  
the pallet lacks about two degrees of   
angular movement for the tooth to       
escape4 ,it is thus evident that the    
relations1 as shown in our drawing1 are 
in favor of the train or mainspring     
power over hairspring resistance as     
three is to two1 while the average is   
only as eleven to ten2 that is1 the     
escape wheel in its entire effort passes
 through eleven degrees of angular      
motion1 while the pallets and fork move 

through ten degrees4 ,the student will  
thus see we have arranged to give the   
train-power an advantage where it is    
most needed to overcome the opposing    
influence of the hairspring4            
,illustration3 ,fig4 #ib  ,as regards   
the exalted adhesion of the parallel    
surfaces1 we fancy there is more harm   
feared than really exists1 because1 to  
take the worst view of the situation1   
such parallelism only exists for the    
briefest duration1 in a practical sense1
 because theoretically these surfaces   
never slide on each other as parallel   
planes4 ,mathematically considered1 the 
theoretical plane represented by the    
impulse face of the tooth approaches    
parallelism with the plane represented  
by the impulse face of the pallet1      
arrives at parallelism and instantly    
passes away from such parallelism4      
,,to ,,draw ,a ,,pallet ,,in ,,any      
,,position4  ,as delineated in ,fig4    
#ib1 the impulse planes of the tooth and
 pallet are in contact2 but we have it  

in our power to delineate the pallet at 
any point we choose between the arcs p  
s4 ,to describe and illustrate the above
 remark1 we say the lines ,b e and ,b f 
embrace five degrees of angular motion  
of the pallet4 ,now1 the impulse plane  
of the pallet occupies four of these    
five degrees4 ,we do not draw a radial  
line from ,b inside of the line ,b e to 
show where the outer angle of the       
impulse plane commences1 but the reader 
will see that the impulse plane is drawn
 one degree on the arc p below the line 
,b e4 ,we continue the line h h to      
represent the impulse face of the tooth1
 and measure the angle ,b n h and find  
it to be twenty-seven degrees4 ,now     
suppose we wish to delineate the        
entrance pallet as if not in contact    
with the escape-wheel tooth--for        
illustration1 say1 we wish the inner    
angle of the pallet to be at the point v
 on the arc s4 ,we draw the radial line 
,b l through v2 and if we draw another  
line so it passes through the point v at

 an angle of twenty-seven degrees to ,b 
l1 and continue said line so it crosses 
the arc p1 we delineate the impulse face
 of our pallet4  ,we measure the angle i
 n ,b1 ,fig4 #ib1 and find it to be     
seventy-four degrees2 we draw the line v
 t to the same angle with v ,b1 and we  
define the inner face of our pallet in  
the new position4 ,we draw a line       
parallel with v t from the intersection 
of the line v y with the arc p1 and we  
define our locking face4 ,if now we     
revolve the lines we have just drawn on 
the center ,b until the line l ,b       
coincides with the line f ,b1 we will   
find the line y y to coincide with h h1 
and the line v v' with n i4   ,,higher  
,,mathematics ,,applied ,,to ,,the      
,,lever ,,escapement4  ,we have now     
instructed the reader how to delineate  
either tooth or pallet in any           
conceivable position in which they can  
be related to each other4 ,probably     
nothing has afforded more efficient aid 
to practical mechanics than has been    

afforded by the graphic solution of     
abstruce mathematical problems2 and if  
we add to this the means of correction  
by mathematical calculations which do   
not involve the highest mathematical    
acquirements1 we have approached pretty 
close to the actual requirements of the 
practical watchmaker4  ,illustration3   
,fig4 #ic  ,to better explain what we   
mean1 we refer the reader to ,fig4 #ic1 
where we show preliminary drawings for  
delineating a lever escapement4 ,we wish
 to ascertain by the graphic method the 
distance between the centers of action  
of the escape wheel and the pallet      
staff4 ,we make our drawing very        
carefully to a given scale1 as1 for     
instance1 the radius of the arc a is #e4
 ,after the drawing is in the condition 
shown at ,fig4 #ic we measure the       
distance on the line b between the      
points 7centers7 ,a ,b1 and we thus by  
graphic means obtain a measure of the   
distance between ,a ,b4 ,now1 by the use
 of trigonometry1 we have the length of 

the line ,a f 7radius of the arc a7 and 
all the angles given1 to find the length
 of f ,b1 or ,a ,b1 or both f ,b and ,a 
,b4 ,by adopting this policy we can     
verify the measurements taken from our  
drawings4 ,suppose we find by the       
graphic method that the distance between
 the points ,a ,b is #e4gh1 and by      
trigonometrical computation find the    
distance to be #e4ggfb4 ,we know from   
this that there is 4#jjch to be         
accounted for somewhere2 but for all    
practical purposes either measurement   
should be satisfactory1 because our     
drawing is about thirty-eight times the 
actual size of the escape wheel of an   
eighteen-size movement4   ,,how ,,the   
,,basis ,,for ,,close ,,measurements    
,,is ,,obtained4  ,let us further       
suppose the diameter of our actual      
escape wheel to be 4#bf1 and we were    
constructing a watch after the lines of 
our drawing4 ,by lines1 in this case1 we
 mean in the same general form and ratio
 of parts2 as1 for illustration1 if the 

distance from the intersection of the   
arc a with the line b to the point ,b   
was one-fifteenth of the diameter of the
 escape wheel1 this ratio would hold    
good in the actual watch1 that is1 it   
would be the one-fifteenth part of 4#bf4
 ,again1 suppose the diameter of the    
escape wheel in the large drawing is #aj
 and the distance between the centers ,a
 ,b is #e4gh2 to obtain the actual      
distance for the watch with the escape  
wheel 4#bf diameter1 we make a statement
 in proportion1 thus3 #aj 3 #e4gh 33    
4#bf to the actual distance between the 
pivot holes of the watch4 ,by           
computation we find the distance to be  
4#ae4 ,these proportions will hold good 
in every part of actual construction4   
,all parts--thickness of the pallet     
stones1 length of pallet arms1          
etc4--bear the same ratio of proportion4
 ,we measure the thickness of the       
entrance pallet stone on the large      
drawing and find it to be 4#dg2 we make 
a similar statement to the one above1   

thus3 #aj 3 4#dg 33 4#bf to the actual  
thickness of the real pallet stone4 ,by 
computation we find it to be 4#jabb4    
,all angular relations are alike1       
whether in the large drawing or the     
small pallets to match the actual escape
 wheel 4#bf in diameter4 ,thus1 in the  
pallet ,d1 ,fig4 #ic1 the impulse face1 
as reckoned from ,b as a center1 would  
occupy four degrees4   ,,make ,a ,,large
 ,,escapement ,,model4  ,reason would   
suggest the idea of having the          
theoretical keep pace and touch with the
 practical4 ,it has been a grave fault  
with many writers on horological matters
 that they did not make and measure the 
abstractions which they delineated on   
paper4 ,we do not mean by this to       
endorse the cavil we so often hear--,oh1
 that is all right in theory1 but it    
will not work in practice4 ,if theory is
 right1 practice must conform to it4    
,the trouble with many theories is1 they
 do not contain all the elements or     
factors of the problem4  ,illustration3 

,fig4 #id  ,near the beginning of this  
treatise we advised our readers to make 
a large model1 and described in detail  
the complete parts for such a model4    
,what we propose now is to make         
adjustable the pallets and fork to such 
a model1 in order that we can set them  
both right and wrong1 and thus          
practically demonstrate a perfect action
 and also the various faults to which   
the lever escapement is subject4 ,the   
pallet arms are shaped as shown at ,a1  
,fig4 #id4 ,the pallets ,b ,b' can be   
made of steel or stone1 and for all     
practical purposes those made of steel  
answer quite as well1 and have the      
advantage of being cheaper4 ,a plate of 
sheet brass should be obtained1 shaped  
as shown at ,c1 ,fig4 #ie4 ,this plate  
is of thin brass1 about ,no4 #ah1 and on
 it are outlined the pallet arms shown  
at ,fig4 #id4  ,illustration3 ,fig4 #ie 
,illustration3 ,fig4 #if  ,illustration3
 ,fig4 #ig  ,illustration3 ,fig4 #ih    
,to make the pallets adjustable1 they   

are set in thick disks of sheet brass1  
as shown at ,d1 ,figs4 #ie1 #if and #ig4
 ,at the center of the plate ,c is      
placed a brass disk ,e1 ,fig4 #ih1 which
 serves to support the lever shown at   
,fig4 #ii4 ,this disk ,e is permanently 
attached to the plate ,c4 ,the lever    
shown at ,fig4 #ii is attached to the   
disk ,e by two screws1 which pass       
through the holes h h4 ,if we now place 
the brass pieces ,d ,d' on the plate ,c 
in such a way that the pallets set in   
them correspond exactly to the pallets  
as outlined on the plate ,c1 we will    
find the action of the pallets to be    
precisely the same as if the pallet arms
 ,a ,a'1 ,fig4 #id1 were employed4      
,illustration3 ,fig4 #ii  ,to enable us 
to practically experiment with and to   
fully demonstrate all the problems of   
lock1 draw1 drop1 etc41 we make quite a 
large hole in ,c where the screws b     
come4 ,to explain1 if the screws b b    
were tapped directly into ,c1 as they   
are shown at ,fig4 #ie1 we could only   

turn the disk ,d on the screw b2 but if 
we enlarge the screw hole in ,c to three
 or four times the natural diameter1 and
 then place the nut e under ,c to       
receive the screw b1 we can then set the
 disks ,d ,d' and pallets ,b ,b' in     
almost any relation we choose to the    
escape wheel1 and clamp the pallets fast
 and try the action4 ,we show at ,fig4  
#ig a view of the pallet ,b'1 disk ,d'  
and plate ,c 7seen in the direction of  
the arrow c7 as shown in ,fig4 #ie4     
,,practical ,,lessons ,,with ,,fork     
,,and ,,pallet ,,action4  ,it will be   
noticed in ,fig4 #ii that the hole g for
 the pallet staff in the lever is       
oblong2 this is to allow the lever to be
 shifted back and forth as relates to   
roller and fork action4 ,we will not    
bother about this now1 and only call    
attention to the capabilities of such   
adjustments when required4 ,at the      
outset we will conceive the fork ,f     
attached to the piece ,e by two screws  
passing through the holes h h1 ,fig4    

#ii4 ,such an arrangement will insure   
the fork and roller action keeping right
 if they are put right at first4 ,fig4  
#ajj will do much to aid in conveying a 
clear impression to the reader4  ,the   
idea of the adjustable features of our  
escapement model is to show the effects 
of setting the pallets wrong or having  
them of bad form4 ,for illustration1 we 
make use of a pallet with the angle too 
acute1 as shown at ,b'''1 ,fig4 #aja4   
,the problem in hand is to find out by  
mechanical experiments and tests the    
consequences of such a change4 ,it is   
evident that the angular motion of the  
pallet staff will be increased1 and that
 we shall have to open one of the       
banking pins to allow the engaging tooth
 to escape4 ,to trace out all the       
consequences of this one little change  
would require a considerable amount of  
study1 and many drawings would have to  
be made to illustrate the effects which 
would naturally follow only one such    
slight change4  ,illustration3 ,fig4    

#ajj  ,illustration3 ,fig4 #aja         
,suppose1 for illustration1 we should   
make such a change in the pallet stone  
of the entrance pallet2 we have         
increased the angle between the lines k 
l by 7say7 one and a half degrees2 by so
 doing we would increase the lock on the
 exit pallet to three degrees1 provided 
we were working on a basis of one and a 
half degrees lock2 and if we pushed back
 the exit pallet so as to have the      
proper degree of lock 7one and a half7  
on it1 the tooth which would next engage
 the entrance pallet would not lock at  
all1 but would strike the pallet on the 
impulse instead of on the locking face4 
,again1 such a change might cause the   
jewel pin to strike the horn of the     
fork1 as indicated at the dotted line m1
 ,fig4 #ii4  ,dealing with such and     
similar abstractions by mental process  
requires the closest kind of reasoning2 
and if we attempt to delineate all the  
complications which follow even such a  
small change1 we will find the job a    

lengthy one4 ,but with a large model    
having adjustable parts we provide      
ourselves with the means for the very   
best practical solution1 and the workman
 who makes and manipulates such a model 
will soon master the lever escapement4  
,,quiz ,,problems ,,in ,,the ,,detached 
,,lever ,,escapement4  ,some years ago a
 young watchmaker friend of the writer  
made1 at his suggestion1 a model of the 
lever escapement similar to the one     
described1 which he used to play with1  
as he termed it--that is1 he would set  
the fork and pallets 7which were        
adjustable7 in all sorts of ways1 right 
ways and wrong ways1 so he could watch  
the results4 ,a favorite pastime was to 
set every part for the best results1    
which was determined by the arc of      
vibration of the balance4 ,by this sort 
of training he soon reached that degree 
of proficiency where one could no more  
puzzle him with a bad lever escapement  
than you could spoil a meal for him by  
disarranging his knife1 fork and spoon4 

,let us1 as a practical example1 take up
 the consideration of a short fork4 ,to 
represent this in our model we take a   
lever as shown at ,fig4 #ii1 with the   
elongated slot for the pallet staff at  
g4 ,to facilitate the description we    
reproduce at ,fig4 #ajb the figure just 
mentioned1 and also employ the same     
letters of reference4 ,we fancy         
everybody who has any knowledge of the  
lever escapement has an idea of exactly 
what a short fork is1 and at the same   
time it would perhaps puzzle them a good
 deal to explain the difference between 
a short fork and a roller too small4    
,illustration3 ,fig4 #ajb               
,illustration3 ,fig4 #ajc  ,in our      
practical problems1 as solved on a large
 escapement model1 say we first fit our 
fork of the proper length1 and then by  
the slot g move the lever back a little1
 leaving the bankings precisely as they 
were4 ,what are the consequences of this
 slight change8 ,one of the first       
results which would display itself would

 be discovered by the guard pin failing 
to perform its proper functions4 ,for   
instance1 the guard pin pushed inward   
against the roller would cause the      
engaged tooth to pass off the locking   
face of the pallet1 and the fork1       
instead of returning against the        
banking1 would cause the guard pin to   
ride the roller during the entire       
excursion of the jewel pin4 ,this fault 
produces a scraping sound in a watch4   
,suppose we attempt to remedy the fault 
by bending forward the guard pin b1 as  
indicated by the dotted outline b' in   
,fig4 #ajc1 said figure being a side    
view of ,fig4 #ajb seen in the direction
 of the arrow a4 ,this policy would     
prevent the engaged pallet from passing 
off of the locking face of the pallet1  
but would be followed by the jewel pin  
not passing fully into the fork1 but    
striking the inside face of the prong of
 the fork at about the point indicated  
by the dotted line m4 ,we can see that  
if the prong of the fork was extended to

 about the length indicated by the      
outline at c1 the action would be as it 
should be4  ,to practically investigate 
this matter to the best advantage1 we   
need some arrangement by which we can   
determine the angular motion of the     
lever and also of the roller and escape 
wheel4 ,to do this1 we provide ourselves
 with a device which has already been   
described1 but of smaller size1 for     
measuring fork and pallet action4 ,the  
device to which we allude is shown at   
,figs4 #ajd1 #aje and #ajf4 ,fig4 #ajd  
shows only the index hand1 which is made
 of steel about #a_/bj thick and shaped 
as shown4 ,the jaws ,b'' are intended to
 grasp the pallet staff by the notches  
e1 and hold by friction4 ,the prongs l l
 are only to guard the staff so it will 
readily enter the notch e4 ,the circle d
 is only to enable us to better hold the
 hand ,b flat4  ,illustration3 ,fig4    
#ajd   ,,how ,,to ,,measure ,,escapement
 ,,angles4  ,from the center of the     
notches e to the tip of the index hand  

,b' the length is #b4 ,this distance is 
also the radius of the index arc ,c4    
,this index arc is divided into thirty  
degrees1 with three or four             
supplementary degrees on each side1 as  
shown4 ,for measuring pallet action we  
only require ten degrees1 and for roller
 action thirty degrees4 ,the arc ,c1    
,fig4 #aje1 can be made of brass and is 
about #a long by  wide2 said arc is     
mounted on a brass wire about #a_/h     
diameter1 as shown at k1 ,fig4 #ajf1    
which is a view of ,fig4 #aje seen in   
the direction of the arrow i4 ,this wire
 k enters a base shown at ,d ,e1 ,fig4  
#ajf1 which is provided with a set-screw
 at j for holding the index arc at the  
proper height to coincide with the hand 
,b4  ,illustration3 ,fig4 #aje          
,illustration3 ,fig4 #ajf  ,a good way  
to get up the parts shown in ,fig4 #ajf 
is to take a disk of thick sheet brass  
about #a in diameter and insert in it a 
piece of brass wire about  diameter and 
#c_/h long1 through which drill axially 

a hole to receive the wire k4 ,after the
 jaws ,b'' are clamped on the pallet    
staff1 we set the index arc ,c so the   
hand ,b' will indicate the angular      
motion of the pallet staff4 ,by placing 
the index hand ,b on the balance staff  
we can get at the exact angular duration
 of the engagement of the jewel pin in  
the fork4  ,of course1 it is understood 
that this instrument will also measure  
the angles of impulse and lock4 ,thus1  
suppose the entire angular motion of the
 lever from bank to bank is ten degrees2
 to determine how much of this is lock  
and how much impulse1 we set the index  
arc ,c so that the hand ,b' marks ten   
degrees for the entire motion of the    
fork1 and when the escapement is locked 
we move the fork from its bank and      
notice by the arc ,c how many degrees   
the hand indicated before it passed of  
its own accord to the opposite bank4 ,if
 we have more than one and a half       
degrees of lock we have too much and    
should seek to remedy it4 ,how8 ,it is  

just the answers to such questions we   
propose to give by the aid of our big   
model4   ,,determination ,,of ,,right   
,,methods4  ,be sure you are right1 then
 go ahead1 was the advice of the        
celebrated ,davie ,crockett4 ,the only  
trouble in applying this motto to       
watchmaking is to know when you are     
right4 ,we have also often heard the    
remark that there was only one right    
way1 but any number of wrong ways4 ,now 
we are inclined to think that most of   
the people who hold to but one right way
 are chiefly those who believe all ways 
but their own ways are wrong4           
,iron-bound rules are seldom sound even 
in ethics1 and are utterly impracticable
 in mechanics4  ,we have seen many      
workmen who had learned to draw a lever 
escapement of a given type1 and lived   
firm in the belief that all lever       
escapements were wrong which were not   
made so as to conform to this certain   
method4 ,one workman believes in        
equidistant lockings1 another in        

circular pallets2 each strong in the    
idea that their particular and peculiar 
method of designing a lever escapement  
was the only one to be tolerated4 ,the  
writer is free to confess that he has   
seen lever escapements of both types1   
that is1 circular pallets and           
equidistant lockings1 which gave        
excellent results4  ,another mooted     
point in the lever escapement is1 to    
decide between the merits of the ratchet
 and the club-tooth escape wheel4       
,english makers1 as a rule1 hold to the 
ratchet tooth1 while ,continental and   
,american manufacturers favor the club  
tooth4 ,the chief arguments in favor of 
the ratchet tooth are3 7a7 ,it will run 
without oiling the pallets2 7b7 in case 
the escape wheel is lost or broken it is
 more readily replaced1 as all          
ratchet-tooth escape wheels are alike1  
either for circular pallets or          
equidistant lockings4 ,the objections   
urged against it are3 7a7 ,excessive    
drop2 7b7 the escape wheel1 being frail1

 is liable to be injured by incompetent 
persons handling it2 7c7 this escapement
 in many instances does require to have 
the pallets oiled4   ,,escapements      
,,compared4  7a7 ,that a ratchet-tooth  
escape wheel requires more drop than a  
club tooth must be admitted without     
argument1 as this form of tooth requires
 from one-half to three-fourths of a    
degree more drop than a club tooth2 7b7 
as regards the frailty of the teeth we  
hold this as of small import1 as any    
workman who is competent to repair      
watches would never injure the delicate 
teeth of an escape wheel2 7c7           
ratchet-tooth lever escapements will    
occasionally need to have the pallets   
oiled4 ,the writer is inclined to think 
that this defect could be remedied by   
proper care in selecting the stone 7ruby
 or sapphire7 and grinding the pallets  
in such a way that the escape-wheel     
teeth will not act against the          
foliations with which all crystalline   
stones are built up4  ,all workmen who  

have had an extended experience in      
repair work are well aware that there   
are some lever escapements in which the 
pallets absolutely require oil2 others  
will seem to get along very nicely      
without4 ,this applies also to ,american
 brass club-tooth escapements2 hence1 we
 have so much contention about oiling   
pallets4 ,the writer does not claim to  
know positively that the pallet stones  
are at fault because some escapements   
need oiling1 but the fact must admit of 
explanation some way1 and is this not at
 least a rational solution8 ,all persons
 who have paid attention to             
crystallography are aware that crystals 
are built up1 and have lines of         
cleavage4 ,in the manufacture of hole   
jewels1 care must be taken to work with 
the axis of crystallization1 or a smooth
 hole cannot be obtained4  ,the         
advantages claimed for the club-tooth   
escapement are many2 among them may be  
cited 7a7 the fact that it utilizes a   
greater arc of impulse of the escape    

wheel2 7b7 the impulse being divided    
between the tooth and the pallet1       
permits greater power to be utilized at 
the close of the impulse4 ,this feature 
we have already explained4 ,it is no    
doubt true that it is more difficult to 
match a set of pallets with an escape   
wheel of the club-tooth order than with 
a ratchet tooth2 still the writer thinks
 that this objection is of but little   
consequence where a workman knows       
exactly what to do and how to do it2 in 
other words1 is sure he is right1 and   
can then go ahead intelligently4  ,it is
 claimed by some that all ,american     
escape wheels of a given grade are exact
 duplicates2 but1 as we have previously 
stated1 this is not exactly the case1 as
 they vary a trifle4 ,so do the pallet  
jewels vary a little in thickness and in
 the angles4 ,suppose we put in a new   
escape wheel and find we have on the    
entrance pallet too much drop1 that is1 
the tooth which engaged this pallet made
 a decided movement forward before the  

tooth which engaged the exit pallet     
encountered the locking face of said    
pallet4 ,if we thoroughly understand the
 lever escapement we can see in an      
instant if putting in a thicker pallet  
stone for entrance pallet will remedy   
the defect4 ,here again we can study the
 effects of a change in our large model 
better than in an escapement no larger  
than is in an ordinary watch4   ,,how   
,,to ,,set ,,pallet ,,stones4  ,there   
have been many devices brought forward  
to aid the workman in adjusting the     
pallet stones to lever watches4 ,before 
going into the details of any such      
device we should thoroughly understand  
exactly what we desire to accomplish4   
,in setting pallet stones we must take  
into consideration the relation of the  
roller and fork action4 ,as has already 
been explained1 the first thing to do is
 to set the roller and fork action as it
 should be1 without regard in a great   
degree to pallet action4  ,illustration3
 ,fig4 #ajg  ,to explain1 suppose we    

have a pallet stone to set in a         
full-plate movement4 ,the first thing to
 do is to close the bankings so that the
 jewel pin will not pass out of the slot
 in the fork on either side2 then       
gradually open the bankings until the   
jewel pin will pass out4 ,this will be  
understood by inspecting ,fig4 #ajg1    
where ,a ,a' shows a lever fork as if in
 contact with both banks1 and the jewel 
pin1 represented at ,b ,b''1 just passes
 the angle a c' of the fork4 ,the circle
 described by the jewel pin ,b is       
indicated by the arc e4 ,it is well to  
put a slight friction under the balance 
rim1 in order that we can try the       
freedom of the guard pin4 ,as a rule1   
all the guard pin needs is to be free   
and not touch the roller4 ,the entire   
point1 as far as setting the fork and   
bankings is concerned1 is to have the   
fork and roller action sound4 ,for all  
ordinary lever escapements the angular  
motion of the lever banked in as just   
described should be about ten degrees4  

