,,mechanical ,,drawing ,,self-,,taught3 
,,comprising  ,,instructions ,,in ,,the 
,,selection ,,and ,,preparation ,,of    
,,drawing ,,instruments1  ,,elementary  
,,instruction ,,in ,,practical          
,,mechanical ,,drawing2  ,,together     
,,with  ,,examples ,,in ,,simple        
,,geometry ,,and ,,elementary           
,,mechanism1 ,,including ,,screw        
,,threads1 ,,gear ,,wheels1 ,,mechanical
 ,,motions1 ,,engines ,,and ,,boilers4  
,,by ,,joshua ,,rose1 ,m4,e41  ,,author 
,,of ,,the ,,complete ,,practical       
,,machinist1 ,,the ,,pattern ,,maker',s 
,,assistant1 ,,the ,,slide ,,valve      
,,illustrated ,,by ,,three ,,hundred    
,,and ,,thirty ,,engravings4            
,,philadelphia3 ,,henry ,,carey ,,baird 
,,co41 ,,industrial ,,publishers1       
,,booksellers ,,and ,,importers1 #haj   
,,walnut ,,street4  ,,london3 ,,sampson 
,,low1 ,,marston1 ,,searle  ,,rivington1
 ,,crown ,,buildings1 #ahh ,,fleet      
,,street4 #ahhg4     ,copyright by      
,,joshua ,,rose4 #ahhc4  ,,philadelphia4

  ,,collins1 ,,printer     ,,preface4   
,the object of this book is to enable   
the beginner to learn to make simple    
mechanical drawings without the aid of  
an instructor1 and to create an interest
 in the subject by giving examples such 
as the machinist meets with in his      
every-day workshop practice4 ,the plan  
of representing in many examples the    
pencil lines1 and numbering the order in
 which they are marked1 the author      
believes to possess great advantages for
 the learner1 since it is the producing 
of the pencil lines that really proves  
the study1 the inking in being merely a 
curtailed repetition of the pencilling4 
,similarly when the drawing of a piece1 
such1 for example1 as a fully developed 
screw thread1 is shown fully developed  
from end to end1 even though the pencil 
lines were all shown1 yet the process of
 construction will be less clear than if
 the process of development be shown    
gradually along the drawing4 ,thus      
beginning at an end of the example the  

first pencil lines only may be shown1   
and as the pencilling progresses to the 
right-hand1 the development may progress
 so that at the other or left-hand end1 
the finished inked in and shaded thread 
may be shown1 and between these two ends
 will be found a part showing each stage
 of development of the thread1 all the  
lines being numbered in the order in    
which they were marked4 ,this prevents a
 confusion of lines1 and makes it more  
easy to follow or to copy the drawing4  
,it is the numerous inquiries from      
working machinists for a book of this   
kind that have led the author to its    
production1 which he hopes and believes 
will meet the want thus indicated1      
giving to the learner a sufficiently    
practical knowledge of mechanical       
drawing to enable him to proceed further
 by copying such drawings as he may be  
able to obtain1 or by the aid of some of
 the more expensive and elaborate books 
already published on the subject4  ,he  
believes that in learning mechanical    

drawing without the aid of an instructor
 the chief difficulty is overcome when  
the learner has become sufficiently     
familiar with the instruments to be     
enabled to use them without hesitation  
or difficulty1 and it is to attain this 
end that the chapter on plotting        
mechanical motions and the succeeding   
examples have been introduced2 these    
forming studies that are easily followed
 by the beginner2 while sufficiently    
interesting to afford to the student    
pleasure as well as profit4  ,,new      
,,york1 ,february1 #ahhc4               
,,contents4   ,,chapter ,i4  ,,the      
,,drawing ,,board4  ,the ,t square      
#ah  ,the triangles                     
#ai  ,curves                            
#ba  ,selecting and testing drawing     
instruments                             
#bb  ,lead pencils                      
#bc  ,mixing ,india ink                 
#be  ,the drawing paper                 
#bf  ,tracing paper                     
#bi  ,the ink                           

#cj  ,testing and selecting ,india ink  
#cj  ,draftsmen's measuring rules       
#cc   ,,chapter ,,ii4  ,,the            
,,preparation ,,and ,,use ,,of ,,the    
,,instruments4  ,preparing the lining   
pen for use                             
#cd  ,the shapes of the lining pen      
points                                  
#ce  ,oil stoning pen points            
#cf  ,preparing the circle pen for use  
#ch  ,the shape for circle pen points   
#ch  ,shaping circle pens for very small
 circles                            #ci 
,a form of pen point recently           
introduced2 forming the pen point       
#ci  ,the method of oil-stoning circle  
pen points                           #dj
  ,the needle point and pen point       
#db  ,how to use the circle pen         
#dc  ,german instrument to avoid        
slipping of a needle point              
#dd  ,how to use the lining pen         
#de  ,applying the ink to the bow-pen   
#df  ,using a straight line or lining   
pen with a ,t square                    

#dg   ,,chapter ,,iii4  ,,lines ,,and   
,,curves4  ,explanation of simple       
geometrical terms2 radius2 explanation  
of     conventional dotted lines        
#dh  ,a line at a right angle to        
another2 a point2 parallel lines        
#di  ,a line produced2 a line bisected2 
a line bounding a circle2 an arc of a   
circle2 segments of a circle2 the chord 
of an arc2 a quadrant of a     circle   
#ej  ,a sector of a circle2 a line      
tangent to a circle2 a semicircle2      
centre of     a circle2 axis of a       
cylinder2 to draw a circle that shall   
pass through     three given points     
#ea  ,to find the centre from which an  
arc of a circle has been struck2 the    
degrees of a circle                     
#eb  ,the protractor                    
#ec  ,to find the angle of one line to  
another                              #ed
  ,to find the angles of three lines one
 to the other                    #ee    
,acute angles and obtuse angles         
#eg  ,triangles2 right angle triangle2  

obtuse angle triangle2 equilateral      
triangle2 isosceles triangle            
#eh  ,scalene triangle2 a quadrangle2   
quadrilateral or tetragon               
#ei  ,rhomboid2 trapezoid2 trapezium    
#fj  ,the construction of polygons      
#fa  ,the names of regular polygons     
#fb  ,the angles of regular polygons2   
the ellipse                             
#fc  ,form of a true ellipse            
#fi  ,the use of a trammel for drawing  
an ellipse                           #gb
  ,to draw a parabola mechanically      
#gc  ,to draw a parabola by lines       
#gd  ,to draw a heart cam               
#ge   ,,chapter ,,iv4  ,,shadow ,,lines 
,,and ,,line-,,shading4  ,section lining
 or cross-hatching                      
#gg  ,to represent cylindrical pieces   
one within the other2 to represent a    
number of pieces one within the other   
#gh  ,to represent pieces put together  
and having slots or keyways through     
them4                                   
#gi  ,effects of shading or             

cross-hatching                          
#hj  ,lines in sectional shading or     
cross-hatching made to denote the       
material     of which the piece is      
composed--lead1 wood1 steel1 brass1     
wrought     iron1 cast iron             
#ha  ,line-shading                      
#hb  ,the shade line to indicate the    
shape of piece2 representation of a     
washer                                  
#hc  ,a key drawn with a shade line2    
shade line applied to a nut2 a ,german  
pen regulated to draw lines of various  
breadths                   #hd  ,example
 of line-shading in perspective drawing1
 shown in a pipe threading     stock and
 die                                    
#he  ,a cylindrical pin line-shaded2 two
 cylindrical pieces that join each      
other2 a lathe centre2 a piece having a 
curved outline            #hf           
,line-shading applied to a ball or      
sphere2 applied to a pin in a socket    
shown in section                        
#hg  ,a piece of tube1 where the        

thickness of the tube is shown2 where   
the     hollow or hole is seen1 the     
piece shown in section2 where the body  
is     bell-mouthed and the hollow curve
 shown by shading                #hh    
,example of line-shading to denote the  
relative distances of various           
surfaces from the eye                   
#hi  ,line-shading to denote that the   
piece represented is of wood2           
shade-lines     being regular or        
irregular                               
#ij   ,,chapter ,v4  ,,marking          
,,dimensions4  ,examples in marking     
dimensions                              
#ia   ,,chapter ,,vi4  ,,the            
,,arrangement ,,of ,,different ,,views4 
,the different views of a mechanical    
drawing2 elevation2 plan2 general       
view2 a figure to represent a solid     
cylinder                      #id  ,to  
represent the different sides of a cube2
 the use of a cross to denote a         
square                                  
#ie  ,a triangular piece requires two or

 three views                        #if 
,to represent a ring having hexagon     
cross section2 examples2 a rectangular  
piece in two views                      
#ih  ,the position of the piece when in 
its place determines the name of the    
view in the drawing                     
#ajc  ,view of a lever                  
#aje  ,best method of projecting one    
view from another2 the two systems of   
different views of a piece              
#ajf   ,,chapter ,,vii4  ,,examples ,,in
 ,,bolts1 ,,nuts ,,and ,,polygons4  ,to 
represent the thread of a small screw   
#aab  ,a bolt with a hexagon head       
#aac  ,united ,states standard sizes for
 forged or unfinished bolts and nuts    
#aaf  ,the basis of the ,franklin       
,institute or ,united ,states standard  
for bolts     and nuts2 hexagonal or    
hexagon heads of bolts                  
#aah  ,comparison of hexagon and square 
heads of bolts2 chamfers            #abj
  ,without chamfer2 best plan for view  
of both square and hexagon heads #abc   

,drawing different views of hexagon     
heads                             #abe  
,to draw a square-headed bolt2 to draw  
the end view of a hexagon head #abe     
,use of the triangle to divide circles  
#abi  ,scales giving the length of the  
sides of polygons                       
#ace  ,to find what a square body which 
measures one inch on each side measures 
across the corners2 to find what        
diameter a cylindrical piece of     wood
 must be turned to which is to be       
squared1 and each side of which         
square must measure an inch             
#acf  ,to find a radius across corners  
of a hexagon or a six sided figure1 the 
length of a side being an inch          
#ach  ,to draw a stud                   
#adb  ,to pencil in a cap nut2          
pencilling for a link having the hubs on
 one side     only                      
#ade  ,link with hubs on both sides2    
pencil lines for a double eye or a      
knuckle     joint                       
#adf  ,double eye or knuckle joint with 

an offset2 a connecting rod end     #adg
  ,a rod end with a round stem          
#adh  ,a bolt with a square under the   
head                                    
#adi  ,example in which the corner where
 the round stem meets the square        
under the head is sharp2 a centre punch 
giving an example in     which the flat 
sides gradually run out upon a circle1  
the edges     forming curves            
#aej   ,,chapter ,,viii4  ,,screw       
,,threads ,,and ,,spirals4  ,screw      
threads for small bolts with the angles 
of the thread drawn in1 and     the     
method of doing this                    
#aeb  ,a double thread2 a round top and 
bottom thread such as the ,whitworth    
thread2 a left hand thread2 to draw     
screw threads of a large     diameter   
#aef  ,drawing the curves for screw     
threads                                 
#aeg  ,to draw the ,united ,states      
standard thread                         
#afj  ,to draw a square thread          
#afb  ,form of template for drawing the 

curves of threads                   #afe
  ,to show the thread depth in a top or 
end view of a nut2 to draw a spiral     
spring                                  
#aff  ,to obtain an accurate division of
 the lines that divide the pitch    #afg
   ,,chapter ,,ix4  ,,examples ,,for    
,,practice4  ,a locomotive spring2 a    
stuffing box and gland2 working drawings
 of a     coupling rod2 dimensions and  
directions marked2 a connecting rod     
drawn and put together as it would be   
for the lathe1 vise1 or erecting        
shop                                    
#afi  ,drawings for the blacksmith      
#agb  ,a locomotive frame               
#agd  ,reducing scales                  
#age  ,making a drawing to scale        
#agg   ,,chapter ,x4  ,,projections4  ,a
 spiral wound around a cylinder whose   
end is cut off at an angle    #agh  ,a  
cylindrical body joining another at a   
right-angle2 a ,tee for     example     
#ahj  ,other examples of ,tees          
#aha  ,example of a cylinder            

intersecting a cone                     
#ahf  ,a cylindrical body whose top face
 if viewed from one point would appear  
as     a straight line1 or from another 
a circle                        #ahh    
,,chapter ,,xi4  ,,drawing ,,gear       
,,wheels4  ,names of the curves and     
lines of gear teeth                     
#aic  ,how to draw spur wheel teeth     
#aid  ,professor ,willis' scale of tooth
 proportions                            
#aie  ,the application of the scale     
#aig  ,how to find the curve for the    
tooth face                              
#aih  ,to trace hypocycloides for the   
flanks of teeth                         
#bjj  ,sectional view of a section of a 
wheel for showing the dimensions through
     the arms and hub                   
#bjb  ,to draw an edge view of a wheel2 
rules for drawing the teeth of wheels2  
bevel gear wheels                       
#bjc  ,the construction to find the     
curves                                  
#bjd  ,to draw the arcs for the teeth   

#bje  ,to draw the pitch circle of the  
inner and small end of the pinion       
teeth                                   
#bjf  ,one-half of a bevel gear and an  
edge view projected from the same       
#bjg  ,a pair of bevel wheels shown in  
section2 drawing of a part of an ,ames  
lathe feed motion2 small bevel gears    
#bjh  ,example in which part of the gear
 is shown with teeth in1 and the        
remainder illustrated by circles2       
drawings of part of the feed     motion 
of a ,niles horizontal tool work boring 
mill               #bji  ,three bevel   
gears1 one of which is line-shaded2 the 
construction of oval     gearing2       
,professor ,rankine's process for       
rectifying and subdividing     circular 
arcs                                    
#baj  ,various examples of laying out   
gear wheels                             
#bad   ,,chapter ,,xii4  ,,plotting     
,,mechanical ,,motions4  ,to find how   
much motion an eccentric will give to   
its rod            #bbc  ,to find how   

much a given amount of motion of a long 
arm will move the     short arm of a    
lever                                   
#bbd  ,example of the end of a lever    
acting directly on a shoe2 a short arm  
having a roller acting upon a larger    
roller                      #bbe  ,a    
link introduced in the place of the     
roller to find the amount of motion     
of the rod2 a lever actuating a plunger 
in a vertical line1 to find     how much
 a given amount of motion of the long   
arm will actuate the     plunger        
#bbf  ,two levers upon their axles or   
shafts1 the arms connected by a link and
     one arm connected to a rod         
#bbg  ,a lever arm and cam in one piece 
on a shaft1 a shoe sliding on the line1 
and held against the cam face by the    
rod1 to find the position of the        
face of the shoe against the cam        
#bbh  ,to find the amount of motion     
imparted in a straight line to a rod1   
attached to an eccentric strap          
#bbi  ,examples in drawing the cut off  

cams employed instead of eccentrics on  
river steamboats in the ,western and    
,southern ,states4 ,different views     
of a pair of cams                       
#bcb  ,the object of using a cam instead
 of an eccentric                    #bcd
  ,method of drawing or marking out a   
full stroke cam                   #bcg  
,illustration of the lines embracing cut
 off cams of varying limits of          
cut-off                                 
#bdj  ,part played by the stroke of the 
engine in determining the conformation  
of cut-off cams2 manner of finding      
essential points of drawings of         
cutoff cams                             
#bda  ,a cam designed to cut off the    
steam at five-eighths of the piston     
stroke                                  
#bdd  ,three-fourths and seven-eighths  
cams                                    
#bdf  ,necessary imperfections in the   
operations of cut-off cams              
#bdg  ,drawing representing the motion  
which a crank imparts to a connecting   

rod                                     
#bdi  ,plotting out the motion of a     
shaper link quick return                
#bej  ,plotting out the ,whitworth quick
 return motion employed in machines     
#bec  ,finding the curves for moulding  
cutters                                 
#beg   ,,chapter ,,xiii4  ,,examples    
,,in ,,line-,,shading ,,and ,,drawing   
,,for ,,line-,,shaded ,,engravings4     
,arrangement of idle pulleys to guide   
bolts from one pulley to another2       
representation of a cutting tool for a  
planing machine           #bfd          
,drawings for photo-engraving           
#bfg  ,drawing for an engraver in wood2 
drawings for engravings by the wax      
process                                 
#bfh  ,engraving made by the wax process
 from a print from a wood engraving2    
engravings of a boiler drilling machine 
#bfi   ,,chapter ,,xiv4  ,,shading ,,and
 ,,coloring ,,drawings4  ,coloring the  
journals of shafts2 simple shading2     
drawing cast-iron1     wrought iron1    

steel and copper                        
#bgg  ,points to be observed in coloring
 and shading2 colored drawings to be    
glued around their edges to the drawing 
board2 to maintain an even     shade of 
color2 mixing colors                    
#bgh  ,to graduate the depth of tint for
 a cylindrical surface              #bgi
  ,the size and use of brushes2 light in
 shading2 example for shading a         
,medart pulley                          
#bhj  ,brush shading                    
#bha  ,to show by the shading that the  
surfaces are highly polished2           
representation of an oil cup2           
representation of an iron planing       
machine                                 
#bhb  ,example in shading of ,blake's   
patent direct acting steam pump         
#bhd  ,example of shading an independent
 condenser                          #bhh
   ,,chapter ,,xv4  ,,examples ,,of     
,,engine ,,work4  ,drawings of an       
automatic high speed engine2 side and   
end views of the     engine2 vertical   

section of the cylinder through the     
valve face  #bhi  ,valve motion2        
governor                                
#bib  ,pillow box1 block crank-pin1     
wheel and main journal                  
#bid  ,side and edge view of the        
connecting rod                          
#bie  ,a two hundred horse power        
horizontal steam boiler for a stationary
 engine2     cross sectional view of the
 boiler shell                           
#bif  ,side elevation1 end view of the  
boiler1 and setting                     
#big  ,working drawings of a one hundred
 horse power engine2 plan and side      
view of the bed plate1 with the main    
bearing and guide bars2 cross           
sections of the bed plate2 side         
elevation of the cylinder1 with end     
view of the same                        
#bii  ,steam chest side and horizontal  
cross section of the cylinder2 steam    
chest     and the valves2 cam wrist     
plate and cut-off mechanism2 shaft for  
the     cam plate2 cross head2 side view

 and section through the centre of      
the eccentric and strap                 
#cja  ,construction of the connecting   
rod                                     
#cjc  ,,index                           
#cje                                    
----------------------------------------
-------------------------------         
,transcriber's note3 ,in this text ,t   
indicates a larger capital letter4      
----------------------------------------
-------------------------------         
,,mechanical ,,drawing  ,,self-,,taught4
  ,,chapter ,i4  ,,the ,,drawing        
,,board4   ,a ,drawing ,board should be 
of soft pine and free from knots1 so    
that it will easily receive the pins or 
tacks used to fasten down the paper4    
,its surface should be flat and level1  
or a little rounding1 so that the paper 
shall lie close to its surface1 which is
 one of the first requisites in making a
 good drawing4 ,its edges should be     
straight and at a right angle one to the
 other1 and the ends of the battens ,b  

,b in ,figure #a should fall a little   
short of the edge ,a of the board1 so   
that if the latter shrinks they will not
 protrude4 ,the size of the board of    
course depends upon the size of the     
paper1 hence it is best to obtain a     
board as small as will answer for the   
size of paper it is intended to use4    
,the student will find it most          
convenient as well as cheapest to learn 
on small drawings rather than large     
ones1 since they take less time to make1
 and cost less for paper2 and although  
they require more skill to make1 yet are
 preferable for the beginner1 because he
 does not require to reach so far over  
the board1 and furthermore1 they teach  
him more quickly and effectively4 ,he   
who can make a fair drawing having short
 lines and small curves can make a      
better one if it has large curves1 etc41
 because it is easier to draw a large   
than a very small circle or curve4 ,it  
is unnecessary to enter into a          
description of the various kinds of     

drawing boards in use1 because if the   
student purchases one he will be duly   
informed of the kinds and their special 
features1 while if he intends to make   
one the sketch in ,figure #a will give  
him all the information he requires1    
save that1 as before noted1 the wood    
must be soft pine1 well seasoned and    
free from knots1 while the battens ,b   
should be dovetailed in and the face of 
the board trued after they are glued and
 driven in4 ,to true the edges square1  
it is best to make the two longest edges
 parallel and straight1 and then the    
ends may be squared from those long     
edges4  ,illustration3 ,fig4 #a4  ,,the 
,t ,,square4  ,drawing squares or ,t    
squares1 as they are termed1 are made of
 wood1 of hard rubber and of steel4     
,there are several kinds of ,t squares2 
in one the blade is solid1 as it is     
shown in ,figure #e on page #bj2 in     
another the back of the square is       
pivoted1 so that the blade can be set to
 draw lines at an angle as well as      

across the board1 which is often very   
convenient1 although this double back   
prevents the triangles1 when used in    
some positions1 from coming close enough
 to the left hand side of the board4 ,in
 an improved form of steel square1 with 
pivoted blade1 shown in ,figure #b1 the 
back is provided with a half circle     
divided into the degrees of a circle1 so
 that the blade can be set to any       
required degree of angle at once4       
,illustration3 ,fig4 #b4  ,illustration3
 ,fig4 #c4  ,illustration3 ,fig4 #d4    
,,the ,,triangles4  ,illustration3 ,fig4
 #e4  ,two triangles are all that are   
absolutely necessary for a beginner4    
,the first is that shown in ,figure #c1 
which is called a triangle of #de       
degrees1 because its edge ,a is at that 
angle to edges ,b and ,c4 ,that in      
,figure #d is called a triangle of #fj  
degrees1 its edge ,a being at #fj       
degrees to ,b1 and at #cj degrees to ,c4
 ,the edges ,p and ,c are at a right    
angle or an angle of #ij degrees in both

 figures2 hence they are in this respect
 alike4 ,by means of these triangles    
alone1 a great many straight line       
drawings may be made with ease without  
the use of a drawing square2 but it is  
better for the beginner to use the      
square at first4 ,the manner of using   
these triangles with the square is shown
 in ,figure #e1 in which the triangle1  
,figure #c1 is shown in three positions 
marked ,d ,e ,f1 and that shown in      
,figure #d is shown in three positions1 
marked respectively ,g ,h and ,i4 ,it is
 obvious1 however1 that by turning ,i   
over1 end for end1 another position is  
attained4 ,the usefulness in these      
particular triangles is because in the  
various positions shown they are capable
 of use for drawing a very large        
proportion of the lines that occur in   
mechanical drawing4 ,the principal      
requirement in their use is to hold them
 firmly to the square-blade without     
moving it1 and without permitting them  
to move upon it4 ,the learner will find 

that this is best attained by so        
regulating the height of the            
square-blade that the line to be drawn  
does not come down too near the bottom  
of the triangle or edge of the          
square-blade1 nor too high on the       
triangle2 that is to say1 too near its  
uppermost point4 ,it is the left-hand   
edge of the triangle that is used1      
whenever it can be done1 to produce the 
required line4  ,illustration3 ,fig4 #f4
   ,,curves4  ,to draw curves that are  
not formed of arcs or parts of circles1 
templates called curves are provided1   
examples of these forms being given in  
,figure #f4 ,they are made in wood and  
in hard rubber1 the latter being most   
durable2 their uses are so obvious as to
 require no explanation4 ,it may be     
remarked1 however1 that the use of      
curves gives excellent practice1 because
 they must be adjusted very accurately  
to produce good results1 and the drawing
 pen must be held in the same vertical  
plane1 or the curve drawn will not be   

true in its outline4   ,,drawing        
,,instruments4  ,it is not intended or  
necessary to enter into an elaborate    
discussion of the various kinds of      
drawing instruments1 since the purchaser
 can obtain a good set of drawing       
instruments from a reputable dealer by  
paying a proportionate price1 and must  
per force learn to use such as his means
 enable him to purchase4 ,it is         
recommended that the beginner purchase  
as good a set of instruments as his     
means will permit1 and that if his means
 are limited he purchase less than a    
full set of instruments1 having the same
 of good quality4  ,all the instruments 
that need be used in the examples of    
this book are as follows3  ,a small     
spring bow-pen for circles1 a lining pen
 or pen for straight lines1 a small     
spring bow-pencil for circles1 a large  
bow-pen with a removable leg to replace 
by a divider leg or a pencil leg1 and   
having an extension piece to increase   
its capacity4  ,the spring bow-pen      

should have a stiff spring1 and should  
be opened out to its full capacity to   
see that the spring acts well when so   
opened out1 keeping the legs stiff when 
opened for the larger diameters4 ,the   
purchaser should see that the joint for 
opening and closing the legs is an easy 
but not a loose fit on the screw1 and   
that the legs will not move sideways4   
,to test this latter1 which is of great 
importance in the spring bow-pencil as  
well as in the pen1 it is well to close 
the legs nearly together and taking one 
leg in one hand and the other leg in the
 other hand 7between the forefinger and 
thumb71 pushing and pulling them        
sideways1 any motion in that direction  
being sufficient to condemn the         
instrument4 ,it is safest and best to   
have the two legs of the bow-pen and    
pencil made from one piece of metal1 and
 not of two separate pieces screwed     
together at the top1 as the screw will  
rarely hold them firmly together4 ,the  
points should be long and fine1 and as  

round as possible4 ,in very small       
instruments separate points that are    
fastened with a screw are objectionable1
 because1 in very small circles1 they   
hide the point and make it difficult to 
apply the instrument to the exact proper
 point or spot on the drawing4  ,the    
joints of the large bow or circle-pen   
should also be somewhat stiff1 and quite
 free from side motion1 and the         
extension piece should be rigidly       
secured when held by the screw4 ,it is a
 good plan in purchasing to put in the  
extension piece1 open the joint and the 
pen to their fullest1 and draw a circle1
 moving the pen in one direction1 and   
then redraw it1 moving it in the other  
direction1 and if one line only appears 
and that not thickened by the second    
drawing1 the pen is a good one4  ,the   
lead pencil should be of hard lead1 and 
it is recommended that they be of the   
,h1 ,h1 ,h1 ,h1 ,h1 ,h1 in the ,english 
grades1 which corresponds to the ,v1 ,v1
 ,h1 of the ,dixon grade4 ,the pencil   

lines should be made as lightly as      
possible2 first1 because the presence of
 the lead on the paper tends to prevent 
the ink from passing to the paper2 and1 
secondly1 because in rubbing out the    
pencil lines the ink lines are reduced  
in blackness and the surface of the     
paper becomes roughened1 so that it will
 soil easier and be harder to clean4 ,in
 order to produce fine pencil lines     
without requiring a very frequent       
sharpening of the pencil it is best to  
sharpen the pencil as in ,figures #g and
 #h1 so that the edge shall be long in  
the direction in which it is moved1     
which is denoted by the arrow in ,figure
 #g4 ,but when very fine work is to be  
done1 as in the case of ,patent ,office 
drawings1 a long1 round point is        
preferable1 because the eye can see     
plainer just where the pencil will begin
 to mark and leave off2 hence the pencil
 lines will not be so liable to overrun4
  ,illustration3 ,fig4 #g4              
,illustration3 ,fig4 #h4  ,in place of  

the ordinary wood-covered lead pencils  
there may be obtained at the drawing    
material stores pencil holders for      
holding the fine1 round sticks of lead1 
and these are by far the best for a     
learner4 ,they are easier to sharpen1   
and will slip in the holder1 giving     
warning when the draftsman is pressing  
them too hard on the paper1 as he is apt
 to do4 ,the best method of trimming    
these leads1 as also lead pencils after 
they have been roughly shaped1 is with a
 small fine file1 holding the file still
 and moving the pencil2 or a good piece 
of emery paper or sand paper is good1   
moving the pencil as before4  ,all lines
 in pencilling as in inking in should   
begin at the left hand and be drawn     
towards the right1 or when triangles are
 used the lines are begun at the bottom 
and drawn towards the top or away from  
the operator4 ,the rubber used should   
not be of a harsh grade1 since that will
 roughen the face of the paper and      
probably cause the ink to run4 ,the less

 rubbing out the better the learner will
 progress1 and the more satisfaction he 
will receive from the results4 ,if it   
becomes necessary to scratch out it is  
best done with a penknife well          
sharpened1 and not applied too forcibly 
to the paper but somewhat lightly1 and  
moved in different and not all in one   
direction4 ,after the penknife the      
rubber may sometimes be used to         
advantage1 since it will1 if of a smooth
 grade1 leave the paper smoother than   
the knife4 ,finally1 before inking in1  
the surface that has been scraped should
 be condensed again by rubbing some     
clean1 hard substance over it which will
 prevent the ink from spreading4 ,the   
end of a paper-cutter or the end of a   
rounded ivory handled drawing instrument
 is excellent for this purpose4         
,illustration3 ,fig4 #i4  ,illustration3
 ,fig4 #aj4  ,it is well to use the     
rubber for general purposes in such a   
way as to fit it for special purposes2  
thus1 in cleaning the sheet of paper1   

the rubber may be applied first1 as in  
,figure #i1 as at ,a1 and then as at ,b1
 and if it be moved sideways at the same
 time it will wear to the form shown in 
,figure #aj1 which will enable it to be 
applied along a line that may require to
 be rubbed out without removing other   
and neighboring lines4 ,if the rubber is
 in the form of a square stick one end  
may be bevelled1 as in ,figure #aa1     
which is an excellent form1 or it may be
 made to have a point1 as in ,figure    
#ab4 ,the object is in each case to     
enable the rubber action to be confined 
to the desired location on the paper1 so
 as to destroy its smooth surface as    
little as possible4  ,illustration3     
,fig4 #aa4  ,illustration3 ,fig #ab4    
,for simple cleaning purposes1 or to    
efface the pencil lines when they are   
drawn very lightly1 squares of          
sponge-rubber answer admirably1 these   
being furnished by the dealers in       
drawing materials4  ,a piece of bread   
will answer a similar purpose1 but it is

 less convenient4  ,for glazed surface  
paper1 as ,bristol-board1 the smoothest 
rubber must be used1 the grade termed   
velvet rubber answering well4   ,,the   
,,drawing ,,paper4  ,whatever kind of   
drawing paper be used it should be kept 
dry1 or the ink1 however good it may be1
 will be apt to run and make a thick    
line that will not have the sharp1 clean
 edges necessary to make lines look     
well4  ,drawing paper is made in various
 qualities1 kinds1 and forms1 as        
follows3 ,the sizes and names of paper  
made in sheets are3  ,cap1              
#ac x #af inches4 ,demy1                
#bj x #ae     ,medium1             #bb x
 #ag     ,royal1              #bd x #ai 
,super ,royal1        #bg x #ai         
,imperial1           #cj x #ba          
,elephant1           #bh x #bb          
,columbier1          #cd x #bc          
,atlas1              #cc x #bf          
,theorem1            #cd x #bh          
,double ,elephant1    #dj x #bf         
,antiquarian1        #eb x #ca          

,emperor1            #dj x #fj          
,uncle ,sam1          #dh x #abj     the
 thickness of the sheets increasing with
 their size4 ,some sheets of paper are  
hot pressed1 to give a smoother surface1
 and thus enable cleaner-edged lines to 
be drawn4  ,illustration3 ,fig4 #ac4    
,for large drawings paper is made in    
rolls of various widths1 but as rolled  
paper is troublesome to lay flat upon   
the drawing board1 it is recommended to 
the learner to obtain the sheets1 which 
may be laid sufficiently flat by means  
of broad headed pins1 such as shown in  
,figure #ac1 which are called thumb     
tacks4 ,these are forced through the    
paper into the board at each corner1 as 
in ,figure #ad at f4 ,on account of the 
large diameter of the stems of these    
thumb tacks1 which unduly pierce and    
damage the board1 and on account also of
 their heads1 by reason of their        
thickness1 coming in the way of the     
square blade1 it will be found          
preferable to use the smallest sizes of 

ordinary iron tacks1 with flat heads1   
whose stems are much finer and heads    
much thinner than thumb tacks4 ,the     
objection to ordinary tacks is that they
 are more difficult to remove1 but they 
are1 as stated1 more desirable for use4 
,illustration3 ,fig4 #ad4               
,illustration3 ,fig4 #ae4  ,if the paper
 is nearly the full size of the board1  
it does not much matter as to its       
precise location on the board1 but      
otherwise it is best to place it as near
 the left-hand edge of the board as     
convenient1 as is shown in ,figure #ad4 
,the lower edge1 ,d1 ,figure #ae1 of the
 paper1 however1 should not be placed   
too near the edge1 ,a1 of the board1    
because if the end ,p of the square back
 comes down below the edge of the board1
 it is more difficult to keep the square
 back true against the end of the board4
  ,the paper must lie flat upon and     
close to the surface of the board1 and a
 sufficient number of tacks must be used
 to effect this purpose4  ,drawings that

 are to be intricate1 or to contain a   
great many lines1 as a drawing of an    
engine or of a machine1 are best pasted 
or glued all around the edges of the    
paper1 which should first be dampened2  
but as the learner will scarcely require
 to make such drawings until he is      
somewhat familiar with and well         
practised in the use of the instruments1
 this part of the subject need not be   
treated here4   ,,tracing ,,paper4  ,for
 taking tracings from drawings tracing  
paper or tracing cloth is used4 ,they   
require to be stretched tightly and     
without wrinkles upon the drawing4 ,to  
effect this object the mucilage should  
be thick1 and the tracing paper should  
be dampened with a sponge after it is   
pasted4 ,it must be thoroughly dry      
before use1 or the ink will run4        
,tracing cloth must be fastened by pins 
or thumb tacks1 and not dampened4 ,the  
drawing should be made on the polished  
side of the cloth1 and any coloring to  
be done should be on the other side1 and

 done after the tracing is removed from 
the drawing4   ,,the ,,ink4  ,india ink 
should always be used for mechanical    
drawing3 ,first1 because it lies upon   
and does not sink into the paper1 and   
is1 therefore1 easily erased2 and1      
secondly1 because it does not corrode or
 injure the drawing instruments4  ,india
 ink is prepared in two forms--in the   
stick and in a liquid form4 ,the stick  
ink is mixed in what are termed saucers1
 or cabinet saucers1 one being placed   
above the other1 so as to exclude the   
dust from settling in it1 and also to   
prevent the rapid evaporation to which  
it is subject4  ,the surface of the     
saucer should be smooth1 as any         
roughness grinds the ink too coarsely1  
whereas the finer it is ground or mixed 
the easier it will flow1 the less       
liability to clog the instruments1 and  
the smoother and more flat it will lie  
upon the paper4 ,in mixing the ink only 
a small quantity of water should be     
used1 the stick of ink being pressed    

lightly upon the saucer and moved       
quickly1 the grinding being continued   
until the ink is mixed quite thickly4   
,this will grind the ink fine as it is  
mixed1 and more water may be added to   
thin it4 ,it is best1 however1 to let   
the ink be somewhat thick for use1 and  
to keep it covered when not in use2 and 
though water may be added if it gets too
 thick1 yet ink that has once dried     
should not be mixed up again1 as it will
 not work so well after having once     
dried4  ,of liquid inks the ,higgins ink
 is by far the best1 being quite equal  
to and much more convenient for use than
 the best stick ink4  ,the difference   
between a good and an inferior ,india   
ink lies chiefly in the extent to which 
the lamp-black1 which is the coloring   
matter1 forms with the water a chemical 
solution rather than a mechanical       
mixture4 ,in inferior ink the lamp-black
 is more or less held in suspension1 and
 by prolonged exposure to the air will  
separate1 so that on being spread the   

solid particles will aggregate by       
themselves and the water by itself4     
,this explains why draughtsmen will1    
after the ink has been exposed to the   
air for an hour or two1 add a drop of   
mucilage to it2 the mucilage thickening 
the solution1 adding weight to the      
water1 and deferring the separation of  
the lamp-black4  ,a good ,india ink is  
jet black1 flows easily1 lies close to1 
does not stand upon or sink into the    
paper1 and has an even lustre1 the      
latter being an indication of fineness4 
,the more perfect the incorporation of  
the lamp-black with the water the easier
 the ink will flow1 the less liable it  
is to clog the instruments1 the more    
even and sharp the edges of the lines1  
and the finer the lines that may be     
drawn4  ,usually ,india ink can only be 
tested by actual trial2 but since it is 
desirable to test before purchasing it1 
it may be mentioned that one method is  
to mix a little on the finger nail1 and 
if it has a bronzy gloss it is a good   

indication4 ,it should also spread out  
and dry without any tendency to         
separate4  ,the best method of testing  
is to mix a very little1 and drop a     
single drop in a tumbler of clear water4
 ,the best ink will diffuse itself over 
the surface1 and if the water is        
disturbed will diffuse itself through   
the water1 leaving it translucent and   
black1 with a slight tinge of bronze    
color4 ,a coarser ink will act in a     
similar manner1 but make the water      
somewhat opaque1 with a blue-black1 or  
dull1 ashy color4 ,a still coarser ink  
will1 when diffused over the surface of 
the water1 show fine specks1 like black 
dust1 on the surface4 ,this is readily  
apparent1 showing that the mixture of   
the ink is not homogeneous4  ,when it is
 an object to have the lines of a       
drawing show as black as possible1 as   
for drawings that are to be             
photo-engraved1 the ink should be mixed 
so thickly as to have a tendency to lift
 when a body1 such as a lead pencil1 is 

lifted out of it4 ,for ,patent ,office  
drawings some will mix it so thickly    
that under the above test it appears a  
little stringy4  ,the thicker the ink   
can be used the better1 because the     
tendency of the carbon to separate is   
less2 and it is for this reason that the
 test mentioned with a tumbler of water 
is so accurate4 ,when ink is to be used 
on parchment1 or glossy tracing-paper1  
it will flow perfectly if a few drops of
 ox-gall be mixed with it2 but on soft  
paper1 or on bristol board1 this will   
cause the ink to spread4  ,for purposes 
of measurement1 there are special rules 
or scales of steel and of paper         
manufactured4 ,the steel rules are      
finely and accurately divided1 and some 
are of triangular form1 so that when    
laid upon the paper the lines divided   
will lie close to the paper1 and the    
light will fall directly on the ruled   
surface4 ,triangular rules or scales are
 therefore much superior to flat ones4  
,the object of having a paper rule or   

scale is1 that the paper will expand and
 contract under varying degrees of      
atmospheric moisture1 the same as the   
drawing paper does4  ,figure #af        
represents a triangular scale1 having   
upon it six different divisions of the  
inch4 ,these are made in different      
patterns1 having either decimal         
divisions or the vulgar fractions4      
,being made of steel1 and nickel-plated1
 they are proof against the moisture of 
the fingers1 and are not subject to the 
variation of the wooden scale4          
,illustration3 ,fig4 #af4     ,,chapter 
,,ii4  ,,the ,,preparation ,,and ,,use  
,,of ,,the ,,instruments4   ,the points 
of drawing instruments require to be    
very accurately prepared and shaped1 to 
enable them to make clean1 clear lines4 
,the object is to have the points as    
sharp as they can be made without       
cutting the paper1 and the curves as    
even and regular as possible4           
,illustration3 ,fig4 #ag4               
,illustration3 ,fig4 #ah4  ,the lining  

pen should be formed as in ,figure #ag1 
which presents an edge and a front view 
of the points4 ,the inside faces should 
be flat across1 and slightly curved in  
their lengths1 as shown4 ,if this curve 
is too great1 as shown exaggerated in   
,figure #ah1 the body of the ink lies   
too near the point and is apt to flow   
too freely1 running over the pen-point  
and making a thick1 ragged line4 ,on the
 other hand1 if the inside faces1       
between which the ink lies1 are too     
parallel and narrow near the points1 the
 ink dries in the pen1 and renders a too
 frequent cleaning necessary4 ,looking  
at the face of the pen as at ,a in      
,figure #ag1 its point should have an   
even curve1 as shown1 the edge being as 
sharp as it can be made without cutting 
the drawing paper4 ,upon this quality   
depends the fineness and cleanness of   
the lines it will make4 ,this thin edge 
should extend around the curve as far as
 the dotted line1 so that it will be    
practicable to slant the pen in either  

of the directions shown in ,figure #ai2 
and it is obvious that its thickness    
must be equal around the arc1 so that   
the same thickness of line will be drawn
 whether the pen be held vertical or    
slanted in either direction4            
,illustration3 ,fig4 #ai4               
,illustration3 ,fig4 #bj4  ,the outside 
faces of the pen should be slightly     
curved1 so that when held vertically1 as
 in ,figure #bj 7the dotted line        
representing the centre of the length of
 the instrument71 and against the square
 blade ,s1 the point will meet the paper
 a short distance from the lower edge of
 ,s as shown4 ,by this means it is not  
necessary to adjust the square edge     
exactly coincident with the line1 but a 
little way from it4 ,this is an         
advantage for two reasons3 first1 the   
trouble of setting the square-edge      
exactly coincident is avoided1 and1     
secondly1 the liability of the ink to   
adhere to the edge of the square-blade  
and flow on to the paper and make a     

thick1 ragged line1 is prevented4  ,the 
square being set as near to the line as 
desired1 the handle may be held at such 
an angle that the pen-point will just   
meet the line when sloped either as in  
,figure #ba or #bb4 ,if1 however1 the   
slope be too much in the direction shown
 in ,figure #ba1 practice is necessary  
to enable the drawing of straight lines 
if they be long ones1 because any       
variation in the angle of the instrument
 to the paper obviously vitiates the    
straightness of the line4 ,if1 on the   
other hand1 the square be too close to  
the line1 and the pen therefore requires
 to be sloped as in ,figure #bb1 the ink
 flowing from the pen-point is apt to   
adhere to the square-edge1 and the      
result will be a ragged1 thick line1 as 
shown in ,figure #bc4  ,illustration3   
,fig4 #ba4  ,illustration3 ,fig4 #bb4   
,illustration3 ,fig4 #bc4               
,illustration3 ,fig4 #bd4               
,illustration3 ,fig4 #be4               
,illustration3 ,fig4 #bf4  ,each of the 

legs should be of equal thickness at the
 pen-point edge1 so that when closed    
together the point will be in the middle
 of the edge4 ,the width and curve of   
each individual point should be quite   
equal1 and the easiest method of        
attaining this end is as follows3  ,take
 a small slip of ,arkansas oil-stone1   
and with the pen-points closed firmly by
 the screw trim the pen-edges to the    
required curve as shown at ,a1 ,figure  
#ag1 making the curve as even as        
possible4 ,then stone the faces until   
this curve is brought up to a sharp edge
 at the point between the two pen-legs  
forming the point4  ,next take a piece  
of #jjj ,french emery paper1 lay it upon
 some flat body like the blade of a     
square1 and smooth the curve of the edge
 enough to take off the fine1 sharp edge
 left by the oil-stone2 then apply the  
outside flat faces of the pen to the    
emery paper again1 bringing the pen-edge
 up sharp4  ,the emery paper will simply
 have smoothed and polished the         

surfaces1 still leaving them too sharp1 
so sharp as to cut the paper1 and to    
take off this sharp edge 7which must    
first be done on the inside faces7 open 
the pen-points as wide as the screw will
 permit4 ,then wrap one thickness of the
 emery paper upon a thin blade1 as upon 
a drawing-triangle1 and pass the open   
pen-points over it1 and move the        
instrument endwise1 taking care to keep 
the inside face level with the surface  
of the emery paper1 so that the         
pen-points shall not cut through4 ,next 
close the pen-points with the screw     
until they nearly1 but not quite1 touch1
 and sweep the edge of the pen-point    
along the emery paper under a slight    
pressure1 so moving the handle that at  
each stroke the whole length around the 
curved end of the pen will meet the     
emery surface4 ,during this motion the  
inside faces of the pen-point must be   
held as nearly vertical as possible1 so 
as to keep the two halves of the        
pen-point equal4  ,the pen is now ready 

for use1 and will draw a fine and clean 
line4  ,it is not usual to employ emery 
paper for the purpose indicated1 but it 
will be found very desirable1 since it  
leaves a smoother surface and edge than 
the oil-stone alone4  ,circle-pens are  
more difficult to put in order than the 
straight-line pen1 especially those for 
drawing the smallest circles1 which     
cannot be well drawn unless the pen is  
of the precise right shape and in the   
best condition4  ,a circle-pen is shown 
in ,figure #bd1 in which ,a represents  
the point-leg and ,b the pen-leg4 ,the  
point-leg must be the longest because it
 requires to enter the drawing paper    
before the pen meets the surface4 ,the  
point should be sharp and round1 for any
 edges or angles on it will cause it to 
widen the hole in the paper when it is  
rotated4 ,to shape the points to prevent
 the enlargement of the centre in the   
paper is one of the most important      
considerations in the use of this       
instrument1 especially when several     

circles require to be drawn from the    
same centre4 ,to accomplish this end the
 inside of the point-leg should be1 as  
near as possible1 parallel to the length
 of the instrument 7which is denoted in 
,figure #bd by the dotted line7 when the
 legs are closed1 as in the figure4 ,if 
the point is at an angle1 as shown in   
,figure #be1 it is obvious that rotating
 it will enlarge the top of the centre  
in the drawing paper4 ,the point should 
be sharp and smooth on its              
circumferential surface1 and so much    
longer than the pen-point that it will  
have sufficient hold in the paper when  
the instrument stands vertical and the  
pen-point meets the surface of it1 which
 amount is about #a_/fdth of an inch4   
,we may now consider the shape of the   
pen-point4 ,its inside surfaces should  
be flat across and to the curve shown in
 ,figure #bd1 not as shown exaggerated  
in ,figure #be1 because in the latter   
the body of the ink will be too near the
 pen-point1 and but little can be placed

 in it without causing it sometimes to  
flow over the edges and down the outside
 of the pen4  ,a form of pen-point      
recently introduced is shaped as in     
,figure #bf1 the object being to have a 
thin stream of ink near the marking     
pen-point and the main body of the ink  
near at hand1 instead of extending up   
the pen1 as would be the case with      
,figure #bd4 ,the advantage thus gained 
is that the ink lies in a more solid    
body1 and having less area of surface   
exposed to the air will not dry so      
quickly in the pen2 but this is more    
than offset by the liability of the ink 
to flow over the crook at ,a1 and cause 
the pen to draw a thick ragged line4    
,the pen-point must be slightly inclined
 toward the needle-point1 to the end    
that they may approach each other close 
enough for drawing very small circles1  
but it should also stand as nearly      
vertical as will permit that end to be  
attained4 ,as this pen is for drawing   
small circles only1 it does not require 

much ink1 and hence may be somewhat     
close together1 as in ,figure #bd2 this 
has the advantage that the point is not 
hidden from observation4  ,in forming   
the pen-point the greatest refinement is
 necessary to enable the drawing of very
 small true circles1 say #a_/afth of an 
inch1 or less1 in diameter4 ,the        
requirements are that the pen-point     
shall meet the surface of the paper when
 the needle-point has entered it        
sufficiently to give the necessary      
support1 and that the instrument shall  
stand vertical1 as shown by the dotted  
line in ,figure #bd4 ,also1 that the pen
 shall then touch the paper at a point  
only1 this point being the apex of a    
fine curve2 that this curve be equal on 
each side of the point of contact with  
the paper2 that both halves forming the 
pen be of equal thickness and width at  
the pointed curve2 and that the point be
 as sharp as possible without cutting   
the paper4  ,the best method of         
attaining these ends is as follows3 ,on 

each side of the pen make1 with an      
oil-stone1 a flat place1 as ,c ,d1      
,figure #bg 7where the pen-point is     
shown magnified71 thus bringing both    
halves to an edge of exactly equal      
length1 and leaving the point flat at   
,d4 ,these flat places must be parallel 
to one another and to the joint between 
the two halves of the pen4 ,as the      
oil-stone may leave a slightly ragged   
edge1 it is a good plan to take a piece 
of #jj ,french emery paper1 lay it on a 
flat surface1 and holding the instrument
 vertically remove the fine edge ,d     
until it will not cut4 ,then with the   
oil-stone shape the curved edge as in   
,figure #bh1 taking care that the curve 
no more than brings the flat place ,d up
 to a true curve and leaves the edge    
sharp1 with only the very point touching
 the paper1 which is represented in the 
cut by the horizontal line4             
,illustration3 ,figures #bg4 #bh4 #bi4  
#cj4 #ca4 #cb4  ,the point must have a  
sharp edge all around the curve1 and the

 two halves must be exactly equal in    
width1 for if one half is wider than the
 other1 as in ,figure #bi at a1 or as in
 ,figure #cj at b1 it will be impossible
 to draw a very small circle true4 ,so1 
likewise1 the two halves of the pen must
 be of exactly equal length1 and not one
 half longer than the other1 as in      
,figures #ca or #cb1 which would tend to
 cut the paper1 and also render the     
drawing of true small circles           
impracticable4  ,when the pen is closed 
to draw a very small circle the two     
halves of the pen-leg should have an    
equal degree of contact with the surface
 of the paper1 and then as the legs are 
opened out to draw larger circles the   
contact of the outside half of the pen  
will have less contact with the paper4  
,the smaller the circle1 the more       
difficult it is to keep the point-leg   
from slipping out of the centre1 and the
 more difficult it is to draw a clear   
line and true circle2 hence the points  
should be shaped to the best advantage  

for drawing these small circles1 by     
oil-stoning the pen1 as already         
described1 and then finishing it as     
follows3  ,after the oil-stoning1 open  
the two valves of the pen-leg wide      
enough to admit a piece of #jjj ,french 
emery paper wrapped once around a very  
thin blade1 and move the pen endwise as 
described for the straight-line pen4    
,this will smooth the inner surfaces and
 remove any fine wire-edge that the     
oil-stone may leave4 ,close the two     
halves of the pen again1 and lightly    
emery-paper the outside faces1 which    
will leave the edge sharp enough to cut 
the paper4 ,the removal of the sharp    
edge still left1 to the exact degree1   
requires great care4 ,it may best be    
done by closing the pen until its two   
halves very nearly1 but not quite1      
touch1 then adjust it to mark a circle  
of about #c_/af inch diameter1 and      
strike a number of circles in different 
locations upon the surface of a piece of
 #jjjj ,french emery paper4  ,in marking

 these circles1 however1 let the        
instrument stand out of the             
perpendicular1 and do very little while 
standing vertically4 ,indeed1 it is well
 to strike a number of half-circles1    
first from right to left and then from  
left to right1 and finally draw a full  
circle1 sloping the pen on one side1    
gradually raising it vertically1 and    
finally sloping it to the other side4   
,this will insure that the pen has      
contact at its extreme point1 and leave 
that point fine and keen1 but not enough
 so to cut the paper4 ,to test the pen1 
draw small circles with the pen rotated 
first in one direction and then in the  
other1 closing its points so as to mark 
a fine line1 which1 if the pen is       
properly shaped1 will be clear and fine1
 while if improperly formed the circle  
drawn with the pen rotated in one       
direction will not coincide with that   
drawn while rotating it in the other4   
,the same circle may be drawn over      
several times to make a thorough test4  

,if a drawing instrument will draw a    
fine line correctly1 it will be found to
 answer for thick lines which are more  
easily made4  ,in thus preparing the    
instruments1 the operator will find that
 if he occasionally holds the points in 
the right position with regard to the   
light1 he will be able to see plainly if
 the work is proceeding evenly and      
equally1 for if one-half of the pen is  
thicker at the point or edge than the   
other1 it will show a brighter line4    
,this is especially the case with       
instruments that have become dull by    
use1 for in that case the edges will be 
found quite bright1 and any inequality  
of thickness shows plainly4             
,illustration3 ,fig #cc4  ,illustration3
 ,fig4 #cd4  ,it follows1 from what has 
been said1 that the needle-point and    
pen-point should stand vertical when in 
use1 and to effect this the instruments1
 except in the smallest sizes1 are      
provided with joints1 such as shown at  
,a and ,b in the bow-pencil or          

circle-pencil1 in ,figure #cc4 ,these   
joints should be sufficiently stiff that
 they will not move too easily1 and yet 
will move rather than that the legs     
should sensibly spring without moving at
 the joint4 ,the needle-point leg should
 be adjusted by means of the joint1 to  
stand vertical1 and the same remarks    
apply equally to the pen-leg2 but in the
 case of the pencil-leg it is the pencil
 itself and not the leg that requires   
attention1 the joint ,b being so        
adjusted that the pencil either stands  
vertical1 or1 what is perhaps           
preferable1 so that it stands inclined  
slightly towards the needle-point4 ,in  
sharpening the pencil the inner face ,c 
may be made concave or at least vertical
 and flat1 and the outer convex or else 
bevelled and flat1 producing a fine and 
long edge rounded in its length of edge4
 ,in using the circle-pencil and        
circle-pen it will be found more        
convenient to rotate it in the direction
 of the arrow in ,figure #cd4 ,it should

 be held lightly to the paper1 and the  
learner will find that he has a natural 
tendency to hold it too firmly and press
 it too heavily1 which is especially to 
be avoided4  ,if in drawing a small     
circle the needle-point slips out of the
 paper1 it is because the pencil-point  
is too long2 or1 what is the same thing1
 the needle-point does not protrude far 
enough out from the leg4 ,or if the     
instrument requires to be leaned over   
too much to make the pencil or pen mark1
 it is because the pen or pencil is not 
far enough out1 and this again may cause
 the needle-point to slip out of the    
paper4  ,illustration3 ,fig4 #ce4       
,illustration3 ,fig4 #cf4  ,in ,figure  
#ce is shown a ,german instrument       
especially designed to avoid this       
slipping4 ,the peculiarity of this      
instrument consists in the arrangement  
of the centre point1 which remains      
stationary whilst the pen or pencil1    
resting by its own weight on the paper1 
is guided round by gently turning1      

without pressure1 the small knob at the 
upper end of the tube4 ,by this means   
the misplacing or sliding of the        
centre-point and the cutting of the     
paper by the pen are avoided4 ,by means 
of this fixed centre-point any number of
 concentric circles may be drawn1       
without making a hole of very           
distinguishable size on the paper4      
,illustration3 ,fig #cg4  ,in applying  
the ink to the bow-pen as to all other  
instruments1 care must be taken that the
 ink lies between the points only and   
not on the outside1 for in the latter   
case the ink will flow down too freely  
and make a broad1 ragged line1 perhaps  
getting on the edge of the square blade 
or triangle1 and causing a blot of ink  
on the drawing4  ,in using a straight   
line or lining pen with a ,t square it  
may be used as in ,figure #cf1 being    
nearly vertical1 as shown1 and moved    
from left to right as denoted by the    
arrow1 ,s representing the square blade4
 ,but in using it1 or a pencil1 with a  

straight edge or a triangle unsupported 
by the square blade1 the latter should  
be steadied by letting the fingers rest 
upon it while using the instrument1 the 
operation being shown in ,figure #cg4   
,the position1 ,figure #cf1 is suitable 
for long lines1 and that in ,figure #cg 
for small drawings1 where the pen       
requires close adjustment to the lines4 
,,chapter ,,iii4  ,,lines ,,and         
,,curves4   ,although the beginner will 
find that a study of geometry is not    
essential to the production of such     
elementary examples of mechanical       
drawing as are given in this book1 yet  
as more difficult examples are essayed  
he will find such a study to be of great
 advantage and assistance4 ,meantime the
 following explanation of simple        
geometrical terms is all that is        
necessary to an understanding of the    
examples given4  ,the shortest distance 
between two points is termed the radius2
 and1 in the case of a circle1 means the
 distance from the centre to the        

perimeter measured in a straight line4  
,illustration3 ,fig4 #ch4               
,illustration3 ,fig4 #ci4               
,illustration3 ,fig4 #dj4  ,dotted      
lines1 thus1 -----1 mean the direction  
and the points at which a dimension is  
taken or marked4 ,dotted lines1         
thus1-----1 simply connect the same     
parts or lines in different views of the
 object4 ,thus in ,figure #ch are a side
 and an end view of a rivet1 and the    
dotted lines show that the circles on   
the end view correspond to the circle of
 the diameters of the head and of the   
stem1 and therefore represent their     
diameters while showing that both are   
round4 ,a straight line is in geometry  
termed a right line4  ,a line at a right
 angle to another is said to be         
perpendicular to it2 thus1 in ,figures  
#ci1 #dj1 and #da1 lines ,a are in each 
case perpendicular to line ,b1 or line  
,b is in each case perpendicular to line
 ,a4  ,a point is a position or location
 supposed to have no size1 and in cases 

where necessary is indicated by a dot4  
,illustration3 ,fig4 #da4               
,illustration3 ,fig4 #db4               
,illustration3 ,fig4 #dc4  ,parallel    
lines are those equidistant one from the
 other throughout their length1 as in   
,figure #db4 ,lines maybe parallel      
though not straight2 thus1 in ,figure   
#dc1 the lines are parallel4            
,illustration3 ,fig4 #dd4               
,illustration3 ,fig4 #de4               
,illustration3 ,fig4 #df4  ,a line is   
said to be produced when it is extended 
beyond its natural limits3 thus1 in     
,figure #dd1 lines ,a and ,b are        
produced in the point ,c4  ,a line is   
bisected when the centre of its length  
is marked3 thus1 line ,a in ,figure #de 
is bisected1 at or in1 as it is termed1 
e4  ,the line bounding a circle is      
termed its circumference or periphery   
and sometimes the perimeter4  ,a part of
 this circumference is termed an arc of 
a circle or an arc2 thus ,figure #df    
represents an arc4 ,when this arc has   

breadth it is termed a segment2 thus    
,figures #dg and #dh are segments of a  
circle4 ,a straight line cutting off an 
arc is termed the chord of the arc2     
thus1 in ,figure #dh1 line ,a is the    
chord of the arc4  ,illustration3 ,fig4 
#dg4  ,illustration3 ,fig4 #dh4         
,illustration3 ,fig4 #di4               
,illustration3 ,fig4 #ej4               
,illustration3 ,fig4 #ea4  ,a quadrant  
of a circle is one quarter of the same1 
being bounded on two of its sides by two
 radial lines1 as in ,figure #di4  ,when
 the area of a circle that is enclosed  
within two radial lines is either less  
or more than one quarter of the whole   
area of the circle the figure is termed 
a sector2 thus1 in ,figure #ej1 ,a and  
,b are both sectors of a circle4  ,a    
straight line touching the perimeter of 
a circle is said to be tangent to that  
circle1 and the point at which it       
touches is that to which it is tangent2 
thus1 in ,figure #ea1 line ,a is tangent
 to the circle at point ,b4 ,the half of

 a circle is termed a semicircle2 thus1 
in ,figure #eb1 ,a ,b and ,c are each a 
semicircle4  ,illustration3 ,fig4 #eb4  
,illustration3 ,fig4 #ec4  ,the point   
from which a circle or arc of a circle  
is drawn is termed its centre4 ,the line
 representing the centre of a cylinder  
is termed its axis2 thus1 in ,figure    
#ec1 dot d represents the centre of the 
circle1 and line b b the axial line of  
the cylinder4  ,to draw a circle that   
shall pass through any three given      
points3 ,let ,a ,b and ,c in ,figure #ed
 be the points through which the        
circumference of a circle is to pass4   
,draw line ,d connecting ,a to ,c1 and  
line ,e connecting ,b to ,c4 ,bisect ,d 
in ,f and ,e in ,g4 ,from ,f as a centre
 draw the semicircle ,o1 and from ,g as 
a centre draw the semicircle ,p2 these  
two semicircles meeting the two ends of 
the respective lines ,d ,e4 ,from ,b as 
a centre draw arc ,h1 and from ,c the   
arc ,i1 bisecting ,p in ,j4 ,from ,a as 
a centre draw arc ,k1 and from ,c the   

arc ,l1 bisecting the semicircle ,o in  
,m4 ,draw a line passing through ,m and 
,f1 and a line passing through ,j and   
,q1 and where these two lines intersect1
 as at ,q1 is the centre of a circle ,r 
that will pass through all three of the 
points ,a ,b and ,c4  ,illustration3    
,fig4 #ed4  ,illustration3 ,fig4 #ee4   
,to find the centre from which an arc of
 a circle has been struck3 ,let ,a ,a in
 ,figure #ee be the arc whose centre is 
to be found4 ,from the extreme ends of  
the arc bisect it in ,b4 ,from end ,a   
draw the arc ,c1 and from ,b the arc ,d4
 ,then from the end ,a draw arc ,g1 and 
from ,b the arc ,f4 ,draw line ,h       
passing through the two points of       
intersections of arcs ,c ,d1 and line ,i
 passing through the two points of      
intersection of ,f ,g1 and where ,h and 
,i meet1 as at ,j1 is the centre from   
which the arc was drawn4  ,a degree of a
 circle is the #a_/cfj part of its      
circumference4 ,the whole circumference 
is supposed to be divided into #cfj     

equal divisions1 which are called the   
degrees of a circle2 but1 as one-half of
 the circle is simply a repetition of   
the other half1 it is not necessary for 
mechanical purposes to deal with more   
than one-half1 as is done in ,figure    
#ef4 ,as the whole circle contains #cfj 
degrees1 half of it will contain        
one-half of that number1 or #ahj2 a     
quarter will contain #ij1 and an eighth 
will contain #de degrees4 ,in the       
protractors 7as the instruments having  
the degrees of a circle marked on them  
are termed7 made for sale the edges of  
the half-circle are marked off into     
degrees and half-degrees2 but it is     
sufficient for the purpose of this      
explanation to divide off one quarter by
 lines #aj degrees apart1 and the other 
by lines #e degrees apart4 ,the diameter
 of the circle obviously makes no       
difference in the number of decrees     
contained in any portion of it4 ,thus1  
in the quarter from #j to #ij1 there are
 #ij degrees1 as marked2 but suppose the

 diameter of the circle were that of    
inner circle d1 and one-quarter of it   
would still contain #ij degrees4        
,illustration3 ,fig4 #ef4  ,so1         
likewise1 the degrees of one line to    
another are not always taken from one   
point1 as from the point ,o1 but from   
any one line to another4 ,thus the line 
marked #abj is #fj degrees from line    
#ahj1 or line #ij is #fj degrees from   
line #aej4 ,similarly in the other      
quarter of the circle #fj degrees are   
marked4 ,this may be explained further  
by stating that the point ,o or zero may
 be situated at the point from which the
 degrees of angle are to be taken4 ,here
 it may be remarked that1 to save       
writing the word degrees1 it is usual to
 place on the right and above the       
figures a small  deg41 as is done in    
,figure #ef1 the #fj deg4 meaning sixty 
degrees1 the  deg41 of course1 standing 
for degrees4  ,illustration3 ,fig4 #eg4 
,suppose1 then1 we are given two lines1 
as a and b in ,figure #eg1 and are      

required to find their angle one to the 
other4 ,then1 if we have a protractor1  
we may apply it to the lines and see how
 many degrees of angle they contain4    
,this word contain means how many       
degrees of angle there are between the  
lines1 which1 in the absence of a       
protractor1 we may find by prolonging   
the lines until they meet in a point as 
at c4 ,from this point as a centre we   
draw a circle ,d1 passing through both  
lines a1 b4 ,all we now have to do is to
 find what part1 or how much of the     
circumference1 of the circle is enclosed
 within the two lines4 ,in the example  
we find it is the one-twelfth part2     
hence the lines are #cj degrees apart1  
for1 as the whole circle contains #cfj1 
then one-twelfth must contain #cj1      
because #cfj_/ab  #cj4  ,illustration3  
,fig4 #eh4  ,if we have three lines1 as 
lines ,a ,b and ,c in ,figure #eh1 we   
may find their angles one to the other  
by projecting or prolonging the lines   
until they meet as at points ,d1 ,e1 and

 ,f1 and use these points as the centres
 wherefrom to mark circles as ,g1 ,h1   
and ,i4 ,then1 from circle ,h1 we may1  
by dividing it1 obtain the angle of ,a  
to ,b or of ,b to ,a4 ,by dividing      
circle ,i we may obtain the angle of ,a 
to ,c or of ,c to ,a1 and by dividing   
circle ,g we may obtain the angle of ,b 
to ,c or of ,c to ,b4  ,illustration3   
,fig4 #ei4  ,it may happen1 and1 indeed1
 generally will do so1 that the first   
attempt will not succeed1 because the   
distance between the lines measured1 or 
the arc of the circle1 will not divide  
the circle without having the last      
division either too long or too short1  
in which case the circle may be divided 
as follows3 ,the compasses set to its   
radius1 or half its diameter1 will      
divide the circle into #f equal         
divisions1 and each of these divisions  
will contain #fj degrees of angle1      
because #cfj 7the number of degrees in  
the whole circle7 _/#f 7the number of   
divisions7  #fj1 the number of degrees  

in each division4 ,we may1 therefore1   
subdivide as many of the divisions as   
are necessary for the two lines whose   
degrees of angle are to be found4 ,thus1
 in ,figure #ei1 are two lines1 ,c1 ,d1 
and it is required to find their angle  
one to the other4 ,the circle is divided
 into six divisions1 marked respectively
 from #a to #f1 the division being made 
from the intersection of line ,c with   
the circle4 ,as both lines fall within  
less than a division1 we subdivide that 
division as by arcs a1 b1 which divide  
it into three equal divisions1 of which 
the lines occupy one division4 ,hence1  
it is clear that they are at an angle of
 #bj degrees1 because twenty is         
one-third of sixty4 ,when the number of 
degrees of angle between two lines is   
less than #ij1 the lines are said to    
form an acute angle one to the other1   
but when they are at more than #ij      
degrees of angle they are said to form  
an obtuse angle4 ,thus1 in ,figure #fj1 
,a and ,c are at an acute angle1 while  

,b and ,c are at an obtuse angle4 ,f and
 ,g form an acute angle one to the      
other1 as also do ,g and ,b1 while ,h   
and ,a are at an obtuse angle4 ,between 
,i and ,j there are #ij degrees of      
angle2 hence they form neither an acute 
nor an obtuse angle1 but what is termed 
a right-angle1 or an angle of #ij       
degrees4 ,e and ,b are at an obtuse     
angle4 ,thus it will be perceived that  
it is the amount of inclination of one  
line to another that determines its     
angle1 irrespective of the positions of 
the lines1 with respect to the circle4  
,illustration3 ,fig4 #fj4   ,,triangles4
  ,a right-angled triangle is one in    
which two of the sides are at a right   
angle one to the other4 ,figure #fa     
represents a right-angled triangle1 ,a  
and ,b forming a right angle4 ,the side 
opposite1 as ,c1 is called the          
hypothenuse4 ,the other sides1 ,a and   
,b1 are called respectively the base and
 the perpendicular4  ,illustration3     
,fig4 #fa4  ,illustration3 ,fig4 #fb4   

,illustration3 ,fig4 #fc4               
,illustration3 ,fig4 #fd4  ,an          
acute-angled triangle has all its angles
 acute1 as in ,figure #fc4  ,an         
obtuse-angled triangle has one obtuse   
angle1 as ,a1 ,figure #fb4  ,when all   
the sides of a triangle are equal in    
length and the angles are all equal1 as 
in ,figure #fc1 it is termed an         
equilateral triangle1 and either of its 
sides may be called the base4 ,when two 
only of the sides and two only of the   
angles are equal1 as in ,figure #fd1 it 
is termed an isosceles triangle1 and the
 side that is unequal1 as ,a in the     
figure1 is termed the base4             
,illustration3 ,fig4 #fe4               
,illustration3 ,fig4 #ff4  ,when all the
 sides and angles are unequal1 as in    
,figure #fe1 it is termed a scalene     
triangle1 and either of its sides may be
 called the base4  ,the angle opposite  
the base of a triangle is called the    
vertex4  ,illustration3 ,fig4 #fg4      
,illustration3 ,fig4 #fh4  ,a figure    

that is bounded by four straight lines  
is termed a quadrangle1 quadrilateral or
 tetragon4 ,when opposite sides of the  
figure are parallel to each other it is 
termed a parallelogram1 no matter what  
the angle of the adjoining lines in the 
figure may be4 ,when all the angles are 
right angles1 as in ,figure #ff1 the    
figure is called a rectangle4 ,if the   
sides of a rectangle are of equal       
length1 as in ,figure #fg1 the figure is
 called a square4 ,if two of the        
parallel sides of a rectangle are longer
 than the other two sides1 as in ,figure
 #ff1 it is called an oblong4 ,if the   
length of the sides of a parallelogram  
are all equal and the angles are not    
right angles1 as in ,figure #fh1 it is  
called a rhomb1 rhombus or diamond4 ,if 
two of the parallel sides of a          
parallelogram are longer than the other 
two1 and the angles are not right       
angles1 as in ,figure #fi1 it is called 
a rhomboid4 ,if two of the parallel     
sides of a quadrilateral are of unequal 

lengths and the angles of the other two 
sides are not equal1 as in ,figure #gj1 
it is termed a trapezoid4               
,illustration3 ,fig4 #fi4               
,illustration3 ,fig4 #gj4               
,illustration3 ,fig4 #ga4  ,if none of  
the sides of a quadrangle are parallel1 
as in ,figure #ga1 it is termed a       
trapezium4  ,,the ,,construction ,,of   
,,polygons4  ,illustration3 ,fig4 #ga;a4
  ,illustration3 ,fig4 #gb4  ,the term  
polygon is applied to figures having    
flat sides equidistant from a common    
centre4 ,from this centre a circle may  
be struck that will touch all the       
corners of the sides of the polygon1 or 
the point of each side that is central  
in the length of the side4 ,in drawing a
 polygon1 one of these circles is used  
upon which to divide the figure into the
 requisite number of divisions for the  
sides4 ,when the dimension of the       
polygon across its corners is given1 the
 circle drawn to that dimension         
circumscribes the polygon1 because the  

circle is without or outside of the     
polygon and touches it at its corners   
only4 ,when the dimension across the    
flats of the polygon is given1 or when  
the dimension given is that of a circle 
that can be inscribed or marked within  
the polygon1 touching its sides but not 
passing through them1 then the polygon  
circumscribes or envelops the circle1   
and the circle is inscribed or marked   
within the polygon4 ,thus1 in ,figure   
#ga a1 the circle is inscribed within   
the polygon1 while in ,figure #gb the   
polygon is circumscribed by the circle2 
the first is therefore a circumscribed  
and the second an inscribed polygon4 ,a 
regular polygon is one the sides of     
which are all of an equal length4       
,,names ,,of ,,regular ,,polygons4  ,a  
figure of #c sides is called a ,trigon4 
#d                 ,tetragon4   polygon 
#e                 ,pentagon4           
#f                 ,hexagon4            
#g                 ,heptagon4           
#h                 ,octagon4            

#i                 ,enneagon or         
,nonagon4  ,illustration3 ,fig4 #gc4    
,illustration3 ,fig4 #gd4  ,the angles  
of regular polygons are designated by   
their degrees of angle1 at the centre   
and at the circumference4 ,by the angle 
at the centre is meant the angle of a   
side to a radial line2 thus in ,figure  
#gc is a hexagon1 and at ,c is a radial 
line2 thus the angle of the side ,d to  
,c is #fj degrees4 ,or if at the two    
ends of a side1 as ,a1 two radial lines 
be drawn1 as ,b1 ,c1 then the angles of 
these two lines1 one to the other1 will 
be the angle at the centre4 ,the angle  
at the circumference is the angle of one
 side to its next neighbor2 thus the    
angle at the circumference in a hexagon 
is #abj degrees1 as shown in the figure 
for the sides ,e1 ,f4 ,it is obvious    
that as all the sides are of equal      
length1 they are all at the same angle  
both to the centre and to one another4  
,in ,figure #gd is a trigon1 the angles 
at its centre being #abj1 and the angle 

at the circumference being #fj1 as      
marked4  ,the angles of regular         
polygons3  ,trigon1 at the centre1 #abj 
deg41 at the circumference1 #fj deg44   
,tetragon1              #ij deg41       
#ij deg44 ,pentagon1              #gb   
deg41                    #ajh deg44     
,hexagon1               #fj deg41       
#abj deg44 ,octagon1               #de  
deg41                    #ace deg44     
,enneagon1              #dj deg41       
#adj deg44 ,decagon1               #cf  
deg41                    #add deg44     
,dodecagon1             #cj deg41       
#aej deg44   ,,the ,,ellipse4  ,an      
ellipse is a figure bounded by a        
continuous curve1 whose nature will be  
shown presently4  ,the dimensions of an 
ellipse are taken at its extreme length 
and narrowest width1 and they are       
designated in three ways1 as by the     
length and breadth1 by the major and    
minor axis 7the major axis meaning the  
length1 and the minor the breadth of the
 figure71 and the conjugate and         

transverse diameters1 the transverse    
meaning the shortest1 and the conjugate 
the longest diameter of the figure4  ,in
 this book the terms major and minor    
axis will be used to designate the      
dimensions4  ,the minor and major axes  
are at a right angle one to the other1  
and their point of intersection is      
termed the axis of the ellipse4  ,in an 
ellipse there are two points situated   
upon the line representing the major    
axis1 and which are termed the foci when
 both are spoken of1 and a focus when   
one only is referred to1 foci simply    
being the plural of focus4 ,these foci  
are equidistant from the centre of the  
ellipse1 which is formed as follows3    
,two pins are driven in on the major    
axis to represent the foci ,a and ,b1   
,figure #ge1 and around these pins a    
loop of fine twine is passed2 a pencil  
point1 ,c1 is then placed in the loop   
and pulled outwards1 to take up the     
slack of the twine4 ,the pencil is held 
vertical and moved around1 tracing an   

ellipse as shown4  ,illustration3 ,fig4 
#ge4  ,now it is obvious1 from this     
method of construction1 that there will 
be at every point in the pencil's path a
 length of twine from the final point to
 each of the foci1 and a length from one
 foci to the other1 and the length of   
twine in the loop remaining constant1 it
 is demonstrated that if in a true      
ellipse we take any number of points in 
its curve1 and for each point add       
together its distance to each focus1 and
 to this add the distance apart of the  
foci1 the total sum obtained will be the
 same for each point taken4             
,illustration3 ,fig4 #gf4               
,illustration3 ,fig4 #gg4  ,in ,figures 
#gf and #gg are a series of ellipses    
marked with pins and a piece of twine1  
as already described4 ,the corresponding
 ellipses1 as ,a in both figures1 were  
marked with the same loop1 the          
difference in the two forms being due to
 the difference in distance apart of the
 foci4 ,again1 the same loop was used   

for ellipses ,b in both figures1 as also
 for ,c and ,d4 ,from these figures we  
perceive that--  #ast4 ,with a given    
width or distance apart of foci1 the    
larger the dimensions are the nearer the
 form of the figure will approach to    
that of a circle4  #b;d4 ,the nearer the
 foci are together in an ellipse1 having
 any given dimensions1 the nearer the   
form of the figure will approach that of
 a circle4  #c;d4 ,that the proportion  
of length to width in an ellipse is     
determined by the distance apart of the 
foci4  #dth4 ,that the area enclosed    
within an ellipse of a given            
circumference is greater in proportion  
as the distance apart of the foci is    
diminished2 and1  #eth4 ,that an ellipse
 may be given any required proportion of
 width to length by locating the foci at
 the requisite distance apart4  ,the    
form of a true ellipse may be very      
nearly approached by means of the arcs  
of circles1 if the centres from which   
those arcs are struck are located in the

 most desirable positions for the form  
of ellipse to be drawn4  ,illustration3 
,fig4 #gh4  ,thus in ,figure #gh are    
three ellipses whose forms were         
pencilled in by means of pins and a loop
 of twine1 as already described1 but    
which were inked in by finding four arcs
 of circles of a radius that would most 
closely approach the pencilled line2 a b
 are the foci of all three ellipses ,a1 
,b1 and ,c2 the centre for the end      
curves of a are at c and d1 and those   
for its side arcs are at e and f4 ,for  
,b the end centres are at g and h1 and  
the side centres at i and j4 ,for ,c the
 end centres are at k1 l1 and the side  
centres at m and n4 ,it will be noted   
that1 first1 all the centres for the end
 curves fall on the line of the length  
or major axis1 while all those for the  
sides fall on the line of width or the  
minor axis2 and1 second1 that as the    
dimensions of the ellipses increase1 the
 centres for the arcs fall nearer to the
 axis of the ellipse4 ,now in proportion

 as a greater number of arcs of circles 
are employed to form the figure1 the    
nearer it will approach the form of a   
true ellipse2 but in practice it is not 
usual to employ more than eight1 while  
it is obvious that not less than four   
can be used4 ,when four are used they   
will always fall somewhere on the lines 
on the major and minor axis2 but if     
eight are used1 two will fall on the    
line of the major axis1 two on the line 
of the minor axis1 and the remaining    
four elsewhere4  ,illustration3 ,fig4   
#gi4  ,in ,figure #gi is a construction 
wherein four arcs are used4 ,draw the   
line a b1 the major axis1 and at a right
 angle to it the line c d1 the minor    
axis of the figure4 ,now find the       
difference between the length of half   
the two axes as shown below the figure1 
the length of line f 7from g to i7      
representing half the length of the     
figure 7as from a to e71 and the length 
or radius from g to h equalling that    
from e to d2 hence from h to i is the   

difference between half the major and   
half the minor axis4 ,with the radius 7h
 i71 mark from e as a centre the arcs j 
k1 and join j k by line l4 ,take half   
the length of line l and from j as a    
centre mark a line on a to the arc m4   
,now the radius of m from e will be the 
radius of all the centres from which to 
draw the figure2 hence we may draw in   
the circle m and draw line s1 cutting   
the circle4 ,then draw line o1 passing  
through m1 and giving the centre p4     
,from p we draw the line q1 cutting the 
intersection of the circle with line a  
and giving the centre r4 ,from r we draw
 line s1 meeting the circle and the line
 c1 d1 giving us the centre t4 ,from t  
we draw line u1 passing through the     
centre m4 ,these four lines o1 q1 s1 u  
are prolonged past the centres1 because 
they define what part of the curve is to
 be drawn from each centre3 thus from   
centre m the curve from v to w is drawn1
 from centre t the curve from w to x is 
drawn4 ,from centre r the curve from x  

to y is drawn1 and from centre p the    
curve from y to v is drawn4 ,it is to be
 noted1 however1 that after the point m 
is found1 the remaining lines may be    
drawn very quickly1 because the line o  
from m to p may be drawn with the       
triangle of #de degrees resting on the  
square blade4 ,the triangle may be      
turned over1 set to point p and line q  
drawn1 and by turning the triangle again
 the line s may be drawn from point r2  
finally the triangle may be again turned
 over and line u drawn1 which renders   
the drawing of the circle m unnecessary4
  ,to draw an elliptical figure whose   
proportion of width to breadth shall    
remain the same1 whatever the length of 
the major axis may be3 ,take any square 
figure and bisect it by the line ,a in  
,figure #hj4 ,draw1 in each half of the 
square1 the diagonals ,e ,f1 ,g ,h4     
,from ,p as a centre with the radius ,p 
,r draw the arc ,s ,e ,r4 ,with the same
 radius draw from ,o as a centre the arc
 ,t ,d ,v4 ,with radius ,l ,c draw arc  