,as explained in former examples1 if the
 fork action is entirely sound and the  
lever only vibrates through an arc of   
nine degrees1 it is quite as well to    
make the pallets conform to this arc as 
to make the jewel pin carry the fork    
through full ten degrees4 ,again1 if the
 lever vibrates through eleven degrees1 
it is as well to make the pallets       
conform to this arc4  ,the writer is    
well aware that many readers will cavil 
at this idea and insist that the workman
 should bring all the parts right on the
 basis of ten degrees fork and lever    
action4 ,in reply we would say that no  
escapement is perfect1 and it is the    
duty of the workman to get the best     
results he can for the money he gets for
 the job4 ,in the instance given above1 
of the escapement with nine degrees of  
lever action1 when the fork worked all  
right1 if we undertook to give the fork 
the ten degrees demanded by the stickler
 for accuracy we would have to set out  
the jewel pin or lengthen the fork1 and 

to do either would require more time    
than it would to bring the pallets to   
conform to the fork and roller action4  
,it is just this knowing how and the    
decision to act that makes the          
difference in the workman who is worth  
to his employer twelve or twenty-five   
dollars per week4  ,we have described   
instruments for measuring the angle of  
fork and pallet action1 but after one   
has had experience he can judge pretty  
nearly and then it is seldom necessary  
to measure the angle of fork action as  
long as it is near the proper thing1 and
 then bring the pallets to match the    
escape wheel after the fork and roller  
action is as it should be--that is1 the 
jewel pin and fork work free1 the guard 
pin has proper freedom1 and the fork    
vibrates through an arc of about ten    
degrees4  ,usually the workman can      
manipulate the pallets to match the     
escape wheel so that the teeth will have
 the proper lock and drop at the right  
instant1 and again have the correct lock

 on the next succeeding pallet4 ,the    
tooth should fall but a slight distance 
before the tooth next in action locks   
it1 because all the angular motion the  
escape wheel makes except when in       
contact with the pallets is just so much
 lost power1 which should go toward     
giving motion to the balance4  ,there   
seems to be a little confusion in the   
use of the word drop in horological     
phrase1 as it is used to express the act
 of parting of the tooth with the       
pallet4 ,the idea will be seen by       
inspecting ,fig4 #ajh1 where we show the
 tooth ,d and pallet ,c as about parting
 or dropping4 ,when we speak of banking 
up to the drop we mean we set the       
banking screws so that the teeth will   
just escape from each pallet4 ,by the   
term fall we mean the arc the tooth     
passes through before the next pallet is
 engaged4 ,this action is also          
illustrated at ,fig4 #ajh1 where the    
tooth ,d1 after dropping from the pallet
 ,c1 is arrested at the position shown  

by the dotted outline4 ,we designate    
this arc by the term fall1 and we       
measure this motion by its angular      
extent1 as shown by the dotted radial   
lines i f and i g4 ,as we have          
explained1 this fall should only extend 
through an arc of one and a half        
degrees1 but by close escapement        
matching this arc can be reduced to one 
degree1 or even a trifle less4          
,illustration3 ,fig4 #ajh  ,we shall    
next describe an instrument for holding 
the escape wheel and pallets while      
adjusting them4 ,as shown at ,fig4 #ajg1
 the fork ,a' is banked a little close  
and the jewel pin as shown would1 in    
some portions1 rub on ,c'1 making a     
scraping sound4   ,,how ,,to ,,make ,,an
 ,,escapement ,,matching ,,tool4        
,illustration3 ,fig4 #aji  ,a point has 
now been reached where we can use an    
escapement matcher to advantage4 ,there 
are several good ones on the market1 but
 we can make one very cheaply and also  
add our own improvements4 ,in making    

one1 the first thing to be provided is a
 movement holder4 ,any of the three-jaw 
types of such holders will answer1      
provided the jaws hold a movement plate 
perfectly parallel with the bed of the  
holder4 ,this will be better understood 
by inspecting ,fig4 #aji1 which is a    
side view of a device of this kind seen 
edgewise in elevation4 ,in this ,b      
represents the bed plate1 which supports
 three swing jaws1 shown at ,c1 ,figs4  
#aji and #aaj4 ,the watch plate is      
indicated by the parallel dotted lines  
,a1 ,fig4 #aji4 ,the seat a of the swing
 jaws ,c must hold the watch plate ,a   
exactly parallel with the bed plate ,b4 
,in the cheap movement holders these    
seats 7a7 are apt to be of irregular    
heights1 and must be corrected for our  
purpose4 ,we will take it for granted   
that all the seats a are of precisely   
the same height1 measured from ,b1 and  
that a watch plate placed in the jaws ,c
 will be held exactly parallel with the 
said bed ,b4 ,we must next provide two  

pillars1 shown at ,d ,e1 ,figs4 #aji and
 #aaa4 ,these pillars furnish support   
for sliding centers which hold the top  
pivots of the escape wheel and pallet   
staff while we are testing the depths   
and adjusting the pallet stones4 ,it    
will be understood that these pillars ,d
 ,e are at right angles to the plane of 
the bed ,b1 in order that the slides    
like ,g ,n on the pillars ,d ,e move    
exactly vertical4 ,in fact1 all the     
parts moving up and down should be      
accurately made1 so as not to destroy   
the depths taken from the watch plate   
,a4 ,suppose1 to illustrate1 that we    
place the plate ,a in position as shown1
 and insert the cone point n1 ,figs4    
#aji and #aab1 in the pivot hole for the
 pallet staff1 adjusting the slide ,g ,n
 so that the cone point rests accurately
 in said pivot hole4 ,it is further     
demanded that the parts ,i ,h ,f ,g ,n  
,d be so constructed and adjusted that  
the sliding center ,i moves truly       
vertical1 and that we can change ends   

with said center ,i and place the hollow
 cone end m1 ,fig4 #aab1 so it will     
receive the top pivot of the pallet     
staff and hold it exactly upright4      
,illustration3 ,fig4 #aaj               
,illustration3 ,fig4 #aaa               
,illustration3 ,fig4 #aab  ,the idea of 
the sliding center ,i is to perfectly   
supply the place of the opposite plate  
of the watch and give us exactly the    
same practical depths as if the parts   
were in their place between the plates  
of the movement4 ,the foot of the pillar
 ,d has a flange attached1 as shown at  
f1 which aids in holding it perfectly   
upright4 ,it is well to cut a screw on  
,d at ,d'1 and screw the flange f on    
such screw and then turn the lower face 
of f flat to aid in having the pillar ,d
 perfectly upright4   ,,details ,,of    
,,fitting ,,up ,,escapement ,,matcher4  
,it is well to fit the screw ,d'        
loosely1 so that the flange f will come 
perfectly flat with the upper surface of
 the base plate ,b4 ,the slide ,g ,n on 

the pillar ,d can be made of two pieces 
of small brass tube1 one fitting the    
pillar ,d and the other the bar ,f4 ,the
 slide ,g ,n is held in position by the 
set screw g1 and the rod ,f by the set  
screw h4  ,illustration3 ,fig4 #aac     
,illustration3 ,fig4 #aad  ,the piece ,h
 can be permanently attached to the rod 
,f4 ,we show separate at ,figs4 #aac and
 #aad the slide ,g ,n on an enlarged    
scale from ,fig4 #aji4 ,fig4 #aad is a  
view of ,fig4 #aac seen in the direction
 of the arrow e4 ,all joints and movable
 parts should work free1 in order that  
the center ,i may be readily and        
accurately set4 ,the parts ,h ,f are    
shown separate and enlarged at ,figs4   
#aae and #aaf4 ,the piece ,h can be made
 of thick sheet brass securely attached 
to ,f in such a way as to bring the     
,v-shaped groove at right angles to the 
axis of the rod ,f4 ,it is well to make 
the rod ,f about #a_/h in diameter1     
while the sliding center ,i need not be 
more than #a_/af in diameter4 ,the cone 

point n should be hardened to a spring  
temper and turned to a true cone in an  
accurately running wire chuck4          
,illustration3 ,fig4 #aae               
,illustration3 ,fig4 #aaf  ,the hollow  
cone end m of ,i should also be         
hardened1 but this is best done after   
the hollow cone is turned in4 ,the      
hardening of both ends should only be at
 the tips4 ,the sliding center ,i can be
 held in the ,v-shaped groove by two    
light friction springs1 as indicated at 
the dotted lines s s1 ,fig4 #aae1 or a  
flat plate of ,no4 #bd or #be sheet     
brass of the size of ,h can be employed1
 as shown at ,figs4 #aaf and #aag1 where
 o represents the plate of ,no4 #bd     
brass1 p p the small screws attaching   
the plate o to ,h1 and k a clamping     
screw to fasten ,i in position4 ,it will
 be found that the two light springs s  
s1 ,fig4 #aae will be the most          
satisfactory4 ,the wire legs1 shown at  
,l1 will aid in making the device set   
steady4 ,the pillar ,e is provided with 

the same slides and other parts as      
described and illustrated as attached to
 ,d4 ,the position of the pillars ,d and
 ,e are indicated at ,fig4 #aaj4        
,illustration3 ,fig4 #aag               
,illustration3 ,fig4 #aah  ,we will next
 tell how to flatten ,f to keep ,h      
exactly vertical4 ,to aid in            
explanation1 we will show 7enlarged7 at 
,fig4 #aah the bar ,f shown in ,fig4    
#aji4 ,in flattening such pieces to     
prevent turning1 we should cut away     
about two-fifths1 as shown at ,fig4     
#aai1 which is an end view of ,fig4 #aah
 seen in the direction of the arrow c4  
,in such flattening we should not only  
cut away two-fifths at one end1 but we  
must preserve this proportion from end  
to end4 ,to aid in this operation we    
make a fixed gage of sheet metal1 shaped
 as shown at ,i1 ,fig4 #abj4            
,illustration3 ,fig4 #aai   ,,escapement
 ,,matching ,,device ,,described4       
,illustration3 ,fig4 #abj  ,in practical
 construction we first file away about  

two-fifths of ,f and then grind the flat
 side on a glass slab to a flat1 even   
surface and1 of course1 equal thickness 
from end to end4 ,we reproduce the      
sleeve ,g as shown at ,fig4 #aac as if  
seen from the left and in the direction 
of the axis of the bar ,f4 ,to prevent  
the bar ,f turning on its axis1 we      
insert in the sleeve ,g a piece of wire 
of the same size as ,f but with         
three-fifths cut away1 as shown at y1   
,fig4 #aba4 ,this piece y is soldered in
 the sleeve ,g so its flat face stands  
vertical4 ,to give service and          
efficiency to the screw h1 we thicken   
the side of the sleeve ,f by adding the 
stud w1 through which the screw h works4
 ,a soft metal plug goes between the    
screw h and the bar ,f1 to prevent ,f   
being cut up and marred4 ,it will be    
seen that we can place the top plate of 
a full-plate movement in the device     
shown at ,fig4 #aji and set the vertical
 centers ,i so the cone points n will   
rest in the pivot holes of the escape   

wheel and pallets4 ,it is to be         
understood that the lower side of the   
top plate is placed uppermost in the    
movement holder4  ,illustration3 ,fig4  
#aba  ,if we now reverse the ends of the
 centers ,i and let the pivots of the   
escape wheel and pallet staff rest in   
the hollow cones of these centers ,i1 we
 have the escape wheel and pallets in   
precisely the same position and relation
 to each other as if the lower plate was
 in position4 ,it is further to be      
supposed that the balance is in place   
and the cock screwed down1 although the 
presence of the balance is not          
absolutely necessary if the banking     
screws are set as directed1 that is1 so 
the jewel pin will just freely pass in  
and out of the fork4   ,,how ,,to ,,set 
,,pallet ,,stones4  ,we have now come to
 setting or manipulating the pallet     
stones so they will act in exact        
conjunction with the fork and roller4   
,to do this we need to have the shellac 
which holds the pallet stones heated    

enough to make it plastic4 ,the usual   
way is to heat a piece of metal and     
place it in close proximity to the      
pallets1 or to heat a pair of pliers and
 clamp the pallet arms to soften the    
cement4  ,of course1 it is understood   
that the movement holder cannot be moved
 about while the stones are being       
manipulated4 ,the better way is to set  
the movement holder on a rather heavy   
plate of glass or metal1 so that the    
holder will not jostle about2 then set  
the lamp so it will do its duty1 and    
after a little practice the setting of a
 pair of pallet stones to perfectly     
perform their functions will take but a 
few minutes4 ,in fact1 if the stones    
will answer at all1 three to five       
minutes is as much time as one could    
well devote to the adjustment4 ,the     
reader will see that if the lever is    
properly banked all he has to do is to  
set the stones so the lock1 draw and    
drop are right1 when the entire         
escapement is as it should be1 and will 

need no further trial or manipulating4  
,,chapter ,,ii4  ,,the ,,cylinder       
,,escapement4   ,there is always in     
mechanical matters an underlying        
combination of principles and relations 
of parts known as theory4 ,we often hear
 the remark made that such a thing may  
be all right in theory1 but will not    
work in practice4 ,this statement has no
 foundation in fact4 ,if a given        
mechanical device accords strictly with 
theory1 it will come out all right      
practically4 ,mental conceptions of a   
machine are what we may term their      
theoretical existence4  ,when we make   
drawings of a machine mentally          
conceived1 we commence its mechanical   
construction1 and if we make such       
drawings to scale1 and add a            
specification stating the materials to  
be employed1 we leave only the merest   
mechanical details to be carried out2   
the brain work is done and only finger  
work remains to be executed4  ,with     
these preliminary remarks we will take  

up the consideration of the cylinder    
escapement invented by ,robert ,graham  
about the year #agbj4 ,it is one of the 
two so-called frictional rest dead-beat 
escapements which have come into popular
 use1 the other being the duplex4       
,usage1 or1 to put it in other words1   
experience derived from the actual      
manufacture of the cylinder escapement1 
settled the best forms and proportions  
of the several parts years ago4 ,still1 
makers vary slightly on certain lines1  
which are important for a man who       
repairs such watches to know and be able
 to carry out1 in order to put them in a
 condition to perform as intended by the
 manufacturers4 ,it is not knowing these
 lines which leaves the average         
watchmaker so much at sea4 ,he cuts and 
moves and shifts parts about to see if  
dumb luck will not supply the correction
 he does not know how to make4 ,this    
requisite knowledge does not consist so 
much in knowing how to file or grind as 
it does in discriminating where such    

application of manual dexterity is to be
 applied4 ,and right here let us make a 
remark to which we will call attention  
again later on4 ,the point of this      
remark lies in the question--,how many  
of the so-called practical watchmakers  
could tell you what proportion of a     
cylinder should be cut away from the    
half shell8 ,how many could explain the 
difference between the real and apparent
 lift8 ,comparatively few1 and yet a    
knowledge of these things is as         
important for a watchmaker as it is for 
a surgeon to understand the action of a 
man's heart or the relations of the     
muscles to the bones4   ,,essential     
,,parts ,,of ,,the ,,cylinder           
,,escapement4  ,the cylinder escapement 
is made up of two essential parts1 viz43
 the escape wheel and the cylinder4 ,the
 cylinder escape wheel in all modern    
watches has fifteen teeth1 although     
,saunier1 in his ,modern ,horology1     
delineates a twelve-tooth wheel for     
apparently no better reason than because

 it was more easily drawn4 ,we1 in this 
treatise1 will consider both the        
theoretical action and the practical    
construction1 but more particularly the 
repair of this escapement in a thorough 
and complete manner4  ,at starting out1 
we will first agree on the names of the 
several parts of this escapement1 and to
 aid us in this we will refer to the    
accompanying drawings1 in which ,fig4   
#abb is a side elevation of a cylinder  
complete and ready to have a balance    
staked on to it4 ,fig4 #abc shows the   
cylinder removed from the balance       
collet4 ,figs4 #abd and #abe show the   
upper and lower plugs removed from the  
cylinder4 ,fig4 #abf is a horizontal    
section of ,fig4 #abb on the line i4    
,fig4 #abg is a side view of one tooth  
of a cylinder escape wheel as if seen in
 the direction of the arrow f in ,fig4  
#abf4 ,fig4 #abh is a top view of two   
teeth of a cylinder escape wheel4 ,the  
names of the several parts usually      
employed are as follows3                

,a4--,upper or ,main ,shell4            
,a'4--,half ,shell4                     
,a''4--,column4       ,a'''4--,small    
,shell4   ,b ,b' ,b''4--,balance        
,collet4          ,g4--,upper ,plug4    
,h4--,lower ,plug4                      
g4--,entrance ,lip of ,cylinder4        
h4--,exit ,lip of ,cylinder4            
c4--,banking ,slot4                     
,c4--,tooth4          ,d4--,u arm4      
,e4--,stalk of ,pillar4          ,i4--,u
 space4          l4--,point of ,tooth4  
k4--,heel of ,tooth4  ,the cylinder     
escapement has two engagements or       
actions1 during the passage of each     
tooth2 that is1 one on the outside of   
the cylinder and one on the inside of   
the shell4 ,as we shall show later on1  
the cylinder escapement is the only     
positively dead-beat escapement in use1 
all others1 even the duplex1 having a   
slight recoil during the process of     
escaping4  ,when the tooth of a cylinder
 escape wheel while performing its      
functions1 strikes the cylinder shell1  

it rests dead on the outer or inner     
surface of the half shell until the     
action of the balance spring has brought
 the lip of the cylinder so that the    
impulse face of the tooth commences to  
impart motion or power to the balance4  
,illustration3 ,fig4 #abb               
,illustration3 ,fig4 #abc               
,illustration3 ,fig4 #abd               
,illustration3 ,fig4 #abe               
,illustration3 ,fig4 #abf               
,illustration3 ,fig4 #abg               
,illustration3 ,fig4 #abh  ,most writers
 on horological matters term this act   
the lift1 which name was no doubt       
acquired when escapements were chiefly  
confined to pendulum clocks4 ,very      
little thought on the matter will show  
any person who inspects ,fig4 #abf that 
if the tooth ,c is released or escapes  
from the inside of the half shell of the
 cylinder ,a1 said cylinder must turn or
 revolve a little in the direction of   
the arrow j1 and also that the next     
succeeding tooth of the escape wheel    

will engage the cylinder on the outside 
of the half shell1 falling on the dead  
or neutral portion of said cylinder1 to 
rest until the hairspring causes the    
cylinder to turn in the opposite        
direction and permitting the tooth now  
resting on the outside of the cylinder  
to assume the position shown on the     
drawing4  ,the first problem in our     
consideration of the theoretical action 
of the cylinder escapement1 is to       
arrange the parts we have described so  
as to have these two movements of the   
escape wheel of like angular values4 ,to
 explain what we mean by this1 we must  
premise by saying1 that as our escape   
wheel has fifteen teeth and we make each
 tooth give two impulses in alternate   
directions we must arrange to have these
 half-tooth movements exactly alike1 or1
 as stated above1 of equal angular      
values2 and also each impulse must      
convey the same power or force to the   
balance4 ,all escape wheels of fifteen  
teeth acting by half impulses must impel

 the balance during twelve degrees      
7minus the drop7 of escape-wheel action2
 or1 in other words1 when a tooth passes
 out of the cylinder from the position  
shown at ,fig4 #abf1 the form of the    
impulse face of the tooth and the shape 
of the exit lip of the cylinder must be 
such during twelve degrees 7less the    
drop7 of the angular motion of the      
escape wheel4 ,the entire power of such 
an escape wheel is devoted to giving    
impulse to the balance4  ,the extent of 
angular motion of the balance during    
such impulse is1 as previously stated1  
termed the lifting angle4 ,this lifting 
angle is by horological writers again   
divided into real and apparent lifts4   
,this last division is only an imaginary
 one1 as the real lift is the one to be 
studied and expresses the arc through   
which the impulse face of the tooth     
impels the balance during the act of    
escaping1 and so1 as we shall           
subsequently show1 should no more be    
counted than in the detached lever      

escapement1 where a precisely similar   
condition exists1 but is never          
considered or discussed4  ,we shall for 
the present take no note of this lifting
 angle1 but confine ourselves to the    
problem just named1 of so arranging and 
designing our escape-wheel teeth and    
cylinder that each half of the tooth    
space shall give equal impulses to the  
balance with the minimum of drop4 ,to do
 this we will make a careful drawing of 
an escape-wheel tooth and cylinder on an
 enlarged scale2 our method of making   
such drawings will be on a new and      
original system1 which is very simple   
yet complete4   ,,drawing ,,the         
,,cylinder ,,escapement4  ,all          
horological--and for that matter all    
mechanical--drawings are based on two   
systems of measurements3 7#a7 ,linear   
extent2 7#b7 angular movement4 ,for the 
first measurement we adopt the inch and 
its decimals2 for the second we adopt   
degrees1 minutes and seconds4 ,for      
measuring the latter the usual plan is  

to employ a protractor1 which serves the
 double purpose of enabling us to lay   
off and delineate any angle and also to 
measure any angle obtained by the       
graphic method1 and it is thus by this  
graphic method we propose to solve very 
simply some of the most abstruce        
problems in horological delineations4   
,as an instance1 we propose to draw our 
cylinder escapement with no other       
instruments than a steel straight-edge1 
showing one-hundredths of an inch1 and a
 pair of dividers2 the degree           
measurement being obtained from arcs of 
sixty degrees of radii1 as will be      
explained further on4  ,in describing   
the method for drawing the cylinder     
escapement we shall make a radical      
departure from the systems usually laid 
down in text-books1 and seek to simplify
 the formulas which have heretofore been
 given for such delineations4 ,in       
considering the cylinder escapement we  
shall pursue an analytical course and   
strive to build up from the underlying  

principles4 ,in the drawings for this   
purpose we shall commence with one      
having an escape wheel of #aj radius1   
and our first effort will be the primary
 drawing shown at ,fig4 #abi4 ,here we  
establish the point ,a for the center of
 our escape wheel1 and from this center 
sweep the short arc a a with a #aj      
radius1 to represent the circumference  
of our escape wheel4 ,from ,a we draw   
the vertical line ,a ,b1 and from the   
intersection of said line with the arc a
 a we lay off twelve degree spaces on   
each side of the line ,a ,b on said arc 
a and establish the points b c4 ,from ,a
 as a center we draw through the points 
b c the radial lines b' c'4  ,to define 
the face of the incline to the teeth we 
set our dividers to the radius of any of
 the convenient arcs of sixty degrees   
which we have provided1 and sweep the   
arc t t4 ,from the intersection of said 
arc with the line ,a b' we lay off on   
said arc sixty-four degrees and         
establish the point g and draw the line 

b g4 ,why we take sixty-four degrees for
 the angle ,a b g will be explained     
later on1 when we are discussing the    
angular motion of the cylinder4 ,by     
dividing the eleventh degree from the   
point b on the arc a a into thirds and  
taking two of them1 we establish the    
point y and draw the radial line ,a y'4 
,where this line ,a y' intersects the   
line b g we name the point n1 and in it 
is located the point of the escape-wheel
 tooth4 ,that portion of the line b g   
which lies between the points b and n   
represents the measure of the inner     
diameter of the cylinder1 and also the  
length of the chord of the arc which    
rounds the impulse face of the tooth4   
,we divide the space b n into two equal 
portions and establish the point e1     
which locates the position of the center
 of the cylinder4 ,from ,a as a center  
and through the point e we sweep the arc
 e' e'1 and it is on this line that the 
points establishing the center of the   
cylinder will in every instance be      

located4 ,from ,a as a center1 through  
the point n we sweep the arc k1 and on  
this line we locate the points of the   
escape-wheel teeth4 ,for delineating the
 curved impulse faces of the            
escape-wheel teeth we draw from the     
point e and at right angles to the line 
b g the line e o4 ,we next take in our  
dividers the radius of the arc k1 and   
setting one leg at either of the points 
b or n1 establish with the other leg the
 point p' on the line e o1 and from the 
point p' as a center we sweep the arc b 
v n1 which defines the curve of the     
impulse faces of the teeth4 ,from ,a as 
a center through the point p' we sweep  
the arc p1 and in all instances where we
 desire to delineate the curved face of 
a tooth we locate either the position of
 the point or the heel of such tooth1   
and setting one leg of our dividers at  
such point1 the other leg resting on the
 arc p1 we establish the center from    
which to sweep the arc defining the face
 of said tooth4   ,,advantages ,,gained 

,,in ,,shaping4  ,the reason for giving 
a curved form to the impulse face of the
 teeth of cylinder escape wheels are    
somewhat intricate1 and the problem     
involves several factors4 ,that there   
are advantages in so shaping the incline
 or impulse face is conceded1 we        
believe1 by all recent manufacturers4   
,the chief benefit derived from such    
curved impulse faces will be evident    
after a little thought and study of the 
situation and relation of parts as shown
 in ,fig4 #abi4 ,it will be seen on     
inspection that the angular motion      
imparted to the cylinder by the impulse 
face of the tooth when curved as shown1 
is greater during the first half of the 
twelve degrees of escape-wheel action   
than during the last half1 thus giving  
the escape wheel the advantage at the   
time the balance spring increases its   
resistance to the passage of the        
escape-wheel tooth across the lip of the
 cylinder4 ,or1 in other words1 as the  
ratio of resistance of the balance      

spring increases1 in a like ratio the   
curved form of the impulse face of the  
tooth gives greater power to the        
escape-wheel action in proportion to the
 angular motion of the escape wheel4    
,hence1 in actual service it is found   
that cylinder watches with curved       
impulse planes to the escape-wheel teeth
 are less liable to set in the pocket   
than the teeth having straight impulse  
faces4   ,,the ,,outer ,,diameter ,,of  
,,the ,,cylinder4  ,illustration3 ,fig4 
#abi  ,to define the remainder of the   
form of our escape-wheel tooth we will  
next delineate the heel4 ,to do this we 
first define the outer diameter of our  
cylinder1 which is the extent from the  
point n to c1 and after drawing the line
 n c we halve the space and establish   
the point x1 from which point as a      
center we sweep the circle w w1 which   
defines the outer circumference of our  
cylinder4 ,with our dividers set to     
embrace the extent from the point n to  
the point c we set one leg at the point 

b1 and with the other leg establish on  
the arc k the point h4 ,we next draw the
 line b h1 and from the point b draw the
 line b f at right angle to the line b  
h4 ,our object for drawing these lines  
is to define the heel of our            
escape-wheel tooth by a right angle line
 tangent to the circle w1 from the point
 b2 which circle w represents the curve 
of the outer circumference of the       
cylinder4 ,we shape the point of the    
tooth as shown to give it the proper    
stability1 and draw the full line j to a
 curve from the center ,a4 ,we have now 
defined the form of the upper face of   
the tooth4 ,how to delineate the ,u arms
 will be taken up later on1 as1 in the  
present case1 the necessary lines would 
confuse our drawing4  ,we would here    
take the opportunity to say that there  
is a great latitude taken by makers as  
regards the extent of angular impulse   
given to the cylinder1 or1 as it is     
termed1 the actual lift4 ,this latitude 
governs to a great extent the angle ,a b

 g1 which we gave as sixty-four degrees 
in our drawing4 ,it is well to          
understand that the use of sixty-four   
degrees is based on no hard-and-fast    
rules1 but varies back and forth1       
according as a greater or lesser angle  
of impulse or lift is employed4  ,in    
practical workshop usage the impulse    
angle is probably more easily estimated 
by the ratio between the diameter of the
 cylinder and the measured 7by lineal   
measure7 height of the impulse plane4   
,or1 to be more explicit1 we measure the
 radial extent from the center ,a       
between the arcs a k on the line ,a b1  
and use this for comparison with the    
outer diameter of the cylinder4  ,we can
 readily see that as we increase the    
height of the heel of the impulse face  
of our tooth we must also increase the  
angle of impulse imparted to the        
cylinder4 ,with the advantages of       
accurate micrometer calipers now        
possessed by the horological student it 
is an easy matter to get at the angular 

extent of the real lift of any cylinder4
 ,the advantage of such measuring       
instruments is also made manifest in    
determining when the proper proportion  
of the cylinder is cut away for the half
 shell4  ,illustration3 ,fig4 #acj  ,in 
the older methods of watchmaking it was 
a very common rule to say1 let the      
height of the incline of the tooth be   
one-seventh of the outer diameter of the
 cylinder1 and at the same time the     
trade was furnished with no tools except
 a clumsy douzieme gage2 but with       
micrometer calipers which read to       
one-thousandths of an inch such rules   
can be definitely carried into effect   
and not left to guess work4 ,let us     
compare the old method with the new3    
,suppose we have a new cylinder to put  
in2 we have the old escape wheel1 but   
the former cylinder is gone4 ,the       
old-style workman would take a round    
broach and calculate the size of the    
cylinder by finding a place where the   
broach would just go between the teeth1 

and the size of the broach at this point
 was supposed to be the outer diameter  
of the cylinder4 ,by our method we      
measure the diameter of the escape wheel
 in thousandths of an inch1 and from    
this size calculate exactly what the    
diameter of the new cylinder should be  
in thousandths of an inch4 ,suppose1 to 
further carry out our comparison1 the   
escape wheel which is in the watch has  
teeth which have been stoned off to     
permit the use of a cylinder which was  
too small inside1 or1 in fact1 of a     
cylinder too small for the watch3 in    
this case the broach system would only  
add to the trouble and give us a        
cylinder which would permit too much    
inside drop4   ,,drawing ,a ,,cylinder4 
,we have already instructed the pupil   
how to delineate a cylinder escape wheel
 tooth and we will next describe how to 
draw a cylinder4 ,as already stated1 the
 center of the cylinder is placed to    
coincide with the center of the chord of
 the arc which defines the impulse face 

of the tooth4 ,consequently1 if we      
design a cylinder escape wheel tooth as 
previously described1 and setting one   
leg of our compasses at the point e     
which is situated at the center of the  
chord of the arc which defines the      
impulse face of the tooth and through   
the points d and b we define the inside 
of our cylinder4 ,we next divide the    
chord d b into eight parts and set our  
dividers to five of these parts1 and    
from e as a center sweep the circle h   
and define the outside of our cylinder4 
,from ,a as a center we draw the radial 
line ,a e'4 ,at right angles to the line
 ,a e' and through the point e we draw  
the line from e as a center1 and with   
our dividers set to the radius of any of
 the convenient arcs which we have      
divided into sixty degrees1 we sweep the
 arc i4 ,where this arc intersects the  
line f we term the point k1 and from    
this point we lay off on the arc i #bbj 
degrees1 and draw the line l e l'1 which
 we see coincides with the chord of the 

impulse face of the tooth4 ,we set our  
dividers to the same radius by which we 
sweep the arc i and set one leg at the  
point b for a center and sweep the arc  
j'4 ,if we measure this arc from the    
point j' to intersection of said arc j' 
with the line l we will find it to be   
sixty-four degrees1 which accounts for  
our taking this number of degrees when  
we defined the face of our escape-wheel 
tooth1 ,fig4 #abi4  ,there is no reason 
why we should take twenty-degrees for   
the angle k e l except that the         
practical construction of the larger    
sizes of cylinder watches has           
established the fact that this is about 
the right angle to employ1 while in     
smaller watches it frequently runs up as
 high as twenty-five4 ,although the     
cylinder is seemingly a very simple     
escapement1 it is really a very abstruce
 one to follow out so as to become      
familiar with all of its actions4       
,,the ,,cylinder ,,proper ,,considered4 
,illustration3 ,fig4 #aca  ,we will now 

proceed and consider the cylinder       
proper1 and to aid us in understanding  
the position and relation of the parts  
we refer to ,fig4 #aca1 where we repeat 
the circles d and h1 shown in ,fig4     
#acj1 which represents the inside and   
outside of the cylinder4 ,we have here  
also repeated the line f of ,fig4 #acj  
as it cuts the cylinder in half1 that   
is1 divides it into two segments of #ahj
 degrees each4 ,if we conceive of a     
cylinder in which just one-half is cut  
away1 that is1 the lips are bounded by  
straight radial lines1 we can also      
conceive of the relation and position of
 the parts shown in ,fig4 #acj4 ,the    
first position of which we should take  
cognizance is1 the tooth ,d is moved    
back to the left so as to rest on the   
outside of our cylinder4 ,the cylinder  
is also supposed to stand so that the   
lips correspond to the line f4 ,on      
pressing the tooth ,d forward the       
incline of the tooth would attack the   
entrance lip of the cylinder at just    

about the center of the curved impulse  
face1 imparting to the cylinder twenty  
degrees of angular motion1 but the point
 of the tooth at d would exactly        
encounter the inner angle of the exit   
lip1 and of course the cylinder would   
afford no rest for the tooth2 hence1 we 
see the importance of not cutting away  
too much of the half shell of the       
cylinder4  ,but before we further       
consider the action of the tooth ,d in  
its action as it passes the exit lip of 
the cylinder we must finish with the    
action of the tooth on the entrance lip4
 ,a very little thought and study of    
,fig4 #acj will convince us that the    
incline of the tooth as it enters the   
cylinder will commence at t1 ,fig4 #acj1
 but at the close of the action the     
tooth parts from the lip on the inner   
angle4 ,now it is evident that it would 
require greater force to propel the     
cylinder by its inner angle than by the 
outer one4 ,to compensate for this we   
round the edge of the entrance lip so   

that the action of the tooth instead of 
commencing on the outer angle commences 
on the center of the edge of the        
entrance lip and also ends its action on
 the center of the entrance lip4 ,to    
give angular extent enough to the shell 
of the cylinder to allow for rounding   
and also to afford a secure rest for the
 tooth inside the cylinder1 we add six  
degrees to the angular extent of the    
entrance lip of the cylinder shell1 as  
indicated on the arc o'1 ,fig4 #aca1    
three of these degrees being absorbed   
for rounding and three to insure a dead 
rest for the tooth when it enters the   
cylinder4   ,,why ,,the ,,angular       
,,extent ,,is ,,increased4  ,without    
rounding the exit lip the action of the 
tooth on its exit would be entirely on  
the inner angle of the shell4 ,to       
obviate this it is the usual practice to
 increase the angular extent of the     
cylinder ten degrees1 as shown on the   
arc o' between the lines f and p1 ,fig4 
#aca4 ,why we should allow ten degrees  

on the exit lip and but six degrees on  
the entrance lip will be understood by  
observing ,fig4 #acj1 where the radial  
lines s and r show the extent of angular
 motion of the cylinder1 which would be 
lost if the tooth commenced to act on   
the inner angle and ended on the outer  
angle of the exit lip4 ,this arc is a   
little over six degrees1 and if we add a
 trifle over three degrees for rounding 
we would account for the ten degrees    
between the lines f and p1 ,fig4 #aca4  
,it will now be seen that the angular   
extent is #aif degrees4 ,if we draw the 
line w we can see in what proportion the
 measurement should be made between the 
outer diameter of the cylinder and the  
measure of the half shell4 ,it will be  
seen on measurement that the distance   
between the center e and the line w is  
about one-fifteenth part of the outer   
diameter of the cylinder and            
consequently with a cylinder which      
measures #de_/ajjj of an inch in        
diameter1 now the half shell should     

measure half of the entire diameter of  
the cylinder plus one-fifteenth part of 
such diameter1 or #be thousandths of an 
inch4  ,after these proportions are     
understood and the drawing made1 the eye
 will get accustomed to judging pretty  
near what is required2 but much the     
safer plan is to measure1 where we have 
the proper tools for doing so4 ,most    
workmen have an idea that the depth or  
distance at which the cylinder is set   
from the escape wheel is a matter of    
adjustment2 while this is true to a     
certain extent1 still there is really   
only one position for the center of the 
cylinder1 and that is so that the center
 of the pivot hole coincides exactly    
with the center of the chord to the     
curve of the impulse face of the tooth  
or the point e1 ,fig4 #acj4 ,any        
adjustment or moving back and forth of  
the chariot to change the depth could   
only be demanded where there was some   
fault existing in the cylinder or where 
it had been moved out of its proper     

place by some genius as an experiment in
 cylinder depths4 ,it will be evident on
 observing the drawing at ,fig4 #aca    
that when the cylinder is performing an 
arc of vibration1 as soon as the        
entrance lip has passed the point       
indicated by the radial line e x the    
point of the escape-wheel tooth will    
commence to act on the cylinder lip and 
continue to do so through an arc of     
forty degrees1 or from the lines x to l4
   ,,making ,a ,,working ,,model4  ,to  
practically study the action of the     
cylinder escapement it is well to make a
 working model4 ,it is not necessary    
that such a model should contain an     
entire escape wheel2 all that is really 
required is two teeth cut out of brass  
of the proper forms and proportions and 
attached to the end of an arm #d-g_/h   
long with studs riveted to the ,u arms  
to support the teeth4 ,this ,u arm is   
attached to the long arm we have just   
mentioned4 ,a flat ring of heavy sheet  
brass is shaped to represent a short    

transverse section of a cylinder4 ,this 
segment is mounted on a yoke which turns
 on pivots4 ,in making such a model we  
can employ all the proportions and exact
 forms of the larger drawings made on a 
ten-inch radius4 ,such a model becomes  
of great service in learning the        
importance of properly shaping the lips 
of the cylinder4 ,and right here we beg 
to call attention to the fact that in   
the ordinary repair shop the proper     
shape of cylinder lips is entirely      
neglected4   ,,proper ,,shape ,,of      
,,cylinder ,,lips4  ,the workman buys a 
cylinder and whether the proper amount  
is cut away from the half shell1 or the 
lips1 the correct form is entirely      
ignored1 and still careful attention to 
the form of the cylinder lips adds full 
ten per cent4 to the efficiency of the  
motive force as applied to the cylinder4
 ,in making study drawings of the       
cylinder escapement it is not necessary 
to employ paper so large that we can    
establish upon it the center of the arc 

which represents the periphery of our   
escape wheel1 as we have at our disposal
 two plans by which this can be         
obviated4 ,first1 placing a bit of      
bristol board on our drawing-board in   
which we can set one leg of our dividers
 or compasses when we sweep the         
peripheral arc which we use in our      
delineations2 second1 making three arcs 
in brass or other sheet metal1 viz43 the
 periphery of the escape wheel1 the arc 
passing through the center of the chord 
of the arc of the impulse face of the   
tooth1 and the arc passing through the  
point of the escape-wheel tooth4 ,of    
these plans we favor the one of sticking
 a bit of cardboard on the drawing board
 outside of the paper on which we are   
making our drawing4  ,illustration3     
,fig4 #acb  ,at ,fig4 #acb we show the  
position and relation of the several    
parts just as the tooth passes into the 
shell of the cylinder1 leaving the lip  
of the cylinder just as the tooth parted
 with it4 ,the half shell of the        

cylinder as shown occupies #aif degrees 
or the larger arc embraced between the  
radial lines k and l4 ,in drawing the   
entrance lip the acting face is made    
almost identical with a radial line     
except to round the corners for about   
one-third the thickness of the cylinder 
shell4 ,no portion1 however1 of the lip 
can be considered as a straight line1   
but might be described as a flattened   
curve4  ,illustration3 ,fig4 #acc  ,a   
little study of what would be required  
to get the best results after making    
such a drawing will aid the pupil in    
arriving at the proper shape1 especially
 when he remembers that the thickness of
 the cylinder shell of a twelve-line    
watch is only about five one-thousandths
 of an inch4 ,but because the parts are 
small we should not shirk the problem of
 getting the most we possibly can out of
 a cylinder watch4  ,the extent of arc  
between the radial lines k f1 as shown  
in ,fig4 #acb1 is four degrees4         
,although in former drawings we showed  

the angular extent added as six degrees1
 as we show the lip m in ,fig4 #acb1 two
 degrees are lost in rounding4 ,the     
space k f on the egress or exit side is 
intended to be about four degrees1 which
 shows the extent of lock4 ,we show at  
,fig4 #acc the tooth ,d just having     
passed out of the cylinder1 having      
parted with the exit lip p4  ,in making 
this drawing we proceed as with ,fig4   
#acb by establishing a center for our   
radius of #aj outside of our drawing    
paper and drawing the line ,a ,a to such
 center and sweeping the arcs a b c4 ,we
 establish the point e1 which represents
 the center of our cylinder1 as before4 
,we take the space to represent the     
radial extent of the outside of our     
cylinder in our dividers and from e as a
 center sweep a fine pencil line1       
represented by the dotted line t in our 
drawing2 and where this circle          
intersects the arc a we name it the     
point s2 and it is at this point the    
heel of our escape-wheel tooth must part

 with the exit lip of the cylinder4     
,from e as a center and through the     
point s we draw the line e l''4 ,with   
our dividers set to the radius of any   
convenient arc which we have divided    
into degrees1 we sweep the short arc d'4
 ,the intersection of this arc with the 
line e l'' we name the point u2 and from
 e as a center we draw the radial line e
 u f'4 ,we place the letter f'' in      
connection with this line because it    
7the line7 bears the same relations to  
the half shell of the cylinder shown in 
,fig4 #acc that the line f does to the  
half shell 7,d7 shown in ,fig4 #acb4 ,we
 draw the line f'' f'''1 ,fig4 #acc1    
which divides the cylinder into two     
segments of #ahj degrees each4 ,we take 
the same space in our dividers with     
which we swept the interior of the      
cylinder in ,fig4 #acb and sweep the    
circle v1 ,fig4 #acc4 ,from e as a      
center we sweep the short arc d''1 ,fig4
 #acc1 and from its intersection of the 
line f'' we lay off six degrees on said 

arc d'' and draw the line e' k''1 which 
defines the angular extent of our       
entrance lip to the half shell of the   
cylinder in ,fig4 #acc4 ,we draw the    
full lines of the cylinder as shown4    
,we next delineate the heel of the tooth
 which has just passed out of the       
cylinder1 as shown at ,d'1 ,fig4 #acc4  
,we now have a drawing showing the      
position of the half shell of the       
cylinder just as the tooth has passed   
the exit lip4 ,this drawing also        
represents the position of the half     
shell of the cylinder when the tooth    
rests against it on the outside4 ,if we 
should make a drawing of an escape-wheel
 tooth shaped exactly as the one shown  
at ,fig4 #acb and the point of the tooth
 resting at x1 we would show the        
position of a tooth encountering the    
cylinder after a tooth which has been   
engaged in the inside of the shell has  
passed out4 ,by following the           
instructions now given1 we can delineate
 a tooth in any of its relations with   

the cylinder shell4   ,,delineating ,,an
 ,,escape-,,wheel ,,tooth ,,while ,,in  
,,action4  ,we will now go through the  
operation of delineating an escape-wheel
 tooth while in action4 ,the position we
 shall assume is the one in which the   
cylinder and escape-wheel tooth are in  
the relation of the passage of half the 
impulse face of the tooth into the      
cylinder4 ,to do this is simple enough3 
,we first produce the arcs a b c1 ,fig4 
#acc1 as directed1 and then proceed to  
delineate a tooth as in previous        
instances4 ,to delineate our cylinder in
 the position we have assumed above1 we 
take the space between the points e d in
 our dividers and setting one leg at d  
establish the point g1 to represent the 
center of our cylinder4 ,if we then     
sweep the circle h from the center of g 
we define the inner surface of the shell
 of our cylinder4  ,strictly speaking1  
we have not assumed the position we     
stated1 that is1 the impulse face of the
 tooth as passing half way into the     

cylinder4 ,to comply strictly with our  
statement1 we divide the chord of the   
impulse face of the tooth ,a into eight 
equal spaces1 as shown4 ,now as each of 
these spaces represent the thickness of 
the cylinder1 if we take in our dividers
 four of these spaces and half of       
another1 we have the radius of a circle 
passing the center of the cylinder      
shell4 ,consequently1 if with this space
 in our dividers we set the leg at d1 we
 establish on the arc b the point i4 ,we
 locate the center of our cylinder when 
one-half of an entering tooth has passed
 into the cylinder4 ,if now from the new
 center with our dividers set at four of
 the spaces into which we have divided  
the line e f we can sweep a circle      
representing the inner surface of the   
cylinder shell1 and by setting our      
dividers to five of these spaces we can1
 from i as a center1 sweep an arc       
representing the outside of the cylinder
 shell4 ,for all purposes of practical  
study the delineation we show at ,fig4  