,r ,c ,v1 and from ,k as a centre draw  
arc ,s ,b ,t4  ,illustration3 ,fig4 #hj4
  ,illustration3 ,fig4 #ha4  ,a very    
near approach to the true form of a true
 ellipse may be drawn by the            
construction given in ,figure #ha1 in   
which ,a ,a and ,b ,b are centre lines  
passing through the major and minor axis
 of the ellipse1 of which a is the axis 
or centre1 b c is the major axis1 and a 
e half the minor axis4 ,draw the        
rectangle b f g c1 and then the diagonal
 line b e2 at a right angle to b e draw 
line f h1 cutting ,b ,b at i4 ,with     
radius a e and from a as a centre draw  
the dotted arc e j1 giving the point j  
on line ,b ,b4 ,from centre k1 which is 
on the line ,b ,b and central between b 
and j1 draw the semicircle b m j1       
cutting ,a ,a at l4 ,draw the radius of 
the semicircle b m j1 cutting it at m1  
and cutting f g at n4 ,with the radius m
 n mark on ,a ,a at and from a as a     
centre the point o4 ,with radius h o and
 from centre h draw the arc p o q4 ,with

 radius a l and from b and c as centres1
 draw arcs cutting p o q at the points p
 q4 ,draw the lines h p r and h q s and 
also the lines p i t and q v w4 ,from h 
as a centre draw that part of the       
ellipse lying between r and s1 with     
radius p r2 from p as a centre draw that
 part of the ellipse lying between r and
 t1 with radius q s1 and from q as a    
centre draw the ellipse from s to w1    
with radius i t2 and from i as a centre 
draw the ellipse from t to b and with   
radius v w1 and from v as a centre draw 
the ellipse from w to c1 and one-half of
 the ellipse will be drawn4 ,it will be 
seen that the whole construction has    
been performed to find the centres h1 p1
 q1 i and v1 and that while v and i may 
be used to carry the curve around on the
 other side of the ellipse1 new centres 
must be provided for h p and q1 these   
new centres corresponding in position to
 h p q4 ,divesting the drawing of all   
the lines except those determining its  
dimensions and the centres from which   

the ellipse is struck1 we have in       
,figure #hb the same ellipse drawn half 
as large4 ,the centres v1 p1 q1 h       
correspond to the same centres in       
,figure #ha1 while v'1 p'1 q'1 h' are in
 corresponding positions to draw in the 
other half of the ellipse4 ,the length  
of curve drawn from each centre is      
denoted by the dotted lines radiating   
from that centre2 thus1 from h the part 
from r to s is drawn2 from h' that part 
from r' to s'4 ,at the ends the         
respective centres v are used for the   
parts from w to w' and from t to t'     
respectively4  ,illustration3 ,fig4 #hb4
  ,illustration3 ,fig4 #hc4  ,the most  
correct method of drawing an ellipse is 
by means of an instrument termed a      
trammel1 which is shown in ,figure #hc4 
,it consists of a cross frame in which  
are two grooves1 represented by the     
broad black lines1 one of which is at a 
right angle to the other4 ,in these     
grooves are closely fitted two sliding  
blocks1 carrying pivots ,e ,f1 which may

 be fastened to the sliding blocks1     
while leaving them free to slide in the 
grooves at any adjusted distance apart4 
,these blocks carry an arm or rod having
 a tracing point 7as pen or pencil7 at  
,g4 ,when this arm is swept around by   
the operator1 the blocks slide in the   
grooves and the pen-point describes an  
ellipse whose proportion of width to    
length is determined by the distance    
apart of the sliding blocks1 and whose  
dimensions are determined by the        
distance of the pen-point from the      
sliding block4 ,to set the instrument1  
draw lines representing the major and   
minor axes of the required ellipse1 and 
set off on these lines 7equidistant from
 their intersection71 to mark the       
required length and width of ellipse4   
,place the trammel so that the centre of
 its slots is directly over the point or
 centre from which the axes are marked  
7which may be done by setting the       
centres of the slots true to the lines  
passing through the axis7 and set the   

pivots as follows3 ,place the           
pencil-point ,g so that it coincides    
with one of the points as ,c1 and place 
the pivot ,e so that it comes directly  
at the point of intersection of the two 
slots1 and fasten it there4 ,then turn  
the arm so that the pencil-point ,g     
coincides with one of the points of the 
minor axis as ,d1 the arm lying parallel
 to ,b ,d1 and place the pivot ,f over  
the centre of the trammel and fasten it 
there1 and the setting is complete4     
,illustration3 ,fig4 #hd4  ,to draw a   
parabola mechanically3 ,in ,figure #hd  
,c ,d is the width and ,h ,j the height 
of the curve4 ,bisect ,h ,d in ,k4 ,draw
 the diagonal line ,j ,k and draw ,k ,e1
 cutting ,k at a right angle to ,j ,k1  
and produce it in ,e4 ,with the radius  
,h ,e1 and from ,j as a centre1 mark    
point ,f1 which will be the focus of the
 curve4 ,at any convenient distance     
above ,j fasten a straight-edge ,a ,b1  
setting it parallel to the base ,c ,d of
 the parabola4 ,place a square ,s with  

its back against the straight-edge1     
setting the edge ,o ,n coincident with  
the line ,j ,h4 ,place a pin in the     
focus ,f1 and tie to it one end of a    
piece of twine4 ,place a tracing-point  
at ,j1 pass the twine around the        
tracing-point1 bringing down along the  
square-blade and fasten it at ,n1 with  
the tracing-point kept against the edge 
of the square and the twine kept taut2  
slide the square along the              
straight-edge1 and the tracing-point    
will mark the half ,j ,c of the         
parabola4 ,turn the square over and     
repeat the operation to trace the other 
half ,j ,d4 ,this method corresponds to 
the method of drawing an ellipse by the 
twine and pins1 as already described4   
,illustration3 ,fig4 #he4  ,to draw a   
parabola by lines3 ,bisect the width ,a 
,b in ,figure #he1 and divide each half 
into any convenient number of equal     
divisions2 and through these points of  
division draw vertical lines1 as #a1 #b1
 #c1 etc4 7in each half74 ,divide the   

height ,a ,d at one end and ,b ,e at the
 other into as many equal divisions as  
the half of ,a ,b is divided into4 ,from
 the points of divisions #a1 #b1 #c1    
etc41 on lines ,a ,d and ,b ,e1 draw    
lines pointing to ,c1 and where these   
lines intersect the corresponding       
vertical lines are points through which 
the curve may be drawn4 ,thus on the    
side ,a ,d of the curve1 the            
intersection of the two lines marked #a 
is a point in the curve2 the            
intersection of the two lines marked #b 
is another point in the curve1 and so   
on4   ,,to ,,draw ,a ,,heart ,,cam4     
,illustration3 ,fig4 #hf4  ,draw the    
line ,a ,b1 ,figure #hf1 equal to the   
length of stroke required4 ,divide it   
into any number of equal parts1 and from
 ,c as a centre draw circles through the
 points of division4 ,draw the outer    
circle and divide its circumference into
 twice as many equal divisions as the   
line ,a ,b was divided into4 ,draw      
radial lines from each point of division

 on the circle1 and the points of       
intersection of the radial lines with   
the circles are points for the outline  
of the cam1 and through these points a  
curved line may be drawn giving the     
shape of the cam4 ,it is obvious that   
the greater the number of divisions on  
,a ,b1 the more points and the more     
perfect the curve may be drawn4         
,,chapter ,,iv4  ,,shadow ,,lines ,,and 
,,line ,,shading4  ,,section ,,lining   
,,or ,,cross-,,hatching4   ,when the    
interior of a piece is to be shown as a 
piece cut in half1 or when a piece is   
broken away1 as is done to make more of 
the parts show1 or show more clearly1   
the surface so broken away or cut off is
 section-lined or cross-hatched2 that is
 to say1 diagonal lines are drawn across
 it1 and to distinguish one piece from  
another these lines are drawn at varying
 angles and of varying widths apart4 ,in
 ,figure #hg is given a view of three   
cylindrical pieces4 ,it may be known to 
be a sectional view by the              

cross-hatching or section lines4 ,it    
would be a difficult matter to represent
 the three pieces put together without  
showing them in section1 because1 in an 
outline view1 the collars and recesses  
would not appear4 ,each piece could of  
course be drawn separately1 but this    
would not show how they were placed when
 put together4 ,they could be shown in  
one view if they were shaded by lines   
and a piece shown broken out where the  
collars and1 recesses are1 but line     
shading is too tedious for detail       
drawings1 beside involving too much     
labor in their production4              
,illustration3 ,fig4 #hg4  ,figure #hh  
represents a case in which there are    
three cylindrical pieces one within the 
other1 the two inner ones being fastened
 together by a screw which is shown     
dotted in in the end view1 and whose    
position along the pieces is shown in   
the side view4 ,the edges of the        
fracture in the outer piece are in this 
case cross-hatched1 to show the line of 

fracture4  ,illustration3 ,fig4 #hh4    
,illustration3 ,fig4 #hi4  ,in          
cross-hatching it is better that the    
diagonal lines do not quite meet the    
edges of the piece1 than that they      
should in the least overrun1 as is shown
 in ,figure #hi1 where in the top half  
the diagonals slightly overrun1 while in
 the lower half they do not quite meet  
the outlines of the piece4  ,in ,figure 
#ij are shown in section a number of    
pieces one within the other1 the central
 bore being filled with short plugs4    
,all the cross-hatching was done with   
the triangle of #fj degrees and that of 
#ij degrees4 ,it is here shown that with
 these two triangles only1 and a        
judicious arrangement of the diagonals1 
an almost infinite number of pieces may 
be shown in cross section without any   
liability of mistaking one for the      
other1 or any doubt as to the form and  
arrangement of the pieces2 for1 beside  
the difference in spacing in the        
cross-hatching1 there are no two        

adjoining pieces with the diagonals     
running in the same direction4 ,it will 
be seen that the narrow pieces are most 
clearly defined by a close spacing of   
the cross-hatching4  ,illustration3     
,fig4 #ij4  ,in ,figure #ia are shown   
three pieces put together and having    
slots or keyways through them4 ,the     
outer shell is shown to be in one piece 
from end to end1 because the            
cross-hatching is not only equally      
spaced1 but the diagonals are in the    
same direction2 hence it would be known 
that ,d1 ,f1 ,h1 and ,e were slots or   
recesses through the piece4 ,the same   
remarks apply to piece ,b1 wherein ,g1  
,j1 ,k are recesses or slots4 ,piece ,c 
is shown to have in its bore a recess at
 ,l4 ,in the case of ,b1 as of ,a1 there
 would be no question as to the piece   
being all one from end to end1          
notwithstanding that the two ends are   
completely severed where the slots ,g1  
,i1 come1 because the spacing and       
direction of the cross-hatching are     

equal on each side of the slots1 which  
they would not be if they were separate 
pieces4  ,illustration3 ,fig4 #ia4      
,illustration3 ,fig4 #ib4  ,section     
shading or cross-hatching may sometimes 
cause the lines of the drawing to appear
 crooked to the eye4 ,thus1 in ,figure  
#ib1 the key edge on the right appears  
curved inwards1 while on the left the   
key edge appears curved outwards1       
although such is not actually the case4 
,the same effect is produced in ,figure 
#ic on the right-hand edge of the key1  
but not on the left-hand edge4          
,illustration3 ,fig4 #ic  ,illustration3
 ,fig4 #id4  ,a remarkable instance of  
this kind is shown in ,figure #id1 when 
the vertical lines appear to the eye to 
be at a considerable angle one to the   
other1 although they are parallel4  ,the
 lines in sectional shading or          
cross-hatching may be made to denote the
 material of which the piece is to be   
composed4 ,thus ,professor ,unwin has   
proposed the system shown in the        

,figures #ie and #if4 ,this may be of   
service in some cases1 but it would     
involve very much more labor than it is 
worth in ordinary machine shop drawings1
 except in the case of cast iron and    
wood1 these two being shown in the      
simplest and the usual manner4 ,it is   
much better to write the name of the    
material beneath the piece in a detail  
drawing4  ,illustration3 ,fig4 #ie4     
,illustration3 ,fig4 #if4   ,,line      
,,shading4  ,mechanical drawings are    
made to look better and to show more    
distinctly by being line shaded or      
shaded by lines4 ,the simplest form of  
line shading is by the use of the shade 
or shadow line4  ,in a mechanical       
drawing the light is supposed1 for the  
purposes of line shading or of coloring1
 to come in from the upper left-hand    
corner of the drawing paper2 hence it   
falls directly upon the upper and       
left-hand lines of each piece1 which are
 therefore represented by fine lines1   
while the right hand and lower edges of 

the piece being on the shadow side may  
therefore1 with propriety1 be           
represented by broader lines1 which are 
called shadow or shade lines4 ,these    
lines will often serve to indicate the  
shape of some part of the piece         
represented1 as will be seen from the   
following examples4 ,in ,figure #ig is a
 piece that contains a hole1 the fact   
being shown by the circle being         
thickened at ,a4 ,if the circle were    
thickened on the other side as at ,b1 in
 ,figure #ih1 it would show that it     
represented a cylindrical stem instead  
of a hole4  ,illustration3 ,fig4 #ig4   
,illustration3 ,fig4 #ih4               
,illustration3 ,fig4 #ii4  ,in ,figure  
#ii is represented a washer1 the        
surfaces that are in the shadow side    
being shown in a shade line or shadow   
line1 as it is often called4  ,in       
,figure #ajj is a key drawn with a shade
 line1 while in ,figure #aja the shade  
line is shown applied to a nut4 ,the    
shade line may be produced in straight  

lines by drawing the line twice over1   
and slightly inclining the pen1 or by   
opening the pen points a little4 ,for   
circles1 however1 it may be produced    
either by slightly moving the centre    
from which the circle is drawn1 or by   
going over the shade part twice1 and    
slightly pressing the instrument as it  
moves1 so as to gradually spring the    
legs farther apart1 the latter plan     
being generally preferable4             
,illustration3 ,fig4 #ajj4              
,illustration3 ,fig4 #aja4              
,illustration3 ,fig4 #ajb4  ,figure #ajb
 shows a ,german pen1 that can be       
regulated to draw lines of various      
breadths4 ,the head of the adjusting    
screw is made rather larger than usual1 
and is divided at the under side into   
twenty divisional notches1 each         
alternate notch being marked by a figure
 on the face4 ,by this arrangement a    
uniform thickness of line may be        
maintained after filling or clearing the
 pen1 and any desired thickness may be  

repeated1 without any loss of time in   
trial of thickness on the paper4 ,a     
small spring automatically holds the    
divided screw-head in any place4 ,with  
very little practice the click of the   
spring in the notches becomes a         
sufficient guide for adjustment1 without
 reference to the figures on the        
screw-head4 ,another meritorious feature
 of this pen is that it is armed with   
sapphire points1 which retain their     
sharpness very long1 and thus save the  
time and labor required to keep ordinary
 instruments in order for the           
performance of fine work4  ,an example  
of line shading in perspective drawing  
is shown in the drawing of a pipe       
threading stock and die in ,figure #ajc4
  ,illustration3 ,fig4 #ajc4  ,shading  
by means of lines may be used with      
excellent effect in mechanical drawing1 
not only to distinguish round from flat 
surfaces1 but also to denote to the eye 
the relative distances of surfaces4     
,figure #ajd represents a cylindrical   

pin line shaded4 ,as the light is       
supposed to come in from the upper      
left-hand corner1 it will evidently fall
 more upon the left-hand half of the    
stem1 and of the collar or bead1 hence  
those parts are shaded with lighter or  
finer lines than the right-hand sides   
are4  ,illustration3 ,fig4 #ajd4        
,illustration3 ,fig4 #aje4  ,two        
cylindrical pieces that join each other 
may be line shaded at whatever angle    
they may join4 ,figure #aje represents  
two such pieces1 one at a right angle to
 the other1 both being of equal         
diameter4  ,illustration3 ,fig4 #ajf4   
,figure #ajf represents a drawing of a  
lathe centre shaded by lines1 the lines 
on the taper parts meeting those on the 
parallel part ,a1 and becoming more     
nearly parallel to the axis of the piece
 as the centre of the piece is          
approached4 ,the same is the case where 
a piece having a curved outline is      
drawn1 which is shown in ,figure #ajg1  
where the set of the bow-pen is         

gradually increased for drawing the     
shade lines of the curves4 ,the centres 
of the shade curves fall in each case   
upon a line at a right angle to the axis
 of the piece1 as upon the lines ,a1 ,b1
 ,c1 the dotted lines showing the radius
 for each curve4  ,illustration3 ,fig4  
#ajg4  ,the lines are made finer by     
closing the pen points by means of the  
screw provided for that purpose4 ,the   
pen requires for this purpose to be     
cleaned of the ink that is apt to dry in
 it4  ,in ,figure #ajh line shading is  
shown applied to a ball or sphere1 while
 in ,figure #aji it is shown applied to 
a pin in a socket which is shown in     
section4 ,by showing the hollow in      
connection with the round piece1 the    
difference between the two is quite     
clearly seen1 the light falling most    
upon the upper half of the pin and the  
lower half of the hole4 ,this perhaps is
 more clearly shown in the piece of tube
 in ,figure #aaj1 where the thickness of
 the tube showing is a great aid to the 

eye4 ,so1 likewise1 the hollow or hole  
is more clearly seen where the piece is 
shown in section1 as in ,figure #aaa1   
which is the case even though the piece 
be taper as in the figure4 ,if the body 
be bell-mouthed1 as in ,figure #aab1 the
 hollow curve is readily shown by the   
shading2 but to line shade a hollow     
curve without any of these aids to the  
eye1 as say1 to show a half of a tin    
tube1 is a very difficult matter if the 
piece is to look natural2 and all that  
can be done is to shade the top darkly  
and let the light fall mostly at and    
near the bottom4 ,an example of line    
shading to denote the relative distances
 from the eye of various surfaces is    
given in ,figure #aac1 where the        
surfaces most distant are the most      
shaded4 ,the flat surfaces are lined    
with lines of equal breadth1 the degrees
 of shading being governed by the width 
apart of the lines4  ,illustration3     
,fig4 #ajh4  ,illustration3 ,fig4 #aji4 
,illustration3 ,fig4 #aaj4              

,illustration3 ,fig4 #aaa4              
,illustration3 ,fig4 #aab4              
,illustration3 ,fig4 #aac4  ,line       
shading is often used to denote that the
 piece represented is to be of wood1 the
 shade lines being in some cases regular
 in combination with regular ones1 or   
entirely irregular1 as in ,figure #aad4 
,illustration3 ,fig4 #aad4     ,,chapter
 ,v4  ,,marking ,,dimensions4   ,the    
dimensions of mechanical drawings are   
best marked in red ink so that they will
 show plainly1 and that the lines       
denoting the points at which the        
dimension is given shall not be         
confounded with the lines of the        
drawing4  ,the dimension figures should 
be as large as the drawing will         
conveniently admit2 and should be marked
 at every point at which a shoulder or  
change of form or dimension occurs1     
except in the case of straight tapers   
which have their dimensions marked at   
each end of the taper4  ,in the case of 
a single piece standing by itself the   

dimension figures may be marked all     
standing one way1 so as to be read      
without changing the position of the    
operator or requiring to turn the       
drawing around4 ,this is done in ,figure
 #aae1 which represents the drawing of a
 key4 ,the figures are here placed      
outside the drawing in all cases where  
it can be done1 which1 in the case of a 
small drawing1 leaves the same clearer4 
,illustration3 ,fig4 #aae4  ,in ,figure 
#aaf the dimensions are marked1 running 
parallel to the dimension for which they
 are given1 so that all measures of     
length stand lengthwise1 and those of   
breadth across the drawing4             
,illustration3 ,fig4 #aaf4  ,figure #aag
 represents a key with a sharp-cornered 
step in it4 ,here the two dimensions    
forming the steps cannot both be        
coincident with it2 hence they are      
marked as near to it as convenient1 it  
being understood that they apply to the 
step1 and not to one side of it4 ,when  
the step has a round instead of a sharp 

corner1 the radius of the arc of the    
corner may be marked1 as shown in       
,figure #aah4  ,illustration3 ,fig4     
#aag4  ,figure #aai represents a key    
drawn in perspective1 so that all the   
dimensions may be marked on one view4   
,perspective sketches may be used for   
single pieces1 as they denote the shape 
of the piece more clearly to the eye4   
,on account of the skill required in    
their production1 they are not1 however1
 used in mechanical drawing1 except as  
in the case of ,patent-,office or       
similar drawings1 where the form and    
construction rather than the dimension  
is the information sought to be         
conveyed4  ,illustration3 ,fig4 #aah4   
,illustration3 ,fig4 #aai4     ,,chapter
 ,,vi4  ,,the ,,arrangement ,,of        
,,different ,,views4  ,,the ,,different 
,,views ,,of ,a ,,mechanical ,,drawing4 
,the word elevation1 as applied to      
mechanical drawing1 means simply a view2
 hence a side elevation is a side view1 
or an end elevation is an end view4     

,the word plan is employed in place of  
the word top2 hence a plan view is a top
 view1 or a view looking down upon the  
top of the piece4  ,a general view means
 a view showing the machine put together
 or assembled1 while a detail drawing is
 one containing a detail1 as a part of  
the machine or a single piece           
disconnected from the other parts of the
 whole machine4  ,it is obviously       
desirable in a mechanical drawing to    
present the piece of work in as few     
views as possible1 but in all cases     
there must be a sufficient number to    
permit of the dimensions in every       
necessary direction to be marked on the 
drawing4 ,suppose1 then1 that in ,figure
 #abj we have to represent a solid      
cylinder1 whose length equals its       
diameter1 and it is obvious that both   
the diameter and length may be marked in
 the one view given2 hence1 a second    
view1 such as shown by the circle in    
,figure #aba1 is unnecessary1 except it 
be to distinguish the body from a cube1 

in which the one view would also be     
sufficient whereon to mark all the      
dimensions necessary to enable the piece
 to be made4 ,it happens1 however1 that 
a cube and a cylinder are the only two  
figures upon which all the dimensions   
can be marked on one view of the piece1 
and as cylindrical pieces are much more 
common in machine work than cubes are1  
it is taken for granted that1 where the 
pieces are cylindrical1 but one view    
shall be used1 and that where they are  
cubes either two views shall be given1  
or where they are square a cross shall  
be marked upon the parts that are       
square2 thus1 in ,figure #abb1 is shown 
a cross formed by the lines ,a ,b across
 the face of the drawing1 which saves   
making a second view4  ,illustration3   
,fig4 #abj4  ,illustration3 ,fig4 #aba4 
,illustration3 ,fig4 #abb4              
,illustration3 ,fig4 #abc4  ,it would   
appear that under some conditions this  
might lead to error2 as1 for example1   
take the piece in ,figure #abc1 and     

there is nothing to denote which is the 
length and which is the diameter of the 
piece1 but there is a certain amount of 
custom in such cases than will usually  
determine this point2 thus1 the piece   
will be given a name1 as pin or disk1   
the one denoting that its diameter is   
less than its length1 and the other that
 its diameter is greater than its       
length4 ,in the absence of any such     
name1 it would be in practice assumed   
that it was a pin and not a disk2       
because1 if it were a disk1 it would    
either be named or shaded1 or a second  
view given to show its unusual form1 the
 disk being a more unusual form than the
 pin-form in mechanical structures4 ,as 
an example of the use of the cross to   
denote a square1 we have ,figure #abd1  
which represents a piece having a       
hexagon head1 section a1 a'1 that is    
rectangular1 a collar b1 a square part  
c1 and a round stem d4 ,here it will be 
noted that it is the rectangular part a1
 a'1 that renders necessary two views1  

and that in the absence of the cross1   
yet another view would be necessary to  
show that part c is square4             
,illustration3 ,fig4 #abd4              
,illustration3 ,fig4 #abe4  ,a          
rectangular piece always requires two   
views and sometimes three4 ,in ,figure  
#abe1 for example1 is a piece that would
 require a side view to show the length 
and breadth1 and an edge view to show   
the thickness4 ,suppose the piece to be 
wedge-shaped in any direction2 then     
another view will be necessary1 as is   
shown in ,figs4 #abf and #abg4 ,in the  
former the wedge or taper is in the     
direction of its length1 while in the   
latter it is in the direction of its    
thickness4 ,outline views1 however1 will
 not in some cases show the form of the 
figure1 however many views be presented4
 ,an example of this is given in ,figure
 #abh1 which represents a ring having a 
hexagon cross section4 ,a sectional edge
 view is here necessary in order to show
 the hexagonal form4 ,another example of

 this kind1 which occurs more frequently
 in practice1 is a cupped ring such as  
shown in ,figure #abi4  ,illustration3  
,fig4 #abf4  ,illustration3 ,fig4 #abg4 
,illustration3 ,fig4 #abh4              
,illustration3 ,fig4 #abi4   ,,examples4
  ,let it be required to draw a         
rectangular piece such as is shown in   
two views in ,figure #acj1 and the      
process for the pencil lines is as      
follows3  ,illustration3 ,fig4 #acj4    
,with the bow-pencil set to half the    
required length and breadth of the      
square the arcs #a1 #b1 #c and #d1 in   
,figure #aca1 are marked1 and then the  
lines #e and #f1 letting them run past  
the width of the arcs #c and #d4 ,there 
is no need to pencil in lines #g and #h1
 since they can be inked in without     
pencilling1 because it is known that    
they must meet the arcs #c and #d and   
terminate at the lines #e and #f4 ,the  
top and bottom lines of the edge view   
are merely prolongations of lines #e and
 #f2 hence the lines #i and #aj are     

drawn the requisite distance apart for  
the thickness and to meet the top and   
bottom lines4 ,the lines are then inked 
in1 the pencil lines rubbed out1 and the
 drawing will appear as in ,figure #acj4
  ,illustration3 ,fig4 #aca4            
,illustration3 ,fig4 #acb4  ,suppose1   
however1 that the piece has a step in   
it1 as in ,figure #acb1 and the         
pencilling will be as in ,figure #acc4  
,from the centre1 the arcs #a1 #b1 #c   
and #d for the outer1 and arcs #e1 #f1  
#g and #h for the inner square are      
marked2 lines #i and #aj1 and their     
prolongations1 #aa and #ab1 for the edge
 view1 are then pencilled2 lines #ac and
 #ad1 and their prolongations1 #ae and  
#af1 are then pencilled1 and dots to    
show the locations for lines #ba and #bb
 maybe marked and the pencilling is     
complete4 ,lines #ag1 #ah1 #ai1 #bj1    
#ba1 #bb1 and #bc may then be inked in1 
in the order named1 and then lines #i1  
#aj1 #aa1 #ab1 #ac1 #ad1 #ae and #af1   
when the inking in will be complete4    

,illustration3 ,fig4 #acc4  ,in inking  
in horizontal lines begin at the top and
 mark in each line as the square comes  
to it2 and in inking the vertical ones  
begin always at the left hand line and  
mark the lines as they are come to1     
moving the square or the triangle to the
 right1 and great care should be taken  
not to let the lines cross where they   
meet1 as at the corners1 since this     
would greatly impair the appearance of  
the drawing4  ,these figures have been  
drawn without the aid of a centre line1 
because from their shapes it was easy to
 dispense with it1 but in most cases a  
centre line is necessary2 thus in       
,figure #acd we have a body having a    
number of steps4 ,the diameters of these
 steps are marked by arcs1 as in the    
previous examples1 and their lengths may
 be marked by applying the measuring    
rule direct to the drawing paper and    
making the necessary pencil mark4  ,but 
it would be tedious to mark the         
successive steps true one with the other

 by measuring each step1 because one    
step would require to be pencilled in   
before the next could be marked4 ,to    
avoid this the centre line #a1 ,figure  
#acd1 is first marked1 and the arcs for 
the steps are then marked as shown4     
,centre lines are also necessary to show
 the alignment of one part to another2  
thus in ,figure #ace is a cube with a   
hole passing through it4 ,the dotted    
lines in the side view show that the    
hole passes clear through the piece and 
is a parallel one1 while the centre     
line1 being central to the outline      
throughout the piece1 shows that the    
hole is equidistant1 all through1 from  
the walls of the piece4  ,illustration3 
,fig4 #acd4  ,illustration3 ,fig4 #ace4 
,the pencil lines for this piece would  
be marked as in ,figure #acf1 line #a   
representing the centre line from which 
all the arcs are marked4 ,it will be    
noted that the length of the piece is   
marked by arcs which occur1 because     
being a cube the set of the compasses   

for arcs #b1 #c1 #d and #e will answer  
without altering to mark arcs #f and #g4
  ,illustration3 ,fig4 #acf4  ,if the   
hole in the piece were a taper or       
conical one1 it would be denoted by the 
dotted lines1 as in ,figure #acg1 and   
that the taper is central to the body is
 shown by these dotted lines being      
equidistant from the centre line4       
,illustration3 ,fig4 #acg4  ,suppose one
 of the sides to be tapered1 as is the  
side ,a1 in ,figure #ach1 and that the  
hole is not central1 and both facts will
 be shown by the centre lines #a and #b 
in the figure4 ,the measurement of face 
,a would be marked from ,a to line ,b at
 each end1 but the distance the hole was
 out of the centre would be marked by   
the distance between the centre line #b 
and the edge ,c of the piece4           
,illustration3 ,fig4 #ach4  ,if the hole
 did not pass entirely through the      
piece1 the dotted lines would show it1  
as in ,figure #aci4  ,illustration3     
,fig4 #aci4  ,illustration3 ,fig4 #adj4 

,the designations of the views of a     
piece of work depend upon the position  
in which the piece stands1 when in place
 upon the machine of which it forms a   
part4 ,thus in ,figure #adj is a lever1 
and if its shaft stood horizontal when  
the piece is in place in the machine1   
the view given is an end one1 but       
suppose that the shaft stood vertical1  
and the same view becomes a plan or top 
view4  ,illustration3 ,fig4 #ada4       
,illustration3 ,fig4 #adb4  ,in ,figure 
#adb is a view of a lever which is a    
side view if the lever stands           
horizontal1 and lever ,b hangs down1 or 
a plan view if the shaft stands         
horizontal1 but lever ,b stands also    
horizontal4 ,we may take the same       
drawing and turn it around on the paper 
as in ,figure #adc1 and it becomes a    
side view if the shaft stands vertical1 
and a plan view if the shaft stands     
horizontal and arm ,d vertical above it4
  ,in a side or an end view1 the piece  
that projects highest in the drawing is 

highest when upon the machine2 also in a
 side elevation the piece that is at the
 highest point in the drawing extends   
farthest upward when the piece is on the
 machine4 ,but in a plan or top view the
 height of vertical pieces is not shown1
 as appears in the case of arm ,d in    
,figure #adc4  ,illustration3 ,fig4     
#adc4  ,in either of the levers1        
,figures #adb or #adc1 all the          
dimensions could be marked if an        
additional view were given1 but this    
will not be the case if an eye have a   
slot in it1 as at ,e1 in ,figure #add1  
or a jaw have a tongue in it1 as at ,f3 
hence1 end views of the eye and the jaw 
must be given1 which may be most        
conveniently done by showing them       
projected from the ends of those parts  
as in the figure4  ,this naturally      
brings us to a consideration as to the  
best method of projecting one view from 
another4 ,as a general rule1 the side   
elevation or side view is the most      
important1 because it shows more of the 

parts and details of the work2 hence it 
should be drawn first1 because it       
affords more assistance in drawing the  
other views4  ,illustration3 ,fig4 #add4
  ,there are two systems of placing the 
different views of a piece4 ,in the     
first the views are presented as the    
piece would present itself if it were   
laid upon the paper for the side view1  
and then turned or rolled upon the paper
 for the other views1 as shown in       
,figure #ade1 in which the piece        
consists of five sections or members1   
marked respectively ,a1 ,b1 ,c1 ,d1 and 
,e4 ,now if the piece were turned or    
rolled so that the end face of ,b were  
uppermost1 and the member ,e was        
beneath1 it will1 by the operation of   
turning it1 have assumed the position in
 the lower view marked position #b2     
while if it were turned over upon the   
paper in the opposite direction it would
 assume the position marked #c4 ,this   
gives to the mind a clear idea of the   
various views and positions2 but it     

possesses some disadvantages3 thus1 if  
position #a is a side elevation or view 
of the piece1 as it stands when in place
 of the machine1 then ,e is naturally   
the bottom member2 but it is shown in   
the top view of the drawing1 hence what 
is actually the bottom view of the piece
 7position #c7 becomes the top view in  
the drawing4 ,a second disadvantage is  
that if we desire to put in dotted      
lines1 to show how one view is derived  
from the other1 and denote corresponding
 parts1 then these dotted lines must be 
drawn across the face of the drawing1   
making it less distinct2 thus the dotted
 lines connecting stem ,e in position #a
 to ,e in position #c1 pass across the  
faces of both ,a and ,b of position #a4 
,illustration3 ,fig4 #ade4              
,illustration3 ,fig4 #adf4  ,in a large 
drawing1 or one composed of many members
 or parts1 it would1 therefore1 be out  
of the question to mark in the dotted   
lines4 ,a further disadvantage in a     
large drawing is that it is necessary to

 go from one side of the drawing to the 
other to see the construction of the    
same part4  ,illustration3 ,fig4 #adg4  
,to obviate these difficulties1 a modern
 method is to suppose the piece1 instead
 of rolling upon the paper1 to be lifted
 from it1 turned around to present the  
required view1 and then moved upwards on
 the paper for a top view1 sideways for 
a side view1 and below for a bottom     
view4 ,thus the three views of the piece
 in ,figure #ade would be as in ,figure 
#adf1 where position #b is obtained by  
supposing the piece to be lifted from   
position #a1 the bottom face turned     
uppermost1 and the piece moved down the 
paper to position #b1 which is a bottom 
view of the piece1 and the bottom view  
in the drawing4 ,similarly1 if the piece
 be lifted from position #a1 and the top
 face in that figure is turned          
uppermost1 and the piece is then slid   
upwards on the paper1 view #c is        
obtained1 being a top view of the piece 
as it lies in position #a1 and the top  

view in the drawing4 ,now suppose we    
require to find the shape of member ,b1 
then in ,figure #ade we require to look 
at the top of position #a1 and then down
 below to position #b4  ,illustration3  
,fig4 #adh4  ,but in ,figure #adf we    
have the side view and end view both    
together1 while the dotted lines do not 
require to cross the face of the side   
view4 ,now suppose we take a similar    
piece1 and suppose its end faces1 as ,f1
 ,g1 to have holes in them1 which       
require to be shown in both views1 and  
under the one system the drawing would1 
if the dotted lines were drawn across1  
appear as in ,figure #adg1 whereas under
 the other system the drawing would     
appear as in ,figure #adh4 ,and it      
follows that in cases where it is       
necessary to draw dotted lines from one 
view to the other1 it is best to adopt  
the new system4     ,,chapter ,,vii4    
,,examples ,,in ,,bolts1 ,,nuts1 ,,and  
,,polygons4   ,illustration3 ,fig4 #adi4
  ,illustration3 ,fig4 #aej4            

,illustration3 ,fig4 #aea4  ,let it be  
required to draw a machine screw1 and it
 is not necessary1 and therefore not    
usual in small screws to draw the full  
outline of the thread1 but to represent 
it by thick and thin lines running      
diagonally across the bolt1 as in       
,figure #adi1 the thick ones            
representing the bottom1 and the thin   
ones the top of the thread4 ,the pencil 
lines would be drawn in the order shown 
in ,figure #aej4 ,line #a is the centre 
line1 and line #b a line to represent   
the lower side of the head2 from the    
intersection of these two lines as a    
centre 7as at ,a7 short arcs #c and #f1 
showing the diameter of the thread1 are 
marked1 and the arcs #e and #f1         
representing the depth of the thread1   
are marked4 ,the arc #g1 representing   
the head1 is then marked4 ,the vertical 
lines #h1 #i1 #aj1 and #aa are then     
marked1 and the outline of the screw is 
complete4 ,the thick lines representing 
the bottom of the thread are next marked

 in1 as in ,figure #aea1 extending from 
line #i to line #aj4 ,midway between    
these lines fine ones are made for the  
tops of the thread4 ,all the lines being
 pencilled in1 they may be inked in with
 the drawing instruments1 taking care   
that they do not overrun one another4   
,when the pencil lines are rubbed out1  
the sketch will appear as in ,figure    
#adi4  ,illustration3 ,fig4 #aeb4  ,for 
a bolt with a hexagon head the lines    
would be drawn in the order shown in    
,figure #aeb4 ,at a right-angle to      
centre line #a1 line two is drawn4 ,the 
pencil-compasses are then set to half   
the diameter of the bolt1 and from point
 ,a arcs #c and #f are pencilled1 thus  
showing the width of the front flat of  
the head1 as well as the diameter of the
 stem4 ,from the point where these arcs 
meet line #b1 and with the same radius1 
arcs #e and #f are marked1 showing the  
widths of the other two flats of the    
head4 ,the thickness of the head and the
 length of the bolt head may then be    

marked either by placing a rule on line 
#a and marking the short lines 7such as 
line #g7 a cross line #a1 or the        
pencil-compasses may be set to the rule 
and the lengths marked from point ,a4   
,in the ,united ,states standard for    
bolt heads and nuts the thickness of the
 head is made equal to the diameter of  
the bolt4 ,with the compasses set for   
the arcs #c and #d1 we may in two steps1
 from ,a along the centre line1 mark off
 the thickness of the head without using
 the rule4 ,but as the rule has to be   
applied along line #a to mark line #g   
for the length of the bolt1 it is just  
as easy to mark the head thickness at   
the same time4 ,the line #h showing the 
length of the thread may be marked at   
the same time as the other lengths are  
marked1 and the outlines #i1 #aj1 #aa1  
#ab1 #ac may be drawn in the order      
named4 ,we have now to mark the arcs at 
the top of the flats of the head to show
 the chamfer1 and to explain how these  
arcs are obtained we have in ,figure    

#aec an enlarged view of the head4 ,it  
is evident that the smallest diameter of
 the chamfer is represented by the      
circle ,a1 and therefore the length of  
the line ,b must equal ,a4 ,it is also  
evident that the outer edge of the      
chamfer will meet the corners at an     
equal depth 7from the face of the nut71 
as represented by the line ,c ,c1 and it
 is obvious that the curves that        
represent the outline of the chamfer on 
each side of the head or nut will       
approach the face of the head or nut at 
an equal distance1 as denoted by the    
line ,d ,d4 ,it follows that the curve  
must in each case be such as will1 at   
each of its ends1 meet the line ,c1 and 
at its centre meet the line ,d ,d1 the  
centres of the respective curves being  
marked in the figure by ,x4             
,illustration3 ,fig4 #aec4  ,it is      
sufficiently accurate1 therefore1 for   
all practical purposes to set the pencil
 on the centre-line at the point ,a in  
,figure #aeb and mark the curve #ad1 and

 to then set the compasses by trial to  
mark the other two curves of the        
chamfer1 so that they shall be an equal 
distance with arc #ad from line #i1 and 
join lines #aj and #ac at the same      
distance from line #i that #ad joins    
lines #c and #d1 so that as in ,figure  
#aec all three of the arcs would touch a
 line as ,c1 and another line as ,d4    
,illustration3 ,fig4 #aed4  ,the ,united
 ,states standard sizes for forged or   
unfinished bolts and nuts are given in  
the following table1 ,figure #aed       
showing the dimensions referred to in   
the table4  ,,united ,,states ,,standard
 ,,dimensions ,,of ,,bolts ,,and ,,nuts4
  ,,key3 ,a3 ,nominal4 ,d4 ,b3          
,effective499 ,c3 ,standard ,number of  
threads per inch4                       
----------------------------------------
---------------------------------       
,,bolt4                ,,bolt ,,head    
,,and ,,nut4                            
----------------------------------------
-------------------------------         

,diameter4             ,long diameter1  
,short               -------------      
,i1 or diameter   diameter              
across corners4  of                     
---------------- hexagon                
,a    ,b       ,c      ,hexa-   ,square4
 and                                    
gon4            square1   ,depth of     
,depth of                               
or width  nut1      bolt                
across ,j4 ,h4        head1 ,k4         
----------------------------------------
----------------------------    #a_/d   
4#ahe   #bj         #i_/af   #bc_/cb    
#a_/b       #a_/d      #a_/d   #e_/af   
4#bdj   #ah        #aa_/af   #bg_/cb    
#ai_/cb     #e_/af     #ai_/fd    #c_/h 
4#bid   #af        #be_/cb   #ca_/cb    
#aa_/af     #c_/h      #aa_/cb   #g_/af 
4#cde   #ad        #bi_/cb #a-c_/cb     
#be_/cb     #g_/af     #be_/fd    #a_/b 
4#djj   #ac      #a       #a-a_/d       
#g_/h       #a_/b      #g_/af   #i_/af  
4#ded   #ab      #a-a_/h   #a-c_/h      
#ca_/cb     #i_/af     #ca_/fd    #e_/h 

4#ejg   #aa      #a-g_/cb  #a-a_/b      
#a-a_/af      #e_/h      #ag_/cb        
#c_/d  4#fbj   #aj      #a-g_/af        
#a-c_/d    #a-a_/d       #c_/d          
#e_/h    #g_/h  4#gca    #i             
#a-ba_/cb #b-a_/cb   #a-g_/af      #g_/h
      #bc_/cb  #a      4#hcg    #h      
#a-g_/h   #b-e_/af   #a-e_/h     #a     
#ac_/af  #a-a_/h  4#idj    #g           
#b-c_/cb  #b-i_/af   #a-ac_/af   #a-a_/h
      #bi_/cb  #a-a_/d #a4jfe    #g     
#b-e_/af  #b-bg_/cb  #b         #a-a_/d 
#a  #a-c_/h #a4afj    #f      #b-ag_/cb 
#c-c_/cb   #b-c_/af    #a-c_/h          
#a-c_/cb  #a-a_/b #a4bhd    #f          
#b-c_/d   #c-aa_/cb  #b-c_/h     #a-a_/b
    #a-c_/af  #a-e_/h #a4chi    #e-a_/b 
#b-ca_/cb #c-e_/h    #b-i_/af    #a-e_/h
    #a-i_/cb  #a-c_/d #a4dia    #e      
#c-c_/af  #c-g_/h    #b-c_/d     #a-c_/d
    #a-c_/h  #a-g_/h #a4faf    #e       
#c-ac_/cb #d-e_/cb   #b-ae_/af   #a-g_/h
    #a-ae_/cb  #b     #a4gab    #d-a_/b 
#c-ai_/cb #d-ac_/cb  #c-a_/h     #b     
#a-i_/af  #b-a_/d #a4ifb    #d-a_/b     

#d-a_/cb  #d-ae_/af  #c-a_/b     #b-a_/d
    #a-c_/d  #b-a_/b #b4agf    #d       
#d-ae_/cb #e-ae_/cb  #c-g_/h     #b-a_/b
    #a-ae_/af  #b-c_/d #b4dbf    #d     
#d-bi_/cb #f        #d-a_/d     #b-c_/d 
#b-a_/h  #c     #b4fbi    #c-a_/b       
#e-aa_/cb #f-ag_/cb  #d-e_/h     #c     
#b-e_/af  #c-a_/d #b4hgi    #c-a_/b     
#e-be_/cb #g-a_/af   #e         #c-a_/d 
#b-a_/b  #c-a_/b #c4ajj    #c-a_/d      
#f-g_/cb  #g-ai_/cb  #e-c_/h     #c-a_/b
    #b-aa_/af  #c-c_/d #c4cag    #c     
#f-e_/h   #h-a_/h    #e-c_/d     #c-c_/d
    #b-g_/h   444  #c4efg    #c         
#g-a_/af  #h-ba_/cb  #f-a_/h     #d     
#c-a_/af  #d-a_/d #c4gih    #b-g_/h     
#g-a_/b   #i-c_/af   #f-a_/b     #d-a_/d
    #c-a_/d  #d-a_/b #d4jbh    #b-c_/d  
#g-ae_/af #i-bc_/cb  #f-g_/h     #d-a_/b
    #c-g_/af  #d-c_/d #d4bef    #b-e_/h 
#h-c_/h  #aj-a_/d    #g-a_/d     #d-c_/d
    #c-e_/h  #e     #d4dhj    #b-a_/b   
#h-ac_/afaj-be_/cb  #g-e_/h     #e      
#c-ac_/af  #e-a_/d #d4gcj    #b-a_/b    
#i-a_/d  #aa-e_/af   #h         #e-a_/d 

#d  #e-a_/b #d4iec    #b-c_/h           
#i-aa_/afaa-bg_/cb  #h-c_/h     #e-a_/b 
#d-c_/af  #e-c_/d #e4bjc    #b-c_/h     
#aj-c_/cb #ab-c_/h    #h-c_/d           
#e-c_/d    #d-c_/h  #f     #e4dbc       
#b-a_/d #aj-ag_/cbab-bi_/cb  #i-a_/h    
#f        #d-i_/af                      
----------------------------------------
---------------------------- 99         
,diameter at the root of the thread4    
,the basis of the ,franklin ,institute  
or ,united ,states standard for the     
heads of bolts and for nuts is as       
follows3  ,the short diameter or width  
across the flats is equal to one and    
one-half times the diameter plus #a_/h  
inch for rough or unfinished bolts and  
nuts1 and one and one-half times the    
bolt diameter plus1 #a_/af inch for     
finished heads and nuts4 ,the thickness 
is1 for rough heads and nuts1 equal to  
the diameter of the bolt1 and for       
finished heads and nuts #a_/af inch     
less4  ,illustration3 ,fig4 #aee4       
,illustration3 ,fig4 #aef4  ,the        

hexagonal or hexagon 7as they are termed
 in the shop7 heads of bolts may be     
presented in two ways1 as is shown in   
,figures #aee and #aef4  ,the latter is 
preferable1 inasmuch as it shows the    
width across the flats1 which is the    
dimension that is worked to1 because it 
is where the wrench fits1 and therefore 
of most importance2 whereas the latter  
gives the length of a flat1 which is not
 worked to1 except incidentally1 as it  
were4 ,there is the objection to the    
view of the head1 given in ,figure #aef1
 however1 that unless it is accompanied 
by an end view it somewhat resembles a  
similar view of a square head for a     
bolt4 ,it may be distinguished          
therefrom1 however1 in the following    
points3  ,if the amount of chamfer is   
such as to leave the chamfer circle 7as 
circle ,a1 in ,figure #aec7 of smaller  
diameter than the width across the flats
 of the bolt-head1 the outline of the   
sides of the head will pass above the   
arcs at the top of the flats1 and there 

will be two small flat places1 as ,a and
 ,b1 in ,figure #aef 7representing the  
angle of the chamfer71 which will not   
meet the arcs at the top of the flats1  
but will join the sides above those     
arcs1 as in the figure2 which is also   
the case in a similar view of a         
square-headed bolt4 ,it may be          
distinguished therefrom1 however1 in the
 following points3  ,if the amount of   
chamfer is such as to leave the chamfer 
circle 7,a1 ,figure #aec7 of smaller    
diameter than the width across the flats
 of the bolt-head1 the outline of the   
sides will pass above the arc on the    
flats1 as is shown in ,figure #aeg1 in  
which the chamfer ,a meets the side of  
the head at ,b1 and does not1 therefore1
 meet the arc ,c4 ,the length of side   
lying between ,b and ,d in the side view
 corresponds with the part lying between
 ,e and ,f in the end view4             
,illustration3 ,fig4 #aeg4  ,if we      
compare this head with similar views of 
a square head ,g1 both being of equal   

widths1 and having their chamfer circles
 at an equal distance from the sides of 
the flats1 and at the same angle1 we    
perceive at once that the amount of     
chamfer necessary to give the same      
distance between the chamfer circle and 
the side of the bolt 7that is1 the      
distance from ,j to ,k1 being equal to  
that from ,l to ,m71 the length of the  
chamfer ,n for the square head so       
greatly exceeds the length ,a for the   
hexagon head that the eye detects the   
difference at once1 and is instinctively
 informed that ,g must be square1       
independently of the fact that in the   
case of the square head1 ,n meets the   
arc ,o1 while in the hexagon head1 ,a1  
which corresponds to ,n1 does not meet  
the arc ,c1 which corresponds to ,o4    
,when1 however1 the chamfer is drawn1   
but just sufficient to meet the flats1  
as in the case of the hexagon ,h1 and   
the square ,i1 in ,figure #aeg1 the     
chamfer line passes from the chamfer    
circle to the side of the head1 and the 

distinction is greater1 as will be seen 
by comparing head ,h with head ,i1 both 
being of equal width1 having the same   
angle of chamfer1 and an amount just    
sufficient to meet the sides of the     
flats4 ,here it will be seen that in the
 hexagon ,h1 each side of the head1 as  
,p1 meets the chamfer circle ,a4        
,whereas1 in the square head these two  
lines are joined by the chamfer line ,q1
 the figures being quite dissimilar4    
,illustration3 ,fig4 #aeh4  ,it is      
obvious that whatever the degree or     
angle of the chamfer may be1 the        
diameter of the chamfer circle will be  
the same in any view in which the head  
may be presented4 ,thus1 in ,figure     
#aeh1 the line ,g in the side view is in
 length equal to the diameter of circle 
,g1 in the end view1 and so long as the 
angle of the chamfer is forty-five      
degrees1 as in all the views hitherto   
given1 the width of the chamfer will be 
equal at corresponding points in the    
different views2 thus in the figure the 

widths ,a and ,b in the two views are   
equal4  ,illustration3 ,fig4 #aei4  ,if 
the other view showing a corner of the  
head in front of the head be given1 the 
same fact holds good1 as is shown in    
,figure #aei4 ,that the two outside     
flats should appear in the drawing to be
 half the width of the middle flat is   
also shown in ,figure #aeh1 where ,d and
 ,e are each half the width of ,c4 ,let 
us now suppose1 that the chamfer be     
given some other angle than that of #de 
degrees1 and we shall find that the     
effect is to alter the curves of the    
chamfer arcs on the flats1 as is shown  
in ,figure #afj1 where these arcs ,e1   
,c1 ,d are shown less curved1 because   
the chamfer ,b has more angle to the    
flats4 ,as a result1 the width or       
distance between the arcs and line ,g is
 different in the two views4 ,on this   
account it is better to draw the chamfer
 at #de degrees1 as correct results may 
be obtained with the least trouble4  ,if
 no chamfer at all is to be given1 a    

hexagon head may still be distinguished 
from a square one1 providing that the   
view giving three sides of the head1 as 
in ,figure #aeh1 is shown1 because the  
two sides ,d and ,e being half the width
 of the middle one ,c1 imparts the      
information that it is a hexagon head4  
,if1 however1 the view showing but two  
of the sides and a corner in front is   
given1 and no chamfer is used1 it could 
not be known whether the head was to be 
hexagon or square1 unless an end view be
 given1 as in ,figure #afa4             
,illustration3 ,fig4 #afj4  ,if the view
 showing a full side of the head of a   
square-headed bolt is given1 then either
 an end view must be given1 as in       
,figure #afb1 or else a single view with
 a cross on its head1 as in ,figure     
#afc1 may be given4  ,it is the better  
plan1 both in square and hexagon heads1 
to give the view in which the full face 
of a flat is presented1 that is1 as in  
,figures #aee and #afc2 because1 in the 
case of the square1 the length of a side

 and the width across the head are both 
given in that view2 whereas if two sides
 are shown1 as in ,figure #afa1 the     
width across flats is not given1 and    
this is the dimension that is wanted to 
work to1 and not the width across       
corners4 ,in the case of a hexagon the  
middle of the three flats is equal in   
width to the diameter of the bolt1 and  
the other two are one-half its width2   
all three1 therefore1 being marked with 
the same set of compasses as gives the  
diameter of the body of the bolt1 were  
as shown in ,figure #aeb4 ,for the width
 across flats there is an accepted      
standard2 hence there is no need to mark
 it upon the drawing1 unless in cases   
where the standard is to be departed    
from1 in which event an end view may be 
added1 or the view showing two sides may
 be given4  ,illustration3 ,fig #afa4   
,illustration3 ,fig4 #afb4              
,illustration3 ,fig4 #afc4              
,illustration3 ,fig4 #afd4  ,to draw a  
square-headed bolt1 the pencil lines are

 marked in the order shown by figures in
 ,figure #afd4 ,the inking in is done in
 the order of the letters a1 b1 c1 etc4 
,it will be observed that pencil lines  
#b1 #i1 and #aj are not drawn to cross1 
but only to meet the lines at their     
ends1 a point that1 as before stated1   
should always be carefully attended to4 
,illustration3 ,fig4 #afe  ,to draw the 
end view of a hexagon head1 first draw a
 circle of the diameter across the      
flats1 and then rest the triangle of #fj
 degrees on the blade s of the square1  
as at ,t #a1 in ,figure #afe1 and mark  
the lines a and b4 ,reverse the         
triangle1 as at ,t #b1 and draw lines c 
and d4 ,then place the triangle as in   
,figure #aff1 and draw the lines e and  
f4  ,illustration3 ,fig4 #aff4  ,if the 
other view of the head is to be drawn1  
then first draw the lines a and b in    
,figure #afg with the square1 then with 
the #fj degree triangle1 placed on the  
square ,s1 as at ,t #a1 draw the lines  
c1 d1 and turning the square over1 as at

 ,t #b1 mark lines e and f4             
,illustration3 ,fig4 #afg4  ,if the     
diameter across corners of a square head
 is given1 and it be required to draw   
the head1 the process is as follows3    
,for a view showing one corner in front1
 as in ,figure #afh1 a circle of the    
given diameter across corners is        
pencilled1 and the horizontal           
centre-line a is marked1 and the        
triangle of #de degrees is rested       
against the square blade ,s1 as in      
position ,t #a1 and lines b and c       
marked1 b being marked first2 and the   
triangle is then slid along the square  
blade to position ,t #a1 when line c is 
marked1 these two lines just meeting the
 horizontal line a1 where it meets the  
circle4 ,the triangle is then moved to  
the left1 and line d1 joining the ends  
of b and c1 is marked1 and by moving it 
still farther to the left to position ,t
 #b1 line e is marked4 ,lines b1 c1 d1  
and e are1 of course1 the only ones     
inked in4  ,illustration3 ,fig4 #afh4   

,illustration3 ,fig4 #afi4  ,if the     
flats are to lie in the other direction1
 the pencilling will be done as in      
,figure #afi4 ,the circle is marked as  
before1 and with the triangle placed as 
shown at ,t #a1 line a1 passing through 
the centre of the circle1 is drawn4 ,by 
moving the triangle to the right its    
edge ,b will be brought into position to
 mark line b1 also passing through the  
centre of the circle4 ,all that remains 
is to join the ends of these two lines1 
using the square blade for lines c1 d1  
and the triangle for e and f1 its       
position on the square blade being      
denoted at ,t #c2 lines c1 d1 e1 f1 are 
the ones inked in4  ,illustration3 ,fig4
 #agj4  ,for a hexagon head we have the 
processes1 ,figures #agj and #aga4 ,the 
circle is struck1 and across it line a1 
,figure #agj1 passing through its       
centre1 the triangle of sixty degrees   
will mark the sides b1 c1 and d1 e1 as  
shown1 and the square blade is used for 
f1 g4  ,illustration3 ,fig4 #aga4  ,the 

chamfer circles are left out of these   
figures to reduce the number of lines   
and so keep the engraving clear4 ,figure
 #aga shows the method of drawing a     
hexagon head when the diameter across   
corners is given1 the lines being drawn 
in the alphabetical order marked1 and   
the triangle used as will now be        
understood4  ,illustration3 ,fig4 #agb4 
,illustration3 ,fig4 #agc4  ,it may now 
be pointed out that the triangle may be 
used to divide circles much more quickly
 than they could be divided by stepping 
around them with compasses4 ,suppose1   
for example1 that we require to divide a
 circle into eight equal parts1 and we  
may do so as in ,figure #agb1 line a    
being marked from the square1 and lines 
b1 c and d from the triangle of         
forty-five degrees2 the lines to be     
inked in to form an octagon need not be 
pencilled1 as their location is clearly 
defined1 being lines joining the ends of
 the lines crossing the circle1 as for  
example1 lines e1 f4  ,let it be        

required to draw a polygon having twelve
 equal sides1 and the triangle of sixty 
is used1 marking all the lines within   
the circle in ,figure #agc1 except a1   
for which the square blade is used2 the 
only lines to be inked in are such as b1
 c4 ,in this example there is a corner  
at the top and bottom1 but suppose it   
were required that a flat should fall   
there instead of a corner2 then all we  
have to do is to set the square blade ,s
 at the required angle1 as in ,figure   
#agd1 and then proceed as before1       
bearing in mind that the point of the   
circle nearest to the square blade1     
straight-edge1 or whatever the triangle 
is rested on1 is always a corner of a   
polygon having twelve sides4            
,illustration3 ,fig4 #agd4              
,illustration3 ,fig4 #age4  ,in both of 
these examples we have assumed that the 
diameter across corners of the polygon  
was given1 but suppose the diameter     
across the flats were given1 and the    
construction is a little more           

complicated4 ,circle a1 a1 in ,figure   
#age1 is drawn of the required diameter 
across the flats1 and the lines of      
division are drawn across with the      
triangle of #fj as before2 the triangle 
of #de is then used to draw the four    
lines1 b1 c1 d1 e1 joining the ends of  
lines i1 j1 k1 l1 and touching the inner
 circle1 a1 a4 ,the outer circle is then
 pencilled in1 touching the lines of    
division where they meet the lines b1 c1
 d1 e1 and the rest of the lines for the
 sides of the polygon may then be drawn 
within the outer circle1 as at g1 h4    
,illustration3 ,fig4 #agf4  ,it is      
obvious1 also1 that the triangle may be 
used to draw slots radiating from a     
centre1 as in ,figure #agf1 where it is 
desired to draw a chuck-plate having #f 
slots4 ,the triangle of #fj is used to  
draw the centre lines1 a1 b1 c1 etc41   
for the slots4 ,from the centre1 the    
arcs e1 f1 g1 h1 etc41 are marked1      
showing where the centres will fall for 
describing the half circles forming the 

ends of the slots4 ,then half circles1  
i1 j1 k1 l1 etc41 being drawn1 the sides
 of the slots may be drawn in with the  
triangle1 and the outer circle and the  
slots inked in4  ,if the slots are not  
to radiate from the centre of the circle
 the process is as follows3  ,the outer 
circle a1 ,figure #agg1 being drawn1 an 
inner one b is drawn1 its radius        
equalling the amount2 the centres of the
 slots are to point to one side of the  
centre of circle a4 ,the triangle is    
then used to divide the circle into the 
requisite number of divisions c for the 
slots1 and arcs i1 j1 are then drawn for
 the lengths of the slots4 ,the centre  
lines e are then drawn1 passing through 
the lines c1 and the arcs i1 j1 etc41   
and touching the perimeter of the inner 
circle b2 arcs f1 g1 are then marked in1
 and their sides joined with the        
triangle adjusted by hand4 ,all that    
would be inked in black are the outer   
circle and the slots1 but the inner     
circle b and a centre line of one of the

 slots should be marked in red ink to   
show how the inclination of the slot was
 obtained1 and therefore its amount4    
,illustration3 ,fig4 #agg4  ,for a      
five-sided figure it is best to step    
around the circumference of the circle  
with the compasses1 but for a           
three-sided one1 or trigon1 the         
construction is as follows3 ,it will be 
found that the compasses set to the     
radius of a circle will accurately      
divide it into six equal divisions1 as  
is shown in ,figure #agh2 hence every   
other one of these divisions will be the
 location for a corner of a trigon4     
,the circle being drawn1 a line ,a1     
#agi1 is drawn through its centre1 and  
from its intersection with the circle as
 at b1 here a step on each side is      
marked as c1 d1 then lines c to d1 and c
 and d to e1 where ,a meets1 the circle 
will describe a trigon4 ,if the figure  
is to stand vertical1 all that is       
necessary is to draw the line a         
vertical1 as in ,figure #ahj4 ,a ready  

method of getting the dimension across  
corners1 across the flats1 or the length
 of a side of a given polygon1 is by    
means of diagrams1 such as shown in the 
following figures1 which form excellent 
examples for practice4  ,illustration3  
,fig4 #agh4  ,illustration3 ,fig4 #agi4 
,illustration3 ,fig4 #ahj4  ,draw the   
line ,o ,p1 ,figure #aha1 and at a right
 angle to it the line ,o ,b2 divide     
these two lines into parts of one inch1 
as shown in the cut1 which is divided   
into inches and quarter inches1 and from
 these points of division draw lines    
crossing each other as shown4           
,illustration3 ,fig4 #aha4  ,from the   
point ,o1 draw diagonal lines1 at       
suitable angles to the line ,o ,p4 ,as  
shown in the cut1 these diagonal lines  
are marked3  #dj   degrees for #e sided 
figures4 #de             #f          #di
             #g          #eb-a_/b       
#h          #ee-a_/b         #i         
,but still others could be added for    
figures having a greater number of      

sides4  #a4 ,now it will be found as    
follows3 ,half the diameter1 or the     
radius of a piece of cylindrical work   
being given1 and the number of sides it 
is to have being stated1 the length of  
one side will be the distance measured  
horizontally from the line ,o ,b to the 
diagonal line for that particular number
 of sides4  ,,example4--,a piece of work
 is #b-a_/b inches in diameter1 and is  
required to have #i sides3 what will be 
the length of the sides or flats8  ,now 
the half diameter or radius of #b-a_/b  
inches is #a-a_/d inches4 ,then look    
along the line ,o ,b for #a-a_/d1 which 
is denoted in the cut by figures and the
 arrow ,a2 set one point of the         
compasses at ,a1 and the other at the   
point of crossing of the diagonal line  
with the #a-a_/d horizontal line1 as    
shown in the figure at a1 and from ,a to
 a is the length of one side4  ,again3  
,a piece of work1 #d inches in diameter1
 is to have #i sides3 how long will each
 side be8  ,now half of #d is #b1 hence 

from ,b to b is the length of each side4
  ,but suppose that from the length of  
each side1 and the number of sides1 it  
is required to find the diameter to     
which to turn the piece2 that is1 its   
diameter across corners1 and we simply  
reverse the process thus3 ,a body has #i
 sides1 each side measures #bg_/cb3 what
 is its diameter across corners8  ,take 
a rule1 apply it horizontally on the    
figure1 and pass it along till the      
distance from the line ,o ,b to the     
diagonal line marked #i sides measures  
#bg_/cb1 which is from #a-a_/d on ,o ,b 
to a1 and the #a-a_/d is the radius1    
which1 multiplied by #b1 gives #b-a_/b  
inches1 which is the required diameter  
across corners4  ,for any other number  
of sides the process is just the same4  
,thus3 ,a body is #c-a_/b inches in     
diameter1 and is to have #e sides3 what 
will be the length of each side8 ,now   
half of #c-a_/b is #a-c_/d2 hence from  
#a-c_/d on the line ,o ,b to the point  
,c1 where the diagonal line crosses the 

#a-c_/d line1 is the length of each of  
the sides4  #b4 ,it will be found that  
the length of a side of a square being  
given1 the size of the square1 measured 
across corners1 will be the length of   
the diagonal line marked #de degrees1   
from the point ,o to the figures        
indicating1 on the line ,o ,b or on the 
line ,o ,p1 the length of one side4     
,,example4--,a square body measures #a  
inch on each side3 what does it measure 
across the corners8 ,answer3 ,from the  
point ,o1 along diagonal line marked #de
 degrees1 to the point where it crosses 
the lines #a 7as denoted in the figure  
by a dot74  ,again3 ,a cylindrical piece
 of wood requires to be squared1 and    
each side of the square must measure an 
inch3 what diameter must the piece be   
turned to8  ,now the diagonal line      
marked #de degrees passes through the   
#a-;inch line on ,o ,b1 and the inch    
line on ,o ,p1 at the point where these 
lines meet2 hence all we have to do is  
to run the eye along either of the lines

 marked inch1 and from its point of     
meeting the #de degrees line1 to the    
point ,o1 is the diameter to turn the   
piece to4  ,there is another way1       
however1 of getting this same           
measurement1 which is to set a pair of  
compasses from the line #a on ,o ,b1 to 
line #a on ,o ,p1 as shown by the line  
,d1 which is the full diameter across   
corners4 ,this is apparent1 because from
 point ,o1 along line ,o ,b1 to #a1     
thence to the dot1 thence down to line  
#a on ,o ,p1 and along that to ,o1      
encloses a square1 of which either from 
,o to the dot1 or the length of the line
 ,d1 is the measurement across corners1 
while the length of each side1 or       
diameter across the flats1 is from point
 ,o to either of the points #a1 or from 
either of the points #a to the dot4     
,illustration3 ,fig4 #ahb4  ,after      
graphically demonstrating the           
correctness of the scale we may simplify
 it considerably4 ,in ,figure #ahb1     
therefore1 we have applications shown4  

,a is a hexagon1 and if one of its sides
 be measured1 it will be found that it  
measures the same as along line #a from 
,o ,b to the diagonal line #de degrees1 
which distance is shown by a thickened  
line4  ,at #a-a_/b is shown a           
seven-sided figure1 whose diameter is #c
 inches1 and radius #a-a_/b inches1 and 
if from the point at #a-a_/b 7along the 
thickened horizontal line71 to the      
diagonal marked #di degrees1 be         
measured1 it will be found exactly equal
 to the length of a side on the polygon4
  ,at ,c is shown part of a nine-sided  
polygon1 of #b-;inch radius1 and the    
length of one of its sides will be found
 to equal the distance from the diagonal
 line marked #eb-a_/b degrees1 and the  
line ,o ,b at #b4  ,let it now be noted 
that if from the point ,o1 as a centre1 
we describe arcs of circles from the    
points of division on ,o ,b to ,o ,p1   
one end of each arc will meet the same  
figure on ,o ,p as it started from at ,o
 ,b1 as is shown in ,figure #aha1 and it

 becomes apparent that in the length of 
diagonal line between ,o and the        
required arc we have the radius of the  
polygon4  ,,example4--,what is the      
radius across corners of a hexagon or   
six-sided figure1 the length of a side  
being an inch8  ,turning to our scale we
 find that the place where there is a   
horizontal distance of an inch between  
the diagonal #de degrees1 answering to  
six-sided figures1 is along line #a     
7,figure #ahb71 and the radius of the   
circle enclosing the six-sided body is1 
therefore1 an inch1 as will be seen on  
referring to circle ,a4 ,but it will be 
noted that the length of diagonal line  
#de degrees1 enclosed between the point 
,o and the arc of circle from #a on ,o  
,b to one on ,o ,p1 measures also an    
inch4 ,hence we may measure the radius  
along the diagonal lines if we choose4  
,this1 however1 simply serves to        
demonstrate the correctness of the      
scale1 which1 being understood1 we may  
dispense with most of the lines1        

arriving at a scale such as shown in    
,figure #ahc1 in which the length of the
 side of the polygon is the distance    
from the line ,o ,b1 measured           
horizontally to the diagonal1           
corresponding to the number of sides of 
the polygon4 ,the radius across corners 
of the polygon is that of the distance  
from ,o along ,o ,b to the horizontal   
line1 giving the length of the side of  
the polygon1 and the width across       
corners for a given length of one side  
of the square1 is measured by the length
 of the lines ,a1 ,b1 ,c1 etc4 ,thus1   
dotted line #b shows the length of the  
side of a nine-sided figure1 of #b-;inch
 radius1 the radius across corners of   
the figure being #b inches4             
,illustration3 ,fig4 #ahc4  ,the dotted 
line #b-a_/b shows the length of the    
side of a nine-sided polygon1 having a  
radius across corners of #b-a_/b inches4
 ,the dotted line #a shows the diameter1
 across corners1 of a square whose sides
 measure an inch1 and so on4            

,illustration3 ,fig4 #ahd4  ,this scale 
lacks1 however1 one element1 in that the
 diameter across the flats of a regular 
polygon being given1 it will not give   
the diameter across the corners4 ,this1 
however1 we may obtain by a somewhat    
similar construction4 ,thus1 in ,figure 
#ahd1 draw the line ,o ,b1 and divide it
 into inches and parts of an inch4 ,from
 these points of division draw          
horizontal lines2 from the point ,o draw
 the following lines and at the         
following angles from the horizontal    
line ,o ,p4  ,illustration3 ,fig4 #ahe4 
,a line at #ge deg4 for polygons having 
#ab sides4          #gb deg4            
#aj             #fg-a_/b deg4           
#h             #fj deg4                 
#f     ,from the point ,o to the        
numerals denoting the radius of the     
polygon is the radius across the flats1 
while from point ,o to the horizontal   
line drawn from those numerals is the   
radius across corners of the polygon4   
,illustration3 ,fig4 #ahf4  ,a hexagon  

measures two inches across the flats3   
what is its diameter measured across the
 corners8 ,now from point ,o to the     
horizontal line marked #a inch1 measured
 along the line of #fj degrees1 is #a   
#e-cbnds inches3 hence the hexagon      
measures twice that1 or #b #e-afths     
inches across corners4 ,the proof of the
 construction is shown in the figure1   
the hexagon and other polygons being    
marked simply for clearness of          
illustration4  ,illustration3 ,fig4     
#ahg4  ,illustration3 ,fig4 #ahh4  ,let 
it be required to draw the stud shown in
 ,figure #ahe1 and the construction     
would be1 for the pencil lines1 as shown
 in ,figure #ahf2 line #a is the centre 
line1 arcs1 #b and #c give the large1   
and arcs #d and #e the small diameter1  
to touch which lines #f1 #g1 #h1 and #i 
may be drawn4 ,lines #aj1 #aa1 and #ab  
are then drawn for the lengths1 and it  
remains to draw the curves in4 ,in      
drawing these curves great exactitude is
 required to properly find their        

centres2 nothing looks worse in a       
drawing than an unfair or uneven        
junction between curves and straight    
lines4 ,to find the location for these  
centres1 set the compasses to the       
required radius for the curve1 and from 
the point or corner ,a draw the arcs b  
and c1 from c mark the arc e1 and from b
 the arc d1 and where d and e cross is  
the centre for the curve f4             
,illustration3 ,fig4 #ahi4  ,similarly  
for the curve h1 set the compasses on i 
and mark the arc g1 and from the point  
where it crosses line #f1 draw the curve
 h4 ,in inking in it is best to draw in 
all curves or arcs of circles first1 and
 the straight lines that join them      
afterward1 because1 if the straight     
lines are drawn first1 it is a difficult
 matter to alter the centres of the     
curves to make them fall true1 whereas1 
after the curves are drawn it is an easy
 matter1 if it should be necessary1 to  
vary the line a trifle1 so as to make it
 join the curves correctly and fair4 ,in

 inking in these curves also1 care must 
be taken not to draw them too short or  
too long1 as this would impair the      
appearance very much1 as is shown in    
,figure #ahg4  ,illustration3 ,fig4     
#aij4  ,illustration3 ,fig4 #aia4  ,to  
draw the piece shown in ,figure #ahh1   
the lines are drawn in the order        
indicated by the letters in ,figure     
#ahi1 the example being given for       
practice4 ,it is well for the beginner  
to draw examples of common objects1 such
 as the hand hammer in ,figure #aij1 or 
the chuck plate in ,figure #aia1 which  
afford good examples in the drawing of  
arcs and circles4  ,in ,figure #aia a is
 a cap nut1 and the order in which the  
same would be pencilled in is indicated 
by the respective numerals4 ,the circles
 #c and #d represent the thread4        
,illustration3 ,fig4 #aia a4  ,in       
,figure #aib is shown the pencilling for
 a link having the hubs on one side     
only1 so that a centre line is          
unnecessary on the edge view1 as all the

 lengths are derived from the top view1 
while the thickness of the stem and     
height of the hubs may be measured from 
the line ,a4 ,in ,figure #aic there are 
hubs 7on both sides of the link7 of     
unequal height1 hence a centre line is  
necessary in both views1 and from this  
line all measurements should be marked4 
,illustration3 ,fig4 #aib4              
,illustration3 ,fig4 #aic4  ,in ,figure 
#aid are represented the pencil lines   
for a double eye or knuckle joint1 as it
 is sometimes termed1 an example that it
 is desirable for the student to draw in
 various sizes1 as it is representative 
of a large class of work4  ,these eyes  
often have an offset1 and an example of 
this is given in ,figure #aie1 in which 
,a is the centre line for the stem      
distant from the centre line ,b of the  
eyes to the amount of offset required4  
,illustration3 ,fig4 #aid4              
,illustration3 ,fig4 #aie4              
,illustration3 ,fig4 #aif4              
,illustration3 ,fig4 #aig4  ,in ,figure 

#aif is an example of a connecting rod  
end4 ,from a point1 as ,a1 we draw arcs1
 as ,b ,c for the width1 and ,e ,d for  
the length of the block1 and through ,a 
we draw the centre line4 ,it is obvious1
 however1 that we may draw the centre   
line first1 and apply the measuring rule
 direct to the paper1 and mark lines in 
place of the arcs ,b1 ,c1 ,d1 ,e1 and   
,f1 ,g1 which are for the stem4 ,as the 
block joins the stem in a straight line1
 the latter is evidently rectangular1 as
 will be seen by referring to ,figure   
#aig1 which represents a rod end with a 
round stem1 the fact that the stem is   
round being clearly shown by the curves 
,a ,b4 ,the radius of these curves is   
obtained as follows3 ,it is obvious that
 they will join the rod stem at the same
 point as the shoulder curves do1 as    
denoted by the dotted vertical line4 ,so
 likewise they join the curves ,e ,f at 
the same point in the rod length as the 
shoulder curves1 both curves in fact    
being formed by the same round corner or

 shoulder4 ,the centre of the radius of 
,a or ,b must therefore be the same     
distance from the centre of the rod as  
is the centre from which the shoulder   
curve is struck1 and at the same time at
 such a distance from the corner 7as ,e 
or ,f7 that the curve will meet the     
centre line of the rod at the same point
 in its length as the shoulder curves   
do4  ,illustration3 ,fig4 #aih4  ,figure
 #aih gives an example1 in which the    
similar curved lines show that a part is
 square4 ,the figure represents a bolt  
with a square under the head4 ,as but   
one view is given1 that fact alone tells
 us that it must be round or square4    
,now we might mark a cross on the square
 part1 to denote that it is square2 but 
this is unnecessary1 because the curves 
,f ,g show such to be the case4 ,these  
curves are marked as follows3 ,with the 
compasses set to the radius ,e1 one     
point is rested at ,a1 and arc ,b is    
drawn2 then one point of the compass is 
rested at ,c1 and arc ,d is drawn2      

giving the centre for the curve ,f by a 
similar process on the other side of the
 figure1 curve ,g is drawn4 ,point ,c is
 obtained by drawing the dotted line    
across where the outline curve meets the
 stem4 ,suppose that the corner where   
the round stem meets the square under   
the head was a sharp one instead of a   
curve1 then the traditional cross would 
require to be put on the square1 as in  
,figure #aii2 or the cross will be      
necessary if the corner be a round one1 
if the stem is reduced in diameter1 as  
in ,figure #bjj4  ,illustration3 ,fig4  
#aii4  ,illustration3 ,fig4 #bjj4       
,illustration3 ,fig4 #bja4  ,figure #bja
 represents a centre punch1 giving an   
example1 in which the flat sides        
gradually run out upon a circle1 the    
edges forming curves1 as at ,a1 ,b1 etc4
 ,the length of these curves is         
determined as follows3 ,they must begin 
where the taper of the punch joins the  
parallel1 or at ,c1 ,c1 and they must   
end on that part of the taper stem where

 the diameter is equal to the diameter  
across the flats of the octagon4 ,all   
that is to be done then is to find the  
diameter across the flats on the end    
view1 and mark it on the taper stem1 as 
at ,d1 ,d1 which will show where the    
flats terminate on the taper stem4 ,and 
the curved lines1 as ,a1 ,b1 may be     
drawn in by a curve that must meet at   
the line ,c1 and also in a rounded point
 at line ,d4     ,,chapter ,,viii4      
,,screw ,,threads ,,and ,,spirals4      
,illustration3 ,fig4 #bjb4              
,illustration3 ,fig4 #bjc4  ,the screw  
thread for small bolts is represented by
 thick and thin lines1 such as was shown
 in ,figure #aeb1 but in larger sizes2  
the angles of the thread also are drawn 
in1 as in ,figure #bjb1 and the method  
of doing this is shown in ,figure #bjc4 
,the centre line #a and lines #b and #c 
for the full diameter of the thread     
being drawn1 set the compasses to the   
required pitch of the thread1 and       
stepping along line #b1 mark the arcs   