#acc is to be preferred1 because1 if we 
carry out all the details we have       
described1 the lines would become       
confused4 ,we set our dividers at five  
of the spaces on the line e f and from g
 as a center sweep the circle j1 which  
delineates the outer surface of our     
cylinder shell4  ,let us now1 as we     
directed in our former instructions1    
draw a flattened curve to represent the 
acting surface of the entrance lip of   
our cylinder as if it were in direct    
contact with the impulse face of the    
tooth4 ,to delineate the exit lip we    
draw from the center g1 ,fig4 #acd1 to  
the radial line g k1 said line passing  
through the point of contact between the
 tooth and entrance lip of the cylinder4
 ,let us next continue this line on the 
opposite side of the point g1 as shown  
at g k'1 and we thus bisect the cylinder
 shell into two equal parts of #ahj     
degrees each4 ,as we previously         
explained1 the entire extent of the     
cylinder half shell is #aif degrees4 ,we

 now set our dividers to the radius of  
any convenient arc which we have divided
 into degrees1 and from g as a center   
sweep the short arc l l1 and from the   
intersection of this arc with the line g
 k' we lay off sixteen degrees on the   
said arc l and establish the point n1   
from g as a center draw the radial line 
g n'4 ,take ten degrees from the same   
parent arc and establish the point m1   
then draw the line g m'4 ,now the arc on
 the circles h j between the lines g n' 
and g m limits the extent of the exit   
lip of the cylinder and the arc between 
the lines g k' and g m' represents the  
locking surface of the cylinder shell4  
,illustration3 ,fig4 #acd  ,to delineate
 the ,u arms we refer to ,fig4 #ace4    
,here1 again1 we draw the arc a b c and 
delineate a tooth as before4 ,from the  
point e located at the heel of the tooth
 we draw the radial line e e'4 ,from the
 point e we lay off on the arc a five   
degrees and establish the point p2 we   
halve this space and draw the short     

radial line p' s' and p s4 ,from the    
point e on the arc ,a we lay off        
twenty-four degrees and establish the   
point t1 which locates the heel of the  
next tooth in advance of ,a4 ,at two and
 a half degrees to the right of the     
point t we locate the point r and draw  
the short radial line r s4 ,on the arc b
 and half way between the lines p s and 
r s1 we establish the point u1 and from 
it as a center we sweep the arc v       
defining the curve of the ,u arms4  ,we 
have now given minute instructions for  
drawing a cylinder escapement in all its
 details except the extent of the       
banking slot of the cylinder1 which is  
usually made to embrace an angular      
extent of #bgj degrees2 consequently1   
the pillar of the cylinder will not     
measure more than ninety degrees of     
angular extent4  ,there is no escapement
 constructed where carefully-made       
drawings tend more to perfect knowledge 
of the action than the cylinder4 ,but it
 is necessary with the pupil to         

institute a careful analysis of the     
actions involved4 ,in writing on a      
subject of this kind it is extremely    
perplexing to know when to stop2 not    
that there is so much danger of saying  
too much as there is not having the     
words read with attention4  ,as an      
illustration1 let us consider the       
subject of depth between the cylinder   
and the escape wheel4 ,as previously    
stated1 #aif degrees of cylinder shell  
should be employed2 but suppose we find 
a watch in which the half shell has had 
too much cut away1 so the tooth on      
entering the half shell after parting   
with the entrance lip does not strike   
dead on the inside of the shell1 but    
encounters the edge of the exit lip4 ,in
 this case the impulse of the balance   
would cause the tooth to slightly       
retrograde and the watch would go but   
would lack a good motion4 ,in such an   
instance a very slight advance of the   
chariot would remedy the fault--not     
perfectly remedy it1 but patch up1 so to

 speak--and the watch would run4        
,illustration3 ,fig4 #ace  ,in this day1
 fine cylinder watches are not made1 and
 only the common kind are met with1 and 
for this reason the student should      
familiarize himself with all the        
imaginary faults which could occur from 
bad construction4 ,the best way to do   
this is to delineate what he 7the       
student7 knows to be a faulty           
escapement1 as1 for instance1 a cylinder
 in which too much of the half shell is 
cut away2 but in every instance let the 
tooth be of the correct form4 ,then     
delineate an escapement in which the    
cylinder is correct but the teeth       
faulty2 also change the thickness of the
 cylinder shell1 so as to make the teeth
 too short4 ,this sort of practice makes
 the pupil think and study and he will  
acquire a knowledge which will never be 
forgotten1 but always be present to aid 
him in the puzzles to which the         
practical watchmaker is every day       
subject4  ,the ability to solve these   

perplexing problems determines in a     
great degree the worth of a man to his  
employer1 in addition to establishing   
his reputation as a skilled workman4    
,the question is frequently asked1 ,how 
can ,i profitably employ myself in spare
 time8 ,it would seem that a watchmaker 
could do no better than to carefully    
study matters horological1 striving     
constantly to attain a greater degree of
 perfection1 for by so doing his earning
 capacity will undoubtedly be increased4
     ,,chapter ,,iii4  ,,the            
,,chronometer ,,escapement4             
,undoubtedly the detent1 or1 as it is   
usually termed1 the chronometer         
escapement1 is the most perfect of any  
of our portable time measurers4         
,although the marine chronometer is in a
 sense a portable timepiece1 still it is
 not1 like a pocket watch1 capable of   
being adjusted to positions4 ,as we are 
all aware1 the detent escapement is used
 in fine pocket watches1 still the      
general feeling of manufacturers is not 

favorable to it4 ,much of this feeling  
no doubt is owing to the mechanical     
difficulties presented in repairing the 
chronometer escapements when the detent 
is broken1 and the fact that the spring 
detent could not be adjusted to         
position4 ,we shall have occasion to    
speak of position adjustments as relate 
to the chronometer escapement later on4 
,,advantages ,,of ,,the ,,chronometer4  
,we will proceed now to consider briefly
 the advantages the detent escapement   
has over all others4 ,it was soon       
discovered in constructing portable     
timepieces1 that to obtain the best     
results the vibrations of the balance   
should be as free as possible from any  
control or influence except at such     
times as it received the necessary      
impulse to maintain the vibrations at a 
constant arc4 ,this want undoubtedly led
 to the invention of the detent         
escapement4 ,the early escapements were 
all frictional escapements1 i4e41 the   
balance staff was never free from the   

influence of the train4 ,the verge      
escapement1 which was undoubtedly the   
first employed1 was constantly in       
contact with the escape wheel1 and was  
what is known as a recoiling beat1 that 
is1 the contact of the pallets actually 
caused the escape wheel to recoil or    
turn back4 ,such escapements were too   
much influenced by the train1 and any   
increase in power caused the timepiece  
to gain4 ,the first attempt to correct  
this imperfection led to the invention  
and introduction of the fusee1 which    
enabled the watchmaker to obtain from a 
coiled spring nearly equal power during 
the entire period of action4 ,the next  
step in advance was the dead-beat       
escapement1 which included the cylinder 
and duplex4 ,in these frictional        
escapements the balance staff locked the
 train while the balance performed its  
arc of vibration4  ,,frictional         
,,escapements ,,in ,,high ,,favor4      
,these frictional escapements held favor
 with many eminent watchmakers even     

after the introduction of the detached  
escapements4 ,it is no more than natural
 we should inquire1 why8 ,the idea with 
the advocates of the frictional rest    
escapements was1 the friction of the    
tooth acted as a corrective1 and led no 
doubt to the introduction of            
going-barrel watches4 ,to illustrate1   
suppose in a cylinder watch we increase 
the motive power1 such increase of power
 would not1 as in the verge escapement1 
increase the rapidity of the vibrations2
 it might1 in fact1 cause the timepiece 
to run slower from the increased        
friction of the escape-wheel tooth on   
the cylinder2 also1 in the duplex       
escapement the friction of the locking  
tooth on the staff retards the          
vibrations4  ,dr4 ,hooke1 the inventor  
of the balance spring1 soon discovered  
it could be manipulated to isochronism1 
i4e41 so arcs of different extent would 
be formed in equal time4 ,of course1 the
 friction-rest escapement requiring a   
spring to possess different properties  

from one which would be isochronal with 
a perfectly detached escapement1 these  
two frictional escapements also         
differing1 the duplex requiring other   
properties from what would isochronize a
 spring for a cylinder escapement4      
,although pocket watches with duplex and
 cylinder escapements having balances   
compensated for heat and cold and       
balance springs adjusted to isochronism 
gave very good results1 careful makers  
were satisfied that an escapement in    
which the balance was detached and free 
to act during the greater proportion of 
the arc of vibration and uncontrolled by
 any cause1 would do still better1 and  
this led to the detent escapement4      
,,faults ,,in ,,the ,,detent            
,,escapement4  ,as stated previously1   
the detent escapement having pronounced 
faults in positions which held it back1 
it is probable it would never have been 
employed in pocket watches to any extent
 if it had not acquired such a high     
reputation in marine chronometers4 ,let 

us now analyze the influences which     
surround the detent escapement in a     
marine chronometer and take account of  
the causes which are combined to make it
 an accurate time measurer1 and also    
take cognizance of other interfering    
causes which have a tendency to prevent 
desired results4 ,first1 we will imagine
 a balance with its spring such as we   
find in fine marine chronometers4 ,it   
has small pivots running in             
highly-polished jewels2 such pivots are 
perfectly cylindrical1 and no larger    
than are absolutely necessary to endure 
the task imposed upon them--of carrying 
the weight of the balance and endure    
careful handling4  ,to afford the       
necessary vibrations a spring is fitted1
 usually of a helical form1 so disposed 
as to cause the balance to vibrate in   
arcs back and forth in equal time1      
provided these arcs are of equal extent4
 ,it is now to be taken note of that we 
have it at our disposal and option to   
make these arcs equal in time duration1 

i4e41 to make the long or short arcs the
 quickest or to synchronize them4 ,we   
can readily comprehend we have now      
established a very perfect measure of   
short intervals of time4 ,we can also   
see if we provide the means of          
maintaining these vibrations and        
counting them we should possess the     
means of counting the flights of time   
with great accuracy4 ,the conditions    
which surround our balance are very     
constant1 the small pivots turning in   
fine hard jewels lubricated with an oil 
on which exposure to the action of the  
air has little effect1 leaves but few   
influences which can interfere with the 
regular action of our balance4 ,we add  
to the influences an adjustable         
correction for the disturbances of heat 
and cold1 and we are convinced that but 
little could be added4   ,,antagonistic 
,,influences4  ,in this combination we  
have pitted two antagonistic forces     
against each other1 viz41 the elasticity
 of the spring and the weight and       

inertia of the balance2 both forces are 
theoretically constant and should       
produce constant results4 ,the          
mechanical part of the problem is simply
 to afford these two forces perfect     
facilities to act on each other and     
compel each to realize its full effect4 
,we must also devise mechanical means to
 record the duration of each conflict1  
that is1 the time length of each        
vibration4 ,many years have been spent  
in experimenting to arrive at the best  
propositions to employ for the several  
parts to obtain the best practical      
results4 ,consequently1 in designing a  
chronometer escapement we must not only 
draw the parts to a certain form1 but   
consider the quality and weight of      
material to employ4  ,to illustrate what
 we have just said1 suppose1 in drawing 
an escape wheel1 we must not only       
delineate the proper angle for the      
acting face of the tooth1 but must also 
take cognizance of the thickness of the 
tooth4 ,by thickness we mean the        

measurement of extent of the tooth in   
the direction of the axis of the escape 
wheel4 ,an escape-wheel tooth might be  
of the best form to act in conveying    
power to the balance and yet by being   
too thin soon wear or produce excessive 
friction4 ,how thick an escape wheel    
should be to produce best results1 is   
one of the many matters settled only by 
actual workshop experience4   ,,factors 
,,that ,,must ,,be ,,considered4  ,even 
this experience is in every instance    
modified by other influences4 ,to       
illustrate3 ,let us suppose in the      
ordinary to-day marine chronometer the  
escape-wheel teeth exerted a given      
average force1 which we set down as so  
many grains4 ,now1 if we should employ  
other material than hammer-hardened     
brass for an escape wheel it would      
modify the thickness2 also1 if we should
 decrease the motive power and increase 
the arc of impulse4 ,or1 if we should   
diminish the extent of the impulse arc  
and add to the motive force1 every      

change would have a controlling         
influence4 ,in the designs we shall     
employ1 it is our purpose to follow such
 proportions as have been adopted by our
 best makers1 in all respects1 including
 form1 size and material4 ,we would say1
 however1 there has been but little     
deviation with our principal            
manufacturers of marine chronometers for
 the last twenty years as regards the   
general principle on which they were    
constructed1 the chief aim being to     
excel in the perfection of the several  
parts and the care taken in the several 
adjustments4  ,before we proceed to take
 up the details of constructing a       
chronometer escapement we had better    
master the names for the several parts4 
,we show at ,fig4 #acf a complete plan  
of a chronometer escapement as if seen  
from the back1 which is in reality the  
front or dial side of the top plate4    
,the chronometer escapement consists of 
four chief or principal parts1 viz43    
,the escape wheel1 a portion of which is

 shown at ,a2 the impulse roller ,b2    
unlocking or discharging roller ,c1 and 
the detent ,d4 ,these principal parts   
are made up of sub-parts3 thus1 the     
escape wheel is composed of arms1 teeth1
 recess and collet1 the recess being the
 portion of the escape wheel sunk1 to   
enable us to get wide teeth actions on  
the impulse pallet4 ,the collet is a    
brass bush on which the wheel is set to 
afford better support to the escape     
wheel than could be obtained by the     
thinned wheel if driven directly on the 
pinion arbor4 ,the impulse roller is    
composed of a cylindrical steel collet  
,b1 the impulse pallet d 7some call it  
the impulse stone71 the safety recess b 
b4 ,the diameter of the impulse collet  
is usually one-half that of the escape  
wheel4 ,this impulse roller is staked   
directly on the balance staff1 and its  
perfection of position assured by       
resting against the foot of the shoulder
 to which the balance is secured4 ,this 
will be understood by inspecting ,fig4  

#acg1 which is a vertical longitudinal  
section of a chronometer balance staff1 
the lower side of the impulse roller    
being cupped out at c with a ball       
grinder and finished a ball polish4     
,illustration3 ,fig4 #acf               
,illustration3 ,fig4 #acg  ,it will be  
seen the impulse roller is staked flat  
against the hub ,e of the balance staff4
 ,the unlocking roller1 or1 as it is    
also called1 the discharging roller1 ,c1
 is usually thinner than the impulse    
roller and has a jewel similar to the   
impulse jewel a shown at f4 ,this roller
 is fitted by friction to the lower part
 of the balance staff and for additional
 security has a pipe or short socket e  
which embraces the balance staff at g4  
,the pipe e is usually flattened on     
opposite sides to admit of employing a  
special wrench for turning the          
discharging roller in adjusting the     
jewel for opening the escapement at the 
proper instant to permit the escape     
wheel to act on the impulse jewel a4    

,the parts which go to make up the      
detent ,d consist of the detent foot ,f1
 the detent spring h1 the detent blade  
i1 the jewel pipe j1 the locking jewel  
7or stone7 s1 the horn of the detent k1 
the gold spring 7also called the        
auxiliary and lifting spring7 m4 ,this  
lifting or gold spring m should be made 
as light and thin as possible and stand 
careful handling4  ,we cannot impress on
 our readers too much the importance of 
making a chronometer detent light4 ,very
 few detents1 even from the hands of our
 best makers1 are as light as they might
 be4 ,we should in such construction    
have very little care for clumsy workmen
 who may have to repair such mechanism4 
,this feature should not enter into     
consideration4  ,we should only be      
influenced by the feeling that we are   
working for best results1 and it is     
acting under this influence that we     
devote so much time to establishing a   
correct idea of the underlying          
principles involved in a marine         

chronometer1 instead of proceeding      
directly to the drawing of such an      
escapement and give empirical rules for 
the length of this or the diameter of   
that4 ,as1 for instance1 in finishing   
the detent spring h1 suppose we read in 
text books the spring should be reduced 
in thickness1 so that a weight of one   
pennyweight suspended from the pipe j   
will deflect the detent 4 ,this is a    
rule well enough for people employed in 
a chronometer factory1 but for the      
horological student such fixed rules    
7even if remembered7 would be of small  
use4 ,what the student requires is sound
 knowledge of the whys1 in order that he
 may be able to thoroughly master this  
escapement4   ,,functions ,,of ,,the    
,,detent4  ,we can see1 after a brief   
analysis of the principles involved1    
that the functions required of the      
detent ,d are to lock the escape wheel  
,a and hold it while the balance        
performs its excursion1 and that the    
detent or recovering spring h must have 

sufficient strength and power to perform
 two functions3 7#a7 ,return the locking
 stone s back to the proper position to 
arrest and hold the escape wheel2 7#b7  
the spring h must also be able to       
resist1 without buckling or cockling1   
the thrust of the escape wheel1         
represented by the arrows p o4 ,now we  
can readily understand that the lighter 
we make the parts i j k m1 the weaker   
the spring h can be4 ,you say1 perhaps1 
if we make it too weak it will be liable
 to buckle under the pressure of the    
escape wheel2 this1 in turn1 will depend
 in a great measure on the condition of 
the spring h4 ,suppose we have it       
straight when we put it in position1 it 
will then have no stress to keep it     
pressed to the holding1 stop or banking 
screw1 which regulates the lock of the  
tooth4 ,to obtain this stress we set the
 foot ,f of the detent around to the    
position indicated by the dotted lines r
 and n1 and we get the proper tension on
 the detent spring to effect the lock1  

or rather of the detent in time to lock 
the escape wheel2 but the spring h1     
instead of being perfectly straight1 is 
bent and consequently not in a condition
 to stand the thrust of the escape      
wheel1 indicated by the arrows o p4     
,,obtaining ,,the ,,best ,,conditions4  
,now the true way to obtain the best    
conditions is to give the spring h a set
 curvature before we put it in place1   
and then when the detent is in the      
proper position the spring h will have  
tension enough on it to bring the jewel 
s against the stop screw1 which         
regulates the lock1 and still be        
perfectly straight4 ,this matter is of  
so much importance that we will give    
further explanation4 ,suppose we bend   
the detent spring h so it is curved to  
the dotted line t1 ,fig4 #acf1 and then 
the foot ,f would assume the position   
indicated at the dotted line r4 ,we next
 imagine the foot ,f to be put in the   
position shown by the full lines1 the   
spring h will become straight again and 

in perfect shape to resist the thrust of
 the escape wheel4  ,little ways and    
methods like the above have long been   
known to the trade1 but for some reason 
are never mentioned in our text books4  
,a detent spring #b_/ajjj thick and     
#hj_/ajjj wide will stand the thrust for
 any well-constructed marine chronometer
 in existence1 and yet it will not      
require half a pennyweight to deflect it
 one-fourth of an inch4 ,it is a good   
rule to make the length of the detent   
from the foot ,f to the center of the   
locking jewel pipe j equal to the       
diameter of the escape wheel1 and the   
length of the detent spring h           
two-sevenths of this distance4 ,the     
length of the horn k is determined by   
the graphic plan and can be taken from  
the plotted plan4 ,the end1 however1    
should approach as near to the          
discharging jewel as possible and not   
absolutely touch4 ,the discharging      
7gold7 spring m is attached to the blade
 i of the detent with a small screw l   

cut in a ,no4 #ah hole of a ,swiss      
plate4 ,while there should be a slight  
increase in thickness in the detent     
blade at w1 where the gold spring is    
attached1 still it should be no more    
than to separate the gold spring m from 
the detent blade i4   ,,important       
,,considerations4  ,it is important the 
spring should be absolutely free and not
 touch the detent except at its point of
 attachment at w and to rest against the
 end of the horn k1 and the extreme end 
of k1 where the gold spring rests1      
should only be what we may term a dull  
or thick edge4 ,the end of the horn k   
7shown at y7 is best made1 for          
convenience of elegant construction1    
square--that is1 the part y turns at    
right angles to k and is made thicker   
than k and at the same time deeper2 or1 
to make a comparison to a clumsy        
article1 y is like the head of a nail1  
which is all on one side4 ,some makers  
bend the horn k to a curve and allow the
 end of the horn to arrest or stop the  

gold spring2 but as it is important the 
entire detent should be as light as     
possible1 the square end best answers   
this purpose4 ,the banking placed at j  
should arrest the detent as thrown back 
by the spring h at the point of         
percussion4 ,this point of percussion is
 a certain point in a moving mass where 
the greatest effort is produced and     
would be somewhere near the point x1 in 
a bar ,g turning on a pivot at z1 ,fig4 
#ach4 ,it will be evident1 on inspection
 of this figure1 if the bar ,g was      
turning on the center z it would not    
give the hardest impact at the end v1 as
 parts of its force would be expended at
 the center z4  ,illustration3 ,fig4    
#ach   ,,decisions ,,arrived ,,at ,,by  
,,experience4  ,experience has decided  
that the impulse roller should be about 
half the diameter of the escape wheel1  
and experience has also decided that an 
escape wheel of fifteen teeth has the   
greatest number of advantages2 also1    
that the balance should make #ad1djj    

vibrations in one hour4 ,we will accept 
these proportions and conditions as     
best1 from the fact that they are now   
almost universally adopted by our best  
chronometer makers4 ,although it would  
seem as if these proportions should have
 established themselves earlier among   
practical men1 we shall in these        
drawings confine ourselves to the       
graphic plan1 considering it preferable4
 ,in the practical detail drawing we    
advise the employment of the scale      
given1 i4e41 delineating an escape wheel
 #aj in diameter4 ,the drawings which   
accompany the description are one-fourth
 of this size1 for the sake of          
convenience in copying4  ,with an escape
 wheel of fifteen teeth the impulse arc 
is exactly twenty-four degrees1 and of  
course the periphery of the impulse     
roller must intersect the periphery of  
the escape wheel for this arc 7#bd74    
,the circles ,a ,b1 ,fig4 #aci1         
represent the peripheries of these two  
mobiles1 and the problem in hand is to  

locate and define the position of the   
two centers a c4 ,these1 of course1 are 
not separated1 the sum of the two radii1
 i4e41 #e  #b 7in the large drawing71 as
 these circles intersect1 as shown at d4
 ,arithmetically considered1 the problem
 is quite difficult1 but graphically1   
simple enough4 ,after we have swept the 
circle ,a with a radius of #e1 we draw  
the radial line a f1 said line extending
 beyond the circle ,a4   ,,locating     
,,the ,,center ,,of ,,the ,,balance     
,,staff4  ,somewhere on this line is    
located the center of the balance staff1
 and it is the problem in hand to locate
 or establish this center4 ,now1 it is  
known the circles which define the      
peripheries of the escape wheel and the 
impulse roller intersect at e e#b4 ,we  
can establish on our circle ,a where    
these intersections take place by laying
 off twelve degrees1 one-half of the    
impulse arc on each side of the line of 
centers a f on this circle and          
establishing the points e e#b4 ,these   

points e e#b being located at the       
intersection of the circles ,a and ,b1  
must be at the respective distances of  
#e and #b distance from the center of   
the circles ,a ,b2 consequently1 if we  
set our dividers at #b and place one leg
 at e and sweep the short arc g#b1 and  
repeat this process when one leg of the 
dividers is set at e#b1 the intersection
 of the short arcs g and g#b will locate
 the center of our balance staff4 ,we   
have now our two centers established1   
whose peripheries are in the relation of
 #b to #a4  ,to know1 in the chronometer
 which we are supposed to be            
constructing1 the exact distance apart  
at which to plant the hole jewels for   
our two mobiles1 i4e41 escape wheel and 
balance staff1 we measure carefully on  
our drawing the distance from a to c    
7the latter we having just established7 
and make our statement in the rule of   
three1 as follows3 ,as 7#aj7 the        
diameter of drawn escape wheel is to our
 real escape wheel so is the measured   

distance on our drawing to the real     
distance in the chronometer we are      
constructing4  ,it is well to use great 
care in the large drawing to obtain     
great accuracy1 and make said large     
drawing on a sheet of metal4 ,this      
course is justified by the degree of    
perfection to which measuring tools have
 arrived in this day4 ,it will be found 
on measurement of the arc of the circle 
,b1 embraced between the intersections e
 e#b1 that it is about forty-eight      
degrees4 ,how much of this we can       
utilize in our escapement will depend   
very much on the perfection and accuracy
 of construction4  ,illustration3 ,fig4 
#aci  ,we show at ,fig4 #adj three teeth
 of an escape wheel1 together with the  
locking jewel ,e and impulse jewel ,d4  
,now1 while theoretically we could      
commence the impulse as soon as the     
impulse jewel ,d was inside of the      
circle representing the periphery of the
 escape wheel1 still1 in practical      
construction1 we must allow for         

contingencies4 ,before it is safe for   
the escape wheel to attack the impulse  
jewel1 said jewel must be safely inside 
of said escape wheel periphery1 in order
 that the attacking tooth shall act with
 certainty and its full effect4 ,a good 
deal of thought and study can be        
bestowed to great advantage on the      
action of a chronometer escapement4 ,let
 us examine the conditions involved4 ,we
 show in ,fig4 #adj the impulse jewel ,d
 just passing inside the circle of the  
periphery of the escape wheel4 ,now the 
attendant conditions are these3 ,the    
escape wheel is locked fast and         
perfectly dead1 and in the effort of    
unlocking it has to first turn backward 
against the effort of the mainspring2   
the power of force required for this    
effort is derived from the balance in   
which is stored up1 so to speak1 power  
from impulses imparted to the balance by
 former efforts of the escape wheel4 ,in
 actual fact1 the balance at the time   
the unlocking takes place is moving with

 nearly its greatest peripheral velocity
 and1 as stated above1 the escape wheel 
is at rest4  ,here comes a very delicate
 problem as regards setting the         
unlocking or discharging jewel4 ,let us 
first suppose we set the discharging    
jewel so the locking jewel frees its    
tooth at the exact instant the impulse  
jewel is inside the periphery of the    
escape wheel4 ,as just stated1 the      
escape wheel is not only dead but       
actually moving back at the time the    
release takes place4 ,now1 it is evident
 that the escape wheel requires an      
appreciable time to move forward and    
attack the impulse jewel1 and during    
this appreciable time the impulse jewel 
has been moving forward inside of the   
arc ,a ,a1 which represents the         
periphery of the escape wheel4 ,the     
proper consideration of this problem is 
of more importance in chronometer making
 than we might at first thought have    
imagined1 consequently1 we shall dwell  
upon it at some length4   ,,how ,,to    