#d1 #e1 #f1 etc41 for the full length   
the thread is to be marked4 ,with the   
triangle resting against the ,t-square1 
the lines #g1 #h1 #i1 etc4 7for the full
 length of the thread71 are drawn from  
the points #d1 #e1 #f1 on line #b4      
,these give one side of the thread4     
,reversing the drawing triangle1 angles 
#aj1 #aa1 etc41 are then drawn1 which   
will complete the outline of the thread 
at the top of the bolt4 ,we may now mark
 the depth of the thread by drawing line
 #ab1 and with the compasses set on the 
centre line transfer this depth to the  
other side of the bolt1 as denoted by   
the arcs #ac and #ad4 ,touching arc #ad 
we mark line #ae for the thread depth on
 that side4 ,we have now to get the     
slant of the thread across the bolt4 ,it
 is obvious that in passing once around 
the bolt the thread advances to the     
amount of the pitch as from a to b2     
hence1 in passing half way around1 it   
will advance from a to c2 we therefore  
draw line #af at a right-angle to the   

centre line1 and a line that touches the
 top of the threads at a1 where it meets
 line #b1 and also meets line #af1 where
 it touches line #c1 is the angle or    
slope for the tops of the threads1 which
 may be drawn across by lines1 as #ah1  
#ai1 #bj1 etc4 ,from these lines the    
sides of the thread may be drawn at the 
bottom of the bolt1 marking first the   
angle on one side1 as by lines #ba1 #bb1
 #bc1 etc41 and then the angles on the  
other1 as by lines #bd1 #be1 etc4       
,illustration3 ,fig4 #bjd4  ,there now  
remain the bottoms of the thread to     
draw1 and this is done by drawing lines 
from the bottom of the thread on one    
side of the bolt to the bottom on the   
other1 as shown in the cut by a dotted  
line2 hence1 we may set a square blade  
to that angle1 and mark in these lines1 
as #bf1 #bg1 #bh1 etc41 and the thread  
is pencilled in complete4  ,if the      
student will follow out this example    
upon paper1 it will appear to him that  
after the thread had been marked out on 

one side of the bolt1 the angle of the  
thread might be obtained1 as shown by   
lines #af and #ag1 and that the bottoms 
of the thread as well as the tops might 
be carried across the bolt to the other 
side4 ,figure #bjd represents a case in 
which this has been done1 and it will be
 observed that the lines denoting the   
bottom of the thread do not meet the    
bottoms of the thread1 which occurs for 
the reason that the angle for the bottom
 is not the same as that for the top of 
the thread4  ,illustration3 ,fig4 #bje4 
,illustration3 ,fig4 #bjf4  ,in inking  
in the thread1 it enhances the          
appearance to give the bottom of the    
thread and the right-hand side of the   
same1 heavy shade lines1 as in ,figure  
#bjb1 a plan that is usually adopted for
 threads of large diameter and coarse   
pitch4  ,a double thread1 such as in    
,figure #bje1 is drawn in the same way1 
except that the slant of the thread is  
doubled1 and the square is to be set for
 the thread-pitch ,a1 ,a1 both for the  

tops and bottoms of the thread4         
,illustration3 ,fig #bjg4  ,a round top 
and bottom thread1 as the ,whitworth    
thread1 is drawn by single lines1 as in 
,figure #bjf4 ,a left-hand thread1      
,figure #bjg1 is obviously drawn by the 
same process as a right-hand one1 except
 that the slant of the thread is given  
in the opposite direction4  ,for screw  
threads of a large diameter it is not   
uncommon to draw in the thread curves as
 they appear to the eye1 and the method 
of doing this is shown in ,figure #bjh4 
,the thread is first marked on both     
sides of the bolt1 as explained1 and    
instead of drawing1 straight across the 
bolt1 lines to represent the tops and   
bottoms of the thread1 a template to    
draw the curves by is required4 ,to get 
these curves1 two half-circles1 one     
equal in diameter to the top1 and one   
equal to the bottom of the thread1 are  
drawn1 as in ,figure #bjh4              
,illustration3 ,fig4 #bjh4  ,these      
half-circles are divided into any       

convenient number of equal divisions3   
thus in ,figure #bjh1 each has eight    
divisions1 as a1 b1 c1 etc41 for the    
outer1 and i1 j1 k1 etc41 for the inner 
one4 ,the pitch of the thread is then   
divided off by vertical lines into as   
many equal divisions as the half-circles
 are divided into1 as by the lines a1 b1
 c1 etc41 to o4 ,of these1 the seven    
from a1 to h1 correspond to the seven   
from a' to g'1 and are for the top of   
the thread1 and the seven from i to o   
correspond to the seven on the inner    
half-circle1 as i1 j1 k1 etc4           
,horizontal lines are then drawn from   
the points of the division to meet the  
vertical lines of division2 thus the    
horizontal dotted line from a' meets the
 vertical line a1 and where they meet1  
as at ,a1 a dot is made4 ,where the     
dotted line from b' meets vertical line 
b1 another dot is made1 as at ,b1 and so
 on until the point ,g is found4 ,a     
curve drawn to pass from the top of the 
thread on one side of the bolt to the   

top of the other side1 and passing      
through these points1 as from ,a to ,g1 
will be the curve for the top of the    
thread1 and from this curve a template  
may be made to mark all the other       
thread-tops from1 because manifestly all
 the tops of the thread on the bolt will
 be alike4  ,for the bottoms of the     
thread1 lines are similarly drawn1 as   
from i' to meet i1 where dot ,i is      
marked4 ,j is got from j' and j1 while  
,k is got from the intersection of k'   
with k1 and so on1 the dots from ,i to  
,o being those through which a curve is 
drawn for the bottom of the thread1 and 
from this curve a template also may be  
made to mark all the thread bottoms4 ,we
 have in our example used eight points  
of division in each half-circle1 but    
either more or less points maybe used1  
the only requisite being that the pitch 
of the thread must be divided into as   
many divisions as the two half-circles  
are4 ,but it is not absolutely necessary
 that both half-circles be divided into 

the same number of equal divisions4     
,thus1 suppose the large half-circle    
were divided into ten divisions1 then   
instead of the first half of the pitch  
being divided into eight 7as from a to  
h7 it would require to have ten lines4  
,but the inner half-circle may have     
eight only1 as in our example4 ,it is   
more convenient1 however1 to use the    
same number of divisions for both       
circles1 so that they may both be       
divided together by lines radiating from
 the centre4 ,the more the points of    
division1 the greater number of points  
to draw the curves through2 hence it is 
desirable to have as many as possible1  
which is governed by the pitch of the   
thread1 it being obvious that the finer 
the pitch the less the number of        
distinct and clear divisions it is      
practicable to divide it into4 ,in our  
example the angles of the thread are    
spread out to cause these lines to be   
thrown further apart than they would be 
in a bolt of that diameter2 hence it    

will be seen that in threads of but two 
or three inches in diameter the lines   
would fall very close together1 and     
would require to be drawn finely and    
with care to keep them distinct4        
,illustration3 ,fig4 #bjh a4            
,illustration3 ,fig4 #bji4  ,the curves 
for a ,united ,states standard form of  
thread are obtained in the same manner  
as from the ,v thread in ,figure #bjh1  
but the thread itself is more difficult 
to draw4 ,the construction of this      
thread is shown in ,figure #bjh1 it     
having a flat place at the top and at   
the bottom of the thread4 ,a common ,v  
thread has its sides at an angle of #fj 
degrees1 one to the other1 the top and  
bottom meeting in a point4 ,the ,united 
,states standard is obtained from       
drawing a common ,v thread and dividing 
its depth into eight equal divisions1 as
 at x1 in ,figure #bjh a1 and cutting   
off one of these divisions at the top   
and filling in one at the bottom to form
 flat places1 as shown in the figure4   

,but the thread cannot be sketched on a 
bolt by this means unless temporary     
lines are used to get the thread from1  
these temporary lines being drawn to    
represent a bolt one-fourth the depth of
 the thread too large in diameter4      
,thus1 in ,figure #bjh a1 it is seen    
that cutting off one-eighth the depth of
 the thread reduces the diameter of the 
thread4 ,it is necessary1 then1 to draw 
the flat place on top of the thread     
first1 the order of procedure being     
shown in ,figure #bji4 ,the lines for   
the full diameter of the thread being   
drawn1 the pitch is stepped off by arcs1
 as #a1 #b1 #c1 etc42 and from these1   
arcs1 as #d1 #e1 #f1 etc41 are marked   
for the width of the flat places at the 
tops of the threads4 ,then one side of  
the thread is marked off by lines1 as   
#g1 which meet the arcs #a1 #b1 #c1     
etc41 as at a1 c1 etc4 ,similar lines1  
as #h and #i1 are marked for the other  
side of the thread1 these lines1 #g1 #h 
and #i1 projecting until they cross each

 other4 ,line #aj is then drawn1 making 
a flat place at the bottom of the thread
 equal in width to that at the top4     
,line #ab is then drawn square across   
the bolt1 starting from the bottom of   
the thread1 and line #ac is drawn       
starting from the corner f on one side  
of the thread and meeting line #ab on   
the other side of the thread1 which     
gives the angle for the tops of the     
thread4 ,the depth of the thread may    
then be marked on the other side of the 
bolt by the arcs d and e1 and the line  
#ad4 ,the tops of all the threads may   
then be drawn in1 as by lines #ae1 #af1 
#ag and #ah1 and by lines1 as #ai1 etc41
 the thread sides may be drawn on the   
other side of the bolt4 ,all that       
remains is to join the bottoms of the   
threads by lines across the bolt1 and   
the pencil lines will be complete1 ready
 to ink in4 ,if the thread is to be     
shown curved instead of drawn straight  
across1 the curve may be obtained by the
 construction in ,figure #bjh1 which is 

similar to that in ,figure #bjg1 except 
that while the pitch is divided off into
 #af divisions1 the whole of these #af  
divisions are not used to get the       
curves1 some of them being used twice   
over2 thus for the bottom the eight     
divisions from b to i are used1 while   
for the tops the eight from g to o are  
used4 ,hence g1 h and i are used for    
getting both curves1 the divisions from 
a to b and from o to p being taken up by
 the flat top and bottom of the thread4 
,it will be noted that in ,figure #bjg1 
the top of the thread is drawn first1   
while in ,figure #bjh the bottom is     
drawn first1 and that in the latter 7for
 the ,u4,s4 standard7 the pitch is      
marked from centre to centre of the     
flats of the thread4  ,illustration3    
,fig4 #baj4  ,to draw a square thread   
the pencil lines are marked in the order
 shown in ,figure #baj1 in which #a     
represents the centre line and #b1 #c1  
#d and #e1 the diameter and depth of the
 thread4 ,the pitch of the thread is    

marked off by arcs1 as #f1 #g1 etc41 or 
by laying a rule directly on the centre 
line and marking with a lead pencil4 ,to
 obtain the slant of the thread1 lines  
#h and #i are drawn1 and from these line
 #aj1 touching #h and #i where they meet
 lines #b and #e2 the threads may then  
be drawn in from the arcs as #f1 #g1    
etc4 ,the side of the thread will show  
at the top and the bottom as at ,a ,b1  
because of the coarse pitch and the     
thread on the other or unseen side of   
the bolt slants1 as denoted by the lines
 #ab1 #ac2 and hence to draw the sides  
,a ,b1 the triangle must be set from one
 thread to the next on the opposite side
 of the bolt1 as denoted by the dotted  
lines #ab and #ac4  ,illustration3 ,fig4
 #baa4  ,if the curves of the thread are
 to be drawn in1 they may be obtained as
 in ,figure #baa1 which is substantially
 the same as described for a ,v thread4 
,the curves f1 representing the sides of
 the thread1 terminate at the centre    
line g1 and the curves e are equidistant

 with the curves c from the vertical    
lines d4 ,as the curves f above the line
 are the same as f below the line1 the  
template for f need not be made to      
extend the whole distance across1 but   
one-half only2 as is shown by the dotted
 curve g1 in the construction for       
finding the curve for square-threaded   
nuts in ,figure #bab4  ,illustration3   
,fig4 #bab4  ,illustration3 ,fig4 #bac4 
,a specimen of the form of template for 
drawing these curves is shown in ,figure
 #bac2 g g1 is the centre line parallel 
to the edges ,r1 ,s2 lines m1 n1        
represent the diameter of the thread at 
the top1 and o1 p1 that at the bottom or
 root2 edge a is formed to the points   
7found by the constructions in the      
figures as already explained7 for the   
tops of the thread1 and edge f is so    
formed for the curve at the thread      
bottoms4 ,the edge1 as ,s or ,r1 is laid
 against the square-blade to steady it  
while drawing in the curves4 ,it may be 
noted1 however1 that since the curve is 

the same below the centre line as it is 
above1 the template may be made to serve
 for one-half the thread diameter1 as at
 f1 where it is made from o to g1 only  
being turned upside down to draw the    
other half of the curve2 the notches cut
 out at x1 x1 are merely to let the     
pencil-lines in the drawing show plainly
 when setting the template4  ,when the  
thread of a nut is shown in section1 it 
slants in the opposite direction to that
 which appears on the bolt-thread1      
because it shows the thread that fits to
 the opposite side of the bolt1 which1  
therefore1 slants in the opposite       
direction1 as shown by the lines #ab and
 #ac in ,figure #baj4  ,in a top or end 
view of a nut the thread depth is       
usually shown by a simple circle1 as in 
,figure #bad4  ,illustration3 ,fig4     
#bad4  ,to draw a spiral spring1 draw   
the centre line ,a1 and lines ,b1 ,c1   
,figure #bae1 distant apart the diameter
 the spring is to be less the diameter  
of the wire of which it is to be made4  

,on the centre line ,a mark two lines a 
b1 c d1 representing the pitch of the   
spring4 ,divide the distance between a  
and b into four equal divisions1 as by  
lines #a1 #b1 #c1 letting line #c meet  
line ,b4 ,line e meeting the centre line
 at line a1 and the line ,b at its      
intersection with line #c1 is the angle 
of the coil on one side of the spring2  
hence it may be marked in at all the    
locations1 as at e f1 etc4 ,these lines 
give at their intersections with the    
lines ,c and ,b the centres for the half
 circles g1 which being drawn1 the sides
 h1 i1 j1 k1 etc41 of the spring1 may   
all be marked in4 ,by the lines m1 n1 o1
 p1 the other sides of the spring may be
 marked in4  ,illustration3 ,fig4 #bae4 
,the end of the spring is usually marked
 straight across1 as at ,l4 ,if it is   
required to draw the coils curved       
instead of straight across1 a template  
must be made1 the curve being obtained  
as already described for threads4 ,it   
may be pointed out1 however1 that to    

obtain as accurate a division as        
possible of the lines that divide the   
pitch1 the pitch may be divided upon a  
diagonal line1 as ,f1 ,figure #baf1     
which will greatly facilitate the       
operation4  ,illustration3 ,fig4 #baf4  
,before going into projections it may be
 as well to give some examples for      
practice4  ,illustration3 ,fig4 #bai4   
7,page #afi47     ,,chapter ,,ix4       
,,examples ,,for ,,practice4   ,figure  
#bag represents a simple example for    
practice1 which the student may draw the
 size of the engraving1 or he may draw  
it twice the size4 ,it is a locomotive  
spring1 composed of leaves or plates1   
held together by a central band4        
,illustration3 ,fig4 #bag4  ,figure #bah
 is an example of a stuffing box and    
gland1 supposed to stand vertical1 hence
 the gland has an oil cup or receptacle4
  ,in ,figure #bai are working drawings 
of a coupling rod1 with the dimensions  
and directions marked in4  ,it may be   
remarked1 however1 that the drawings of 

a workshop are1 where large quantities  
of the same kind of work is done1 varied
 in character to suit some special      
departments--that is to say1 special    
extra drawings are made for these       
departments4 ,in ,figures #bbj and #bba 
is a drawing of a connecting rod drawn1 
put together as it would be for the     
lathe1 vise or erecting shop4           
,illustration3 ,fig4 #bah4              
,illustration3 ,fig4 #bai4              
,illustration3 ,fig4 #bbj4              
,illustration3 ,fig4 #bba4  ,to the two 
views shown there would be necessary    
detail sketches of the set screws1      
gibbs1 and keys1 all the rest being     
shown2 the necessary dimensions being1  
of course1 marked on the general drawing
 and on the details4  ,in so simple a   
thing as a connecting rod1 however1     
there would be no question as to how the
 parts go together2 hence detail        
drawings of each separate piece would   
answer for the lathe or vise bands4     
,but in many cases this would not be the

 case1 and the drawing would require to 
show the parts put together1 and be     
accompanied with such detail sketches as
 might be necessary to show parts that  
could not be clearly defined in the     
general views4  ,the blacksmith1 for    
example1 is only concerned with the     
making of the separate pieces1 and has  
no concern as to how the parts go       
together4 ,furthermore1 there are parts 
and dimensions in the general drawing   
with which the blacksmith has nothing to
 do4  ,thus the location and dimensions 
of the keyways1 the dimensions of the   
brasses1 and the location of the bolt   
holes1 are matters that have no         
reference to the blacksmith's work1     
because the keyways1 bolt holes1 and    
set-screw holes would be cut out of the 
solid in the machine shop4 ,it is       
customary1 therefore1 to send to the    
blacksmith shop drawings containing     
separate views of each piece drawn to   
the shape it is to be forged2 and drawn 
full size1 or else on a scale           

sufficiently large to make each part    
show clearly without close inspection1  
marking thereon the full sizes1 and     
stating beneath the number of pieces of 
each detail4 7,as in ,figure #bbb1 which
 represents the iron work of the        
connecting rod in ,figure #bbj74 ,in    
some cases the finished sizes are       
marked1 and it is left to the           
blacksmith's judgment how much to leave 
for the finishing4 ,this is undesirable1
 because either the blacksmith is left  
to judge what parts are to be finished1 
or else there must be on the drawing    
instructions on this point1 or else     
signs or symbols that are understood to 
convey the information4 ,it is better1  
therefore1 to make for the blacksmith a 
special sketch1 and mark thereon the    
full-forged sizes1 stating on the       
drawing that such is the case4          
,illustration3 ,fig4 #bbb  ,as to the   
material of which the pieces are to be  
made1 the greater part of blacksmith    
work is made of wrought iron1 and it is1

 therefore1 unnecessary to write wrought
 iron beneath each piece4 ,when the     
pieces are to be of steel1 however1 it  
should be marked on the drawing and     
beneath the piece4 ,in special cases1 as
 where the greater part of the work of  
the shop is of steel1 the rule may1 of  
course1 be reversed1 and the parts made 
of iron may be the ones marked1 whereas 
when parts are sometimes of iron1 and at
 others of steel1 each piece should be  
marked4  ,as a general rule the         
blacksmith knows1 from the custom of the
 shop or the nature of the work1 what   
the quality or kind of iron is to be1   
and it is1 therefore1 only in           
exceptional cases that they need to be  
mentioned on the drawing4 ,thus in a    
carriage manufactory1 ,norway or ,swede 
iron will be found1 as well as the      
better grades of refined iron1 but the  
blacksmith will know what iron to use1  
for certain parts1 or the shop may be so
 regulated that the selection of the    
iron is not left to him4 ,in marking the

 number of pieces required1 it is better
 to use the word thus than the words of 
this1 or off this1 because it is shorter
 and more correct1 for the forging is   
not taken off the drawing1 nor is it of 
the same2 the drawing gives the shape   
and the size1 and the word thus conveys 
that idea better than of1 off1 or like  
this4  ,in shops where there are many of
 the same pieces forged1 the blacksmith 
is furnished with sheet-iron templates  
that he can lay directly upon the       
forging and test its dimensions at once1
 which is an excellent plan in large    
work4 ,such templates are1 of course1   
made from the drawings1 and it becomes a
 question as to whether their dimensions
 should be the forged or the finished   
ones4 ,if they are the forged1 they may 
cause trouble1 because a forging may    
have a scant place that it is difficult 
for the blacksmith to bring up to the   
size of the template1 and he is in doubt
 whether there is enough metal in the   
scant place to allow the job to clean   

up4 ,it is better1 therefore1 to make   
them to finished sizes1 so that he can  
see at once if the work will clean up1  
notwithstanding the scant place4 ,this  
will lead to no errors in large work1   
because such work is marked out by      
lines1 and the scant part will therefore
 be discovered by the machinist1 who    
will line out the piece accordingly4    
,figure #bbc is a drawing of a          
locomotive frame1 which the student may 
as well draw three or four times as     
large as the engraving1 which brings us 
to the subject of enlarging or reducing 
scales4   ,,reducing ,,scales4          
,illustration3 ,fig4 #bbc4              
,illustration3 ,fig4 #bbd4              
,illustration3 ,fig4 #bbe4  ,it is      
sometimes necessary to reduce a drawing 
to a smaller scale1 or to find a minute 
fraction of a given dimension1 such     
fraction not being marked on the lineal 
measuring rules at hand4 ,figure #bbd   
represents a scale for finding minute   
fractions4 ,draw seven lines parallel to

 each other1 and equidistant draw       
vertical lines dividing the scale into  
half-inches1 as at a1 b1 c1 etc4 ,divide
 the first space e d into equal halves1 
draw diagonal lines1 and number them as 
in the figure4 ,the distance of point   
#a1 which is at the intersection of     
diagonal with the second horizontal     
line1 will be #a_/bd inch from vertical 
line e4 ,point #b will be #b_/bd inch   
from line e1 and so on4 ,for tenths of  
inches there would require to be but six
 horizontal lines1 the diagonals being  
drawn as before4 ,a similar scale is    
shown in ,figure #bbe4 ,draw the lines  
,a ,b1 ,b ,d1 ,d ,c1 ,c ,a1 enclosing a 
square inch4 ,divide each of these lines
 into ten equal divisions1 and number   
and letter them as shown4 ,draw also the
 diagonal lines ,a #a1 a #b1 ,b #c1 and 
so on2 then the distances from the line 
,a ,c to the points of intersection of  
the diagonals with the horizontal lines 
represent hundredths of an inch4        
,suppose1 for example1 we trace one     

diagonal line in its path across the    
figure1 taking that which starts from ,a
 and ends at #a on the top horizontal   
line2 then where the diagonal intersects
 horizontal line #a1 is #ii_/ajj from   
the line ,b ,d1 and #a_/ajj from the    
line ,a ,c1 while where it intersects   
horizontal line #b1 is #ih_/ajj from    
line ,b ,d1 and #b_/ajj from line ,a ,c1
 and so on4 ,if we require to set the   
compasses to #fg_/ajj inch1 we set them 
to the radius of n1 and the figure #c on
 line ,b ,d1 because from that #c to the
 vertical line d #d is #f_/aj or        
#fj_/ajj inch1 and from that vertical   
line to the diagonal at n is seven      
divisions from the line ,c ,d of the    
figure4  ,in making a drawing to scale1 
however1 it is an excellent plan to draw
 a line and divide it off to suit the   
required scale4 ,suppose1 for example1  
that the given scale is one-quarter     
size1 or three inches per foot2 then a  
line three inches long may be divided   
into twelve equal divisions1            

representing twelve inches1 and these   
may be subdivided into half or quarter  
inches and so on4 ,it is recommended to 
the beginner1 however1 to spend all his 
time making simple drawings1 without    
making them to scale1 in order to become
 so familiar with the use of the        
instruments as to feel at home with     
them1 avoiding the complication of early
 studies that would accompany drawing to
 scale4     ,,chapter ,x4               
,,projections4   ,in projecting1 the    
lines in one view are used to mark those
 in other views1 and to find their      
shapes or curvature as they will appear 
in other views4 ,thus1 in ,figure #bbe;a
 we have a spiral1 wound around a       
cylinder whose end is cut off at an     
angle4 ,the pitch of the spiral is the  
distance ,a ,b1 and we may delineate the
 curve of the spiral looking at the     
cylinder from two positions 7one at a   
right-angle to the other1 as is shown in
 the figure71 by means of a circle      
having a circumference equal to that of 

the cylinder4  ,the circumference of    
this circle we divide into any number of
 equidistant divisions1 as from #a to   
#bd4 ,the pitch ,a ,b of the spiral or  
thread is then divided off also into #bd
 equidistant divisions1 as marked on the
 left hand of the figure2 vertical lines
 are then drawn from the points of      
division on the circle to the points    
correspondingly numbered on the lines   
dividing the pitch2 and where line #a on
 the circle intersects line #a on the   
pitch is one point in the curve4        
,similarly1 where point #b on the circle
 intersects line #b on the pitch is     
another point in the curve1 and so on   
for the whole #bd divisions on the      
circle and on the pitch4 ,in this view1 
however1 the path of the spiral from    
line #g to line #ai lies on the other   
side of the cylinder1 and is marked in  
dotted lines1 because it is hidden by   
the cylinder4 ,in the right-hand view1  
however1 a different portion of the     
spiral or thread is hidden1 namely from 

lines #a to #ac inclusive1 being an     
equal proportion to that hidden in the  
left-hand view4  ,illustration3 ,fig4   
#bbe a4  ,the top of the cylinder is    
shown in the left-hand view to be cut   
off at an angle to the axis1 and will   
therefore appear elliptical2 in the     
right-hand view1 to delineate this oval1
 the same vertical lines from the circle
 may be carried up as shown on the right
 hand1 and horizontal lines may be drawn
 from the inclined face in one view     
across the end of the other view1 as at 
,p2 the divisions on the circle may be  
carried up on the right-hand view by    
means of straight lines1 as ,q1 and arcs
 of circle1 as at ,r1 and vertical lines
 drawn from these arcs1 as line ,s1 and 
where these vertical lines ,s intersect 
the horizontal lines as ,p1 are points  
in the ellipse4  ,let it be required to 
draw a cylindrical body joining another 
at a right-angle2 as for example1 a     
,tee1 such as in ,figure #bbf1 and the  
outline can all be shown in one view1   

but it is required to find the line of  
junction of one piece1 ,a1 with the     
other1 ,b2 that is1 find or mark the    
lines of junction ,c4 ,now when the     
diameters of ,a and ,b are equal1 the   
line of junction ,c is a straight line1 
but it becomes a curved one when the    
diameter of ,a is less than that of ,b1 
or vice versa2 hence it may be as well  
to project it in both cases4 ,for this  
purpose the three views are necessary4  
,one-quarter of the circle of ,b1 in the
 end view1 is divided off into any      
number of equal divisions2 thus we have 
chosen the divisions marked a1 b1 c1 d1 
e1 etc42 a quarter of the top view is   
similarly divided off1 as at f1 g1 h1 i1
 j2 from these points of division lines 
are projected on to the side view1 as   
shown by the dotted lines k1 l1 m1 n1 o1
 p1 etc41 and where these lines meet1 as
 denoted by the dots1 is in each case a 
point in the line of junction of the two
 cylinders ,a1 ,b4  ,illustration3 ,fig4
 #bbf4  ,illustration3 ,fig4 #bbg4      

,figure #bbg represents a ,tee1 in which
 ,b is less in diameter than ,a2 hence  
the two join in a curve1 which is found 
in a similar manner1 as is shown in     
,figure #bbg4 ,suppose that the end and 
top views are drawn1 and that the side  
view is drawn in outline1 but that the  
curve of junction or intersection is to 
be found4 ,now it is evident that since 
the centre line #a passes through the   
side and end views1 that the face a1 in 
the end view1 will be even with the face
 a' in the side view1 both being the    
same face1 and as the full length of the
 side of ,b in the end view is marked by
 line b1 therefore line c projected down
 from b will at its junction with line  
b'1 which corresponds to line b1 give   
the extreme depth to which b' extends   
into the body ,a1 and therefore1 the    
apex of the curve of intersection of ,b 
with ,a4 ,to obtain other points1 we    
divide one-quarter of the circumference 
of the circle ,b in the top view into   
four equal divisions1 as by lines d1 e1 

f1 and from the points of division we   
draw lines j1 i1 g1 to the centre line  
marked #b1 these lines being thickened  
in the cut for clearness of             
illustration4 ,the compasses are then   
set to the length of thickened line g1  
and from point h1 in the end view1 as a 
centre1 the arc g' is marked4 ,with the 
compasses set to the length of thickened
 line i1 and from h as a centre1 arc i' 
is marked1 and with the length of       
thickened line j as a radius and from h 
as a centre arc j' is marked2 from these
 arcs lines k1 l1 m are drawn1 and from 
the intersection of k1 l1 m1 with the   
circle of ,a1 lines n1 o1 p are let     
fall4 ,from the lines of division1 d1 e1
 f1 the lines q1 r1 s are drawn1 and    
where lines n1 o1 p join lines q1 r1 s1 
are points in the curve1 as shown by the
 dots1 and by drawing a line to         
intersect these dots the curve is       
obtained on one-half of ,b4 ,since the  
axis of ,b is in the same plane as that 
of ,a1 the lower half of the curve is of

 the same curvature as the upper1 as is 
shown by the dotted curve4              
,illustration3 ,fig4 #bbh4  ,in ,figure 
#bbh the axis of piece ,b is not in the 
same plane as that of ,d1 but to one    
side of it to the distance between the  
centre lines ,c1 ,d1 which is most      
clearly seen in the top view4 ,in this  
case the process is the same except in  
the following points3 ,in the side view 
the line w1 corresponding to the line w 
in the end view1 passes within the line 
x before the curve of intersection      
begins1 and in transferring the lengths 
of the full lines b1 c1 d1 e1 f to the  
end view1 and marking the arcs b'1 c'1  
d'1 e'1 f'1 they are marked from the    
point w 7the point where the centre line
 of ,b intersects the outline of ,a71   
instead of from the point x4 ,in all    
other respects the construction is the  
same as that in ,figure #bbg4           
,illustration3 ,fig4 #bbi4  ,in these   
examples the axis of ,b stands at a     
right-angle to that of ,a4 ,but in      

,figure #bbi is shown the construction  
where the axis of ,b is not at a        
right-angle to ,a4 ,in this case there  
is projected from ,b1 in the side view1 
an end view of ,b as at ,b'1 and across 
this end at a right-angle to the centre 
line of ,b is marked a centre line ,c ,c
 of ,b'1 which is divided as before by  
lines d1 e1 f1 g1 h1 their respective   
lengths being transferred from ,w as a  
centre1 and marked by the arcs d'1 e'1  
f'1 which are marked on a vertical line 
and carried by horizontal lines1 to the 
arc of ,a as at i1 j1 k4 ,from these    
points1 i1 j1 k1 the perpendicular lines
 l1 m1 n1 o1 are dropped1 and where     
these lines meet lines p1 q1 r1 s1 t1   
are points in the curve of intersection 
of ,b with ,a4 ,it will be observed that
 each of the lines m1 n1 o1 serves for  
two of the points in the curve2 thus1 m 
meets q and s1 while n meets p and t1   
and o meets the outline on each side of 
,b1 in the side view1 and as i1 j1 k are
 obtained from d and e1 the lines g and 

h might have been omitted1 being        
inserted merely for the sake of         
illustration4  ,in ,figure #bcj is an   
example in which a cylinder intersects a
 cone1 the axes being parallel4 ,to     
obtain the curve of intersection in this
 case1 the side view is divided by any  
convenient number of lines1 as a1 b1 c1 
etc41 drawn at a right-angle to its axis
 ,a ,a1 and from one end of these lines 
are let fall the perpendiculars f1 g1 h1
 i1 j2 from the ends of these 7where    
they meet the centre line of ,a in the  
top view71 half-circles k1 l1 m1 n1 o1  
are drawn to meet the circle of ,b in   
the top view1 and from their points of  
intersection with ,b1 lines p1 q1 r1 s1 
t1 are drawn1 and where these meet lines
 a1 b1 c1 d and e1 which is at u1 v1 w1 
x1 y1 are points in the curve4          
,illustration3 ,fig4 #bcj4              
,illustration3 ,fig4 #bca4  ,it will be 
observed1 on referring again to ,figure 
#bbi1 that the branch or cylinder ,b    
appears to be of elliptical section on  

its end face1 which occurs because it is
 seen at an angle to its end surface2   
now the method of finding the ellipse   
for any given degree of angle is as in  
,figure #bca1 in which ,b represents a  
cylindrical body whose top face would1  
if viewed from point ,i1 appear as a    
straight line1 while if viewed from     
point ,j it would appear in outline a   
circle4 ,now if viewed from point ,e its
 apparent dimension in one direction    
will obviously be defined by the lines  
,s1 ,z4 ,so that if on a line ,g ,g at a
 right angle to the line of vision ,e1  
we mark points touching lines ,s1 ,z1 we
 get points #a and #b1 representing the 
apparent dimension in that direction    
which is the width of the ellipse4 ,the 
length of the ellipse will obviously be 
the full diameter of the cylinder ,b2   
hence from ,e as a centre we mark points
 #c and #d1 and of the remaining points 
we will speak presently4 ,suppose now   
the angle the top face of ,b is viewed  
from is denoted by the line ,l1 and     

lines ,s'1 ,z1 parallel to ,l1 will be  
the width for the ellipse whose length  
is marked by dots1 equidistant on each  
side of centre line ,g' ,g'1 which equal
 in their widths one from the other the 
full diameter of ,b4 ,in this           
construction the ellipse will be drawn  
away from the cylinder ,b1 and the      
ellipse1 after being found1 would have  
to be transferred to the end of ,b4 ,but
 since centre line ,g ,g is obviously at
 the same angle to ,a ,a that ,a ,a is  
to ,g ,g1 we may start from the centre  
line of the body whose elliptical       
appearance is to be drawn1 and draw a   
centre line ,a ,a at the same angle to  
,g ,g as the end of ,b is supposed to be
 viewed from4 ,this is done in ,figure  
#bca a1 in which the end face of ,b is  
to be drawn viewed from a point on the  
line ,g ,g1 but at an angle of #de      
degrees2 hence line ,a ,a is drawn at an
 angle of #de degrees to centre line ,g 
,g1 and centre line ,e is drawn from the
 centre of the end of ,b at a right     

angle to ,g ,g1 and from where it cuts  
,a ,a1 as at ,f1 a side view of ,b is   
drawn1 or a single line of a length     
equal to the diameter of ,b may be drawn
 at a right angle to ,a ,a and          
equidistant on each side of ,f4 ,a line1
 ,d ,d1 at a right angle to ,a ,a1 and  
at any convenient distance above ,f1 is 
then drawn1 and from its intersection   
with ,a ,a as a centre1 a circle ,c     
equal to the diameter of ,b is drawn2   
one-half of the circumference of ,c is  
divided off into any number of equal    
divisions as by arcs a1 b1 c1 d1 e1 f4  
,from these points of division1 lines g1
 h1 i1 j1 k1 l are drawn1 and also lines
 m1 n1 o1 p1 q1 r4 ,from the            
intersection of these last lines with   
the face in the side view1 lines s1 t1  
u1 t1 w1 x1 y1 z are drawn1 and from    
point ,f line ,e is drawn4 ,now it is   
clear that the width of the end face of 
the cylinder will appear the same from  
any point of view it may be looked at1  
hence the sides ,h ,h are made to equal 

the diameter of the cylinder ,b and     
marked up to centre line ,e4            
,illustration3 ,fig4 #bca a4            
,illustration3 ,fig4 #bcb4  ,it is      
obvious also that the lines s1 z1 drawn 
from the extremes of the face to be     
projected will define the width of the  
ellipse1 hence we have four of the      
points 7marked respectively #a1 #b1 #c1 
#d7 in the ellipse4 ,to obtain the      
remaining points1 lines t1 u1 v1 w1 x1 y
 7which start from the point on the face
 ,f where the lines m1 n1 o1 p1 q1 r1   
respectively meet it7 are drawn across  
the face of ,b as shown4 ,the compasses 
are then set to the radius g2 that is1  
from centre line ,d to division a on the
 circle1 and this radius is transferred 
to the face to be projected the         
compass-point being rested at the       
intersection of centre line ,g and line 
t1 and two arcs as #e and #f drawn1     
giving two more points in the curve of  
the ellipse4 ,the compasses are then set
 to the length of line h 7that is1 from 

centre line ,d to point of division b71 
and this distance is transferred1       
setting the compasses on centre line ,g 
where it is intersected by line u1 and  
arcs #g1 #h are marked1 giving two more 
points in the ellipse4 ,in like manner  
points #i and #aj are obtained from the 
length of line i1 #aa and #ab from that 
of j2 points #ac and #ad from the length
 of k1 and #ae and #af from l1 and the  
ellipse may be drawn in from these      
points4  ,it may be pointed out1        
however1 that since points #e and #f are
 the same distance from ,g that points  
#ae and #af are1 and since points #g and
 #h are the same distance from ,g that  
points #ac and #ad are1 while points #i 
and #aj are the same distance from ,g   
that #aa and #ab are1 the lines1 j1 k1 l
 are unnecessary1 since l and g are of  
equal length1 as are also h and k and i 
and j4 ,in ,figure #bcb the cylinders   
are line shaded to make them show       
plainer to the eye1 and but three lines 
7a1 b1 c7 are used to get the radius    

wherefrom to mark the arcs where the    
points in the ellipse shall fall2 thus1 
radius a gives points #a1 #b1 #c and #d2
 radius b gives points #e1 #f1 #g and   
#h1 and radius c gives #i1 #aj1 #aa and 
#ab1 the extreme diameter being obtained
 from lines ,s1 ,z1 and ,h1 ,h4         
,,chapter ,,xi4  ,,drawing ,,gear       
,,wheels4   ,the names given to the     
various lines of a tooth on a gear-wheel
 are as follows3  ,in ,figure #bcc1 ,a  
is the face and ,b the flank of a tooth1
 while ,c is the point1 and ,d the root 
of the tooth2 ,e is the height or depth1
 and ,f the breadth4 ,p ,p is the pitch 
circle1 and the space between the two   
teeth1 as ,h1 is termed a space4        
,illustration3 ,fig4 #bcc4              
,illustration3 ,fig4 #bcd4  ,it is      
obvious that the points of the teeth and
 the bottoms of the spaces1 as well as  
the pitch circle1 are concentric to the 
axis of the wheel bore4 ,and to pencil  
in the teeth these circles must be fully
 drawn1 as in ,figure #bcd1 in which ,p 