,,set ,,the ,,discharging ,,jewel4      
,illustration3 ,fig4 #adj               
,theoretically1 the escape-wheel tooth  
should encounter the impulse jewel at   
the time--instant--both are moving with 
the same velocity4 ,it is evident then  
that there can be no special rule given 
for this1 i4e41 how to set the          
discharging jewel so it will free the   
tooth at exactly the proper instant1    
from the fact that one chronometer train
 may be much slower in getting to move  
forward from said train being heavy and 
clumsy in construction4 ,let us make an 
experiment with a real chronometer in   
illustration of our problem4 ,to do so  
we remove our balance spring and place  
the balance in position4 ,if we start   
the balance revolving in the direction  
of the arrow y1 ,fig4 #adj1 it will     
cause the escapement to be unlocked and 
the balance to turn rapidly in one      
direction and with increasing velocity  
until1 in fact1 the escape wheel has but
 very little effect on the impulse      

jewel2 in fact1 we could1 by applying   
some outside source of power--like      
blowing with a blow pipe on the         
balance--cause the impulse jewel to pass
 in advance of the escape wheel2 that   
is1 the escape-wheel tooth would not be 
able to catch the impulse jewel during  
the entire impulse arc4 ,let us suppose1
 now1 we set our unlocking or           
discharging jewel in advance1 that is1  
so the escapement is really unlocked a  
little before the setting parts are in  
the positions and relations shown in    
,fig4 #ada4 ,under the new conditions   
the escape wheel would commence to move 
and get sufficient velocity on it to act
 on the impulse jewel as soon as it was 
inside of the periphery of the escape   
wheel4 ,if the balance was turned slowly
 now the tooth of the escape wheel would
 not encounter the impulse jewel at all1
 but fall into the passing hollow n2 but
 if we give the balance a high velocity1
 the tooth would again encounter and act
 upon the jewel in the proper manner4   

,experienced adjusters of chronometers  
can tell by listening if the            
escape-wheel tooth attacks the impulse  
jewel properly1 i4e41 when both are     
moving with similar velocities4 ,the    
true sound indicating correct action is 
only given when the balance has its     
maximum arc of vibration1 which should  
be about #a revolutions1 or perform an  
arc of #bbe degrees on each excursion4  
,fig4 #adb is a side view of ,fig4 #ada 
seen in the direction of the arrow y4   
,we have mentioned a chariot to which   
the detent is attached1 but we shall    
make no attempt to show it in the       
accompanying drawings1 as it really has 
no relation to the problem in hand2     
i4e41 explaining the action of the      
chronometer escapement1 as the chariot  
relates entirely to the convenience of  
setting and adjusting the relation of   
the second parts4 ,the size1 or better1 
say1 the inside diameter of the pipe at 
,c1 ,fig4 #adc1 which holds the locking 
jewel1 should be about one-third of a   

tooth space1 and the jewel made to fit  
perfectly4 ,usually1 jewelmakers have a 
tendency to make this jewel too frail1  
cutting away the jewel back of the      
releasing angle 7n1 ,fig4 #adc7 too     
much4   ,a ,,good ,,form ,,of ,,locking 
,,stone4  ,a very practical form for a  
locking stone is shown in transverse    
section at ,fig4 #adc4 ,in construction 
it is a piece of ruby1 or1 better1      
sapphire cut to coincide to its axis of 
crystallization1 into first a solid     
cylinder nicely fitting the pipe ,c and 
finished with an after-grinding1 cutting
 away four-tenths of the cylinder1 as   
shown at ,i1 ,fig4 #adc4 ,here the line 
m represents the locking face of the    
jewel and the line o the clearance to   
free the escaping tooth1 the angle at n 
being about fifty-four degrees4 ,this   
angle 7n7 should leave the rounding of  
the stone intact1 that is1 the rounding 
of the angle should be left and not made
 after the flat faces m o are ground and
 polished4 ,the circular space at ,i is 

filled with an aluminum pin4 ,the sizes 
shown are of about the right relative   
proportions2 but we feel it well to     
repeat the statement made previously1 to
 the effect that the detent to a        
chronometer cannot well be made too     
light4  ,illustration3 ,fig4 #ada       
,illustration3 ,fig4 #adb               
,illustration3 ,fig4 #adc  ,the         
so-called gold spring shown at ,h1      
,figs4 #ada and #adb1 should also be as 
light as is consistent with due strength
 and can be made of the composite metal 
used for gold filled goods1 as the only 
real benefit to be derived from         
employing gold is to avoid the necessity
 of applying oil to any part of the     
escapement4 ,if such gold metal is      
employed1 after hammering to obtain the 
greatest possible elasticity to the     
spring1 the gold is filed away1 except  
where the spring is acted upon by the   
discharging jewel h4 ,we have previously
 mentioned the importance of avoiding   
wide1 flat contacts between all acting  

surfaces1 like where the gold spring    
rests on the horn of the detent at p2   
also where the detent banks on the      
banking screw1 shown at ,g1 ,fig4 #adb4 
,under this principle the impact of the 
face of the discharging jewel with the  
end of the gold spring should be        
confined to as small a surface as is    
consistent with what will not produce   
abrasive action4 ,the gold spring is    
shaped as shown at ,fig4 #adb and loses1
 in a measure1 under the pipe of the    
locking jewel1 a little more than       
one-half of the pipe below the blade of 
the detent being cut away1 as shown in  
,fig4 #adc1 where the lines r r show the
 extent of the part of the pipe which   
banks against the banking screw ,g4 ,in 
this place even1 only the curved surface
 of the outside of the pipe touches the 
screw ,g1 again avoiding contact of     
broad surfaces4  ,we show the gold      
spring separate at ,fig4 #add4 ,a slight
 torsion or twist is given to the gold  
spring to cause it to bend with a true  

curvature in the act of allowing the    
discharging pallet to pass back after   
unlocking4 ,if the gold spring is filed 
and stoned to the right flexure1 that   
is1 the thinnest point properly placed  
or1 say1 located1 the gold spring will  
not continue in contact with the        
discharging pallet any longer time or   
through a greater arc than during the   
process of unlocking4 ,to make this     
statement better understood1 let us     
suppose the weakest part of the gold    
spring ,h is opposite the arrow y1 ,fig4
 #ada1 it will readily be understood the
 contact of the discharging stone h     
would continue longer than if the point 
of greatest 7or easiest7 flexure was    
nearer to the pipe ,c4 ,if the end ,d#b 
of the horn of the detent is as near as 
it should be to the discharging stone   
there need be no fear but the escapement
 will be unlocked4 ,the horn ,d#b of the
 detent should be bent until five       
degrees of angular motion of the balance
 will unlock the escape1 and the contact

 of discharging jewel h should be made  
without engaging friction4 ,this        
condition can be determined by observing
 if the jewel seems to slide up 7toward 
the pipe ,c7 on the gold spring after   
contact4 ,some adjusters set the jewel  
,j1 ,figs4 #adc and #ada1 in such a way 
that the tooth rests close to the base2 
such adjusters claiming this course has 
a tendency to avoid cockling or buckling
 of the detent spring ,e4 ,such         
adjusters also set the impulse jewel    
slightly oblique1 so as to lean on the  
opposite angle of the tooth4 ,our advice
 is to set both stones in places        
corresponding to the axis of the balance
 staff1 and the escape-wheel mobiles4   
,,the ,,detent ,,spring4  ,illustration3
 ,fig4 #add  ,it will be noticed we have
 made the detent spring ,e pretty wide  
and extended it well above the blade of 
the detent4 ,by shaping the detent in   
this way nearly all the tendency of the 
spring ,e to cockle is annulled4 ,we    
would beg to add to what we said in     

regard to setting jewels obliquely4 ,we 
are unable to understand the advantage  
of wide-faced stones and deep teeth when
 we do not take advantage of the wide   
surfaces which we assert are important4 
,we guarantee that with a detent and    
spring made as we show1 there will be no
 tendency to cockle1 or if there is1 it 
will be too feeble to even display      
itself4 ,those who have had extended    
experience with chronometers cannot fail
 to have noticed a gummy secretion which
 accumulates on the impulse and         
discharging stones of a chronometer1    
although no oil is ever applied to them4
 ,we imagine this coating is derived    
from the oil applied to the pivots1     
which certainly evaporates1 passes into 
vapor1 or the remaining oil could not   
become gummy4 ,we would advise1 when    
setting jewels 7we mean the locking1    
impulse and discharging jewels71 to     
employ no more shellac than is          
absolutely necessary1 depending chiefly 
on metallic contact for security4       

,,details ,,of ,,construction4  ,we will
 now say a few words about the number of
 beats to the hour for a box or marine  
chronometer to make to give the best    
results4 ,experience shows that slow but
 most perfect construction has settled  
that #ad1djj1 or four vibrations of the 
balance to a second1 as the proper      
number1 the weight of balance1 including
 balance proper and movable weights1 to 
be about #e pennyweights1 and the       
compensating curb about #a-b_/aj in     
diameter4 ,the escape wheel1 #ee_/ajj in
 diameter and recessed so as to be as   
light as possible1 should have          
sufficient strength to perform its      
functions properly4 ,the thickness or1  
more properly1 the face extent of the   
tooth1 measured in the direction of the 
axis of the escape wheel1 should be     
about #a_/bj4 ,the recessing should     
extend half way up the radial back of   
the tooth at t4 ,the curvature of the   
back of the teeth is produced with the  
same radii as the impulse roller4 ,to   

locate the center from which the arc    
which defines the back of the teeth is  
swept1 we halve the space between the   
teeth ,a#b and a#d and establish the    
point n1 ,fig4 #ada1 and with our       
dividers set to sweep the circle        
representing the impulse roller1 we     
sweep an arc passing the point of the   
tooth ,a#c and u1 thus locating the     
center w4 ,from the center k of the     
escape wheel we sweep a complete circle1
 a portion of which is represented by   
the arc w v4 ,for delineating other     
teeth we set one leg of our dividers to 
agree with the point of the tooth and   
the other leg on the circle w v and     
produce an arc like z u4   ,,original   
,,designing ,,of ,,the ,,escapement4    
,on delineating our chronometer         
escapement shown at ,fig4 #ada we have  
followed no text-book authority1 but    
have drawn it according to such         
requirements as are essential to obtain 
the best results4 ,an escapement of any 
kind is only a machine1 and merely      

requires in its construction a          
combination of sound mechanical         
principles4 ,neither ,saunier nor       
,britten1 in their works1 give          
instructions for drawing this escapement
 which will bear close analysis4 ,it is 
not our intention1 however1 to criticise
 these authors1 except we can present   
better methods and give correct systems4
   ,,tangential ,,lockings4  ,it has    
been a matter of great contention with  
makers of chronometer and also lever    
escapements as to the advantages of     
tangential lockings4 ,by this term is   
meant a locking the same as is shown at 
,c1 ,fig4 #ada1 and means a detent      
planted at right angles to a line radial
 to the escape-wheel axis1 said radial  
line passing through the point of the   
escape-wheel tooth resting on the       
locking jewel4 ,in escapements not set  
tangential1 the detent is pushed forward
 in the direction of the arrow x about  
half a tooth space4 ,britten1 in his    
,hand-,book1 gives a drawing of such an 

escapement4 ,we claim the chief         
advantage of tangential locking to lie  
in the action of the escape-wheel teeth1
 both on the impulse stone and also on  
the locking stone of the detent4        
,saunier1 in his ,modern ,horology1     
gives the inclination of the front fan  
of the escape-wheel teeth as being at an
 angle of twenty-seven degrees to a     
radial line4 ,britten says twenty       
degrees1 and also employs a             
non-tangential locking4  ,our drawing is
 on an angle of twenty-eight degrees1   
which is as low as is safe1 as we shall 
proceed to demonstrate4 ,for            
establishing the angle of an            
escape-wheel tooth we draw the line ,c  
d1 from the point of the escape-wheel   
tooth resting on the locking stone shown
 at ,c at an angle of twenty-eight      
degrees to radial line ,c k4 ,we have   
already discussed how to locate and     
plant the center of the balance staff4  
,we shall not show in this drawing the  
angular motion of the escape wheel1 but 

delineate at the radial lines c e and c 
f of the arc of the balance during the  
extent of its implication with the      
periphery of the escape wheel1 which arc
 is one of about forty-eight degrees4   
,of this angle but forty-three degrees  
is attempted to be utilized for the     
purpose of impulse1 five degrees being  
allowed for the impulse jewel to pass   
inside of the arc of periphery of the   
escape wheel before the locking jewel   
releases the tooth of the escape wheel  
resting upon it4 ,at this point it is   
supposed the escape wheel attacks the   
impulse jewel1 because1 as we just      
explained1 the locking jewel has        
released the tooth engaging it4 ,now1 if
 the train had no weight1 no inertia to 
overcome1 the escape wheel tooth ,a#b   
would move forward and attack the       
impulse pallet instantly2 but1 in fact1 
as we have already explained1 there will
 be an appreciable time elapse before   
the tooth overtakes the rapidly-moving  
impulse jewel4 ,it will1 of course1 be  

understood that the reference letters   
used herein refer to the illustrations  
that have appeared on preceding pages4  
,if we reason carefully on the matter1  
we will readily comprehend that we can  
move the locking jewel1 i4e41 set it so 
the unlocking will take place in reality
 before the impulse jewel has passed    
through the entire five degrees of arc  
embraced between the radial lines c e   
and c g1 ,fig4 #ada1 and yet have the   
tooth attack the jewel after the five   
degrees of arc4 ,in practice it is safe 
to set the discharging jewel h so the   
release of the held tooth ,a#a will take
 place as soon as the tooth ,a#b is     
inside the principal line of the escape 
wheel4 ,as we previously explained1 the 
contact between ,a#b and the impulse    
jewel i would not in reality occur until
 the said jewel i had fully passed      
through the arc 7five degrees7 embraced 
between the radial lines c e and c g4   
,at this point we will explain why we   
drew the front fan of the escape-wheel  

teeth at the angle of twenty-eight      
degrees4 ,if the fan of impulse jewel i 
is set radial to the axis of the        
balance1 the engagement of the tooth    
,a#b would be at a disadvantage if it   
took place prior to this jewel passing  
through an arc of five degrees inside   
the periphery of the escape wheel4 ,it  
will be evident on thought that if an   
escape-wheel tooth engaged the impulse  
stone before the five-degrees angle had 
passed1 the contact would not be on its 
flat face1 but the tooth would strike   
the impulse jewel on its outer angle4 ,a
 continued inspection will also reveal  
the fact that in order to have the point
 of the tooth engage the flat surface of
 the impulse pallet the impulse jewel   
must coincide with the radial line c g4 
,if we seek to remedy this condition by 
setting the impulse jewel so the face is
 not radial1 but inclined backward1 we  
encounter a bad engaging friction1      
because1 during the first part of the   
impulse action1 the tooth has to slide  

up the face of the impulse jewel4 ,all  
things considered1 the best action is   
obtained with the impulse jewel set so  
the acting face is radial to the balance
 staff and the engagement takes place   
between the tooth and the impulse jewel 
when both are moving with equal         
velocities1 i4e41 when the balance is   
performing with an arc 7or motion7 of #a
 revolutions or #bbe degrees each way   
from a point of rest4 ,under such       
conditions the actual contact will not  
take place before some little time after
 the impulse jewel has passed the       
five-degree arc between the lines c e   
and c g4   ,,the ,,drop ,,and ,,draw    
,,considered4  ,exactly how much drop   
must be allowed from the time the tooth 
leaves the impulse jewel before the     
locking tooth engages the locking jewel 
will depend in a great measure on the   
perfection of workmanship1 but should in
 no instance be more than what is       
absolutely required to make the         
escapement safe4 ,the amount of draw    

given to the locking stone c is usually 
about twelve degrees to the radial line 
k a4 ,much of the perfection of the     
chronometer escapement will always      
depend on the skill of the escapement   
adjuster and not on the mechanical      
perfection of the parts4  ,the jewels   
all have to be set by hand after they   
are made1 and the distance to which the 
impulse jewel protrudes beyond the      
periphery of the impulse roller is      
entirely a matter for hand and eye1 but 
should never exceed #b_/ajjj4 ,after the
 locking jewel c is set1 we can set the 
foot ,f of the detent ,d forward or     
back1 to perfect and correct the        
engagement of the escape-wheel teeth    
with the impulse roller ,b4 ,if we set  
this too far forward1 the tooth ,a#c    
will encounter the roller while the     
tooth ,a#b will be free4  ,we would beg 
to say here there is no escape wheel    
made which requires the same extreme    
accuracy as the chronometer1 as the     
tooth spaces and the equal radial extent

 of each tooth should be only limited by
 our powers toward perfection4 ,it is   
usual to give the detent a locking of   
about two degrees2 that is1 it requires 
about two degrees to open it1 counting  
the center of fluxion of the detent     
spring ,e and five degrees of balance   
arc4   ,,fitting ,,up ,,of ,,the ,,foot4
  ,several attempts have been made by   
chronometer makers to have the foot ,f  
adjustable2 that is1 so it could be     
moved back and forth with a screw1 but  
we have never known of anything         
satisfactory being accomplished in this 
direction4 ,about the best way of       
fitting up the foot ,f seems to be to   
provide it with two soft iron steady    
pins 7shown at j7 with corresponding    
holes in the chariot1 said holes being  
conically enlarged so they 7the pins7   
can be bent and manipulated so the      
detent not only stands in the proper    
position as regards the escape wheel1   
but also to give the detent spring ,e   
the proper elastic force to return in   

time to afford a secure locking to the  
arresting tooth of the escape wheel     
after an impulse has been given4  ,if   
these pins j are bent properly by the   
adjuster1 whoever afterwards cleans the 
chronometer needs only to gently push   
the foot ,f forward so as to cause the  
pins j to take the correct positions as 
determined by the adjuster and set the  
screw l up to hold the foot ,f when all 
the other relations are as they should  
be1 except such as we can control by the
 screw ,g1 which prevents the locking   
jewel from entering too deeply into the 
escape wheel4  ,in addition to being a  
complete master of the technical part of
 his business1 it is also desirable that
 the up-to-date workman should be       
familiar with the subject from a        
historical point of view4 ,to aid in    
such an understanding of the matter we  
have translated from ,l',almanach de    
l',horologerie et de la ,bijouterie the 
matter contained in the following       
chapter4     ,,chapter ,,iv4  ,,history 

,,of ,,escapements4   ,it could not have
 been long after man first became       
cognizant of his reasoning faculties    
that he began to take more or less      
notice of the flight of time4 ,the      
motion of the sun by day and of the moon
 and stars by night served to warn him  
of the recurring periods of light and   
darkness4 ,by noting the position of    
these stellar bodies during his lonely  
vigils1 he soon became proficient in    
roughly dividing up the cycle into      
sections1 which he denominated the hours
 of the day and of the night4 ,primitive
 at first1 his methods were simple1 his 
needs few and his time abundant4        
,increase in numbers1 multiplicity of   
duties1 and division of occupation began
 to make it imperative that a more      
systematic following of these           
occupations should be instituted1 and   
with this end in view he contrived1 by  
means of burning lights or by           
restricting the flowing of water or the 
falling of weights1 to subdivide into   

convenient intervals and in a tolerably 
satisfactory manner the periods of      
light4  ,these modest means then were   
the first steps toward the exact        
subdivisions of time which we now enjoy4
 ,unrest1 progress1 discontent with     
things that be1 we must acknowledge1    
have1 from the appearance of the first  
clock to the present hour1 been the     
powers which have driven on the         
inventive genius of watch and           
clockmakers to designate some new and   
more acceptable system for regulating   
the course of the movement4 ,in         
consequence of this restless search     
after the best1 a very considerable     
number of escapements have been invented
 and made up1 both for clocks and       
watches2 only a few1 however1 of the    
almost numberless systems have survived 
the test of time and been adopted in the
 manufacture of the timepiece as we know
 it now4 ,indeed1 many such inventions  
never passed the experimental stage1 and
 yet it would be very interesting to the

 professional horologist1 the apprentice
 and even the layman to become more     
intimately acquainted with the vast     
variety of inventions made upon this    
domain since the inception of           
horological science4 ,undoubtedly1 a    
complete collection of all the          
escapements invented would constitute a 
most instructive work for the           
progressive watchmaker1 and while we are
 waiting for a competent author to take 
such an exhaustive work upon his hands1 
we shall endeavor to open the way and   
trust that a number of voluntary        
collaborators will come forward and     
assist us to the extent of their ability
 in filling up the chinks4   ,,problems 
,,to ,,be ,,solved4  ,the problem to be 
solved by means of the escapement has   
always been to govern1 within limits    
precise and perfectly regular1 if it be 
possible1 the flow of the motive force2 
that means the procession of the        
wheel-work and1 as a consequence1 of the
 hands thereto attached4 ,at first blush

 it seems as if a continually-moving    
governor1 such as is in use on steam    
engines1 for example1 ought to fulfil   
the conditions1 and attempts have       
accordingly been made upon this line    
with results which have proven entirely 
unsatisfactory4  ,having thoroughly     
sifted the many varieties at hand1 it   
has been finally determined that the    
only means known to provide the most    
regular flow of power consists in       
intermittently interrupting the         
procession of the wheel-work1 and       
thereby gaining a periodically uniform  
movement4 ,whatever may be the system or
 kind of escapement employed1 the       
functioning of the mechanism is         
characterized by the suspension1 at     
regular intervals1 of the rotation of   
the last wheel of the train and in      
transmitting to a regulator1 be it a    
balance or a pendulum1 the power sent   
into that wheel4   ,,escapement ,,the   
,,most ,,essential ,,part4  ,of all the 
parts of the timepiece the escapement is

 then the most essential2 it is the part
 which assures regularity in the running
 of the watch or clock1 and that part of
 parts that endows the piece with real  
value4 ,the most perfect escapement     
would be that one which should perform  
its duty with the least influence upon  
the time of oscillation or vibration of 
the regulating organ4 ,the stoppage of  
the train by the escapement is brought  
about in different ways1 which may be   
gathered under three heads or           
categories4 ,in the two which we shall  
mention first1 the stop is effected     
directly upon the axis of the regulator1
 or against a piece which forms a part  
of that axis2 the tooth of the escape   
wheel at the moment of its disengagement
 remains supported upon or against that 
stop4  ,in the first escapement invented
 and1 indeed1 in some actually employed 
to-day for certain kinds of timekeepers1
 we notice during the locking a         
retrograde movement of the escape wheel2
 to this kind of movement has been given

 the name of recoil escapement4 ,it was 
recognized by the fraternity that this  
recoil was prejudicial to the regularity
 of the running of the mechanism and1   
after the invention of the pendulum and 
the spiral1 inventive makers succeeded  
in replacing this sort of escapement    
with one which we now call the dead-beat
 escapement4 ,in this latter the wheel1 
stopped by the axis of the regulator1   
remains immovable up to the instant of  
its disengagement or unlocking4  ,in the
 third category have been collected all 
those forms of escapement wherein the   
escape wheel is locked by an            
intermediate piece1 independent of the  
regulating organ4 ,this latter performs 
its vibrations of oscillation quite     
without interference1 and it is only in 
contact with the train during the very  
brief moment of impulse which is needful
 to keep the regulating organ in motion4
 ,this category constitutes what is     
known as the detached escapement class4 
,of the recoil escapement the principal 

types are3 the verge escapement or      
crown-wheel escapement for both watches 
and clocks1 and the recoil anchor       
escapement for clocks4 ,the cylinder and
 duplex escapements for watches and the 
,graham anchor escapement for clocks are
 styles of the dead-beat escapement most
 often employed4 ,among the detached    
escapements we have the lever and detent
 or chronometer escapements for watches2
 for clocks there is no fixed type of   
detached lever and it finds no          
application to-day4   ,,the ,,verge     
,,escapement4  ,the verge escapement1   
called also the crown-wheel escapement1 
is by far the simplest and presents the 
least difficulty in construction4 ,we   
regret that the world does not know     
either the name of its originator nor   
the date at which the invention made its
 first appearance1 but it seems to have 
followed very closely upon the birth of 
mechanical horology4  ,up to #agej it   
was employed to the exclusion of almost 
all the others4 ,in #ahej a very large  

part of the ordinary commercial watches 
were still fitted with the verge        
escapement1 and it is still used under  
the form of recoil anchor in clocks1    
eighty years after the invention of the 
cylinder escapement1 or in #ahjb4       
,ferdinand ,berthoud1 in his ,history of
 the ,measurement of ,time1 says of the 
balance-wheel escapement3 ,since the    
epoch of its invention an infinite      
variety of escapements have been        
constructed1 but the one which is       
employed in ordinary watches for        
every-day use is still the best4 ,in    
referring to our illustrations1 we beg  
first to call attention to the plates   
marked ,figs4 #ade and #adf4 ,this plate
 gives us two views of a verge          
escapement2 that is1 a balance wheel and
 a verge formed by its two opposite     
pallets4 ,the views are intentionally   
presented in this manner to show that   
the verge ,v may be disposed either     
horizontally1 as in ,fig4 #adf1 or      
vertically1 as in ,fig4 #ade4           