,p is the pitch circle4 ,this circle is 
divided into as many equal divisions as 
the wheel is to have teeth1 these       
divisions being denoted by the radial   
lines1 ,a1 ,b1 ,c1 etc4 ,where these    
divisions intersect the pitch circle are
 the centres from which all the teeth   
curves may be drawn4 ,the compasses are 
set to a radius equal to the pitch1 less
 one-half the thickness of the tooth1   
and from a centre1 as ,r1 two face      
curves1 as ,f ,g1 may be marked2 from   
the next centre1 as at ,s1 the curves ,d
 ,e may be marked1 and so on for all the
 faces2 that is1 the tooth curves lying 
between the outer circle ,x and the     
pitch circle ,p4 ,for the flank curves1 
that is1 the curve from ,p to ,y1 the   
compasses are set to a radius equal to  
the pitch2 and from the sides of the    
teeth the flank curves are drawn4 ,thus 
from ,j1 as a centre flank1 ,k is drawn2
 from ,v1 as a centre flank1 ,h is      
drawn1 and so on4  ,the proportions of  
the teeth for cast gears generally      

accepted in this country are those given
 by ,professor ,willis1 as average      
practice1 and are as follows3  ,depth to
 pitch line1 #c_/aj of the pitch4       
,working depth1       #f_/aj            
,whole depth1         #g_/aj            
,thickness of tooth1  #e_/aa            
,breadth of space1    #f_/aa            
,instead1 however1 of calculating the   
dimensions these proportions give for   
any particular pitch1 a diagram or scale
 may be made from which they may be     
taken for any pitch by a direct         
application of the compasses4 ,a scale  
of this kind is given in ,figure #bce1  
in which the line ,a ,b is divided into 
inches and parts to represent the       
pitches2 its total length representing  
the coarsest pitch within the capacity  
of the scale2 and1 the line ,b ,c 7at a 
right-angle to ,a ,b7 the whole depth of
 the tooth for the coarsest pitch1 being
 #g_/aj of the length of ,a ,b4         
,illustration3 ,fig4 #bce4  ,the other  
diagonal lines are for the proportion of

 the dimensions marked on the figure4   
,thus the depth of face1 or distance    
from the pitch line to the extremity or 
tooth point for a #d inch pitch1 would  
be measured along the line ,b ,c1 from  
the vertical line ,b to the first       
diagonal4 ,the thickness of the tooth   
would be for a #d inch pitch along line 
,b ,c from ,b to the second diagonal1   
and so on4 ,for a #c inch pitch the     
measurement would be taken along the    
horizontal line1 starting from the #c on
 the line ,a ,b1 and so on4 ,on the left
 of the diagram or scale is marked the  
lbs4 strain each pitch will safely      
transmit per inch width of wheel face1  
according to ,professor ,marks4         
,illustration3 ,fig4 #bcf4  ,the        
application of the scale as follows3    
,the pitch circles ,p ,p and ,p' ,p'1   
,figure #bcf1 for the respective wheels1
 are drawn1 and the height of the teeth 
is obtained from the scale and marked   
beyond the pitch circles1 when circles  
,q and ,q' may be drawn4 ,similarly1 the

 depths of the teeth within the pitch   
circles are obtained from the scale or  
diagram and marked within the respective
 pitch circles1 and circles ,r and ,r'  
are marked in4 ,the pitch circles are   
divided off into as many points of equal
 division1 as at a1 b1 c1 d1 e1 etc41 as
 the respective wheels are to have      
teeth1 and the thickness of tooth having
 been obtained from the scale1 this     
thickness is marked from the points of  
division on the pitch circles1 as at f  
in the figure1 and the tooth curves may 
then be drawn in4 ,it may be observed1  
however1 that the tooth thicknesses will
 not be strictly correct1 because the   
scale gives the same chord pitch for the
 teeth on both wheels which will give   
different arc pitches to the teeth on   
the two wheels2 whereas1 it is the arc  
pitches1 and not the chord pitches1 that
 should be correct4 ,this error         
obviously increases as there is a       
greater amount of difference between the
 two wheels4  ,the curves given to the  

teeth in ,figure #bcd are not the proper
 ones to transmit uniform motion1 but   
are curves merely used by draughtsmen to
 save the trouble of finding the true   
curves1 which if it be required1 may be 
drawn with a very near approach to      
accuracy1 as follows1 which is a        
construction given by ,rankine3  ,draw  
the rolling circle ,d1 ,figure #bcg1 and
 draw ,a ,d1 the line of centres4 ,from 
the point of contact at ,c1 mark on ,d1 
a point distant from ,c one-half the    
amount of the pitch1 as at ,p1 and draw 
the line ,p ,c of indefinite length     
beyond ,c4 ,draw the line ,p ,e passing 
through the line of centres at ,e1 which
 is equidistant between ,c and ,a4 ,then
 increase the length of line ,p ,f to   
the right of ,c by an amount equal to   
the radius ,a ,c1 and then diminish it  
to an amount equal to the radius ,e ,d1 
thus obtaining the point ,f and the     
latter will be the location of centre   
for compasses to strike the face curve4 
,illustration3 ,fig4 #bcg4              

,illustration3 ,fig4 #bch4  ,another    
method of finding the face curve1 with  
compasses1 is as follows3 ,in ,figure   
#bch let ,p ,p represent the pitch      
circle of the wheel to be marked1 and ,b
 ,c the path of the centre of the       
generating or describing circle as it   
rolls outside of ,p ,p4 ,let the point  
,b represent the centre of the          
generating circle when it is in contact 
with the pitch circle at ,a4 ,then from 
,b mark off1 on ,b ,c1 any number of    
equidistant points1 as ,d1 ,e1 ,f1 ,g1  
,h1 and from ,a mark on the pitch       
circle1 with the same radius1 an equal  
number of points of division1 as #a1 #b1
 #c1 #d1 #e4 ,with the compasses set to 
the radius of the generating circle1    
that is1 ,a ,b1 from ,b1 as a centre1   
mark the arc ,i1 from ,d1 the arc ,j1   
from ,e1 the arc ,k1 from ,f1 and so on1
 marking as many arcs as there are      
points of division on ,b ,c4 ,with the  
compasses set to the radius of divisions
 #a1 #b1 etc41 step off on arc ,m the   

five divisions1 ,n1 ,o1 ,s1 ,t1 ,v1 and 
at ,v will be a point on the            
epicycloidal curve4 ,from point of      
division #d1 step off on ,l four points 
of division1 as a1 b1 c1 d2 and d will  
be another point on the epicycloidal    
curve4 ,from point #c1 set off three    
divisions1 and so on1 and through the   
points so obtained draw by hand1 or with
 a scroll1 the curve4  ,illustration3   
,fig4 #bci4  ,hypocycloids for the      
flanks of the teeth maybe traced in a   
similar manner4 ,thus in ,figure #bci1  
,p ,p is the pitch circle1 and ,b ,c the
 line of motion of the centre of the    
generating circle to be rolled within ,p
 ,p4 ,from #a to #f are points of equal 
division on the pitch circle1 and ,d to 
,i are arc locations for the centre of  
the generating circle4 ,starting from   
,a1 which represents the location for   
the centre of the generating circle1 the
 point of contact between the generating
 and base circles will be at ,b4 ,then  
from #a to #f are points of equal       

division on the pitch circle1 and from  
,d to ,i are the corresponding locations
 for the centres of the generating      
circle4 ,from these centres the arcs ,j1
 ,k1 ,l1 ,m1 ,n1 ,o1 are struck4 ,the   
six divisions on ,o1 from a to f1 give  
at f a point in the curve4 ,five        
divisions on ,n1 four on ,m1 and so on1 
give1 respectively1 points in the curve4
  ,there is this1 however1 to be noted  
concerning the construction of the last 
two figures4 ,since the circle described
 by the centre of the generating circle 
is of a different arc or curve to that  
of the pitch circle1 the length of an   
arc having an equal radius on each will 
be different4 ,the amount is so small as
 to be practically correct4 ,the        
direction of the error is to give to the
 curves a less curvature1 as though they
 had been produced by a generating      
circle of larger diameter4 ,suppose1 for
 example1 that the difference between   
the arc a1 b1 and its chord is 4#a1 and 
that the difference between the arc #d1 

#e1 and its chord is 4#ja1 then the     
error in one step is 4#ji1 and1 as the  
point f is formed in five steps1 it will
 contain this error multiplied five     
times4 ,point d would contain it        
multiplied three times1 because it has  
three steps1 and so on4  ,the error will
 increase in proportion as the diameter 
of the generating is less than that of  
the pitch circle1 and though in large   
wheels1 working with large wheels1 so   
that the difference between the radius  
of the generating circle and that of the
 smallest wheel is not excessive1 it is 
so small as to be practically           
inappreciable1 yet in small wheels1     
working with large ones1 it may form a  
sensible error4  ,illustration3 ,fig4   
#bdj4  ,for showing the dimensions      
through the arms and hub1 a sectional   
view of a section of the wheel may be   
given1 as in ,figure #bdj1 which        
represents a section of a wheel1 and a  
pinion1 and on these two views all the  
necessary dimensions may be marked4     

,illustration3 ,fig4 #bdj a4 7,page     
#bjc47  ,if it is desired to draw an    
edge view of a wheel 7which the student 
will find excellent practice71 the lines
 for the teeth may be projected from the
 teeth in the side view1 as in ,figure  
#bdj a4 ,thus tooth ,e is projected by  
drawing lines from the corners ,a1 ,b1  
,c1 in the side view across the face in 
the edge view1 as at ,a1 ,b1 ,c in the  
latter view1 and similar lines may be   
obtained in the same way for all the    
teeth4  ,when the teeth of wheels are to
 be cut to form in a gear-cutting       
machine1 the thickness of the teeth is  
nearly equal to the thickness of the    
spaces1 there being just sufficient     
difference to prevent the teeth of one  
wheel from becoming locked in the spaces
 of the other2 but when the teeth are to
 be cast upon the wheel1 the tooth      
thickness is made less than the width of
 the space to an amount that is usually 
a certain proportion of the pitch1 and  
is termed the side clearance4 ,in all   

wheels1 whether with cut or cast teeth1 
there is given a certain amount of top  
and bottom clearance2 that is to say1   
the points of the teeth of one wheel do 
not reach to the bottom of the spaces in
 the other4 ,thus in the ,pratt and     
,whitney system the top and bottom      
clearance is one-eighth of the pitch1   
while in the ,brown and ,sharpe system  
for involute teeth the clearance is     
equal to one-tenth the thickness of the 
tooth4  ,in drawing bevil gear wheels1  
the pitch line of each tooth on each    
wheel1 and the surfaces of the points1  
as well as those at the bottom of the   
spaces1 must all point to a centre1 as  
,e in ,figure #bda1 which centre is     
where the axes of the shafts would meet4
 ,it is unnecessary to mark in the      
correct curves for the teeth1 for       
reasons already stated1 with reference  
to the curves for a spur wheel4 ,but if 
it is required to do so1 the            
construction to find the curves is as   
shown in ,figure #bdb1 in which let ,a  

,a represent the axis of one shaft1 and 
,b that of the other of the pair of     
bevil wheels that are to work together1 
their axes meeting at ,w2 draw the line 
,e at a right angle to ,a ,a1 and       
representing the pitch circle diameter  
of one wheel1 and draw ,f at a right    
angle to ,b1 and representing the pitch 
circle of the other wheel2 draw the line
 ,g ,g1 passing through the point ,w and
 the point ,t1 where the pitch circles  
or lines ,e ,f meet1 and ,g ,g will be  
the line of contact of the tooth of one 
wheel upon the tooth of the other wheel2
 or in other words1 the pitch line of   
the tooth4  ,illustration3 ,fig4 #bda4  
,illustration3 ,fig4 #bdb4  ,draw lines1
 as ,h and ,i1 representing the tooth   
breadth4 ,from ,w1 as a centre1 draw on 
each side of ,g ,g dotted lines1 as ,p1 
representing the height of the tooth    
above and below the pitch line ,g ,g4   
,at a right angle to ,g ,g draw the line
 ,j ,k2 and from where this line meets  
,b1 as at ,q1 mark the arc a1 which will

 represent the pitch circle for the     
large diameter of the pinion ,d4 ,the   
smallest wheel of a pair of gears is    
termed the pinion4 ,draw the arc b for  
the height1 and circle c for the depth  
of the teeth1 thus defining the height  
of the tooth at that end4 ,similarly    
from ,p1 as a centre mark 7for the large
 diameter of wheel ,c17 arcs g1 h1 and  
i1 arc g representing the pitch circle1 
i the height1 and h the depth of the    
tooth4 ,on these arcs draw the proper   
tooth curves in the same manner as for  
spur wheels2 that is1 obtain the curves 
by the construction shown in ,figures   
#bcg1 or by those in ,figures #bch and  
#bci4  ,to obtain the arcs for the other
 end of the tooth1 draw line ,m ,m      
parallel to line ,j ,k2 set the         
compasses to the radius ,r ,l1 and from 
,p1 as a centre1 draw the pitch circle  
k4 ,for the depth of the tooth draw the 
dotted line p1 meeting the circle h and 
the point ,w4 ,a similar line1 from i to
 ,w1 will give the height of the tooth  

at its inner end4 ,then the tooth curves
 may be drawn on these three arcs1 k1 l1
 m1 in the same as if they were for a   
spur wheel4  ,similarly for the pitch   
circle of the inner and small end of the
 pinion teeth1 set the compasses to     
radius ,s ,l1 and from ,q as a centre   
mark the pitch circle d4 ,outside of d  
mark e for the height above pitch lines 
of the tooth1 and inside of d mark the  
arc f for the depth below pitch line of 
the tooth at that end4 ,the distance    
between the dotted lines as p1          
represents the full height of the tooth2
 hence h meets p1 which is the root of  
the tooth on the large wheel4 ,to give  
clearance and prevent the tops of the   
teeth on one wheel from bearing against 
the bottoms of the spaces in the other  
wheel1 the point of the pinion teeth is 
marked below2 thus arc b does not meet h
 or p1 but is short to the amount of    
clearance4 ,having obtained the arcs d1 
e1 f1 the curves may be marked thereon  
as for a spur wheel4 ,a tooth thus      

marked is shown at x1 and from its      
curves between b and c1 a template may  
be made for the large diameter or outer 
end of the pinion teeth4 ,similarly for 
the wheel ,c the outer end curves are   
marked on the arcs g1 h1 i1 and those   
for the other end of the tooth are      
marked between the arcs l1 m4           
,illustration3 ,fig4 #bdc4 7,page #bjg47
  ,illustration3 ,fig4 #bdd4  ,figure   
#bdc represents a drawing of one-half of
 a bevil gear1 and an edge view         
projected from the same4 ,the point ,e  
corresponds to point ,e in ,figure #bda1
 or ,w in #bdb4 ,the line ,f shows that 
the top surface of the teeth points to  
,e4 ,line ,g shows that the pitch line  
of each tooth points to ,e1 and lines ,h
 show that the bottom of the surface of 
a space also points to ,e4 ,line #a     
shows that the sides of each tooth point
 to ,e4 ,and it follows that the outer  
end of a tooth is both higher or deeper 
and also thicker than its inner end2    
thus ,j is thicker and deeper than end  

,k of the tooth4 ,lines ,f ,g1          
representing the top and bottom of a    
tooth in ,figure #bdc1 obviously        
correspond to dotted lines p in ,figure 
#bdb4 ,the outer and inner ends of the  
teeth in the edge view are projected    
from the outer and inner ends in the    
face view1 as is shown by the dotted    
lines carried from tooth ,l in the face 
view1 to tooth ,l in the edge view1 and 
it is obvious from what has been said   
that in drawing the lines for the tooth 
in the edge view they will point to the 
centre ,e4  ,illustration3 ,fig4 #bde4  
,to save work in drawing bevil gear     
wheels1 they are sometimes drawn in     
section or in outline only2 thus in     
,figure #bdd is shown a pair of bevil   
wheels shown in section1 and in ,figure 
#bde is a drawing of a part of an ,ames 
lathe feed motion4 ,b ,c ,d and ,e are  
spur gears1 while ,g ,h and ,i are bevil
 gears1 the cone surface on which the   
teeth lie being left blank1 save at the 
edges where a tooth is in each case     

drawn in4 ,wheel ,d is shown in section 
so as to show the means by which it may 
be moved out of gear with ,c and ,e4    
,small bevil gears may also be          
represented by simple line shading2 thus
 in ,figure #bdg the two bodies ,a and  
,c would readily be understood to be a  
bevil gear and pinion4 ,similarly small 
spur wheels may be represented by simple
 circles in a side view and by line     
shading in an edge view2 thus it would  
answer every practical purpose if such  
small wheels as in ,figures #bdf and    
#bdg at ,d1 ,f1 ,g1 ,k1 ,p1 ,h1 ,i and  
,j1 were drawn as shown4 ,the pitch     
circles1 however1 are usually drawn in  
red ink to distinguish them4            
,illustration3 ,fig4 #bea4 7,page #bji47
  ,illustration3 ,fig4 #bdf4            
,illustration3 ,fig4 #bdg4  ,in ,figure 
#bdh is an example in which part of the 
gear is shown with teeth in1 and the    
remainder is illustrated by circles4    
,in ,figure #bej is a drawing of part of
 the feed motions of a ,niles ,tool     

,works horizontal boring mill1 ,figure  
#bea being an end view of the same1 f is
 a friction disk1 and g a friction      
pinion1 g' is a rack1 ,f is a           
feed-screw1 p is a bevil pinion1 and q a
 bevil wheel2 i1 m1 o1 are gear wheels1 
and ,j a worm operating a worm-pinion   
and the gears shown4  ,figure #bdi      
represents three bevil gears1 the upper 
of which is line shaded1 forming an     
excellent example for the student to    
copy4  ,illustration3 ,fig4 #bdh4  ,the 
construction of oval gearing is shown in
 ,figures #beb1 #bec1 #bed1 #bee1 and   
#bef4 ,the pitch-circle is drawn by the 
construction for drawing an ellipse that
 was given with reference to ,figure    
#ha1 but as that construction is by     
means of arcs of circles1 and therefore 
not strictly correct1 ,professor        
,mc,cord1 in an article on elliptical   
gearing1 says1 concerning it and the    
construction of oval gearing generally1 
as follows3  ,illustration3 ,fig4 #bdi4 
7,page #baj47  ,illustration3 ,fig4     

#bej4  ,illustration3 ,fig4 #beb4  ,but 
these circular arcs may be rectified and
 subdivided with great facility and     
accuracy by a very simple process1 which
 we take from ,prof4 ,rankine's         
,machinery and ,mill ,work1 and is      
illustrated in ,figure #beb4 ,let ,o ,b 
be tangent at ,o to the arc ,o ,d1 of   
which ,c is the centre4 ,draw the chord 
,d ,o1 bisect it in ,e1 and produce it  
to ,a1 making ,o ,a,o ,e2 with centre ,a
 and radius ,a ,d describe an arc       
cutting the tangent in ,b2 then ,o ,b   
will be very nearly equal in length to  
the arc ,o ,d1 which1 however1 should   
not exceed about #fj degrees2 if it be  
#fj degrees1 the error is theoretically 
about #a_/ijj of the length of the arc1 
,o ,b being so much too short2 but this 
error varies with the fourth power of   
the angle subtended by the arc1 so that 
for #cj degrees it is reduced to #a_/af 
of that amount1 that is1 to #a_/addjj4  
,conversely1 let ,o ,b be a tangent of  
given length2 make ,o ,f#a_/d ,o ,b2    

then with centre ,f and radius ,f ,b    
describe an arc cutting the circle ,o ,d
 ,g 7tangent to ,o ,b at ,o7 in the     
point ,d2 then ,o ,d will be            
approximately equal to ,o ,b1 the error 
being the same as in the other          
construction and following the same law4
  ,illustration3 ,fig4 #bec4  ,the      
extreme simplicity of these two         
constructions and the facility with     
which they may be made with ordinary    
drawing instruments make them           
exceedingly convenient1 and they should 
be more widely known than they are4     
,their application to the present       
problem is shown in ,figure #bec1 which 
represents a quadrant of an ellipse1 the
 approximate arcs ,c ,d1 ,e1 ,e ,f1 ,f  
,a having been determined by trial and  
error4 ,in order to space this off1 for 
the positions of the teeth1 a tangent is
 drawn at ,d1 upon which is constructed 
the rectification of ,d ,c1 which is ,d 
,g1 and also that of ,d ,e in the       
opposite direction1 that is1 ,d ,h1 by  

the process just explained4 ,then1      
drawing the tangent at ,f1 we set off in
 the same manner ,f ,i  ,f ,e1 and ,f ,k
  ,f ,a1 and then measuring ,h ,l  ,i   
,k1 we have finally ,g ,l1 equal to the 
whole quadrant of the ellipse4          
,illustration3 ,fig4 #bed4  ,let it now 
be required to lay out twenty-four teeth
 upon this ellipse2 that is1 six in each
 quadrant2 and for symmetry's sake we   
will suppose that the centre of one     
tooth is to be at ,a1 and that of       
another at ,c1 ,figure #bec4 ,we1       
therefore1 divide ,l ,g into six equal  
parts at the points #a1 #b1 #c1 etc41   
which will be the centres of the teeth  
upon the rectified ellipse4 ,it is      
practically necessary to make the spaces
 a little greater than the teeth2 but if
 the greatest attainable exactness in   
the operation of the wheels is aimed at1
 it is important to observe that        
backlash1 in elliptical gearing1 has an 
effect quite different from that        
resulting in the case of circular       

wheels4 ,when the pitch-curves are      
circles1 they are always in contact2 and
 we may1 if we choose1 make the tooth   
only half the breadth of the space1 so  
long as its outline is correct4 ,when   
the motion of the driver is reversed1   
the follower will stand still until the 
backlash is taken up1 when the motion   
will go on with a perfectly constant    
velocity ratio as before4 ,but in the   
case of two elliptical wheels1 if the   
follower stand still while the driver   
moves1 which must happen when the motion
 is reversed if backlash exists1 the    
pitch-curves are thrown out of contact1 
and1 although the continuity of the     
motion will not be interrupted1 the     
velocity ratio will be affected4 ,if the
 motion is never to be reversed1 the    
perfect law of the velocity ratio due to
 the elliptical pitch-curve may be      
preserved by reducing the thickness of  
the tooth1 not equally on each side1 as 
is done in circular wheels1 but wholly  
on the side not in action4 ,but if the  

machine must be capable of acting       
indifferently in both directions1 the   
reduction must be made on both sides of 
the tooth3 evidently the action will be 
slightly impaired1 for which reason the 
backlash should be reduced to a minimum4
 ,precisely what is the minimum is not  
so easy to say1 as it evidently depends 
much upon the excellence of the tools   
and the skill of the workman4 ,in many  
treatises on constructive mechanism it  
is variously stated that the backlash   
should be from one-fifteenth to         
one-eleventh of the pitch1 which would  
seem to be an ample allowance in        
reasonably good castings not intended to
 be finished1 and quite excessive if the
 teeth are to be cut2 nor is it very    
obvious that its amount should depend   
upon the pitch any more than upon the   
precession of the equinoxes4 ,on paper1 
at any rate1 we may reduce it to zero1  
and make the teeth and spaces equal in  
breadth1 as shown in the figure1 the    
teeth being indicated by the double     

lines4 ,those upon the portion ,l ,h are
 then laid off upon ,k ,i1 after which  
these divisions are transferred to the  
ellipse by the second of ,prof4         
,rankine's constructions1 and we are    
then ready to draw the teeth4  ,the     
outlines of these1 as of any other teeth
 upon pitch-curves which roll together  
in the same plane1 depend upon the      
general law that they must be such as   
can be marked out upon the planes of the
 curves1 as they roll by a              
tracing-point1 which is rigidly         
connected with and carried by a third   
line1 moving in rolling contact with    
both the pitch-curves4 ,and since under 
that condition the motion of this third 
line1 relatively to each of the others1 
is the same as though it rolled along   
each of them separately while they      
remained fixed1 the process of          
constructing the generated curves       
becomes comparatively simple4 ,for the  
describing line we naturally select a   
circle1 which1 in order to fulfil the   

condition1 must be small enough to roll 
within the pitch ellipse2 its diameter  
is determined by the consideration that 
if it be equal to ,a ,p1 the radius of  
the arc ,a ,f1 the flanks of the teeth  
in that region will be radial4 ,we have1
 therefore1 chosen a circle whose       
diameter1 ,a ,b1 is three-fourths of ,a 
,p1 as shown1 so that the teeth1 even at
 the ends of the wheels1 will be broader
 at the base than on the pitch line4    
,this circle ought strictly to roll upon
 the true elliptical curve2 and         
assuming1 as usual1 the tracing-point   
upon the circumference1 the generated   
curves would vary slightly from true    
epicycloids1 and no two of those used in
 the same quadrant of the ellipse would 
be exactly alike4 ,were it possible to  
divide the ellipse accurately1 there    
would be no difficulty in laying out    
these curves2 but having substituted the
 circular arcs1 we must now roll the    
generating circle upon these as bases1  
thus forming true epicycloidal teeth1 of

 which those lying upon the same        
approximating arc will be exactly alike4
 ,should the junction of two of these   
arcs fall within the breadth of a tooth1
 as at ,d1 evidently both the face and  
the flank on one side of that tooth will
 be different from those on the other   
side2 should the junction coincide with 
the edge of a tooth1 which is very      
nearly the case at ,f1 then the face on 
that side will be the epicycloid        
belonging to one of the arcs1 its flank 
a hypocycloid belonging to the other2   
and it is possible that either the face 
or the flank on one side should be      
generated by the rolling of the         
describing circle partly on one arc1    
partly on the one adjacent1 which1 upon 
a large scale1 and where the best       
results are aimed at1 may make a        
sensible change in the form of the      
curve4  ,the convenience of the         
constructions given in ,figure #beb is  
nowhere more apparent than in the       
drawing of the epicycloids1 when1 as in 

the case in hand the base and generating
 circles may be of incommensurable      
diameters2 for which reason we have1 in 
,figure #bed1 shown its application in  
connection with the most rapid and      
accurate mode yet known of describing   
those curves4 ,let ,c be the centre of  
the base circle2 ,b1 that of the rolling
 one2 ,a1 the point of contact4 ,divide 
the semi-circumference of ,b into six   
equal parts at #a1 #b1 #c1 etc42 draw   
the common tangent at ,a1 upon which    
rectify the arc ,a #b by process ,no4   
#a2 then by process ,no4 #b set out an  
equal arc ,a #b on the base circle1 and 
stepping it off three times to the right
 and left1 bisect these spaces1 thus    
making subdivisions on the base circle  
equal in length to those on the rolling 
one4 ,take in succession as radii the   
chords ,a #a1 ,a #b1 ,a #c1 etc41 of the
 describing circle1 and with centres #a1
 #b1 #c1 etc41 on the base circle1      
strike arcs either externally or        
internally1 as shown respectively on the

 right and left2 the curve tangent to   
the external arcs is the epicycloid1    
that tangent to the internal ones the   
hypocycloid1 forming the face and flank 
of a tooth for the base circle4         
,illustration3 ,fig4 #bee4  ,in the     
diagram1 ,figure #bec1 we have shown a  
part of an ellipse whose length is ten  
inches1 and breadth six1 the figure     
being half size4 ,in order to give an   
idea of the actual appearance of the    
combination when complete1 we show in   
,figure #bee the pair in gear1 on a     
scale of three inches to the foot4 ,the 
excessive eccentricity was selected     
merely for the purpose of illustration4 
,figure #bee will serve also to call    
attention to another serious            
circumstance1 which is1 that although   
the ellipses are alike1 the wheels are  
not2 nor can they be made so if there be
 an even number of teeth1 for the       
obvious reason that a tooth upon one    
wheel must fit into a space on the      
other2 and since in the first wheel1    

,figure #bee1 we chose to place a tooth 
at the extremity of each axis1 we must  
in the second one place there a space   
instead2 because at one time the major  
axes must coincide2 at another1 the     
minor axes1 as in ,figure #bee4 ,if1    
then1 we use even numbers1 the          
distribution1 and even the forms of the 
teeth1 are not the same in the two      
wheels of the pair4 ,but this           
complication may be avoided by using an 
odd number of teeth1 since1 placing a   
tooth at one extremity of the major     
axes1 a space will come at the other4   
,it is not1 however1 always necessary to
 cut teeth all round these wheels1 as   
will be seen by an examination of       
,figure #bef1 ,c and ,d being the fixed 
centres of the two ellipses in contact  
at ,p4 ,now ,p must be on the line ,c   
,d1 whence1 considering the free foci1  
we see that ,p ,b is equal to ,p ,c1 and
 ,p ,a to ,p ,d2 and the common tangent 
at ,p makes equal angles with ,c ,p and 
,p ,a1 as is also with ,p ,b and ,p ,d2 

therefore1 ,c ,d being a straight line1 
,a ,b is also a straight line and equal 
to ,c ,d4 ,if then the wheels be        
overhung1 that is1 fixed on the ends of 
the shafts outside the bearings1 leaving
 the outer faces free1 the moving foci  
may be connected by a rigid link ,a ,b1 
as shown4  ,illustration3 ,fig4 #bef4   
,this link will then communicate the    
same motion that would result from the  
use of the complete elliptical wheels1  
and we may therefore dispense with the  
most of the teeth1 retaining only those 
near the extremities of the major axes1 
which are necessary in order to assist  
and control the motion of the link at   
and near the dead-points4 ,the arc of   
the pitch-curves through which the teeth
 must extend will vary with their       
eccentricity2 but in many cases it would
 not be greater than that which in the  
approximation may be struck about one   
centre2 so that1 in fact1 it would not  
be necessary to go through the process  
of rectifying and subdividing the       

quarter of the ellipse at all1 as in    
this case it can make no possible       
difference whether the spacing adopted  
for the teeth to be cut would come out  
even or not1 if carried around the      
curve4 ,by this expedient1 then1 we may 
save not only the trouble of drawing1   
but a great deal of labor in making1 the
 teeth round the whole ellipse4 ,we     
might even omit the intermediate        
portions of the pitch ellipses          
themselves2 but as they move in rolling 
contact their retention can do no harm1 
and in one part of the movement will be 
beneficial1 as they will do part of the 
work2 for if1 when turning1 as shown by 
the arrows1 we consider the wheel whose 
axis is ,d as the driver1 it will be    
noted that its radius of contact1 ,c ,p1
 is on the increase2 and so long as this
 is the case the other wheel will be    
compelled to move by contact of the     
pitch lines1 although the link be       
omitted4 ,and even if teeth be cut all  
round the wheels1 this link is a        

comparatively inexpensive and a useful  
addition to the combination1 especially 
if the eccentricity be considerable4 ,of
 course the wheels shown in ,figure #bee
 might also have been made alike1 by    
placing a tooth at one end of the major 
axis and a space at the other1 as above 
suggested4 ,in regard to the variation  
in the velocity ratio1 it will be seen1 
by reference to ,figure #bef1 that if ,d
 be the axis of the driver1 the follower
 will in the position there shown move  
faster1 the ratio of the angular        
velocities being ,p x ,d_/,p x ,b2 if   
the driver turn uniformly1 the velocity 
of the follower will diminish1 until at 
the end of half a revolution1 the       
velocity ratio will be ,p x ,b_/,p x ,d2
 in the other half of the revolution    
these changes will occur in a reverse   
order4 ,but ,p ,d  ,l ,b2 if then the   
centres ,b ,d are given in position1 we 
know ,l ,p1 the major axis2 and in order
 to produce any assumed maximum or      
minimum velocity ratio1 we have only to 

divide ,l ,p into segments whose ratio  
is equal to that assumed value1 which   
will give the foci of the ellipse1      
whence the minor axis may be found and  
the curve described4 ,for instance1 in  
,figure #bee the velocity ratio being   
nine to one at the maximum1 the major   
axis is divided into two parts1 of which
 one is nine times as long as the other2
 in ,figure #bef the ratio is as one to 
three1 so that the major axis being     
divided into four parts1 the distance ,a
 ,c between the foci is equal to two of 
them1 and the distance of either focus  
from the nearest extremity of the major 
axis is equal to one1 and from the more 
remote extremity is equal to three of   
these parts4     ,,chapter ,,xii4       
,,plotting ,,mechanical ,,motions4      
,illustration3 ,fig4 #beg4  ,let it be  
required to find how much motion an     
eccentric will give to its rod1 the     
distance from the centre of its bore to 
the centre of the circumference1 which  
is called the throw1 being the distance 

from ,a to ,b in ,figure #beg4 ,now as  
the eccentric is moved around by the    
shaft1 it is evident that the axis of   
its motion will be the axis ,a of the   
shaft4 ,then from ,a as a centre1 and   
with radius from ,a to ,c1 we draw the  
dotted circle ,d1 and from ,e to ,f will
 be the amount of motion of the rod in  
the direction of the arrow4  ,this      
becomes obvious if we suppose a lead    
pencil to be placed against the         
eccentric at ,e1 and suppose the        
eccentric to make half a revolution1    
whereupon the pencil will be pushed out 
to ,f4 ,if now we measure the distance  
from ,e to ,f1 we shall find it is just 
twice that from ,a to ,b4 ,we may find  
the amount of motion1 however1 in       
another way1 as by striking the dotted  
half circle ,g1 showing the path of     
motion of ,b1 the diameter of this path 
of motion being the amount of lateral   
motion given to the rod4  ,illustration3
 ,fig4 #beh4  ,in ,figure #beh is a two 
arm lever fast upon the same axis or    

shaft1 and it is required to find how   
much a given amount of motion of the    
long arm will move the short one4       
,suppose the distance the long arm moves
 is to ,a4 ,then draw the line ,b from  
,a to the axis of the shaft1 and the    
line ,c the centre line of the long arm4
 ,from the axis of the shaft as a       
centre1 draw the circle ,d1 passing     
through the eye or centre ,e of the     
short arm4 ,take the radius from ,f to  
,g1 and from ,e as a centre mark it on  
,d as at ,h1 and ,h is where ,e will be 
when the long arm moves to ,a4 ,we have 
here simply decreased the motion in the 
same proportion as one arm is shorter   
than the other4 ,the principle involved 
is to take the motion of both arms at an
 equal distance from their axis of      
motion1 which is the axis of the shaft  
,s4  ,illustration3 ,fig4 #bei4  ,in    
,figure #bei we have a case in which the
 end of a lever acts directly upon a    
shoe4 ,now let it be required to find   
how much a given motion of the lever    

will cause the shoe to slide along the  
line x2 the point ,h is here found      
precisely as before1 and from it as a   
centre1 the dotted circle equal in      
diameter to the small circle at ,e is   
drawn from the perimeter of the dotted  
circle1 a dotted line is carried up and 
another is carried up from the face of  
the shoe4 ,the distance ,k between these
 dotted lines is the amount of motion of
 the shoe4  ,in ,figure #bfj we have the
 same conditions as in ,figure #bei1 but
 the short arm has a roller acting      
against a larger roller ,r4 ,the point  
,h is found as before4 ,the amount of   
motion of ,r is the distance of ,k from 
,j2 hence we may transfer this distance 
from the centre of ,r1 producing the    
point ,p1 from which the new position   
may be marked by a dotted circle as     
shown4  ,illustration3 ,fig4 #bfj4  ,in 
,figure #bfa a link is introduced in    
place of the roller1 and it is required 
to find the amount of motion of rod ,r4 
,the point ,h is found as before1 and   

then the length from centre to centre of
 link ,l is found1 and with this radius 
and from ,h as a centre the arc ,p is   
drawn1 and where ,p intersects the      
centre line ,j of ,r is the new position
 for the eye or centre ,q of ,r4        
,illustration3 ,fig4 #bfa4  ,in ,figure 
#bfb we have a case of a similar lever  
actuating a plunger in a vertical line1 
it being required to find how much a    
given amount of motion of the long arm  
will actuate the plunger4 ,suppose the  
long arm to move to ,a1 then draw the   
lines ,b ,c and the circle ,d4 ,take the
 radius or distance ,f1 ,g1 and from ,e 
mark on ,d the arc ,h4 ,mark the centre 
line ,j of the rod4 ,now take the length
 from ,e to ,i of the link1 and from ,h 
as a centre mark arc ,k1 and at the     
intersection of ,k with ,j is where the 
eye ,i will be when the long arm has    
moved to ,a4  ,illustration3 ,fig4 #bfb4
  ,in ,figure #bfc are two levers upon  
their axles or shafts ,s and ,s'2 arm ,a
 is connected by a link to arm ,b1 and  

arm ,c is connected direct to a rod ,r4 
,it is required to find the position of 
centre ,g of the rod eye when ,d is in  
position ,e1 and when it is also in     
position ,f4 ,now the points ,e and ,f  
are1 of course1 on an arc struck from   
the axis ,s1 and it is obvious that in  
whatever position the centre ,h may be  
it will be somewhere on the arc ,i1 ,i1 
which is struck from the centre ,s'4    
,now suppose that ,d moves to ,e1 and if
 we take the radius ,d1 ,h1 and from ,e 
mark it upon the arc ,i as at ,v1 then  
,h will obviously be the new position of
 ,h4 ,to find the new position of ,g we 
first strike the arc ,j1 ,j1 because in 
every position of ,g it will be         
somewhere on the arc ,j1 ,j4 ,to find   
where that will be when ,h is at ,v1    
take the radius ,h1 ,g1 and from ,v as a
 centre mark it on ,j1 ,j1 as at ,k1    
which is the position of ,g when ,d is  
at ,e and ,h is at ,v4 ,for the         
positions when ,d is at ,f we repeat the
 process1 taking the radius ,d1 ,h1 and 