,illustration3 ,figs4 #ade and #adf     
,illustration3 ,fig4 #adg  ,let us      
imagine that our drawing is in motion1  
then will the tooth d1 of the crown     
wheel ,r1 be pushing against the pallet 
,p1 and just upon the point of slipping 
by or escaping1 while the opposite tooth
 e is just about to impinge upon the    
advancing pallet ,p'4 ,this it does1 and
 will at first1 through the impulse     
received from the tooth d be forced back
 by the momentum of the pallet1 that is1
 suffer a recoil2 but on the return     
journey of the pallet ,p'1 the tooth e  
will then add its impulse to the        
receding pallet4 ,the tooth e having    
thus accomplished its mission1 will now 
slip by and the tooth c will come in    
lock with the pallet ,p and1 after the  
manner just described for e1 continue   
the escapement4 ,usually these escape   
wheels are provided with teeth to the   
number of #aa1 #ac or #ae1 and always   
uneven4 ,a great advantage possessed by 
this form of escapement is that it does 

not require any oil1 and it may be made 
to work even under very inferior        
construction4   ,,oldest ,,arrangement  
,,of ,a ,,crown-,,wheel ,,escapement4   
,illustration3 ,fig4 #adh  ,plate #adg  
shows us the oldest known arrangement of
 a crown-wheel escapement in a clock4 ,r
 is the crown wheel or balance wheel    
acting upon the pallets ,p and ,p'1     
which form part of the verge ,v4 ,this  
verge is suspended as lightly as        
possible upon a pliable cord ,c and     
carries at its upper end two arms1 ,b   
and ,b1 called adjusters1 forming the   
balance4 ,two small weights ,d ,d1      
adapted to movement along the rules or  
adjusters serve to regulate the duration
 of a vibration4 ,in ,fig4 #adh we have 
the arrangement adopted in small        
timepieces and watches3 ,b represents   
the regulator in the form of a circular 
balance1 but not yet furnished with a   
spiral regulating spring2 c is the last 
wheel of the train and called the fourth
 wheel1 it being that number distant    

from the great wheel4 ,as will be seen1 
the verge provided with its pallets is  
vertically placed1 as in the preceding  
plate4  ,illustration3 ,fig4 #adi  ,here
 it will quickly be seen that regarded  
from the standpoint of regularity of    
motion1 this arrangement can be         
productive of but meager results4       
,subjected as it is to the influence of 
the slightest variation in the motive   
power and of the least jar or shaking1 a
 balance wheel escapement improvided    
with a regulator containing within      
itself a regulating force1 could not    
possibly give forth anything else than  
an unsteady movement4 ,however1         
mechanical clocks fitted with this      
escapement offer indisputable advantages
 over the ancient clepsydra2 in spite of
 their imperfections they rendered      
important services1 especially after the
 striking movement had been added4 ,for 
more than three centuries both this     
crude escapement and the cruder         
regulator were suffered to continue in  

this state without a thought of         
improvement2 even in #afjj1 when        
,galileo discovered the law governing   
the oscillation of the pendulum1 they   
did not suspect how important this      
discovery was for the science of time   
measurement4   ,,galileo',s             
,,experiments4  ,illustration3 ,fig4    
#aej  ,galileo1 himself1 in spite of his
 genius for investigation1 was so       
engrossed in his researches that he     
could not seem to disengage the simple  
pendulum from the compound pendulums to 
which he devoted his attention2 besides1
 he attributed to the oscillation an    
absolute generality of isochronism1     
which they did not possess2 nor did he  
know how to apply his famous discovery  
to the measurement of time4 ,in fact1 it
 was not till after more than half a    
century had elapsed1 in #afeg1 to be    
exact1 that the celebrated ,dutch       
mathematician and astronomer1 ,huygens1 
published his memoirs in which he made  
known to the world the degree of        

perfection which would accrue to clocks 
if the pendulum were adopted to regulate
 their movement4  ,illustration3 ,fig4  
#aea  ,an attempt was indeed made to    
snatch from ,huygens and confer upon    
,galileo the glory of having first      
applied the pendulum to a clock1 but    
this attempt not having been made until 
some time after the publication of      
,huygens' ,memoirs1 it was impossible to
 place any faith in the contention4 ,if 
,galileo had indeed solved the beautiful
 problem1 both in the conception and the
 fact1 the honor of the discovery was   
lost to him by the laziness and         
negligence of his pupil1 ,viviani1 upon 
whom he had placed such high hopes4 ,one
 thing is certain1 that the right of    
priority of the discovery and the       
recognition of the entire world has been
 incontestably bestowed upon ,huygens4  
,the escapement which ,galileo is       
supposed to have conceived and to which 
he applied the pendulum1 is shown in    
,fig4 #adi4 ,the wheel ,r is supplied   

with teeth1 which lock against the piece
 ,d attached to a lever pivoted at a1   
and also with pins calculated to impart 
impulses to the pendulum through the    
pallet ,p4 ,the arm ,l serves to        
disengage or unlock the wheel by lifting
 the lever ,d upon the return           
oscillation of the pendulum4            
,illustration3 ,fig4 #aeb               
,illustration3 ,fig4 #aec  ,a careful   
study of ,fig4 #aej will discover a     
simple transposition which it became    
necessary to make in the clocks1 for the
 effectual adaptation of the pendulum to
 their regulation4 ,the verge ,v was set
 up horizontally and the pendulum ,b1   
suspended freely from a flexible cord1  
received the impulses through the       
intermediation of the forked arm ,f1    
which formed a part of the verge4 ,at   
first this forked arm was not thought   
of1 for the pendulum itself formed a    
part of the verge4 ,a far-reaching step 
had been taken1 but it soon became      
apparent that perfection was still a    

long way off4 ,the crown-wheel          
escapement forcibly incited the pendulum
 to wider oscillations2 these           
oscillations not being as ,galileo had  
believed1 of unvaried durations1 but    
they varied sensibly with the intensity 
of the motive power4   ,,the            
,,attainment ,,of ,,isochronism ,,by    
,,huygens4  ,huygens rendered his       
pendulum isochronous2 that is1 compelled
 it to make its oscillations of equal   
duration1 whatever might be the arc     
described1 by suspending the pendulum   
between two metallic curves c c'1 each  
one formed by an arc of a cycloid and   
against which the suspending cord must  
lie upon each forward or backward       
oscillation4 ,we show this device in    
,fig4 #aea4 ,in great oscillations1 and 
by that we mean oscillations under a    
greater impulse1 the pendulum would thus
 be shortened and the shortening would  
correct the time of the oscillation4    
,however1 the application of an exact   
cycloidal arc was a matter of no little 

difficulty1 if not an impossibility in  
practice1 and practical men began to    
grope about in search of an escapement  
which would permit the use of shorter   
arcs of oscillation4 ,at ,london the    
horologist1 ,g4 ,clement1 solved the    
problem in #afge with his rack          
escapement and recoil anchor4 ,in the   
interval other means were invented1     
especially the addition of a second     
pendulum to correct the irregularities  
of the first4 ,such an escapement is    
pictured in ,fig4 #aeb4 ,the verge is   
again vertical and carries near its     
upper end two arms ,d ,d1 which are each
 connected by a cord with a pendulum4   
,the two pendulums oscillate constantly 
in the inverse sense the one to the     
other4  ,illustration3 ,fig4 #aed       
,illustration3 ,fig4 #aee   ,,another   
,,two-,,pendulum ,,escapement4  ,we show
 another escapement with two pendulums  
in ,fig4 #aec4 ,these are fixed directly
 upon two axes1 each one carrying a     
pallet ,p ,p' and a segment of a toothed

 wheel ,d ,d1 which produces the effect 
of solidarity between them4 ,the two    
pendulums oscillate inversely one to the
 other1 and one after the other receives
 an impulse4 ,this escapement was       
constructed by ,jean ,baptiste          
,dutertre1 of ,paris4  ,fig4 #aed shows 
another disposition of a double         
pendulum4 ,while the pendulum here is   
double1 it has but one bob2 it receives 
the impulse by means of a double fork   
,f4 ,c ,c represents the cycloidal      
curves and are placed with a view of    
correcting the inequality in the        
duration of the oscillations4 ,in       
watches the circular balances did not   
afford any better results than the      
regulating rods or rules of the clocks1 
and the pendulum1 of course1 was out of 
the question altogether2 it therefore   
became imperative to invent some other  
regulating system4  ,illustration3 ,fig4
 #aef  ,illustration3 ,fig4 #aeg  ,it   
occured to the ,abb d',hautefeuille to  
form a sort of resilient mechanism by   

attaching one end of a hog's bristle to 
the plate and the other to the balance  
near the axis4 ,though imperfect in     
results1 this was nevertheless a        
brilliant idea1 and it was but a short  
step to replace the bristle with a      
straight and very flexible spring1 which
 later was supplanted by one coiled up  
like a serpent2 but in spite of this    
advancement1 the watches did not keep   
much better time4 ,harrison1 the        
celebrated ,english horologist1 had     
recourse to two artifices1 of which the 
one consisted in giving to the pallets  
of the escapement such a curvature that 
the balance could be led back with a    
velocity corresponding to the extension 
of the oscillation2 the second consisted
 of an accessory piece1 the resultant   
action of which was analogous to that of
 the cycloidal curves in connection with
 the pendulum4   ,,correcting           
,,irregularities ,,in ,,the ,,verge     
,,escapement4  ,huygens attempted to    
correct these irregularities in the     

verge escapement in watches by          
amplifying the arc of oscillation of the
 balance itself4 ,he constructed for    
that purpose a pirouette escapement     
shown in ,fig4 #aee1 in which a toothed 
wheel ,a adjusted upon the verge ,v     
serves as an intermediary between that  
and the balance ,b1 upon the axis of    
which was fixed a pinion ,d4 ,by this   
method he obtained extended arcs of     
vibration1 but the vibrations were1 as a
 consequence1 very slow1 and they still 
remained subject to all the             
irregularities arising from the         
variation in the motive power as well as
 from shocks4 ,a little later1 but about
 the same epoch1 a certain ,dr4 ,hook1  
of the ,royal ,society of ,london1      
contrived another arrangement by means  
of which he succeeded1 so it appeared to
 him at least1 in greatly diminishing   
the influence of shock upon the         
escapement2 but many other1 perhaps     
greater1 inconveniences caused his      
invention to be speedily rejected4 ,we  

shall give our readers an idea of what  
,dr4 ,hook's escapement was like4       
,illustration3 ,fig4 #aeh               
,illustration3 ,fig4 #aei  ,on looking  
at ,fig4 #aef we see the escape wheel   
,r1 which was flat and in the form of a 
ratchet2 it was provided with two       
balances4 ,b ,b engaging each other in  
teeth1 each one carrying a pallet ,p ,p'
 upon its axis2 the axes of the three   
wheels being parallel4 ,now1 in our     
drawing1 the tooth a of the escape wheel
 exerts its lift upon the pallet ,p'2   
when this tooth escapes the tooth b will
 fall upon the pallet ,p' on the        
opposite side1 a recoil will be produced
 upon the action of the two united      
balances1 then the tooth b will give its
 impulse in the contrary direction4     
,considerable analogy exists between    
this form of escapement and that shown  
in ,fig4 #aec and intended for clocks4  
,this was the busy era in the           
watchmaker's line4 ,all the great heads 
were pondering upon the subject and     

everyone was on the qui vive for the    
newest thing in the art4  ,in #afgd     
,huygens brought out the first watch    
having a regulating spring in the form  
of a spiral2 the merit of this invention
 was disputed by the ,english savant1   
,dr4 ,hook1 who pretended1 as did       
,galileo1 in the application of the     
pendulum1 to have priority in the idea4 
,huygens1 who had discovered and        
corrected the irregularities in the     
oscillations of the pendulum1 did not   
think of those of the balance with the  
spiral spring4 ,and it was not until the
 close of the year #agej that ,pierre   
,le ,roy and ,ferdinand ,berthoud       
studied the conditions of isochronism   
pertaining to the spiral4   ,,an        
,,invention ,,that ,,created ,,much     
,,enthusiasm4  ,however that may be1    
this magnificent invention1 like the    
adaptation of the pendulum1 was welcomed
 with general enthusiasm throughout the 
scientific world3 without spiral and    
without pendulum1 no other escapement   

but the recoil escapement was possible2 
a new highway was thus opened to the    
searchers4 ,the water clocks 7clepsydr7 
and the hour glasses disappeared        
completely1 and the timepieces which had
 till then only marked the hours1 having
 been perfected up to the point of      
keeping more exact time1 were graced    
with the addition of another hand to    
tell off the minutes4  ,illustration3   
,fig4 #afj  ,illustration3 ,fig4 #afa   
,it was not until #afie that the first  
dead-beat escapement appeared upon the  
scene2 during the interval of over      
twenty years all thought had been       
directed toward the one goal1 viz43 the 
perfecting of the verge escapement2 but 
practice demonstrated that no other     
arrangement of the parts was superior to
 the original idea4 ,for the benefit of 
our readers we shall give a few of these
 attempts at betterment1 and you may see
 for yourselves wherein the trials      
failed4  ,fig4 #aeg represents a verge  
escapement with a ratchet wheel1 the    

pallets ,p ,p' being carried upon       
separate axes4 ,the two axes are rigidly
 connected1 the one to the other1 by    
means of the arms o o'4 ,one of the axes
 carries besides the fork ,f1 which     
transmits the impulse to the pendulum   
,b4 ,in the front view1 at the right of 
the plate1 for the sake of clearness the
 fork and the pendulum are not shown1   
but one may easily see the jointure of  
the arms o o' and their mode of         
operation4  ,another very peculiar      
arrangement of the verge escapement we  
show at ,fig4 #aeh4 ,in this there are  
two wheels1 one1 ,r'1 a small one in the
 form of a ratchet2 the other1 ,r1      
somewhat larger1 called the balance     
wheel1 but being supplied with straight 
and slender teeth4 ,the verge ,v        
carrying the two pallets is pivoted in  
the vertical diameter of the larger     
wheel4 ,the front view shows the modus  
operandi of this combination1 which is  
practically the same as the others4 ,the
 tooth a of the large wheel exerts its  

force upon the pallet ,p1 and the tooth 
b of the ratchet will encounter the     
pallet ,p'4 ,this pallet1 after         
suffering its recoil1 will receive the  
impulse communicated by the tooth b4    
,this escapement surely could not have  
given much satisfaction1 for it offers  
no advantage over the others1 besides it
 is of very difficult construction4     
,illustration3 ,fig4 #afb               
,illustration3 ,fig4 #afc   ,,ingenious 
,,attempts ,,at ,,solution ,,of ,a      
,,difficult ,,problem4  ,much ingenuity 
to a worthy end1 but of little practical
 value1 is displayed in these various   
attempts at the solution of a very      
difficult problem4 ,in ,fig4 #aei we    
have a mechanism combining two escape   
wheels engaging each other in gear2 of  
the two wheels1 ,r ,r'1 one alone is    
driven directly by the train1 the other 
being turned in the opposite direction  
by its comrade4 ,both are furnished with
 pins c c'1 which act alternately upon  
the pallets ,p ,p' disposed in the same 

plane upon the verge ,v and pivoted     
between the wheels4 ,our drawing        
represents the escapement at the moment 
when the pin ,c' delivers its impulse1  
and this having been accomplished1 the  
locking takes place upon the pin ,c of  
the other wheel upon the pallet ,p'4    
,another system of two escape wheels is 
shown in ,fig4 #afj1 but in this case   
the two wheels ,r ,r are driven in a    
like direction by the last wheel ,a of  
the train4 ,the operation of the        
escapement is the same as in ,fig4 #aei4
  ,illustration3 ,fig4 #afd             
,illustration3 ,fig4 #afe  ,in ,fig4    
#afa we have a departure from the road  
ordinarily pursued4 ,here we see an     
escapement combining two levers1        
invented by the ,chevalier de ,bthune   
and applied by ,m4 ,thiout1             
master-horologist1 at ,paris in #agbg4  
,p ,p' are the two levers or pallets    
separately pivoted4 ,upon the axis ,v1  
of the lever ,p1 is fixed a fork which  
communicates the motion to the pendulum4

 ,the two levers are intimately         
connected by the two arms ,b ,b'1 of    
which the former carries an adjusting   
screw1 a well-conceived addition for    
regulating the opening between the      
pallets4 ,the counter-weight ,c compels 
constant contact between the arms ,b    
,b'4 ,the function is always the same1  
the recoil and the impulsion operate    
upon the two pallets simultaneously4    
,this escapement enjoyed a certain      
degree of success1 having been employed 
by a number of horologists who modified 
it in various ways4   ,,various         
,,modifications  ,some of these         
modifications we shall show4 ,for the   
first example1 then1 let ,fig4 #afb     
illustrate4 ,in this arrangement the    
fork is carried upon the axis of the    
pallet ,p'1 which effectually does away 
with the counter-weight ,c1 as shown4   
,somewhat more complicated1 but of the  
same intrinsic nature1 is the           
arrangement displayed in ,fig4 #afc4 ,we
 should not imagine that it enjoyed a   

very extensive application4 ,here the   
two levers are completely independent of
 each other2 they act upon the piece ,b 
,b upon the axis ,v of the fork4 ,the   
counter-weights ,c ,c' maintain the arms
 carrying the rollers ,d ,d' in contact 
with the piece ,b ,b' which thus        
receives the impulse from the wheel ,r4 
,two adjusting screws serve to place the
 escapement upon the center4 ,by degrees
 these fantastic constructions were     
abandoned to make way for the anchor    
recoil escapement1 which was invented1  
as we have said1 in #afge1 by ,g4       
,clement1 a horologist1 of ,london4 ,in 
,fig4 #afd we have the disposition of   
the parts as first arranged by this     
artist4 ,here the pallets are replaced  
by the inclines ,a and ,b of the anchor1
 which is pivoted at ,v upon an axis to 
which is fixed also the fork4 ,the tooth
 a escapes from the incline or lever ,a1
 and the tooth b immediately rests upon 
the lever ,b2 by the action of the      
pendulum the escape wheel suffers a     

recoil as in the pallet escapement1 and 
on the return of the pendulum the tooth 
c gives out its impulse in the contrary 
direction4 ,with this new system it     
became possible to increase the weight  
of the bob and at the same time lessen  
the effective motor power4 ,the travel  
of the pendulum1 or arc of oscillation1 
being reduced in a marked degree1 an    
accuracy of rate was obtained far       
superior to that of the crown-wheel     
escapement4 ,however1 this new          
application of the recoil escapement was
 not adopted in ,france until #afie4    
,illustration3 ,fig4 #aff               
,illustration3 ,fig4 #afg  ,the travel  
of the pendulum1 though greatly reduced1
 still surpassed in breadth the arc in  
which it is isochronous1 and repeated   
efforts were made to give such shape to 
the levers as would compel its          
oscillation within the arc of equal     
time2 a motion which is1 as was         
recognized even at that epoch1 the prime
 requisite to a precise rating4 ,thus1  

in #agbj1 ,julien ,leroy occupied       
himself working out the proper shapes   
for the inclines to produce this desired
 isochronism4 ,searching along the same 
path1 ,ferd4 ,berthoud constructed an   
escapement represented by the ,fig4     
#afe4 ,in it we see the same inclines ,a
 ,b of the former construction1 but the 
locking is effected against the slides  
,c and ,d1 the curved faces of which    
produce isochronous oscillations of the 
pendulum4 ,the tooth b imparts its lift 
and the tooth c will lock against the   
face ,c2 after having passed through its
 recoil motion this tooth c will butt   
against the incline ,a and work out its 
lift or impulse upon it4   ,,the ,,gable
 ,,escapement4  ,illustration3 ,fig4    
#afh  ,illustration3 ,fig4 #afi  ,the   
gable escapement1 shown in ,fig4 #aff1  
allows the use of a heavier pendulum1 at
 the same time the anchor embraces      
within its jaws a greater number of the 
escape-wheel teeth2 an arrangement after
 this manner leads to the conclusion    

that with these long levers of the      
anchor the friction will be considerably
 increased and the recoil faces will1 as
 a consequence1 be quickly worn away4   
,without doubt1 this was invented to    
permit of opening and closing the       
contact points of the anchor more       
easily4 ,under the name of the ,english 
recoil anchor there came into use an    
escapement with a reduced gable1 which  
embraced fewer teeth between the pallets
 or inclines2 we give a representation  
of this in ,fig4 #afg4 ,this system     
seems to have been moderately           
successful4 ,the anchor recoil          
escapement in use in ,germany to-day is 
demonstrated in ,fig4 #afh2 this        
arrangement is also found in the        
,american clocks4 ,as we see1 the anchor
 is composed of a single piece of curved
 steel bent to the desired curves4      
,clocks provided with this escapement   
keep reasonably good time2 the          
resistance of the recoils compensate in 
a measure for the want of isochronism in

 the oscillations of the pendulum4      
,ordinary clocks require considerably   
more power to drive them than finer     
clocks and1 as a consequence1 their     
ticking is very noisy4 ,several means   
have been employed to dampen this noise1
 one of which we show in ,fig4 #afi4    
,illustration3 ,fig4 #agj  ,here the    
anchor is composed of two pieces1 ,a ,b1
 screwed upon a plate ,h pivoting at ,v4
 ,in their arrangement the two pieces   
represent1 as to distance and curvature1
 the counterpart of ,fig4 #afh4 ,at the 
moment of impact their extreme ends     
recoil or spring back from the shock of 
the escape teeth1 but the resiliency of 
the metal is calculated to be strong    
enough to return them immediately to the
 contact studs e e4  ,as a termination  
to this chapter1 we shall mention the   
use made at the present day of the      
recoil lever escapement in repeating    
watches4 ,we give a diagram of this     
construction in ,fig4 #agj4 ,the lever  
here is intended to restrain and        

regulate the motion of the small        
striking work4 ,it is pivoted at ,v and 
is capable of a very rapid oscillatory  
motion1 the arc of which may1 however1  
be fixed by the stud or stop ,d1 which  
limits the swing of the fly ,c4 ,this   
fly is of one piece with the lever and1 
together with the stud ,d1 determines   
the angular motion of the lever4 ,if the
 angle be large that means the path of  
the fly be long1 then the striking train
 will move slowly2 but if the teeth of  
the escape wheel ,r can just pass by    
without causing the lever to describe a 
supplementary or extended arc1 the      
striking work will run off rapidly4     
,,chapter ,v4  ,,putting ,,in ,a ,,new  
,,cylinder4   ,putting in a new cylinder
 is something most watchmakers fancy    
they can do1 and do well2 but still it  
is a job very few workmen can do and    
fulfill all the requirements a job of   
this kind demands under the ever-varying
 conditions and circumstances presented 
in repairs of this kind4 ,it is well to 

explain somewhat at this point3 ,suppose
 we have five watches taken in with     
broken cylinders4 ,out of this number   
probably two could be pivoted to        
advantage and make the watches as good  
as ever4 ,as to the pivoting of a       
cylinder1 we will deal with this later  
on4 ,the first thing to do is to make an
 examination of the cylinder1 not only  
to see if it is broken1 but also to     
determine if pivoting is going to bring 
it out all right4 ,let us imagine that  
some workman has1 at some previous time1
 put in a new cylinder1 and instead of  
putting in one of the proper size he has
 put one in too large or too small4     
,now1 in either case he would have to   
remove a portion of the escape-wheel    
tooth1 that is1 shorten the tooth3      
because1 if the cylinder was too large  
it would not go in between the teeth1   
and consequently the teeth would have to
 be cut or stoned away4 ,if the cylinder
 was too small1 again the teeth would   
have to be cut away to allow them to    

enter the cylinder4 ,all workmen have   
traditions1 rules some call them1 that  
they go by in relation to the right way 
to dress a cylinder tooth2 some         
insisting that the toe or point of the  
tooth is the only place which should be 
tampered with4 ,other workmen insist    
that the heel of the tooth is the proper
 place4 ,now1 with all due              
consideration1 we would say that in     
ninety-nine cases out of a hundred the  
proper thing to do is to let the        
escape-wheel teeth entirely alone4 ,as  
we can understand1 after a moment's     
thought1 that it is impossible to have  
the teeth of the escape wheel too long  
and have the watch run at all2 hence1   
the idea of stoning a cylinder          
escape-wheel tooth should not be        
tolerated4   ,,escape-,,wheel ,,teeth   
vs4 ,,cylinder4  ,it will not do1       
however1 to accept1 and take it for     
granted that the escape-wheel teeth are 
all right1 because in many instances    
they have been stoned away and made too 

short2 but if we accept this condition  
as being the case1 that is1 that the    
escape-wheel teeth are too short1 what  
is the workman going to do about it8    
,the owner of the watch will not pay for
 a new escape wheel as well as a new    
cylinder4 ,the situation can be summed  
up about in this way1 that we will have 
to make the best we can out of a bad    
job1 and pick out and fit a cylinder on 
a compromise idea4  ,in regard to       
picking out a new cylinder1 it may not  
do to select one of the same size as the
 old one1 from the fact that the old one
 may not have been of the proper size   
for the escape wheel1 because1 even in  
new1 cheap watches1 the workmen who run 
in the escapement knew very well the    
cylinder and escape wheel were not      
adapted for each other1 but they were   
the best he had4 ,chapter ,,ii1 on the  
cylinder escapement1 will enable our    
readers to master the subject and hence 
be better able to judge of allowances to
 be made in order to permit imperfect   

material to be used4  ,in illustration1 
let us imagine that we have to put in a 
new cylinder1 and we have none of       
precisely the proper size1 but we have  
them both a mere trifle too large and   
too small1 and the question is which to 
use4 ,our advice is to use the smaller  
one if it does not require the          
escape-wheel teeth to be dressed1 that  
is1 made smaller4 ,why we make this     
choice is based on the fact that the    
smaller cylinder shell gives less       
friction1 and the loss from drop--that  
is1 side play between the escape-wheel  
teeth and the cylinder--will be the same
 in both instances except to change the 
lost motion from inside to outside drop4
  ,in devising a system to be applied to
 selecting a new cylinder1 we meet the  
same troubles encountered throughout all
 watchmakers' repair work1 and chief    
among these are good and convenient     
measuring tools4 ,but even with perfect 
measuring tools we would have to        
exercise good judgment1 as just         

explained4 ,in ,chapter ,,ii we gave a  
rule for determining the outside        
diameter of a cylinder from the diameter
 of the escape wheel2 but such rules and
 tables will1 in nine instances out of  
ten1 have to be modified by attendant   
circumstances--as1 for instance1 the    
thickness of the shell of the cylinder1 
which should be one-tenth of the outer  
diameter of the shell1 but the shell is 
usually thicker4 ,a tolerably safe      
practical rule and one also depending   
very much on the workman's good judgment
 is1 when the escape-wheel teeth have   
been shortened1 to select a cylinder    
giving ample clearance inside the shell 
to the tooth1 but by no means large     
enough to fill the space between the    
teeth4 ,after studying carefully the    
instructions just given we think the    
workman will have no difficulty in      
selecting a cylinder of the right       
diameter4   ,,measuring ,,the ,,heights4
  ,the next thing is to get the proper  
heights4 ,this is much more easily      

arrived at3 the main measurement being  
to have the teeth of the escape wheel   
clear the upper face of the lower plug4 
,in order to talk intelligently we will 
make a drawing of a cylinder and agree  
on the proper names for the several     
parts to be used in this chapter4 ,such 
drawing is shown at ,fig4 #aga4 ,the    
names are3 ,the hollow cylinder1 made up
 of the parts ,a ,a' ,a'' ,a'''1 called 
the shell--,a is the great shell1 ,a'   
the half shell1 ,a'' the banking slot1  
and ,a''' the small shell4 ,the brass   
part ,d is called the collet and        
consists of three parts--the hairspring 
seat ,d1 the balance seat ,d' and the   
shoulder ,d''1 against which the balance
 is riveted4  ,illustration3 ,fig4 #aga 
,the first measurement for fitting a new
 cylinder is to determine the height of 
the lower plug face1 which corresponds  
to the line x x1 ,fig4 #aga4 ,the height
 of this face is such as to permit the  
escape wheel to pass freely over it4 ,in
 selecting a new cylinder it is well to 

choose one which is as wide at the      
banking slot ,a'' as is consistent with 
safety4 ,the width of the banking slot  
is represented by the dotted lines x u4 
,the dotted line v represents the length
 to which the lower pivot y is to be    
cut4  ,illustration3 ,fig4 #agb         
,illustration3 ,fig4 #agc  ,there are   
several little tools on the market used 
for making the necessary measurements1  
but we will describe a very simple one  
which can readily be made4 ,to do so1   
take about a ,no4 #e sewing needle and1 
after annealing1 cut a screw thread on  
it1 as shown at ,fig1 #agb1 where ,e    
represents the needle and t t the screw 
cut upon it4 ,after the screw is cut1   
the needle is again hardened and        
tempered to a spring temper and a long1 
thin pivot turned upon it4 ,the needle  
is now shaped as shown at ,fig4 #agc4   
,the pivot at s should be small enough  
to go easily through the smallest hole  
jewel to be found in cylinder watches1  
and should be about #a_/af long4 ,the   

part at r should be about #c_/af long   
and only reduced in size enough to fully
 remove the screw threads shown at t4   
,illustration3 ,fig4 #agd               
,illustration3 ,fig4 #age               
,illustration3 ,fig4 #agf               
,illustration3 ,fig4 #agg  ,we next     
provide a sleeve or guard for our gage4 
,to do this we take a piece of hard     
brass bushing wire about  long and1     
placing it in a wire chuck1 center and  
drill it nearly the entire length1      
leaving1 say1 #a_/aj at one end to be   
carried through with a small drill4 ,we 
show at ,f1 ,fig4 #agd1 a magnified     
longitudinal section of such a sleeve4  
,the piece ,f is drilled from the end l 
up to the line q with a drill of such a 
size that a female screw can be cut in  
it to fit the screw on the needle1 and  
,f is tapped out to fit such a screw    
from l up to the dotted line p4 ,the    
sleeve ,f is run on the screw t and now 
appears as shown at ,fig4 #age1 with the
 addition of a handle shown at ,g ,g'4  

,it is evident that we can allow the    
pivot s to protrude from the sleeve ,f  
any portion of its length1 and regulate 
such protrusion by the screw t4 ,to     
employ this tool for getting the proper 
length to which to cut the pivot y1     
,fig4 #aga1 we remove the lower cap     
jewel to the cylinder pivot and1        
holding1 the movement in the left hand1 
pass the pivot s1 ,fig4 #age1 up through
 the hole jewel1 regulate the length by 
turning the sleeve ,f until the arm of  
the escape wheel ,i1 ,fig4 #agf1 will   
just turn free over it4 ,now the length 
of the pivot s1 which protrudes beyond  
the sleeve ,f1 coincides with the length
 to which we must cut the pivot y1 ,fig4
 #aga4 ,to hold a cylinder for reducing 
the length of the pivot y1 we hold said 
pivot in a pair of thin-edged cutting   
pliers1 as shown at ,fig4 #agg1 where ,n
 ,n' represent the jaws of a pair of    
cutting pliers and y the pivot to be    
cut4 ,the measurement is made by putting
 the pivot s between the jaws ,n ,n' as 

they hold the pivot4 ,the cutting is    
done by simply filing back the pivot    
until of the right length4   ,,turning  
,,the ,,pivots4  ,we have now the pivot 
y of the proper length1 and what remains
 to be done is to turn it to the right  
size4 ,we do not think it advisable to  
try to use a split chuck1 although we   
have seen workmen drive the shell ,a    
,a''' out of the collet ,d and then turn
 up the pivots y z in said wire chuck4  
,to our judgment there is but one chuck 
for turning pivots1 and this is the     
cement chuck provided with all ,american
 lathes4 ,many workmen object to a      
cement chuck1 but we think no man should
 lay claim to the name of watchmaker    
until he masters the mystery of the     
cement chuck4 ,it is not such a very    
difficult matter1 and the skill once    
acquired would not be parted with       
cheaply4 ,one thing has served to put   
the wax or cement chuck into disfavor1  
and that is the abominable stuff sold by
 some material houses for lathe cement4 

,the original cement1 made and patented 
by ,james ,bottum for his cement chuck1 
was made up of a rather complicated     
mixture2 but all the substances really  
demanded in such cement are ultramarine 
blue and a good quality of shellac4     
,these ingredients are compounded in the
 proportion of #h parts of shellac and  
#a part of ultramarine--all by weight4  
,,how ,,to ,,use ,a ,,cement ,,chuck4   
,the shellac is melted in an iron       
vessel1 and the ultramarine added and   
stirred to incorporate the parts4 ,care 
should be observed not to burn the      
shellac4 ,while warm1 the melted mass is
 poured on to a cold slab of iron or    
stone1 and while plastic made into      
sticks about  in diameter4              
,illustration3 ,fig4 #agh               
,illustration3 ,fig4 #agi  ,we show at  
,fig4 #agh a side view of the outer end 
of a cement chuck with a cylinder in    
position4 ,we commence to turn the lower
 pivot of a cylinder1 allowing the pivot
 z to rest at the apex of the hollow    

cone a1 as shown4 ,there is something of
 a trick in turning such a hollow cone  
and leaving no tit or protuberance in   
the center1 but it is important it      
should be done4 ,a little practice will 
soon enable one to master the job4 ,a   
graver for this purpose should be cut to
 rather an oblique point1 as shown at   
,l1 ,fig4 #agi4 ,the slope of the sides 
to the recess a1 ,fig4 #agh1 should be  
to about forty-five degrees1 making the 
angle at a about ninety degrees4 ,the   
only way to insure perfect accuracy of  
centering of a cylinder in a cement     
chuck is center by the shell1 which is  
done by cutting a piece of pegwood to a 
wedge shape and letting it rest on the  
,t-rest2 then hold the edge of the      
pegwood to the cylinder as the lathe    
revolves and the cement soft and        
plastic4 ,a cylinder so centered will be
 absolutely true4 ,the outline curve at 
c1 ,fig4 #agh1 represents the surface of
 the cement4  ,the next operation is    
turning the pivot to the proper size to 

fit the jewel4 ,this is usually done by 
trial1 that is1 trying the pivot into   
the hole in the jewel4 ,a quicker way is
 to gage the hole jewel and then turn   
the pivot to the right size1 as measured
 by micrometer calipers4 ,in some       
cylinder watches the end stone stands at
 some distance from the outer surface of
 the hole jewel2 consequently1 if the   
measurement for the length of the pivot 
is taken by the tool shown at ,fig4     
#age1 the pivot will apparently be too  
short4 ,when the lower end stone is     
removed we should take note if any      
allowance is to be made for such extra  
space4 ,the trouble which would ensue   
from not providing for such extra end   
shake would be that the lower edge of   
the half shell1 shown at e1 ,fig4 #aga1 
would strike the projection on which the
 stalk of the tooth is planted4 ,after  
the lower pivot is turned to fit the    
jewel the cylinder is to be removed from
 the cement chuck and the upper part    
turned4 ,the measurements to be looked  

to now are1 first1 the entire length of 
the cylinder1 which is understood to be 
the entire distance between the inner   
faces of the two end stones1 and        
corresponds to the distance between the 
lines v d1 ,fig4 #aga4 ,this measurement
 can be got by removing both end stones 
and taking the distance with a ,boley   
gage or a douzieme caliper4   ,a        
,,convenient ,,tool ,,for ,,length      
,,measurement4  ,illustration3 ,fig4    
#ahj  ,a pair of common pinion calipers 
slightly modified makes as good a pair  
of calipers for length measurement as   
one can desire4 ,this instrument is made
 by inserting a small screw in one of   
the blades--the head on the inner side1 
as shown at f1 ,fig4 #ahj4 ,the idea of 
the tool is1 the screw head f rests in  
the sink of the cap jewel or end stone1 
while the other blade rests on the cock 
over the balance4 ,after the adjusting  
screw to the caliper is set1 the spring 
of the blades allows of their removal4  
,the top pivot z of the cylinder is next

 cut to the proper length1 as indicated 
by the space between the screwhead f and
 the other blade of the pinion caliper4 
,the upper pinion z is held in the jaws 
of the cutting pliers1 as shown in ,fig4
 #agg1 the same as the lower one was    
held1 until the proper length between   
the lines d v1 ,fig4 #aga1 is secured1  
after which the cylinder is put back    
into the cement chuck1 as shown at ,fig4
 #agh1 except this time the top portion 
of the cylinder is allowed to protrude  
so that we can turn the top pivot and   
the balance collet ,d1 ,fig4 #aga4  ,the
 sizes we have now to look to is to fit 
the pivot z to the top hole jewel in the
 cock1 also the hairspring seat ,d and  
balance seat ,d'4 ,these are turned to  
diameters1 and are the most readily     
secured by the use of the micrometer    
calipers to be had of any large         
watchmakers' tool and supply house4 ,in 
addition to the diameters named1 we must
 get the proper height for the balance1 
which is represented by the dotted line 

b4 ,the measurement for this can usually
 be obtained from the old cylinder by   
simply comparing it with the new one as 
it rests in the cement chuck4 ,the true 
tool for such measurements is a height  
gage4 ,we have made no mention of       
finishing and polishing the pivots1 as  
these points are generally well         
understood by the trade4   ,,removing   
,,the ,,lathe ,,cement4  ,one point     
perhaps we might well say a few words   
on1 and this is in regard to removing   
the lathe cement4 ,such cement is       
usually removed by boiling in a copper  
dish with alcohol4 ,but there are       
several objections to the practice4 ,in 
the first place1 it wastes a good deal  
of alcohol1 and also leaves the work    
stained4 ,we can accomplish this        
operation quicker1 and save alcohol1 by 
putting the cylinder with the wax on it 
in a very small homeopathic bottle and  
corking it tight4 ,the bottle is then   
boiled in water1 and in a few seconds   
the shellac is dissolved away4 ,the     

balance to most cylinder watches is of  
red brass1 and in some instances of low 
karat gold2 in either case the balance  
should be repolished4 ,to do this dip in
 a strong solution of cyanide of        
potassium dissolved in water2 one-fourth
 ounce of cyanide in half pint of water 
is about the proper strength4 ,dip and  
rinse1 then polish with a chamois buff  
and rouge4  ,illustration3 ,fig4 #aha   
,in staking on the balance1 care should 
be observed to set the banking pin in   
the rim so it will come right2 this is  
usually secured by setting said pin so  
it stands opposite to the opening in the
 half shell4 ,the seat of the balance on
 the collet ,d should be undercut so    
that there is only an edge to rivet down
 on the balance4 ,this will be better   
understood by inspecting ,fig4 #aha1    
where we show a vertical section of the 
collet ,d and cylinder ,a4 ,at g g is   
shown the undercut edge of the balance  
seat1 which is folded over as the       
balance is rivetted fast4  ,about all   

that remains now to be done is to true  
up the balance and bring it to poise4   
,the practice frequently adopted to     
poise a plain balance is to file it with
 a half-round file on the inside1 in    
order not to show any detraction when   
looking at the outer edge of the rim4 ,a
 better and quicker plan is to place the
 balance in a split chuck1 and with a   
diamond or round-pointed tool scoop out 
a little piece of metal as the balance  
revolves4 ,in doing this1 the spindle of
 the lathe is turned by the hand        
grasping the pulley between the finger  
and thumb4 ,the so-called diamond and   
round-pointed tools are shown at o o'1  
,fig4 #ahb4 ,the idea of this plan of   
reducing the weight of a balance is1 one
 of the tools o is rested on the ,t-rest
 and pressed forward until a chip is    
started and allowed to enter until      
sufficient metal is engaged1 then1 by   
swinging down on the handle of the tool1
 the chip is taken out4  ,illustration3 
,fig4 #ahb  ,illustration3 ,fig4 #ahc   

,in placing a balance in a step chuck1  
the banking pin is caused to enter one  
of the three slots in the chuck1 so as  
not to be bent down on to the rim of the
 balance4 ,it is seldom the depth       
between the cylinder and escape wheel   
will need be changed after putting in a 
new cylinder2 if such is the case1      
however1 move the chariot--we mean the  
cock attached to the lower plate4 ,do   
not attempt to change the depth by      
manipulating the balance cock4 ,fig4    
#ahc shows1 at h h1 the form of chip    
taken out by the tool o o'1 ,fig4 #ahb4 
,,index     ,a    ,acid frosting1 #df   
,action drawings1 #ij    ,action of a   
chronometer escapement1 #adb    ,acting 
surface of entrance lip1 #abg           
,actions of cylinder escapement1 #aab   
,adhesion of parallel surfaces1 #id     
,adjustable pallets1 #ih    ,adjusting  
screw for drawing instruments1 #ba      
,analysis of principles involved in     
detent1 #acg    ,analysis of the action 
of a lever escapement1 #hf              

,angle-measuring device1 #fh    ,angular
 extent of shell of cylinder1 #abb      
,angular motion1 drawing an escapement  
to show1 #ia     ,how measured1 #fi     
,of escape wheel1 #cg    ,antagonistic  
influences1 #acc    ,arc of degrees1 #i 
,atmospheric disturbances1 #gd          
,attainment of isochronism1 #aei     ,b 
,balance1 how it controls timekeeping1  
#gc     ,weight and inertia of1 #acc    
,balance spring1 inventor of1 #acb      
,banking slot of cylinder1 #aab         
,bankings1 effect of opening too wide1  
#fc    ,bar compasses1 #ba              
,barometric pressure1 #gd    ,basis for 
close measurements1 #if     ,c          
,cement chuck1 how to use1 #agc         
,chronometer detent1 importance of light
 construction1 #acf    ,chronometer     
escapement1 #aca1 #aee     ,four        
principal parts of1 #acd    ,circular   
pallets1 #bg    ,club-tooth escapement1 
#cj1 #cd    ,club-tooth lever escapement
 with circular pallets and              
tangential lockings1 #hc    ,crown-wheel

 escapement1 #aee    ,cylinder1 drawing 
a1 #abj     ,outer diameter of1 #aaf    
,putting in a new1 #afi    ,cylinder    
escapement1 #aee     ,date of invention1
 etc41 #aaa     ,forms and proportions  
of several parts of1 #aaa     ,names of 
various parts1 #aab    ,cylinder lips1  
proper shape of1 #abd     ,d            
,dead-beat escapement1 #aca1 #ace       
,only one true1 #aab    ,depth1 between 
cylinder and escape wheel1 #abi         
,effect of changing1 #agf    ,designing 
a double roller1 #gg    ,detached       
escapement1 #aee    ,detent1 functions  
of the1 #acg    ,detent escapement1     
#aca1 #aee     ,faults in1 #acb         
,detent spring dimensions1 #ach         
,detent springs1 width of1 #adg         
,discharging jewel1 setting the1 #adb   
,discharging roller1 #acf    ,dividers1 
#i     ,making1 #aj    ,double pendulum1
 #afj    ,double-roller escapement1 #ge 
,draw defined1 #he    ,drawing-board1   
#aa    ,drawing instruments1 #i         
,drawings1 advantage of large1 #bi      

,drop and draw1 #aej    ,duplex         
escapement1 #aca1 #aee     ,e           
,elasticity of spring1 #acc    ,engaging
 friction1 #ha    ,english recoil       
anchor1 #afg    ,entrance lip of        
cylinder escapement1 #abe    ,escapement
 angles1 measuring1 #aja    ,escapement 
error1 study of1 #fd    ,escapement     
matching tool1 #ajf    ,escapement      
model1 #dj     ,balance1 #db            
,balance staff1 #dd     ,bridges1 #da1  
#db     ,escape wheel1 #dc     ,extra   
balance cock1 #de     ,frosting1 #df    
,hairspring1 #db     ,jewel for1 #dc    
,lower plate1 #da     ,main plate1 #da  
,movement for1 #da     ,pallet staff1   
#db     ,pillars1 #dc     ,regulator1   
#df     ,uses of1 #dd     ,wood base    
for1 #da    ,escapements compared1 #ajc 
,escapement of ,dutertre1 #afj          
,escape-wheel action1 #cj               
,escape-wheel1 delineating an1 #aa      
,escape-wheel teeth vs4 cylinder1 #afi  
,escape-wheel tooth in action1          
delineating an1 #abf    ,exit pallet1   