from ,f marking ,p1 and with the radius 
,h1 ,g1 and from ,p as a centre marking 
,q2 then ,p is the new position for ,h1 
and ,q is that for ,g4  ,illustration3  
,fig4 #bfc4  ,in ,figure #bfd a lever   
arm ,a and cam ,c are in one piece on a 
shaft4 ,s is a shoe sliding on the line 
x1 and held against the cam face by the 
rod ,r2 it is required to find the      
position of the face of the shoe against
 the cam when the end of the arm is at  
,d4  ,draw line ,e from ,d to the axis  
of the shaft and line ,f4 ,from the     
shaft axis as a centre draw circle ,w2  
draw line ,j parallel to x4 ,take the   
radius ,g ,h1 and from ,k as a centre   
mark point ,p on ,w2 draw line ,q from  
the shaft axis through ,p1 and mark     
point ,t4 ,from the shaft axis as a     
centre draw from ,t an arc1 cutting ,j  
at ,v1 and ,v is the point where the    
face of the shoe and the face of the cam
 will touch when the arm stands at ,d4  
,illustration3 ,fig4 #bfd4  ,let it be  
required to find the amount of motion   

imparted in a straight line to a rod    
attached to an eccentric strap1 and the 
following construction may be used4 ,in 
,figure #bfe let ,a represent the centre
 of the shaft1 and1 therefore1 the axis 
about which the eccentric revolves4 ,let
 ,b represent the centre of the         
eccentric1 and let it be required to    
find in what position on the line of    
motion x1 the centre ,c of the rod eye  
will be when the centre ,b of the       
eccentric has moved to ,e4 ,now since ,a
 is the axis1 the centre ,b of the      
eccentric must rotate about it as       
denoted by the circle ,d1 and all that  
is necessary to find the position of ,c 
for any position of eccentric is to mark
 the position of ,b on circle ,d1 as at 
,e1 and from that position1 as from ,e1 
as a centre1 and with the length of the 
rod as a radius1 mark the new position  
of ,c on the line x of its motion4 ,with
 the centre of the eccentric at ,b1 the 
line ,q1 representing the faces of the  
straps1 will stand at a right angle to  

the line of motion1 and the length of   
the rod is from ,b to ,c2 when the      
eccentric centre moves to ,e1 the centre
 line of the rod will be moved to       
position ,p1 the line ,q will have      
assumed position ,r1 and point ,c will  
have moved from its position in the     
drawing to ,g on line x4 ,if the        
eccentric centre be supposed to move on 
to ,f1 the point ,c will move to ,h1 the
 radii ,b ,c1 ,e ,g1 and ,f ,h all being
 equal in length4 ,now when the         
eccentric centre is at ,e it will have  
moved one-quarter of a revolution1 and  
yet the point ,c will only have moved to
 ,g1 which is not central between ,c and
 ,h1 as is denoted by the dotted half   
circle ,i4  ,illustration3 ,fig4 #bfe4  
,on the other hand1 while the eccentric 
centre is moving from ,e to ,f1 which is
 but one-quarter of a revolution1 the   
rod end will move from ,g to ,h4 ,this  
occurs because the rod not only moves   
endwise1 but the end connected to the   
eccentric strap moves towards and away  

from the line x4 ,this is shown in the  
figure1 the rod centre line being marked
 in full line from ,b to x4 ,and when ,b
 has moved to ,e1 the rod centre line is
 marked by dotted line ,e1 so that it   
has moved away from the line of motion  
,b x4 ,in ,figure #bff the eccentric    
centre is shown to stand at an angle of 
#de degrees from line q1 which is at a  
right angle to the line of motion x x1  
and the position of the rod end is shown
 at ,c1 ,j and ,h representing the      
extremes of motion1 and ,g the centre of
 the motion4  ,illustration3 ,fig4 #bff4
  ,if now we suppose the eccentric      
centre to stand at ,t1 which is also an 
angle of #de degrees to q1 then the rod 
end will stand at ,k1 which is further  
away from ,g than ,c is2 hence we find  
that on account of the movement of the  
rod out of the straight end motion1 the 
motion of the rod end becomes irregular 
in proportion to that of the eccentric1 
whose action in moving the eye ,c of the
 rod in a straight line is increased 7by

 the rod7 while it is moving through the
 half rotation denoted by ,v in figure1 
and diminished during the other half    
rotation4  ,in many cases1 as1 for      
example1 on the river steamboats in the 
,western and ,southern ,states1 cams are
 employed instead of eccentrics1 and the
 principles involved in drawing or      
marking out such cams are given in the  
following remarks1 which contain the    
substance of a paper read by ,lewis     
,johnson before the ,american ,society  
of ,mechanical ,engineers4 ,in ,figure  
#bfg is a side view of a pair of cams2  
one1 ,c1 being a full stroke cam for    
operating the valve that admits steam to
 the engine cylinder2 and the other1 ,d1
 being a cam to cut off the steam supply
 at the required point in the engine    
stroke4 ,the positions of these cams    
with relation to the position of the    
crank-pin need not be commented upon    
here1 more than to remark that obviously
 the cam ,c must operate to open the    
steam inlet valve in advance of cam ,d1 

which operates to close it and cause the
 steam to act expansively in the        
cylinder1 and that the angle of the     
throw line of the cut-off valve ,d to   
the other cam or to the crank-pin varies
 according as it is required to cut off 
the steam either earlier or later in the
 stroke4  ,illustration3 ,fig4 #bfg4    
,the cam yoke is composed of two halves1
 ,y and ,y'1 bolted together by bolts   
,b1 which have a collar at one end and  
two nuts at the other end1 the inner    
nuts ,n ,n enabling the letting together
 of the two halves of the yoke to take  
up the wear4 ,it is obvious that as the 
shaft revolves and carries the cam with 
it1 it will1 by reason of its shape1    
move the yoke back and forth2 thus1 in  
the position of the parts shown in      
,figure #bfg1 the direction of rotation 
being denoted by the arrow1 cam ,c will1
 as it rotates1 move the yoke to the    
left1 and this motion will occur from   
the time corner a of the cam meets the  
face of ,y' until corner b has passed   

the centre line d4 ,now since that part 
of the circumference lying between      
points a and b of the cam is an arc of a
 circle1 of which the axis of the shaft 
is the centre1 the yoke will remain at  
rest until such time as b has passed    
line d and corner a meets the jaw ,y of 
the yoke2 hence the period of rest is   
determined by the amount of             
circumference that is made concentric to
 the shaft2 or1 in other words1 is      
determined by the distance between a and
 b4  ,the object of using a cam instead 
of an eccentric is to enable the opening
 of the valves abruptly at the beginning
 of the piston stroke1 maintaining a    
uniform steam-port opening during nearly
 the entire length of stroke1 and as    
abruptly closing the valves at the      
termination of the stroke4  ,figure #bfh
 is a top view of the mechanism in      
,figure #bfg2 and ,figure #bfi shows an 
end view of the yoke4 ,at ,b1 in ,figure
 #bfh1 is shown a guide through which   
the yoke-stem passes so as to be guided 

to move in a straight line1 there being 
a guide of this kind on each side of the
 yoke4  ,illustration3 ,fig4 #bfh4  ,the
 two cams are bolted to a collar that is
 secured to the crank-shaft1 and are    
made in halves1 as shown in the figures 
and also in ,figures #bgj and #bga1     
which represent cams removed from the   
other mechanism4 ,to enable a certain   
amount of adjustment of the cams upon   
the collar1 the bolts which hold them to
 the collar fit closely in the holes in 
the collar1 but the cams are provided   
with oblong bolt holes as shown1 so that
 the position of either cam1 either with
 relation to the other cam or with      
relation to the crank-pin1 can be       
adjusted to the extent permitted by the 
length of the oblong holes4             
,illustration3 ,fig4 #bfi4  ,the crank  
is assumed in the figures to be on its  
dead centre nearest to the engine       
cylinder1 and to revolve in the         
direction of the arrows4 ,the cams are  
so arranged that their plain unflanged  

surfaces bolt against the collar4  ,the 
method of drawing or marking out a full 
stroke cam1 such as ,c in ,figure #bfg1 
is illustrated in ,figure #bgb1 in which
 the dimensions are assumed to be as    
follows3  ,diameter of crank shaft1     
#g-a_/b inches2 travel of cam1 #c       
inches2 width of yoke1 #ah inches4      
,illustration3 ,fig4 #bgj4  ,the        
circumference of the cam is composed of 
four curved lines1 ,p1 ,p'1 ,k #a1 and  
,k #b4 ,the position of the centre of   
the crank shaft in this irregularly     
curved body is at ,x4 ,the arcs ,k #a   
and ,k #b differ in radius1 but are     
drawn from the same point1 ,x1 and hence
 are concentric with the crank shaft4   
,the arcs ,p1 ,p'1 are of like radius1  
but are drawn from the opposite points  
,s1 ,s'1 shown at the intersection of   
the arcs ,p1 ,p'1 with the arc ,k #a4   
,thus arcs ,p1 ,p'1 are eccentric to the
 crank shaft4  ,illustration3 ,fig4     
#bga4  ,illustration3 ,fig4 #bgb4       
,illustration3 ,fig4 #bgc4  ,to draw the

 cam place one point of the dividers at 
,x1 which is the centre of the crank    
shaft1 and draw the circle ,e equal to  
width of yoke1 #ah inches4 ,through this
 centre ,x1 draw the two right lines ,a 
and ,b4 ,on the line ,b1 at the         
intersection of the curved line ,e1 draw
 the two vertical lines ,a #a1 ,a #a4   
,with a radius of #aj-a_/b inches1 and  
with one point of the dividers at ,x1   
draw the arc ,k #a4 ,with a radius of   
#g-a_/b inches1 and one point of the    
dividers at ,x1 draw the arc ,k #b4     
,with a radius of #ah inches1 and one   
point of the dividers at the            
intersection of the arc ,e1 with the    
vertical line ,a #a at ,s1 draw the arc 
,p opposite to ,s1 and let it merge or  
lose itself in the curved line ,k #b4   
,draw the other curved line ,p' from the
 other point ,s1 and we have a full     
stroke cam of the dimensions required1  
and which is represented in ,figure     
#bgc1 removed from the lines used in    
constructing it4  ,illustration3 ,fig4  

#bgd4  ,the engravings from and         
including ,figure #bgd illustrate the   
lines embracing cut-off cams of varying 
limits of cut-off1 but all of like      
travel and dimensions1 which are the    
same as those given for the full stroke 
cam in ,figure #bgb4  ,in drawing       
cut-off cams1 the stroke of the engine  
plays a part in determining their       
conformation1 and in the examples shown 
this is assumed to be #d feet4 ,figure  
#bgd illustrates the manner of finding  
essential points in drawing or marking  
out cut-off cams4 ,with ,x as a centre1 
and a radius of #b feet1 draw the circle
 ,e #a1 showing the path of the         
crank-pin in making a revolution4 ,this 
circle has a diameter of #d feet1 equal 
to the stroke of the engine4 ,draw the  
horizontal line ,b1 passing through the 
centre of circle ,e #a4 ,within the     
limits of circle ,e #a1 subdivide line  
,b into eight equal parts1 as at #a1 #b1
 #c1 #d1 etc4 ,draw the vertical lines1 
#a1 #b1 #c1 #d1 etc41 until they each   

intersect the circle ,e #a4             
,illustration3 ,fig4 #bge4  ,with ,x as 
a centre1 draw the circle ,e1 having a  
diameter of #ah inches1 equal to the    
space in the yoke embracing the cam4    
,from the centre ,x draw the series of  
radial lines through the points of      
intersection of the vertical lines #a1  
#b1 #c1 #d1 etc41 from the circle ,e #a1
 and terminating at ,x4 ,we will now    
proceed to utilize the scale afforded by
 ,figure #bgd1 in laying off the cut-off
 cam shown in ,figure #bgf1 of half     
stroke limit4  ,illustration3 ,fig4     
#bgf4  ,with ,x as a centre1 draw the   
circle ,e1 ,figure #bge1 having a       
diameter of #ah inches4 ,bisect this    
circle with the straight lines ,a and   
,b1 which bear the same relation to     
their enclosing circle that the lines   
,a1 ,b1 do to the circle ,e in ,figure  
#bgd4  ,illustration3 ,fig4 #bgg4  ,it  
will be observed1 in ,figure #bgd1 that 
the vertical line ,a is 7at the top     
half7 also ,no4 #d1 representing #d_/h1 

or half of the stroke4 ,with a radius of
 #ah inches1 and one point of the       
dividers placed at ,v1 which is at the  
intersection of the circle ,e with the  
horizontal line ,b in ,figure #bge1 draw
 the arc ,p4 ,with the same radius and  
with one compass point rested at ,v'1   
draw the arc ,p'2 then two arcs1 ,p and 
,p'1 intersecting at the point ,s4      
,with the same radius and one point of  
the compasses at ,s1 draw the arc ,h ,h4
 ,the arcs ,k #a and ,k #b are drawn    
from the centre ,x1 with a radius of    
#aj-a_/b for ,k #a and #g-a_/b inches   
for ,k #b1 and only serve in a half     
stroke cam to intersect the curved lines
 already drawn1 as shown in ,figure     
#bge4 ,in practice1 the sharp corner at 
,s would be objectionable1 owing to     
rapid wear at this point2 and hence a   
modification of the dimensions for this 
half stroke cam would be required to    
obtain a larger wearing surface at the  
point ,s1 but the cam of this limit     
7#a_/b stroke7 is correctly drawn by the

 process described with reference to    
,figure #bge1 the outline of the cam so 
constructed being shown in ,figure #bgf4
  ,illustration3 ,fig4 #bgh4  ,in       
,figure #bgh is shown a cam designed to 
cut off the steam at five-eighths of the
 piston stroke1 the construction lines  
being given in ,figure #bgg1 for which  
draw circle ,e and straight lines ,a and
 ,b1 as in the preceding example4 ,by   
reference to ,figure #bgd it will be    
observed that the diagonal line drawn   
through circle ,e at #e is drawn from   
the straight line marked #e1 which      
intersects circle ,e #a1 and as this    
straight line #e represents five-eighths
 of the stroke laid off on line ,b1 it  
determines the limit of cut-off on the  
five-eighths cam in ,figure #bgg4       
,illustration3 ,fig4 #bgi4  ,turning    
then to ,figure #bgd1 take on circle ,e 
the radius from radial line #d to radial
 line #e1 and mark it in ,figure #bgg   
from the vertical line producing ,v'4   
,now1 with a radius of #ah inches1 and  

one point of the dividers fixed at point
 ,v1 forming the intersection of the    
circle ,e with the horizontal line ,b1  
draw the arc ,p4 ,with the same radius1 
and one point of the dividers fixed at  
point ,v'1 draw the opposite arc ,p'4   
,with a radius of #aj-a_/b inches from  
the centre ,x1 draw the arc ,k #a1      
intersecting lines ,p ,p'1 at ,s ,s4    
,with a radius of #g-a_/b inches1 draw  
the curved line ,k #b1 opposite to      
curved line ,k #a4 ,now1 with a radius  
of #ah inches1 and one point of the     
dividers fixed alternately at ,s ,s1    
draw the arcs ,h1 ,h1 from their        
intersection with the circle ,e1 until  
they merge into the curved line ,k #b4  
,these curved lines embrace a cut-off   
cam of five-eighths limit1 shown        
complete in ,figure #bgh4               
,illustration3 ,fig4 #bhj4  ,from the   
instructions already given it should be 
easy to understand that the             
three-fourths and seven-eighths cams1   
shown in ,figures #bgi1 #bhj1 #bha and  

#bhb1 are drawn by taking the points of 
their cut-off from the same scale shown 
in ,figure #bgd1 at the diagonal points 
#f and #g1 intersecting circle ,e in    
that figure2 and cut-off cams of        
intermediate limit of cut-off can be    
drawn by further subdividing the stroke 
line ,b1 in ,figure #bgd1 into the      
required limits4  ,illustration3 ,fig4  
#bha4  ,cut-off cams of any limit are   
necessarily imperfect in their          
operations as to uniformity of cut-off  
from opposite ends of the slides1 not   
from any defect in the rule for laying  
them off1 but from the well-known fact  
of the crank pin travelling a greater   
distance1 while driven by the piston    
from the centre of the cylinder1 through
 its curved path from the cylinder1 over
 its centre1 and back to the centre of  
the cylinder1 than in accomplishing the 
remaining distance of its path in making
 a complete revolution2 and1 although   
the subdivisions of eighths of the      
stroke line ,b1 in ,figure #bgd1 does   

not truly represent a like division of  
the piston stroke1 owing to deviation1  
caused by inclination of the connecting 
rod in traversing from the centres to   
half stroke1 still it will be found that
 laying off a cut-off cam by this rule  
is more nearly correct than if the      
divisions on stroke line ,b were made to
 correspond exactly with a subdivision  
of piston stroke into eighths4          
,illustration3 ,fig4 #bhb4  ,the cut-off
 in cams laid off by the rules herein   
described is greater in travelling from 
one side of the slides than in          
travelling from the opposite end1 one   
cut-off being more than the actual      
cut-off of piston stroke1 and the other 
less2 and in practical use1 owing to    
play or lost motion in the connections  
from cam to valve1 the actual cut-off is
 less than the theoretical2 hence       
cut-off cams are usually laid off to    
compensate for lost motion2 that is1    
laid off with more limit2 for instance1 
a five-eighths cam would be laid off to 

cut-off at eleven-sixteenths instead of 
five-eighths4  ,illustration3 ,fig4     
#bhc4  ,figure #bhc represents the      
motion a crank1 ,c1 imparts to a        
connecting rod1 represented by the thick
 line ,r1 whose end1 ,b1 is supposed to 
be guided to move in a straight line4   
,the circle ,h represents the path of   
the crank-pin1 and dots #a1 #b1 #c1     
etc41 are #bd different crank-pin       
positions equidistant on the circle of  
crank-pin revolution4 ,suppose the      
crank-pin to have moved to position #a1 
and with the compasses set to the length
 of the rod ,r1 we set one point on the 
centre of position #a1 and mark on the  
line of motion m the line a1 which will 
be the position rod end ,b will have    
moved to4 ,suppose next that the        
crank-pin has moved into position #b1   
and with the compass point on the centre
 of #b we mark line #b1 showing that    
while the crank-pin moved from #a to #b1
 the rod end moved from a to b2 by      
continuing this process we are enabled  

to discern the motion for the whole of  
the stroke4 ,the backward stroke will be
 the same1 for corresponding crank-pin  
positions1 for both strokes2 thus1 when 
the rod end is at #g the crank-pin may  
be at #g or at #ag4 ,this fact enables  
us to find the positions for the        
positions later than #f1 on the other   
side of the circle1 as at #ag1 #af1 #ae1
 etc41 which keeps the engraving clear4 
,illustration3 ,fig4 #bhd4  ,in ,figure 
#bhd a pinion1 ,p1 drives a gear-wheel1 
,d1 on which there is a pin driving the 
sliding die ,a in the link ,l1 which is 
pivoted at ,c1 and connected at its     
upper end to a rod1 ,r1 which is        
connected to a bolt1 ,b1 fast to a      
slide1 ,s4 ,it is required to find the  
motion of ,s1 it moving in a straight   
line1 dotted circle ,h' representing the
 path of the pin in the sliding die ,a1 
arc ,h representing the line of motion  
of the upper end of link ,l1 and lines  
,n1 ,o1 its centre line at the extreme  
ends of its vibrating motion4 ,in       

,figure #bhe the letters of reference   
refer to the same parts as those in     
,figure #bhd4 ,we divide the circle ,h' 
of pin motion into #bd equidistant parts
 marked by dots1 and through these we   
draw lines radiating from centre1 ,c1   
and cutting arc ,h1 obtaining on the arc
 ,h the various positions for end ,z of 
rod ,r1 these positions being marked    
respectively #a1 #b1 #c1 #d1 etc41 up to
 #bd4 ,with a pair of compasses set to  
the length of rod ,r from #a on ,h1 as a
 centre1 we mark on the line of motion  
of the slide1 line a1 which shows where 
the other end of rod ,r will be 7or in  
other words1 it shows the position of   
bolt ,b in ,figure #bhd71 when the      
centre of ,a1 ,figure #bhd1 is in       
position #a1 ,figure #bhe4              
,illustration3 ,fig4 #bhe4  ,from #b on 
arc ,h1 we mark with the compasses line 
b on line ,m1 showing that while the pin
 moved from #a to #b1 the rod ,r would  
move slide ,s1 ,figure #bhd1 from a to  
b1 in ,figure #bhe4 ,from #c we mark c1 

and so on1 all these marks being above  
the horizontal line ,m1 representing the
 line of motion1 and being for the      
forward stroke4 ,for the backward stroke
 we draw the dotted line from position  
#ag up to arc ,h1 and with the compasses
 at #ag mark a line beneath the line ,m 
of motion1 pursuing the same course for 
all the other pin motions1 as #ah1 #ai1 
etc41 until the pin arrives again at    
position #bd1 and the link at ,o1 and   
has made a full revolution1 and we shall
 have the motion of the forward stroke  
above and that of the backward one below
 the line of motion of the slide1 and   
may compare the two4  ,illustration3    
,fig4 #bhf4  ,illustration3 ,fig4 #bhg4 
,illustration3 ,fig4 #bhh4              
,illustration3 ,fig4 #bhi4  ,figures    
#bhf and #bhg represent the ,whitworth  
quick return motion that is employed in 
many machines4 ,f represents a frame    
supporting a fixed journal1 ,b1 on which
 revolves a gear-wheel1 ,g1 operated by 
a pinion1 ,p4 ,at ,a is an arm having   

journal bearing in ,b at ,c4 ,this arm  
is driven by a pin1 ,d1 fast in the     
gear1 ,g2 hence as the gear revolves1   
pin ,d moves ,a around on ,c as a centre
 of motion4 ,a is provided with a slot  
carrying a pin1 ,x1 on which is pivoted 
the rod1 ,r4 ,the motion of end ,n of   
the rod ,r being in a straight line1 ,m1
 it is required to find the positions of
 ,n during twenty-four periods in one   
revolution of ,g4 ,in ,figure #bhh let  
,h' represent the path of motion of the 
driving pin ,d1 about the centre of ,b1 
and ,h the path of motion of ,x about   
the centre ,c2 these two centres        
corresponding to the centres of ,b and  
,c respectively1 in ,figure #bhg4 ,let  
the line ,m correspond to the line of   
motion ,m in ,figure #bhf4 ,now since it
 is the pin ,d1 ,figure #bhg1 that      
drives1 and since its speed of          
revolution is uniform1 we divide its    
circle of motion ,h' into twenty-four   
equal divisions1 and by drawing lines   
radiating from centre ,c1 and passing   

through the lines of division on ,h' we 
get on circle ,h twenty-four positions  
for the pin ,x in ,figure #bhf4 ,then   
setting the compasses to the length of  
the rod 7,r1 ,figure #bhf71 we mark from
 position #a on circle ,h as a centre   
line1 a2 from position #b on ,h we mark 
line b1 and so on for the whole         
twenty-four positions on circle ,h1     
obtaining from a to n for the forward1  
and from n to y for the motion during   
the backward stroke4 ,suppose now that  
the mechanism remaining precisely the   
same as before1 the line ,m of motion be
 in a line with the centres ,c1 ,b1     
instead of at a right angle to it1 as it
 is in ,figure #bhf1 and the motion     
under this new condition will be as in  
,figure #bhi2 the process for finding   
the amount of motion along ,m from the  
motion around ,h being precisely as     
before4  ,illustration3 ,fig4 #bij4  ,in
 ,figure #bij is shown a cutter-head for
 a wood moulding machine1 and it is     
required to find what shape the cutting 

edge of the cutter must be to form a    
moulding such as is shown in the end    
view of the moulding in the figure4 ,now
 the line ,a ,a being at a right angle  
to the line of motion of the moulding as
 it is passed beneath the revolving     
cutter1 or1 what is the same thing1 at a
 right angle to the face of the table on
 which the moulding is moved1 it is     
obvious that the highest point ,c of the
 moulding will be cut to shape by the   
point ,c of the cutter2 and that since  
the line of motion of the end of the    
cutter is the arc ,d1 the lowest part of
 the cutter action upon the moulding    
will be at point ,e4 ,it will also be   
obvious that as the cutter edge passes1 
at each point1 its length across the    
line ,a ,a1 it forms the moulding to    
shape1 while all the cutting action that
 occurs on either side of that line is  
serving simply to remove material4 ,all 
that we have to consider1 therefore1 is 
the action on line ,a ,a4  ,it may be   
observed also that the highest point ,c 

of the cutter edge must not be less than
 #a_/d inch from the corner of the      
cutter head1 which gives room for the   
nut ,n 7that holds the cutter to the    
head7 to pass over the top of the       
moulding in a #b-a_/b inch head4 ,in    
proportion as the heads are made larger1
 however1 less clearance is necessary   
for the nut1 as is shown in ,figure     
#bia1 the cutter edge extending to ,c1  
and therefore nearly up to the corner of
 the head4 ,its path of motion at ,c is 
shown by dotted arc ,b1 which it will be
 observed amply clears the nut ,n4 ,in  
practice1 however1 point ,c is not in   
any size of cutter-head placed nearer   
than #a_/d inch from corner ,x of the   
cutter-head4  ,to find the length of the
 cutter edge necessary to produce a     
given depth of moulding1 we may draw a  
circle i1 ,figure #bib1 equal in        
diameter to the size of the cutter head 
to be used1 and line ,a ,a4 ,the highest
 point of cutting edge being at e1 and  
the lowest at g1 then circles d and f   

represent the line of motion of these   
two points2 and if we mark the cutter   
in1 the necessary length of cutting edge
 on the cutter is obviously from a to b4
  ,illustration3 ,fig4 #bia4            
,illustration3 ,fig4 #bib4  ,now the    
necessary depth of cutter edge being    
found for any given moulding1 or part of
 a moulding1 the curves for the edge may
 be found as follows3 ,suppose the      
moulding is to be half round1 as in the 
end view in ,figure #bij4 ,the width of 
the cutter must of course equal the     
width of the moulding1 and the length or
 depth of cutting edge required may be  
found from the construction shown in    
,figure #bib2 hence all that remains is 
to find the curve for the cutting edge4 
,in ,figure #bic1 let ,a ,a represent   
the centre of the cutter width1 its     
sides being ,f ,f'1 and its end ,b ,b4  
,from centre ,c draw circle ,d1 the     
upper half of which will serve to       
represent the moulding4 ,mark on ,a the 
length or depth the cutting edge        

requires to be1 ascertaining the same   
from the construction shown in ,figure  
#bib1 and mark it as from ,c to ,k'4    
,then draw line ,e ,e1 passing through  
point ,k4 ,draw line ,g1 standing at the
 same angle to ,a ,a as the face h b1   
,figure #bib1 of the cutter does to the 
line ,a ,a1 and draw line ,h ,h1        
parallel to ,g4 ,from any point on ,g1  
as at ,i1 with radius ,j1 draw a quarter
 of a circle1 as ,k4 ,mark off this     
quarter circle into equal points of     
division1 as by #a1 #b1 #c1 etc41 and   
from these points of division draw      
lines1 as a1 b1 c1 etc42 and from these 
lines draw horizontal lines d1 e1 f1    
etc4 ,now divide the lower half of      
circle ,d into twice as many equal      
divisions as quarter circle ,k is       
divided into1 and from these points of  
division draw perpendiculars g1 h1 i1   
etc4 ,and where these perpendiculars    
cross the horizontal lines1 as d1 will  
be points through which the curve may be
 drawn1 three of such points being      

marked by dots at p1 q1 r4 ,if the      
student will1 after having drawn the    
curve by this construction1 draw it by  
the construction that was explained in  
connection with ,figure #gi1 he will    
find the two methods give so nearly     
identical curves1 that the latter and   
more simple method may be used without  
sensible error4  ,illustration3 ,fig4   
#bic4  ,illustration3 ,fig4 #bid4  ,when
 the curves of the moulding are not arcs
 of circles they may be marked as       
follows3  ,take the drawing of the      
moulding and divide each member or step 
of it by equidistant lines1 as a1 b1 c1 
d1 e1 f1 g1 in ,figure #bid2 above the  
moulding draw lines representing the    
cutter1 and having found the depth of   
cutting edge for each member by the     
construction shown in ,figure #bib1     
finding a separate line1 a b1 for each  
member of the moulding1 transfer the    
depths so found to the face of the      
cutter2 divide the depth of each member 
of the cutter into as many equal        

divisions as the corresponding member of
 the moulding is divided into1 as by    
lines h1 i1 j1 k1 l1 m1 n4 ,then draw   
vertical lines1 as o1 p1 q1 r1 etc42 and
 where these lines meet the respective  
lines h1 i1 j1 etc41 are points in the  
curve1 such points being marked on the  
cutter by dots4     ,,chapter ,,xiii4   
,,examples ,,in ,,line-,,shading ,,and  
,,drawings ,,for ,,line-,,shaded        
,,engravings4   ,although in workshop   
drawings1 line-shading is rarely        
employed1 yet where a design rather than
 the particular details of construction 
is to be shown1 line-shading is a       
valuable accessory4 ,figure #bie1 for   
example1 is intended to show an         
arrangement of idle pulleys to guide    
belts from one pulley to another2 the   
principle being that so long as the belt
 passes to a pulley moving in line with 
the line of rotation of the pulley1 the 
belt will run correctly1 although it may
 leave the pulley at considerable angle4
 ,when a belt envelops two pulleys that 

are at a right angle to each other1 two 
guide pulleys are needed in order that  
the belt may1 in passing to each pulley1
 move in the same plane as the pulley   
rotates in1 and the belt is in this case
 given what is termed a quarter twist4  
,it will be observed that by the        
line-shading even the twist of the belt 
is much more clearly shown than it would
 be if left unshaded4  ,an excellent    
example of shading is given in ,figure  
#bif1 which is extracted from the       
,american ,machinist1 and represents a  
cutting tool for a planing machine4 ,the
 figure is from a wood engraving1 but   
the effect may be produced by lines1 the
 black parts being considered as simply 
broad black lines4  ,illustration3 ,fig4
 #bie4  ,the drawings from which        
engravings are made are drawn to conform
 to the process by which the engraving  
is to be produced4 ,drawings that are   
shaded by plain lines may be engraved by
 three methods4 ,first1 the drawing may 
be photo-engraved1 in which process the 

drawing is photographed on the metal1   
and every line appears in the engraving 
precisely as it appears in the drawing4 
,illustration3 ,fig4 #bif4  ,for this   
kind of engraving the drawing may be    
made of any convenient size that is     
larger than the size of engraving to be 
produced1 the reduction of size being   
produced in the photographing process4  
,drawings for photo-engraving require to
 have the lines jet black1 and it is to 
be remembered that if red centrelines   
are marked on the drawing1 they will be 
produced as ordinary black lines in the 
engraving4  ,the shading on a drawing to
 be photo-engraved must be produced by  
lines1 and not by tints1 for tints1     
whether of black or of colors1 will not 
photo-engrave properly4  ,it is         
generally preferred to make the drawing 
for a photo-engraving larger than the   
engraving that is to be made from it1 a 
good proportion being to make the       
drawing twice the length the engraving  
is to be4 ,this serves to reduce the    

magnitude of any roughness in the lines 
of the drawing1 and1 therefore1 to make 
the engraving better than the drawing4  
,the thickness of the lines in the      
drawing should be made to suit the      
amount of reduction to be made1 because 
the lines are reduced in thickness in   
the same proportion as the engraving is 
reduced from the drawing4 ,thus the     
lines on an engraving reduced to        
one-half the dimensions of the drawing  
would be one-half as thick as the lines 
on the drawing4  ,drawings for          
photo-engraving should be made on       
smooth-faced paper2 as1 for example1 on 
,bristol board2 and to make the lines   
clean and clear1 the drawing instruments
 should be in the best of condition1 and
 the paper or ,bristol board quite dry4 
,the ,india rubber should be used as    
little as possible on drawings to be    
photo-engraved1 because1 if used before 
the lines are inked in1 it roughens the 
surface of the paper1 and the inking    
lines will be less smooth and even at   

their edges2 and for this reason it is  
better not to rub out any lines until   
all the lines have been inked in4 ,if   
used to excess after the lines have been
 inked in it serves to reduce the       
blackness of the lines1 and may so pale 
them that they will not properly        
photo-engrave4  ,to make a drawing for  
an engraver in wood it would be drawn   
directly on the face of the box-wood    
block1 on which it is to be engraved4   
,the surface of the block is first      
whitened by a white water color1 as     
,chinese white4 ,if the drawing that is 
to be used as a copy is on sufficiently 
thin paper1 its outline may be traced   
over by pencil lines1 and the copy may  
then be laid face down on the wood block
 and its edges held to the block by wax1
 the pencilled lines being face to the  
block4 ,the outline may then be again   
traced over with a pencil or pointed    
instrument1 causing the imprint of the  
lead pencil lines to be left on the     
whitened surface of the block4 ,if the  

copy is on paper too thick to be thus   
employed1 a tracing may be made and used
 as above2 it being borne in mind that  
the tracing must be laid with the       
pencilled lines on the block1 because   
what is the right hand of the drawing on
 the block is the left hand in the print
 it gives4 ,the shading on wood blocks  
is given by tints of ,india ink aided by
 pencilled lines1 or of course pencilled
 lines only may for less artistic work  
be used4 ,another method is to          
photograph the drawing direct upon the  
surface of the wood block2 it is        
unnecessary1 however1 to enter into this
 part of the subject4  ,the third method
 of producing an engraving from a       
drawing is by means of what is known as 
the wax process4 ,drawings for this     
process should be made on thin paper1   
for the following reasons3 ,the process 
consists1 briefly stated1 in coating a  
copper plate with a layer of wax about  
#a_/cb inch deep1 and in drawing upon   
the wax the lines to compose the        

engraving1 which lines are produced by  
means of tools that remove the wax down 
to the surface of the copper4  ,the     
plate and wax are then placed in a      
battery and a deposit of copper fills in
 the lines and surface of the wax1 thus 
forming the engraving4 ,now if the      
drawing is made on thin paper1 the      
engraver coats the surface of the       
drawing with a dry red pigment1 and with
 a pointed instrument traces over the   
lines of the drawing1 which causes them 
to leave a red imprint on the surface of
 the wax1 and after the drawing is      
removed the engraver cuts these         
imprinted lines in the wax4 ,if the     
drawing is on thick paper1 this method  
of transferring the drawing to the wax  
cannot be used1 and the engraver may    
take a tracing from the drawing and     
transfer from the tracing to the wax4   
,it is obvious1 also1 that for wax      
engravings the drawing should be made of
 the same size that the engraving is    
required to be1 or otherwise the tracing

 process described cannot be used4      
,figure #big represents an engraving    
made by the wax process from a print    
from a wood engraving1 and it is obvious
 that since all the lines drawn on the  
wax sink down to the surface of the     
copper plate1 the shading is virtually  
composed of lines1 the black surfaces   
being where the lines have been         
sufficiently close together and broad to
 remove all the wax enclosed within     
those surfaces4  ,illustration3 ,fig4   
#big4  ,illustration3 ,fig4 #bih4  ,the 
wax process is1 however1 more suitable  
for engravings in plain outline only1   
and is especially excellent when the    
parts are small and the lines fall close
 together2 as1 for example1 in ,figures 
#bih and #bii1 which are engravings of a
 boiler drilling machine1 and were      
produced for the ,american ,machinist by
 tracing over a wood engraving from     
,london1 ,engineering in the manner     
already described4 ,the fineness and    
cleanness of the lines in the wax       

process is here well illustrated1 the   
disposition of the parts being easily   
seen from the engraving1 and easily     
followed in connection with the         
following description3  ,the machine    
consists of two horizontal bed-plates ,a
 #a and ,a #b1 made with ,v slides on   
top1 and placed at right angles to each 
other4 ,upon each of the bed-plates is  
fitted a vertical arm ,b #a and ,b #b1  
each of which carries two saddles1 ,c #a
 and ,c #b1 these being each adjustable 
vertically on its respective arm by     
means of rack and pinion and hand wheels
 ,d #a and ,d #b4 ,the saddles are      
balanced so that the least possible     
exertion is sufficient to adjust them4  
,the vertical arms1 ,b #a and ,b #b1 are
 cast each with a round foot by which   
the arms are attached to the square     
boxes ,e #a and ,e #b1 which are fitted 
to the ,v slides on the horizontal beds 
,a #a and ,a #b1 and are adjustable     
thereon by means of screw and ratchet   
motion ,f #a and ,f #b4 ,each of the    

square boxes has cast on it a small arm 
,g #a and ,g #b1 carrying studs upon    
which run pinions gearing into the      
circular racks at the foot of the       
vertical arms4 ,the square boxes have   
each a circular groove turned in the top
 to receive the bolts by which the      
vertical arms are connected to them1 and
 thus the vertical arms1 and with them  
the drill spindles ,n #a and ,n #b1 are 
adjustable radially with the boiler--the
 adjustment being effected by means of  
the pinions and circular racks4 ,the    
pinions are arranged so that they can be
 worked with the same screw key that is 
used for the bolts in the circular      
grooves4  ,the shell to be drilled is   
placed upon the circular table ,h1 which
 is carried by suitable framework       
adjustable by means of screw on a ,v    
slide ,i1 placed at an angle of #de deg4
 with the horizontal bed-plates4 ,by    
this arrangement1 when the table is     
moved along ,i1 it will approach to or  
recede from all the drills equally4 ,j  