#bf    ,experiments of ,galileo1 #aeh   
,experiments with a chronometer1 #adb   
,extent of angular impulse1 #aah     ,f 
,fall defined1 #ajf    ,faults in the   
detent escapement1 #acb    ,fixed rules1
 of little value to student1 #acg       
,flexure of gold spring1 #adf    ,foot1 
fitting up the1 #aea    ,fork1 testing  
the1 #ga    ,fork action1 #cj           
,theory of1 #ei    ,fork and roller     
action1 #ed    ,formulas for delineating
 cylinder escapement1 #aae              
,frictions1 #bd    ,frictional          
escapement1 #aca1 #acb    ,frictional   
surfaces1 #fc    ,fusee1 #aca     ,g    
,gable escapement1 #afg    ,gage1 a new1
 #agb    ,graham anchor escapement1 #aee
    ,gold spring1 #adf    ,guard point1 
#gi     ,material for1 #gi    ,gummy    
secretion on impulse and discharging    
stones1 #adg     ,h    ,heights in      
cylinders1 how obtained1 #aga    ,hole  
jewels1 distance apart1 #adj     ,i     
,imaginary faults in cylinders1 #abi    
,impulse angle1 #aah    ,impulse arc1   

extent of1 #acd    ,impulse jewel set   
oblique1 #adg    ,impulse planes1       
locating outer angle of1 #ci    ,impulse
 roller1 #acf    ,incline of teeth1 #abb
    ,inertia of balance1 #acc           
,inventions of     ,berthoud1 #afc      
,bthune1 #afe     ,clement1 #aff        
,dr4 ,hook1 #afb     ,harrison1 #afa    
,hautefeuille1 #afa     ,huygens1 #aeh  
,leroy1 #afc     ,thiout1 #afe     ,j   
,jewel pin1 determining size1 #eh       
,cementing in1 #fg     ,settings1 #ff   
,jewel-pin setters1 #fg     ,l    ,lathe
 cement1 #agc     ,removing1 #age       
,lever1 proper length of1 #fa    ,lever 
fork1 horn of1 #fa     prongs of1 #fj   
,lift1 real and apparent1 #aab          
,lifting angle1 #aad    ,lock1 amount   
of1 #bh     ,defined1 #he    ,lock and  
drop testing1 #fi    ,locking jewel1    
moving the1 #adi    ,locking stone1 good
 form of1 #add    ,lower plate1 circular
 opening in1 #ef     ,m    ,marine      
chronometer1 number of beats to hour1   
#adh    ,mathematics1 #ie    ,measuring 

tools1 #aga    ,metal drawings1         
advantages of1 #adj    ,motion1 how     
obtained1 #af    ,movement holder1 #aaj 
,n    ,neutral lockings1 #hd     ,o     
,original designing1 #adh     ,p        
,pallet action1 locating the1 #ij       
,pallet-and-fork action1 #ab1 #ac1 #ag1 
#ah    ,pallet stones1 how to set1 #ajd 
,pallets1 adjusting to match the fork1  
#fe    ,paper for drawing1 #aa          
,parts1 relations of the1 #cb           
,passing hollow1 #fb    ,perfected lever
 escapement1 #hg    ,pivots1 turning1   
#agb    ,point of percussion1 #aci      
,points for drawing instruments1 #bj    
,polishing materials1 #eb    ,power     
leaks1 #af    ,power lost in lever      
escapement1 #hg    ,practical problems  
in the lever escapement1 #ih     ,r     
,radial extent of outside of cylinder1  
#abe    ,ratchet-tooth escape wheel1 #ab
    ,recoil anchor escapement1 #aee     
,recoil escapement1 #aed    ,reduced    
gable escapement1 #afg    ,retrograde   
motion1 #cf    ,roller action1 why #cj  

degrees1 #ee     ,of double roller1 #gh 
,roller diameter1 determining the1 #ee  
,ruling pen1 #i     ,s    ,safety       
action1 #ef    ,scale of inches1 #i     
,screws1 making extra large1 #de        
,screwheads1 fancy1 #de    ,selecting   
new cylinder1 #agj    ,shaping1         
advantages gained in1 #aaf    ,sheet    
steel1 cutting1 #dh    ,short fork1 #ajj
    ,sound as indicator of correct      
action1 #add    ,spring1 elasticity of1 
#acc    ,staking on a balance1 #age     
,steel1 polishing1 #di     ,tempering1  
#di    ,study drawings1 #abd    ,systems
 of measurements1 #aad     ,t           
,tangential lockings1 #hj1 #adh    ,test
 gage for angular movement1 #fe         
,theoretical action of double roller1   
#gf    ,timekeeping1 controlled by      
balance1 #gc    ,tool for length        
measurement1 #agd    ,tools1 measuring1 
#aga    ,triangle1 #ah    ,t-square1 #i 
,u    ,unlocking action1 #ef            
,unlocking roller1 #acf     ,v    ,verge
 escapement1 #aca1 #aee     ,w          

,weight and inertia of balance1 #acc    
,working model of cylinder escapement1  
#abc         99     99     99     99    
99     99    ,,the ,,watch ,,adjuster',s
 ,,manual  ,illustration  ,a ,complete  
and ,practical ,guide for ,watchmakers  
in ,adjusting ,watches and ,chronometers
 for ,isochronism1 ,position1 ,heat and 
,cold4   ,,by ,,charles ,,edgar ,,fritts
 7,,excelsior71  ,author of ,practical  
,hints on ,watch ,repairing1 ,practical 
,treatise on ,balance ,spring1          
,electricity and ,magnetism for         
,watchmakers1 etc41 etc4  ,this         
well-known work is now recognized as the
 standard authority on the adjustments  
and kindred subjects1 both here and in  
,england4 ,it contains an exhaustive    
consideration of the various theories   
proposed1 the mechanical principles on  
which the adjustments are based1 and the
 different methods followed in actual   
practice1 giving all that is publicly   
known in the trade1 with a large amount 
of entirely new practical matter not to 

be found elsewhere1 obtained from the   
best manufacturers and workmen1 as well 
as from the author's own studies and    
experiences4  ,sent postpaid to any part
 of the world on receipt of #b4ej 7#ajs4
 #e;d47    ,,the ,,keystone 7,,sole     
,,agent71   #ai,,th ,,and ,,brown       
,,streets1 ,,philadelphia1 ,u4,s4,a4    
99       99       99       99       99  
,,the ,,art ,,of ,,engraving            
,illustration  ,a ,complete ,treatise on
 the ,engraver's ,art1 with ,special    
,reference to ,letter and ,monogram     
,engraving4 ,specially ,compiled as a   
,standard ,text-,book for ,students and 
a ,reliable ,reference ,book for        
,engravers4  ,this work is the only     
thoroughly reliable and exhaustive      
treatise published on this important    
subject4 ,it is an ideal text-book1     
beginning with the rudiments and leading
 the student step by step to a complete 
and practical mastery of the art4 ,back 
of the authorship is a long experience  
as a successful engraver1 also a        

successful career as an instructor in   
engraving4 ,these qualifications ensure 
accuracy and reliability of matter1 and 
such a course of instruction as is best 
for the learner and qualified engraver4 
,the most notable feature of the new    
treatise is the instructive character of
 the illustrations4 ,there are over #bjj
 original illustrations by the author4  
,a very complete index facilitates      
reference to any required topic4  ,bound
 in ,silk ,cloth--#bjh ,pages and #baf  
,illustrations4  ,sent postpaid to any  
part of the world on receipt of price1  
#a4ej 7#fs4 #c;d47    ,,published ,,by  
,,the ,,keystone1   ,,the ,,organ ,,of  
,,the ,,jewelry ,,and ,,optical         
,,trades1   #ai,,th  ,,brown ,,sts41    
,,philadelphia1 ,u4,s4,a4           99  
99       99       99       99  ,,the    
,,keystone ,,portfolio ,,of ,,monograms 
,illustration3 ,c4,b4,r4  ,illustration3
 ,a4,o4,u4,w  ,illustration3 ,i4,r4,c4  
,illustration3 ,g4,h4,i4  ,this         
portfolio contains #aba combination     

designs4 ,these designs were selected   
from the best of those submitted in a   
prize competition held by ,the          
,keystone1 and will be found of value to
 every one doing engraving4  ,the       
designs are conceded to be the best in  
the market1 excelling in art and novelty
 of combination and skill in execution4 
,they are printed from steel plates on  
stiff1 durable paper1 and contain sample
 monograms in a variety of combinations4
  ,the portfolio is a bench requirement 
that no jeweler can afford to be        
without4 ,it is a necessary supplement  
to any text-book on letter engraving4   
,price1   #ej ,cents 7#bs47             
,,published ,,by ,,the ,,keystone1      
,,the ,,organ ,,of ,,the ,,jewelry ,,and
 ,,optical ,,trades1   #ai,,th  ,,brown 
,,sts41 ,,philadelphia1 ,u4,s4,a4       
99       99       99       99       99  
,,the ,,optician',s ,,manual  ,,vol4 ,i4
  ,,by ,c4,h4 ,,brown1 ,m4,d4  ,graduate
 ,university of ,pennsylvania2          
,professor of ,optics and ,refraction2  

formerly ,physician in ,philadelphia    
,hospital2 ,member of ,philadelphia     
,county1 ,pennsylvania ,state and       
,american ,medical ,societies4          
,illustration  ,the ,optician's ,manual1
 ,vol4 ,i41 has proved to be the most   
popular work on practical refraction    
ever published4 ,the knowledge it       
contains has been more effective in     
building up the optical profession than 
any other educational factor4 ,a study  
of it is essential to an intelligent    
appreciation of ,vol4 ,,ii41 for it lays
 the foundation structure of all optical
 knowledge1 as the titles of its ten    
chapters show3    ,chapter              
,i4--,introductory ,remarks4   ,chapter 
,,ii4--,the ,eye ,anatomically4         
,chapter  ,,iii4--,the ,eye ,optically2 
or1 ,the ,physiology of ,vision4        
,chapter   ,,iv4--,optics4   ,chapter   
,v4--,lenses4   ,chapter                
,,vi4--,numbering of ,lenses4   ,chapter
  ,,vii4--,the ,use and ,value of       
,glasses4   ,chapter ,,viii4--,outfit   

,required4   ,chapter   ,,ix4--,method  
of ,examination4   ,chapter             
,x4--,presbyopia4  ,the ,optician's     
,manual1 ,vol4 ,i41 is complete in      
itself1 and has been the entire optical 
education of many successful opticians4 
,for student and teacher it is the best 
treatise of its kind1 being simple in   
style1 accurate in statement and        
comprehensive in its treatment of       
refractive procedure and problems4 ,it  
merits the place of honor beside ,vol4  
,,ii4 in every optical library4  ,bound 
in ,cloth--#dbb pages--colored plates   
and ,illustrations4  ,sent postpaid on  
receipt of #b4jj 7#hs4 #d;d47           
,,published ,,by ,,the ,,keystone1      
,,the ,,organ ,,of ,,the ,,jewelry ,,and
 ,,optical ,,trades1   #ai,,th  ,,brown 
,,sts41 ,,philadelphia1 ,u4,s4,a4       
99       99       99       99       99  
,,the ,,optician',s ,,manual  ,,vol4    
,,ii4  ,,by ,c4,h4 ,,brown1 ,m4,d4      
,graduate ,university of ,pennsylvania2 
,professor of ,optics and ,refraction2  

formerly ,physician in ,philadelphia    
,hospital2 ,member of ,philadelphia     
,county1 ,pennsylvania ,state and       
,american ,medical ,societies4          
,illustration  ,the ,optician's ,manual1
 ,vol4 ,,ii41 is a direct continuation  
of ,the ,optician's ,manual1 ,vol4 ,i41 
being a much more advanced and          
comprehensive treatise4 ,it covers in   
minutest detail the four great          
subdivisions of practical eye           
refraction1 viz3    ,myopia4            
,hypermetropia4   ,astigmatism4         
,muscular ,anomalies4  ,it contains the 
most authoritative and complete         
researches up to date on these subjects1
 treated by the master hand of an       
eminent oculist and optical teacher4 ,it
 is thoroughly practical1 explicit in   
statement and accurate as to fact4 ,all 
refractive errors and complications are 
clearly explained1 and the methods of   
correction thoroughly elucidated4  ,this
 book fills the last great want in      
higher refractive optics1 and the       

knowledge contained in it marks the     
standard of professionalism4  ,bound in 
,cloth--#djh pages--with illustrations4 
,sent postpaid on receipt of #b4jj 7#hs4
 #d;d47    ,,published ,,by ,,the       
,,keystone1   ,,the ,,organ ,,of ,,the  
,,jewelry ,,and ,,optical ,,trades1     
#ai,,th  ,,brown ,,sts41 ,,philadelphia1
 ,u4,s4,a4           99       99        
99       99       99  ,,skiascopy ,,and 
,,the ,,use ,,of ,,the ,,retinoscope    
,illustration  ,a ,treatise on the      
,shadow ,test in its ,practical         
,application to the ,work of            
,refraction1 with an ,explanation in    
,detail of the ,optical ,principles on  
which the ,science is ,based4  ,this new
 work1 the sale of which has already    
necessitated a second edition1 far      
excels all previous treatises on the    
subject in comprehensiveness and        
practical value to the refractionist4   
,it not only explains the test1 but     
expounds fully and explicitly the       
principles underlying it--not only the  

phenomena revealed by the test1 but the 
why and wherefore of such phenomena4    
,it contains a full description of      
skiascopic apparatus1 including the     
latest and most approved instruments4   
,in depth of research1 wealth of        
illustration and scientific completeness
 this work is unique4  ,bound in cloth2 
contains #bca pages and #gc             
illustrations and colored plates4  ,sent
 postpaid to any part of the world on   
receipt of #a4jj 7#ds4 #b;d47           
,,published ,,by ,,the ,,keystone1      
,,the ,,organ ,,of ,,the ,,jewelry ,,and
 ,,optical ,,trades1   #ai,,th ,,and    
,,brown ,,sts41 ,,philadelphia1         
,u4,s4,a4           99       99       99
       99       99  ,,physiologic       
,,optics  ,ocular ,dioptrics--,functions
 of the ,retina--,ocular ,movements and 
,binocular ,vision  ,,by ,,dr4 ,m4      
,,tscherning  ,adjunct-,director of the 
,laboratory of ,ophthalmology at the    
,sorbonne1 ,paris  ,,authorized         
,,translation  ,,by ,,carl ,,weiland1   

,m4,d4  ,former ,chief of ,clinic in the
 ,eye ,department of the ,jefferson     
,college ,hospital1 ,philadelphia1 ,pa4 
,this is the crowning work on           
physiologic optics1 and will mark a new 
era in optical study4 ,its distinguished
 author is recognized in the world of   
science as the greatest living authority
 on this subject1 and his book embodies 
not only his own researches1 but those  
of the several hundred investigators    
who1 in the past hundred years1 made the
 eye their specialty and life study4    
,tscherning has sifted the gold of all  
optical research from the dross1 and his
 book1 as now published in ,english with
 many additions1 is the most valuable   
mine of reliable optical knowledge      
within reach of ophthalmologists4 ,it   
contains #chj pages and #bab            
illustrations1 and its reference list   
comprises the entire galaxy of          
scientists who have made the century    
famous in the world of optics4  ,the    
chapters on ,ophthalmometry1            

,ophthalmoscopy1 ,accommodation1        
,astigmatism1 ,aberration and ,entoptic 
,phenomena1 etc4--in fact1 the entire   
book contains so much that is new1      
practical and necessary that no         
refractionist can afford to be without  
it4  ,bound in ,cloth4 #chj ,pages1 #bab
 ,illustrations4  ,price1 #c4ej 7#ads4  
#g;d47    ,,published ,,by ,,the        
,,keystone1   ,,the ,,organ ,,of ,,the  
,,jewelry ,,and ,,optical ,,trades1     
#ai,,th  ,,brown ,,sts41 ,,philadelphia1
 ,u4,s4,a4           99       99        
99       99       99  ,,ophthalmic      
,,lenses  ,dioptric ,formul for         
,combined ,cylindrical ,lenses1 ,the    
,prism-,dioptry and ,other ,original    
,papers  ,,by ,,charles ,f4 ,,prentice1 
,m4,e4  ,a new and revised edition of   
all the original papers of this noted   
author1 combined in one volume4 ,in this
 revised form1 with the addition of     
recent research1 these standard papers  
are of increased value4 ,combined for   
the first time in one volume1 they are  

the greatest compilation on the subject 
of lenses extant4  ,this book of over   
#bjj pages contains the following       
papers3    ,ophthalmic ,lenses4         
,dioptric ,formul for ,combined         
,cylindrical ,lenses4   ,the            
,prism-,dioptry4   ,a ,metric ,system of
 ,numbering and ,measuring ,prisms4     
,the ,relation of the ,prism-,dioptry to
 the ,meter ,angle4     ,the ,relation  
of the ,prism-,dioptry to the           
,lens-,dioptry4   ,the ,perfected       
,prismometer4   ,the ,prismometric      
,scale4   ,on the ,practical ,execution 
of ,ophthalmic ,prescriptions involving 
,prisms4   ,a ,problem in ,cemented     
,bi-,focal ,lenses1 ,solved by the      
,prism-,dioptry4   ,why ,strong         
,contra-,generic ,lenses of ,equal      
,power ,fail to ,neutralize     ,each   
,other4   ,the ,advantages of the       
,sphero-,toric ,lens4   ,the ,iris1 as  
,diaphragm and ,photostat4   ,the       
,typoscope4   ,the ,correction of       
,depleted ,dynamic ,refraction          

7,presbyopia74  ,press ,notices on the  
,original ,edition3   ,,ophthalmic      
,,lenses4  ,the work stands alone1 in   
its present form1 a compendium of the   
various laws of physics relative to this
 subject that are so difficult of access
 in scattered treatises4--,new ,england 
,medical ,gazette4  ,it is the most     
complete and best illustrated book on   
this special subject ever               
published4--,horological ,review1 ,new  
,york4  ,of all the simple treatises on 
the properties of lenses that we have   
seen1 this is incomparably the best4444 
,the teacher of the average medical     
student will hail this little work as a 
great boon4--,archives of               
,ophthalmology1 edited by ,h4 ,knapp1   
,m4,d4  ,,dioptric ,,formul ,,for       
,,combined ,,cylindrical ,,lenses4      
,this little brochure solves the problem
 of combined cylinders in all its       
aspects1 and in a manner simple enough  
for the comprehension of the average    
student of ophthalmology4 ,the author is

 to be congratulated upon the success   
that has crowned his labors1 for nowhere
 is there to be found so simple and yet 
so complete an explanation as is        
contained in these pages4--,archives of 
,ophthalmology1 edited by ,h4 ,knapp1   
,m4,d4  ,this exhaustive work of ,mr4   
,prentice is a solution of one of the   
most difficult problems in              
ophthalmological optics4 ,thanks are due
 to ,mr4 ,prentice for the excellent    
manner in which he has elucidated a     
subject which has not hitherto been     
satisfactorily explained4--,the         
,ophthalmic ,review1 ,london4  ,the book
 contains #aaj ,original ,diagrams4     
,bound in cloth4  ,price1 #a4ej 7#fs4   
#c;d47    ,,published ,,by ,,the        
,,keystone1   ,,the ,,organ ,,of ,,the  
,,jewelry ,,and ,,optical ,,trades1     
#ai,,th  ,,brown ,,sts41 ,,philadelphia1
 ,u4,s4,a4           99       99        
99       99       99  ,,optometric      
,,record ,,book   ,a record book1       
wherein to record optometric            

examinations1 is an indispensable       
adjunct of an optician's outfit4  ,the  
,keystone ,optometric ,record ,book was 
specially prepared for this purpose4 ,it
 excels all others in being not only a  
record book1 but an invaluable guide in 
examination4  ,the book contains two    
hundred record forms with printed       
headings1 suggesting1 in the proper     
order1 the course of examination that   
should be pursued to obtain most        
accurate results4  ,each book has an    
index1 which enables the optician to    
refer instantly to the case of any      
particular patient4  ,the ,keystone     
,record ,book diminishes the time and   
labor required for examinations1        
obviates possible oversights from       
carelessness and assures a systematic   
and thorough examination of the eye1 as 
well as furnishes a permanent record of 
all examinations4  ,sent postpaid on    
receipt of #a4jj 7#ds4 #b;d47           
,,published ,,by ,,the ,,keystone1      
,,the ,,organ ,,of ,,the ,,jewelry ,,and

 ,,optical ,,trades1   #ai,,th  ,,brown 
,,sts41 ,,philadelphia1 ,u4,s4,a4       
99       99       99       99       99  
,,the ,,keystone ,,book ,,of ,,monograms
  ,this book contains #bdjj designs and 
over #fjjj different combinations of two
 and three letters4  ,is an essential to
 every jeweler's outfit4 ,it is not only
 necessary for the jeweler's own use and
 guidance1 but also to enable customers 
to indicate exactly what they want1 thus
 saving time and possible               
dissatisfaction4  ,the ,monograms are   
purposely left in outline1 in order to  
show clearly how the letters are        
intertwined or woven together4 ,this    
permits such enlargement or reduction of
 the ,monogram as may be desired1 and as
 much shading1 ornamentation and        
artistic finish as the jeweler may wish 
to add4  ,this comprehensive compilation
 of ,monograms is especially available  
as a reference book in busy seasons4    
,its use saves time1 thought and labor1 
and ensures quick and satisfactory work4

  ,monograms are the fad of the time1   
and there's money for the jeweler in    
,monogram engraving4 ,the knowledge in  
this book can be turned into cash4 ,all 
the various styles of letters are       
illustrated4  ,price1 #a4jj 7#ds4 #b;d47
    ,,published ,,by ,,the ,,keystone1  
,,the ,,organ ,,of ,,the ,,jewelry ,,and
 ,,optical ,,trades1   #ai,,th  ,,brown 
,,sts41 ,,philadelphia1 ,u4,s4,a4       
99       99       99       99       99  
,,the ,,keystone ,,record ,,book ,,of   
,,watch ,,repairs  ,this book is #i  #aa
 inches1 has #abj pages1 and space for  
recording sixteen hundred jobs in       
detail4 ,it is made of linen ledger     
paper1 bound in cloth with leather back 
and corners4  ,price1 #a4jj 7#ds4       
#b;d471 prepaid4  ,no other record book 
on the market is so complete1 and all   
cost more4    ,,published ,,by ,,the    
,,keystone1   ,,the ,,organ ,,of ,,the  
,,jewelry ,,and ,,optical ,,trades1     
#ai,,th  ,,brown ,,sts41 ,,philadelphia1
 ,u4,s4,a4           99       99        

99       99       99    ,,the ,,keystone
   ,,book ,,of ,,guarantees ,,of ,,watch
 ,,repairs    ,this book contains two   
hundred printed guarantees1 and is      
handsomely bound4 ,each guarantee is #c 
#g inches1 and   most carefully worded4 
,jewelers have discovered that the use  
of these guarantees is a most effective 
way to secure and cultivate   public    
confidence4 ,we sell a book of two      
hundred for    #a4jj 7#ds4 #b;d471      
prepaid1    which is one-third less than
 the price charged by others for a      
similar book4    ,,published ,,by ,,the 
,,keystone1   ,,the ,,organ ,,of ,,the  
,,jewelry ,,and ,,optical ,,trades1     
#ai,,th  ,,brown ,,sts41 ,,philadelphia1
 ,u4,s4,a4