#a and ,j #b are girders forming        
additional bearings for the framework of
 the table4 ,the bed-plates and slides  
for the table are bolted and braced     
together1 making the whole machine very 
firm and rigid4 ,power is applied to the
 machine through the cones ,k #a and ,k 
#b1 working the horizontal and vertical 
shafts ,l #a and ,l #b1 etc4 ,on the    
vertical shafts are fitted coarse pitch 
worms sliding on feather keys1 and      
carried with the saddles ,c #a and ,c   
#b1 etc4 ,the worms gearing with the    
worm wheels ,m #a and ,m #b are fitted  
on the sleeves of the steel spindles ,n 
#a and ,n #b4 ,the spindles are fitted  
with self-acting motions ,o #a and ,o   
#b1 which are easily thrown in and out  
of gear4  ,the machine is also used for 
turning the edge of the flanges which   
some makers prefer to have on the end   
plates of marine boilers4 ,the plates   
are very readily fixed to the circular  
table ,h1 and the edge of the flange    
trued up much quicker than by the       

ordinary means of chipping4 ,when the   
machine is used for this purpose1 the   
cross beam ,p1 which is removable1 is   
fastened to the two upright brackets ,r 
#a and ,r #b4 ,the cross beam is cast   
with ,v slides at one side for a little 
more than half its length from one end1 
and on the opposite side for the same   
length1 but from the opposite end4 ,the 
,v slides are each fitted with a tool   
box ,s #a and ,s #b1 having a screw     
adjustment for setting the tool to the  
depth of cut1 and adjustable on the ,v  
slides of the cross beam to the diameter
 of the plate to be turned4 ,this       
arrangement of the machine is also used 
for cutting out the furnace mouths in   
the boiler ends4 ,the plate is fastened 
to the circular table1 the centre of the
 hole to be cut out being placed over   
the centre of table2 one or both of the 
tool boxes may be used4 ,there is       
sufficient space between the upright    
brackets ,r #a and ,r #b1 to allow that 
section of a boiler end which contains  

the furnace mouths to revolve while the 
holes are being cut out2 the plate      
belonging to the end of a boiler of the 
largest diameter that the machine will  
take in for drilling4 ,the holes cut out
 will be from #b feet #c inches in      
diameter and upwards4 ,power for using  
the turntable is applied through the    
cone ,t4 ,the bevel wheels1 worms1 worm 
wheels1 and pinions for driving the     
tables are of cast steel1 which is      
necessary for the rough work of turning 
the flanges4  ,illustration3 ,fig4 #bii4
 7,page #bge47  ,as to the practical    
results of using the machine1 the drills
 are driven at a speed of #cdj feet per 
minute at the cutting edges4 ,a jet of  
soapsuds plays on each drill from an    
orifice #a_/cb in4 in diameter1 and at a
 pressure of #fj lbs4 per square inch4  
,a joint composed of two #a-;inch       
plates1 and having holes #a and         
one-eighth in4 in diameter1 can be      
drilled in about #b-a_/b minutes1 and   
allowing about half a minute for        

adjusting the drill1 each drill will do 
about #bj holes per hour4 ,the machine  
is designed to stand any amount of work 
that the drills will bear4 ,the time    
required for putting on the end of a    
boiler and turning the flange thereon   
7say #ad feet diameter7 is about #b-a_/b
 hours2 much1 however1 depends on the   
state of the flanges1 as sometimes they 
are very rough1 while at others very    
little is necessary to true them up4    
,the time required for putting on the   
plate containing the furnace mouths and 
cutting out three holes #b feet #f in4  
in diameter1 the plate being #a and     
one-eighth in4 thick1 is three hours4   
,of course1 if several boilers of one   
size are being made at the same time1   
the holes in two or more of these plates
 can be cut out at once4 ,the machine is
 of such design that it can be placed   
with one of the horizontal bed-plates   
7say ,a #a71 parallel and close up to a 
wall of the boiler shop2 and when the   
turning apparatus is being used1 the    

vertical arm ,b #b can be swiveled half 
way round on its square box ,e #b1 and  
used for drilling and tapping the stay  
holes in marine boiler ends after they  
are put together2 of course sufficient  
room must be left between bed-plate ,a  
#b1 and the wall of boiler shop parallel
 with it1 to allow for reception of the 
boiler to be operated upon4  ,it would  
obviously be quite difficult to draw    
such drawings as in ,figures #bih and   
#bii on thin paper1 so as to enable the 
drawing to be traced on the wax direct  
by the process before described1 unless 
indeed the draftsman had considerable   
experience in fine work2 hence1 it is   
not uncommon to make the drawing large1 
and on ordinary drawing paper4 ,the     
engraver then has the drawing           
photographed on the surface of the wax1 
and works to the photograph4 ,the       
letters of reference in wax engravings  
are put in by impressing type in the    
wax1 and in this connection it may be   
remarked that the letters ,i and ,o     

should not be used on drawings to be    
engraved by the wax process1 unless they
 are situated outside the outlines of   
the drawing1 because the ,i looks so    
much like part of a dotted line that it 
is often indistinguishable therefrom1   
while the ,o looks like a circle or an  
ellipse4     ,,chapter ,,xiv4  ,,shading
 ,,and ,,coloring ,,drawings4   ,the    
shading or coloring of drawings by tints
 is more employed in large drawings than
 in small ones1 and in ,europe than in  
the ,united ,states2 while on the other 
hand tinting by means of line-shading is
 more employed in the ,united ,states   
than in ,europe1 and more on small      
drawings than on large ones4  ,many     
draftsmen adopt the plan of coloring the
 journals of shafts1 etc41 with a light 
tint1 giving them the deepest tint at   
the circumference to give them a        
cylindrical appearance4 ,this makes the 
drawing much clearer and takes but      
little time to do1 and is especially    
advantageous where the parts are small  

or on a small scale1 so that the lines  
are comparatively close together4  ,for 
simple shading purposes black tints of  
various degrees of darkness may be      
employed1 but it is usual to tint brass 
work with yellow4 ,cast iron with ,india
 ink1 wrought iron with ,prussian blue1 
steel with as light purple tint produced
 by mixing ,india ink1 ,prussian blue   
and a tinge of crimson lake4 ,copper is 
tinted red4 ,on plane surfaces an even  
tint of color is laid1 but if the       
surfaces are cylindrical they are       
usually colored deeper at and near the  
circumference1 and are tinted over the  
colors with light tints of ,india ink to
 show their cylindrical form4  ,if a    
drawing is to be colored or shaded with 
,india ink the paper should be glued all
 around its edges to the drawing board1 
and then dampened evenly all over with a
 sponge1 which will cause the paper to  
shrink and lay close to the surface of  
the drawing board4 ,if1 in applying a   
color or a tint1 the color dries before 

the whole surface is colored1 the color 
will not be of an equal shade2 hence it 
is necessary before applying the color  
to dampen the surface1 if it is a large 
one1 so that the color at one part shall
 not get dry before there has been time 
to go over the whole surface2 a more    
even depth of color is attained by the  
application of several coats of a light 
tint1 than with one coat1 giving the    
full depth of color4 ,but if the paper  
is not allowed to dry sufficiently      
between the coats1 or if it has been    
made too wet previous to the application
 of the colors1 it will run in places1  
leaving other hollows into which the    
color will flow1 making darker-colored  
spots4 ,to avoid this the paper may be  
dried somewhat by the application of    
clean blotting paper4  ,to maintain an  
even shade of color1 it is necessary to 
slightly stir up the color each time the
 brush is dipped into the color saucer  
or palette1 especially when the coloring
 is composed of mixed colors1 because   

the coloring matter is apt to separate  
from the water and sink to the bottom4  
,so1 also1 in mixing colors it is best  
to apply the end of the color to the    
surface of the palette and not to apply 
the brush direct to the cake of color1  
because the color is more completely    
mixed by contact with the palette than  
it can be by the brush1 which may retain
 a speck of color that will1 unless     
washed out1 make a streak upon the      
drawing4  ,to graduate the depth of tint
 for a cylindrical surface1 it is best  
to mix several1 as1 say three depths or 
degrees of tint1 and to first use the   
darkest1 applying it in the direction in
 which the piece is to be shaded        
darkest4 ,the width this dark           
application should be is obviously      
determined by the diameter of the piece4
 ,the next operation is to lighten or   
draw the part1 line or streak thus dark 
colored1 causing it to get paler and    
paler as it approaches the axial line of
 the piece or cylinder4 ,this lightening

 is accomplished as follows3 ,the dark  
streak is applied along such a length of
 the piece that it will not dry before  
there has been time to draw it out or   
lighten it on the side towards the axis4
 ,a separate brush may then be wetted   
and drawn along the edge of the dark    
streak in short strokes1 causing the    
color to run outwards and become lighter
 as it approaches the axis4 ,it will be 
found that during this process the brush
 will occasionally require washing in   
water1 because from continuous contact  
with the dark streak the tint it        
contains will darken4 ,when the first   
coat has been laid and spread or drawn  
out from end to end of the piece1 the   
process may be repeated two or three    
times1 the most even results being      
obtained by making the first dark streak
 not too dark1 and going over the       
drawing several times1 but allowing the 
paper to get very nearly dry between    
each coat4 ,in small cylindrical bodies1
 as1 say #a_/d inch in diameter1 the    

darkest line of shadow may be located at
 the lines representing the diameter of 
the piece1 but in pieces of larger      
diameter the darkest line may be located
 at a short distance from the line that 
denotes the diameter or perimeter on the
 shadow or right-hand side of the piece1
 as is shown in many of the engravings  
that follow4 ,it is obvious that if a   
drawing is to have dimensions marked on 
it1 the coloring or tinting should not  
be deep enough to make it difficult to  
see the dimension figures4  ,the size of
 the brush to be used depends1 of       
course1 upon the size of the piece to be
 shaded or colored1 and it is best to   
keep one brush for the dark tint and to 
never let the brush dry with the tint in
 it1 as this makes it harsh4 ,in a good 
brush the hairs are fine1 lie close     
together when moistened1 are smooth and 
yet sufficiently stiff or elastic to    
bend back slightly when the pressure is 
removed4 ,if1 when under pressure and   
nearly dry1 the hairs will separate or  

the brush has no elasticity in it1 good 
results cannot be obtained4 ,all brushes
 should be well dried after use4  ,the  
light in shading is supposed to come in 
at the left-hand corner of the drawing1 
as was explained with reference to the  
shade line4  ,excellent examples to copy
 and shade with the brush are given as  
follows3  ,figure #cjj represents a     
,medart pulley1 constructed by the      
,hartford ,steam ,engineering ,company2 
the arms and hub are cast in one piece1 
and the rim is a wrought iron band      
riveted to the arms1 whose ends are     
turned or ground true with the hub bore4
 ,the figure is obviously a wood        
engraving1 but it presents the varying  
degrees of shade or shadow with         
sufficient accuracy to form a good      
example to copy and brush shade with    
,india ink4 ,figure #cja represents a   
similar pulley with a double set of     
arms1 forming an excellent example in   
perspective drawing1 as well as for     
brush-shading4  ,illustration3 ,fig4    

#cjj4  ,in brush-shading as with        
line-shading1 the difficulties increase 
with an increase in the size of the     
piece1 and the learner will find that   
after he has succeeded tolerably well in
 shading these small pulleys1 it will be
 quite difficult1 but excellent practice
 to shade the large pulley in ,figure   
#cjb4  ,one of the principal            
considerations is to not let the color  
dry at the edges in one part while      
continuing the shading in another part  
of the same surface1 hence it is best to
 begin at the edge or outline of the    
drawing and carry the work forward as   
quickly as possible1 occasionally       
slightly wetting with water edges that  
require to be left while the shading is 
proceeding in another direction4        
,illustration3 ,fig4 #cja4  ,when it is 
required to show by the shading that the
 surfaces are highly polished1 the      
lighter parts of the shading are made to
 contain what may be termed splashes of 
lighter and darker shadow1 as in ,figure

 #cjc1 which represents an oil cup1     
having a brass casing enclosing a glass 
cylinder1 which appears through the     
openings in the brass shell4  ,figure   
#cjd represents an iron planing machine 
whose line-shading is so evenly effected
 that it affords an excellent example of
 shading4 ,its parts are similar to     
those shown in the iron planer in       
,figure #big1 save that it carries two  
sliding heads1 so as to enable the use1 
simultaneously1 of two cutting tools4   
,illustration3 ,fig4 #cjd4 7,page #bhb47
  ,illustration3 ,fig4 #cjb4  ,a        
superior example in shading is shown in 
,figures #cje and #cjf1 which represent 
a plan and a sectional view of the      
steam-cylinder of a ,blake's patent     
direct-acting steam-pump4 ,the          
construction of the parts is as follows3
 ,a is the steam-piston1 ,h #a and ,h   
are the cylinder steam-passages2 ,m is  
the cylinder exhaust port4              
,illustration3 ,fig4 #cjc4              
,illustration3 ,fig4 #cje4  ,the main   

valve1 whose movement alternately opens 
the ports for the admission of steam to1
 and the escape of steam from1 the main 
cylinder1 is divided into two parts1 one
 of which1 ,c1 slides upon a seat on the
 main cylinder1 and at the same time    
affords a seat for the other part1 ,d1  
which slides upon the upper face of ,c4 
,as shown in the engravings1 ,d is at   
the left-hand end of its stroke1 and ,c 
at the opposite or right-hand end of its
 stroke4 ,steam from the steam-chest1   
,j1 is therefore entering the right-hand
 end of the main cylinder through the   
ports ,e and ,h1 and the exhaust is     
escaping through the ports ,h #a1 ,e #a1
 ,k and ,m1 which causes the main piston
 ,a to move from right to left4 ,when   
this piston has nearly reached the      
left-hand end of its cylinder1 the      
tappet arm1 ,t1 attached to the         
piston-rod1 comes in contact with1 and  
moves the valve rod collar ,o #a and    
valve rod ,p1 and thus causes ,c1       
together with the supplemental valves ,r

 and ,s ,s #a1 which form1 with ,c1 one 
casting1 to be moved from right to left4
 ,this movement causes steam to be      
admitted to the left-hand end of the    
supplemental cylinder1 whereby its      
piston ,b will be forced towards the    
right1 carrying ,d to the opposite or   
right-hand end of its stroke2 for the   
movement of ,s closes ,n 7the steam-port
 leading to the right-hand end71 and the
 movement of ,s #a opens ,n #a 7the     
steam-port leading to the opposite or   
left-hand end71 at the same time the    
movement of ,v opens the right-hand end 
of this cylinder to the exhaust1 through
 the exhaust ports ,x and ,z4 ,the parts
 ,c and ,d now have positions opposite  
to those shown in the engravings1 and   
steam is therefore entering the main    
cylinder through the ports ,e #a and ,h 
#a1 and escaping through the ports ,h1  
,e1 ,k and ,m1 which causes the main    
piston ,a to move in the opposite       
direction1 or from left to right1 and   
operations similar to those already     

described will follow1 when the piston  
approaches the right-hand end of its    
cylinder4 ,by this simple arrangement   
the pump is rendered positive in its    
action2 that is1 it will instantly start
 and continue working the moment steam  
is admitted to the steam-chest1 while at
 the same time the piston is enabled to 
move as slowly as the nature of the duty
 may require4 ,it will be noted that in 
,figure #cje1 the ports of ,c are shown 
through ,d1 whose location is marked by 
dark shading4 ,this obviously is not    
correct1 because ,d being above ,c      
should be shaded lighter than ,c1 and   
again the ports ,e #a and ,k could not  
show dark through the port ,d4 ,they    
might1 of course1 be shown by dotted    
outlines1 but they would not appear to  
such advantage1 and on this account it  
is permissible where artistic effect is 
sought1 the object being to subserve the
 shading to making the mechanism and its
 operation clearly and readily          
understood4  ,illustration3 ,fig4 #cjf4 

,figure #cjg affords another excellent  
example for shading4 ,it consists of an 
independent condenser1 whose            
steam-cylinder and valve mechanism is   
the same as that described with         
reference to ,figures #cje and #cjf4    
,illustration3 ,fig4 #cjg4 7,page #bhh47
  ,illustration3 ,fig4 #cjh4 7,page     
#bhi47  ,illustration3 ,fig4 #cji4      
7,page #bhi47  ,illustration3 ,fig4     
#caj--,,section ,,of ,,cylinder ,,and   
,,steam ,,chest4 7,page #bhi47          
,,chapter ,,xv4  ,,examples ,,in        
,,engine ,,work4   ,in the figures from 
#cjh to #cbh inclusive are given three  
examples in engine work1 all these      
drawings being from ,the ,american      
,machinist4 ,figures #cjh to #cad       
represent drawings of an automatic high 
speed engine designed and made by       
,professor ,john ,e4 and ,william ,a4   
,sweet1 of ,syracuse1 ,new ,york4       
,figure #cjh is a side and #cji an end  
view of the engine4 ,upon a bed-plate is
 bolted two straight frames1 between    

which1 at their upper ends1 the cylinder
 is secured by bolts4 ,the guides for   
the cross-head are bolted to the frame1 
which enables them to be readily removed
 to be replaned when necessary4 ,the    
hand wheel and rod to the right are to  
operate the stop-cock for turning on and
 off the steam to the steam-chest4  ,the
 objects of the design are as follows3  
,figure #caj is a vertical section of   
the cylinder through the valve face1    
also showing the valve in section1 and  
it will be seen that the lower steam    
passage enters the cylinder its full    
depth below the inside bottom1 and that 
the whole inside bottom surface of the  
cylinder slopes or inclines towards the 
entrance of this passage4 ,the object of
 this is to overcome the difficulty     
experienced from the accumulation of    
water in the cylinder1 which1 in the    
vertical engine1 is usually a source of 
considerable annoyance and frequently   
the cause of accident4  ,any water that 
may be present in the bottom finds its  

way by gravity to the port steam        
entrance1 and is forced out by and with 
the exhaust steam at or before the      
commencement of the return stroke4  ,to 
assist in the escape of water from the  
top of the cylinder1 the piston is made 
quite crowning at that end1 the effect  
of which is to collect the water in a   
narrow band1 instead of spreading it    
over a large surface4 ,this materially  
assists in its escape1 and at the same  
time presents a large surface for the   
distribution of any water that may not  
find its way out in advance of the      
piston4  ,the piston is a single casting
 unusually long and light1 and is packed
 with four spring rings of #c_/h inch   
square brass wire4  ,the valve is a     
simple rectangular plate1 working       
between the valve face and a cover      
plate1 the cover plate being held in its
 proper position1 relative to the back  
of the valve1 by steam pressure against 
its outer surface1 and by resting       
against loose distance pieces between   

its inner surface and the valve seat4   
,this construction admits of the valve  
leaving the seat1 if necessary1 to      
relieve the cylinder from water1 as in  
the instance of priming1 and also1 by   
the reduction of these pieces1 admits of
 ready adjustment to contact1 should it 
become necessary4  ,illustration3 ,fig4 
#caa--,,valve ,,motion4  ,the cover     
plate is provided with recesses on its  
inner surface which exactly correspond  
with the ports in the valve face1 and   
the corresponding ports and recesses are
 kept in communication with each other  
by means of relief passages in the      
valve4 ,from this it will be seen that  
the valve is subjected to equal and     
balanced pressure on each of its sides1 
and hence1 is in equilibrium4  ,the     
valve is operated through the valve     
motion1 shown in ,figure #caa1 the      
eccentric rod of which hooks on a       
slightly tapered block that turns on the
 pin of the rock arm1 like an ordinary  
journal box4  ,the expansion1 or        

cut-off1 is automatically regulated by  
the operation of the governor in        
swinging the slotted eccentric in a     
manner substantially equivalent to      
moving it across the shaft1 but is      
however favorably modified by the       
arrangement of the rock arm1 which1 in  
combination with the other motions1     
neutralizes the unfavorable operation of
 the usual shifting eccentric1 and      
which1 in connection with the large     
double port opening1 provides for a good
 use of steam from #j to #c_/d stroke4  
,the governor shown in ,figure #cab is  
of the disc and single ball type1 the   
centrifugal force of the ball being     
counteracted by a powerful spring4      
,friction is reduced to a minimum in the
 governor connection1 by introducing    
steel rollers and hardened steel plates 
in such a manner as to provide rolling  
instead of sliding motion4  ,in order   
that a governor shall correctly perform 
its functions1 it is unquestionably     
necessary that it have power largely in 

excess of the work required of it1 and  
also that the friction shall represent a
 very low percentage of that power4 ,in 
respect to this1 especial means have    
been employed to reduce the friction2   
the valve being balanced1 requires but  
little power to move it1 while the      
governor ball being made heavy for the  
purpose of counterbalancing the weight  
of the eccentric and strap1 its         
centrifugal force when the engine is at 
full speed is enormous1 the spring to   
counteract it having to sustain from two
 to three thousand pounds4 ,under these 
circumstances1 as might be expected1 the
 regulation is remarkably good4 ,this is
 a very important consideration in an   
engine working under the conditions of a
 roll-train engine4  ,illustration3     
,fig4 #cab--;,,governor4  ,illustration3
 ,fig4 #cac--,,section ,,of ,,pillow    
,,block4  ,figure #cac represents a     
section of the pillow block box1        
crank-pin and wheel1 together with the  
main journal4 ,it will be seen that the 

end of the box next the crank wheel has 
a circular groove around its outside1   
and that a corresponding groove in the  
crank wheel projects over this groove4  
,from this latter groove an oil hole of 
liberal size extends1 as shown1 to the  
surface of the crank-pin4 ,any oil      
placed at the upper part of the groove  
on the box finds its way by gravity into
 the groove in the crank wheel1 and is  
carried by centrifugal force to the     
outside surface of the crank-pin2 so    
that whatever other means of lubrication
 may be employed1 this one will always  
be positive in its action4 ,this cut    
also shows the manner in which the box  
overlaps the main journal and forms the 
oil reservoir4  ,illustration3 ,fig4    
#cad--;,,connecting ,,rod4 7,page #bie47
  ,another feature in the construction  
of this box is the means by which it is 
made to adjust itself in line with the  
shaft4 ,it will be observed that it     
rests on the bottom of the jaws of the  
frame on two inclined surfaces1 which   

form equal angles with the axis of the  
shaft when in its normal position1 and  
that by moving longitudinally in either 
direction1 as may be necessary1 the box 
will accommodate itself to a change in  
the alignment of the shaft4 ,in order   
that it may be free to move for this    
purpose it is not fitted with the usual 
fore and aft flanges4 ,by this means any
 slight derangement1 as in either the   
outboard or inboard bearing wearing down
 the fastest1 is taken care of1 the     
movement of the box on the inclined     
surfaces being for this purpose         
equivalent to the operation of a ball   
and socket bearing4  ,figure #cad gives 
a side and an edge view of the          
connecting rod1 the rod being in section
 in the edge view1 and the brasses in   
section lined in both views4  ,the      
cross-head pin1 it will be observed1 is 
tapered1 and is drawn home in the       
cross-head by a bolt2 the sides of the  
pin are flattened somewhat where the    
journal is1 so that the pin may not wear

 oval1 as it is apt to do1 because of   
the pull and thrust strain of the rod   
brasses falling mainly upon the top and 
bottom of the journal1 where the most   
wear therefore takes place4 ,the brasses
 at the crossed end are set up by a     
wedge adjustable by means of the screw  
bolts shown4 ,the cross-head wrist pin  
being removable from the cross-head     
enables the upper end of the rod to have
 a solid end1 since it can be passed    
into place in the crossed and the wrist 
pin inserted through the two4 ,the lower
 ends of the connecting-rod and the     
crank-pin possess a peculiar feature1   
inasmuch as by enlarging the diameter of
 the crank-pin1 the ends of the brasses 
overlap1 to a certain extent1 the ends  
of the journal1 thus holding the oil and
 affording increased lubrication4 ,the  
segments that partly envelop the        
cross-head pin and crank-pin1 and are   
section lined in two directions1        
producing crossing section lines1 or    
small squares1 show that the brasses are

 lined with babbitt metal1 which is     
represented by this kind of             
cross-hatching4 ,these drawings are     
sufficiently open and clear to form very
 good examples to copy and to trace on  
tracing paper4  ,illustration3 ,fig4    
#cae4  ,illustration3 ,fig4 #caf4 7,page
 #bif47  ,illustration3 ,fig4 #cag4     
,figures #cae1 #caf and #cag represent1 
in place upon its setting1 a #bjj       
horse-power horizontal steam-boiler for 
a stationary engine1 and are the design 
of ,william ,h4 ,hoffman4 ,the          
cross-sectional view of the boiler shell
 in ,figure #cae shows the arrangement  
of the tubes1 which1 having clear or    
unobstructed passages between the       
vertical rows of tubes1 permits the     
steam to rise freely and assists the    
circulation of the water4 ,the dry pipe 
7which is also shown in ,figure #caf7 is
 a perforated pipe through which the    
steam passes to the engine cylinder1 its
 object being to carry off the steam as 
dry as possible2 that is to say1 without

 its carrying away with the steam any   
entrained water that may be held in     
suspension4 ,figure #caf is a side      
elevation with the setting shown in     
section1 and ,figure #cag is an end view
 of the boiler and setting at the       
furnace end4 ,the boiler is supported on
 each side by channel iron columns1     
these being riveted to the boiler shell 
angle pieces which rest upon the        
columns4 ,the heat and products of      
combustion pass from the furnace along  
the bottom of the boiler1 and at the end
 pass into and through the tubes and    
thence over the top of the boiler to the
 chimney flue4 ,there is shown in the   
bridge wall an opening1 and its service 
is to admit air to the gases after they 
have passed the bridge wall1 and thus   
complete the combustion of such gases as
 may have remained unconsumed in the    
furnace4 ,the cleansing door at one end 
and that lined with asbestos at the     
other1 are to admit the passage of the  
tube cleaners4 ,the asbestos at the top 

of the boiler shell is to protect it    
from any undue rise in temperature1     
steam being a poorer conductor of heat  
than water1 and it being obvious that if
 one side of the boiler is hotter than  
the other it expands more from the heat 
and becomes longer1 causing the boiler  
to bend1 which strains and weakens it4  
,the sides of the setting are composed  
of a double row of brick walls with an  
air space of three inches between them1 
the object being to prevent as far as   
possible the radiation of heat from the 
walls4 ,the brick-staves are simply     
stays to hold the brick work together   
and prevent its cracking1 as it is apt1 
in the absence of staying1 to do4       
,illustration3 ,fig4 #cah4 7,page #bii47
  ,figures from #cah to #ccj are working
 drawings of a #ajj-;horse engine1      
designed also by ,william ,h4 ,hoffman4 
,figure #cah represents a plan and a    
side view of the bed-plate with the main
 bearing and the guide bars in place4   
,the cylinder is bolted at the stuffing 

box end to the bed-plate1 and is        
supported at the outer end by an        
expansion link pivoted to the bed-plate4
 ,the main bearing is provided with a   
screw for adjusting the height of the   
bottom piece of the bearing1 and thus   
taking up the wear4 ,the guide bars are 
held to the bed in the middle as well as
 at each end4  ,figures #cai and #cbj   
represent cross sections of the         
bed-plate4  ,illustration3 ,fig4        
#cai--;,,cross ,,section ,,of ,,bed     
,,plate ,,near ,,junction ,,with        
,,cylinder4 7,page #bii47               
,illustration3 ,fig4 #cbj4              
,illustration3 ,fig4 #cba--ajj ,h4,p4   
,,horizontal                            
,,steam-,,engine--,,elevation ,,of      
,,cylinder--,,scale #a-a_/b  #a ,,foot4 
7,page #bii47  ,illustration3 ,fig4     
#cbb--ajj ,h4,p4 ,,horizontal           
,,steam-,,engine--,,end ,,view ,,of     
,,cylinder--,,scale #a-a_/b  #a ,,foot4 
7,page #bii47  ,figure #cba represents a
 side elevation of the cylinder1 and    

,figure #cbb an end view of the same1   
the expansion support being for the     
purpose of permitting the cylinder to   
expand and contract under variations of 
temperature without acting to bend the  
bed-plate1 while at the same time the   
cylinder is supported at both ends4 ,the
 cylinder and cylinder covers are       
jacketted with live steam in the        
steam-spaces shown4  ,illustration3     
,fig4 #cbc--ajj ,h4,p4                  
,,engine--,,outside ,,view ,,of         
,,cylinder ,,and ,,steam-,,chest4 7,page
 #cja47  ,illustration3 ,fig4           
#cbd--,,sectional ,,view ,,of ,,cylinder
 ,,and ,,valves--,,scale #a-a_/b        
,,inches  #a ,,foot4 7,page #cja47      
,illustration3 ,fig4 #cbe--,,plan ,,of  
,,cut-,,off ,,device4 7,page #cja47     
,illustration3 ,fig4 #cbf--,,working    
,,drawing ,,of #ajj ,h4,p4              
,,engine--,,details ,,of ,,main ,,valve 
,,motion--,,scale #c  #a ,,foot4 7,page 
#cja47  ,illustration3 ,fig4 #cbh--ajj  
,h4,p4 ,,horizontal                     

,,steam-,,engine--,,cross ,,head4 7,page
 #cja47  ,illustration3 ,fig4 #cbi4     
,fig4 #cbi a4 ,working ,drawings of #ajj
 ,h4,p4 ,steam ,engine--,eccentric and  
,eccentric ,strap--,scale3 #c  #a ,foot4
 7,page #cja47  ,illustration3 ,fig4    
#ccj--ajj ,h4,p4 ,,horizontal           
,,steam-,,engine--,,connecting ,,rod4   
7,page #cjc47  ,a view of the           
steam-chest side of the cylinder is     
given in ,figure #cbc1 and a horizontal 
cross section of the cylinder1 the      
steam-chest and the valves1 is shown in 
,figure #cbd4 ,the main valves are      
connected by a right and left hand      
screw1 to enable their adjustment1 as   
are also the cut-off valves4  ,figures  
#cbe and #cbf show the cam wrist plate  
and the cut-off mechanism4 ,the cam     
wrist plate1 which is of course vibrated
 by the eccentric rod1 has an inclined  
groove1 whose walls are protected from  
wear by steel shoes4 ,in this groove is 
a steel roller upon a pin attached to   
the bell crank operating the main valve 

stem4 ,the operation of the groove is to
 accelerate the motion imparted from the
 eccentric to the valve at one part of  
the latter's travel1 and retard it at   
another1 the accelerated portion being  
during the opening of the port for steam
 admission1 and during its closure for  
cutting off1 which enables the          
employment of a smaller steam-port than 
would otherwise be the case4  ,the shaft
 for the cam plate is carried in a      
bearing at one end1 and fits in a socket
 at the other1 the socket and bearing   
being upon a base plate that is bolted  
to the bed-plate of the engine2 a side  
view of the construction being shown in 
,figure #cbg4  ,figure #cbh represents  
the cross-head1 whose wrist pin is let  
into the cross-head cheeks1 so that it  
may be removed to be turned up true4    
,the clip is to prevent the piston rod  
nut from loosening back of itself4      
,figure #cbi represents a side view2 and
 ,figure #cbi a a section through the   
centre of the eccentric and strap4      

,illustration3 ,fig4 #cbg--,,working    
,,drawing ,,of #ajj ,h4,p4              
,,steam-,,engine4--,,wrist ,,plate4--#c 
#a ,,foot4  ,the eccentric is let into  
the strap and is provided with an eye to
 receive a circular nut by means of     
which the length of the eccentric rod   
may be adjusted1 a hexagon nut being    
upon the other or outer end of the eye4 
,figure #ccj shows the construction of  
the connecting rod1 the brasses of which
 are adjustable to take up the wear and 
to maintain them to correct length1     
notwithstanding the wear1 by means of a 
key on each side of each pair of        
brasses1 the keys being set up by nuts  
and secured by check nuts4     ,,index4 
,ames' lathe feed motion1 drawing a part
 of1 #bjh4  ,angle of three lines1 one  
to the other1 to find1 #ee1 #ef4   of   
two lines1 one to the other1 to find1   
#ed1 #ee1 #ef4  ,angles1 acute and      
obtuse1 #eg4  ,arc of a circle1 an1 #ej4
  ,arcs1 construction with four1 #fg1   
#fh4  ,arcs for the teeth of wheels1 to 

draw1 #bje4  ,arrangement of different  
views1 #id-aaa4  ,automatic high speed  
engine1 drawings of1 #bhi4  ,axis of a  
cylinder1 #ea4   of an ellipse1 #fc4    
,ball or sphere1 representation of by   
line-shading1 #hg1 #hh4  ,bed-plate1    
cross section of1 #bii4   plan and side 
view of1 with main bearing and guide    
bars1 #bii4  ,bell-mouthed body1        
representation of by line-shading1 #hh1 
#hi4  ,bevelled gear1 one-half of1 and  
an edge view projected from the same1   
#bjg4   one of which is line-shaded1    
#baj4   wheels1 #bjc4  ,bevelled gears1 
small1 #bjh4  ,bevelled wheels1 a pair  
of1 in section1 #bjh4  ,bisected line1  
#ej4  ,black lines of a drawing1 how to 
produce1 #cb4  ,blacksmith1 drawings for
 the1 #agb4  ,blake's patent direct     
acting steam pump1 #bhd1 #bhe4  ,boiler 
drilling machine1 a1 #bfi1 #bgj4        
,boiler1 end view of1 #big4   shell1    
sectional view of1 #bif4  ,bolt heads   
and nuts1 ,united ,states standard1     
#aad1 #aah4   to draw a square-headed1  

#abe4   with a hexagon head1 to draw4   
#aac1 #aad4   with a square under the   
head1 #adi4  ,bolts and nuts1 dimensions
 of ,united ,states standard1 #aag4     
,united ,states standard1 forged or     
unfinished1 #aaf4  ,bolts1 nuts and     
polygons1 examples in1 #aab-aea4  ,bow  
pen1 applying the ink to1 #df4   large1 
with a removable leg1 #bb4  ,brass1     
representation of1 by cross-hatching1   
#hb4  ,bread for rubbing out1 #bf4      
,bristol board1 use of rubber on1 #bf4  
,brush-shading1 #bha4  ,brushes1 size   
and use of1 #bhj4   ,cam1 a1 and a lever
 arm in one piece on a shaft1 a shoe    
sliding on the     line1 and held       
against the cam face by the rod1 to find
 the position     of the face of the    
shoe against the cam1 #bbh4   a full    
stroke1 method of drawing or marking    
out1 #bcg-bda4   designed to cut off    
steam at five-eighths of the piston     
stroke1 #bdd-bdf4   heart1 to draw1 #ge1
 #gf4   object of using1 instead of     
eccentric1 #bcd4  ,cam wrist plate1 and 

cut-off mechanism1 #cja4  ,cams1        
cut-off1 employed instead of eccentrics 
on steamboats1 examples in     drawing1 
#bcb4   finding the essential points of 
drawings of1 #bda-bdd4   necessary      
imperfections in the operations of1     
#bdg-bdi4   part played by the stroke of
 the engine in determining the          
conformation     of1 #bda4              
three-fourths and seven-eighths1 #bdf1  
#bdg4  ,cap nut1 to pencil in a1 #adc4  
,cast iron1 representation of1 #bgg4    
representation of by cross-hatching1    
#hb4  ,centre from which an arc of a    
circle has been struck1 to find1 #eb4   
,centre of a circle1 #ea4  ,centre punch
 in which the flat sides run out upon a 
circle1 the edges     forming curves1   
#aej4  ,chamfer circles of bolt heads1  
#abj-abc4   of ,franklin ,institute bolt
 head1 #aai4  ,chord of an arc1 #ej4    
,chuck plate with six slots1 to draw1   
#aca4  ,circle1 degrees of a1 #eb-ee4   
pencil and circle pen1 use of1 #dc1 #dd4
   pens1 #cg1 #ch4   that shall pass    

through any three given points1 to draw1
 #ea4   to divide into six divisions1   
#ef1 #eg4  ,circles1 to divide with the 
triangle1 #abi4   for bolt heads1 to    
draw1 #abh4   ,german instrument for    
drawing1 #dd1 #de4   use of the         
instrument in forming1 #db-de4          
,circular arcs1 ,rankine's process for  
rectifying and subdividing1 #baj4       
,circumference1 #ej4  ,collar1 a        
representation of1 #if4  ,coloring and  
shading1 points to be observed in1 #bgh4
  ,color1 to maintain an even shade of1 
#bgh4  ,colors1 mixing1 #bgh4           
,condenser1 independent1 #bhh4  ,cone1  
cylinder intersecting a1 #ahf4          
,connecting rod1 #afi1 #bie1 #cjc4      
drawing representing the motion   which 
a crank imparts to a1 #bdi1 #bej4   end1
 #adg4  ,copper1 representation of1     
#bgg4  ,corner where the round stem     
meets the square under the head1 #aej4  
,coupling rod1 working drawings of a1   
#afi4  ,crank1 drawing representing the 
motion which it imparts to a connecting 

rod1 #bdi4   pin and wheel1 #bid4       
,cross-hatching or section lining1      
#gg-hb4   made to denote material of    
which the piece is composed1 #ha1 #hb4  
may sometimes cause the lines of the    
drawing to appear crooked to the        
eye1 #hj1 #ha4   representation by1 of a
 section of a number of pieces one      
within the     other1 the central bore  
being filled with short plugs1 #gh1 #gi4
   representation by1 of three pieces   
put together1 having slots or keyways   
through them1 #gi1 #hj4   the diagonal  
lines in1 should not meet the edges of  
the piece1 #gh4  ,cross-head1 #cja4     
,cross1 use of1 to designate a square1  
#ie1 #if4  ,cube1 with a hole passing   
through it1 to draw1 #aja1 #ajb4        
,cupped ring1 representation of1 #ih4   
,curved outline1 representation of1 #hf1
 #hg4  ,curve for tooth face1 how to    
find1 #aih4   representation of the     
radius for1 #hg4  ,curves and lines1    
#dh-gf4   of gear teeth1 names of1 #aic4
  ,curves for moulding cutter1 to find  

the1 #beg-bfc4   of thread1 template for
 drawing1 #afe4   of wheels1            
construction1 to find1 #bjd4   screw    
threads1 drawing1 #aei4   templates     
called1 #ba4   use of1 in practice1 #ba4
  ,cut-off cams1 employed instead of    
eccentrics on steamboats1 examples in   
drawing1 #bcb4   manner of finding      
essential points of drawings of1        
#bda-bdd4   necessary imperfections in  
the operations of1 #bdg-bdi4   part     
played by the stroke of the engine in   
determining the conformation     of1    
#bda4  ,cut-off mechanism1 #cja4        
,cutting tool for a planing machine1    
representation of1 #bfd-bff4  ,cylinder1
 #bii4   a solid1 representation of1    
#id1 #ie4   intersecting a cone1 #ahf   
of an engine1 #bii-cja4   of an engine1 
drawing of1 #bhi4  ,cylindrical body    
joining another at a right angle1 a1    
#ahj4   body whose top face1 if viewed  
from one point1 would appear as a       
straight     line1 or if from another as
 a circle1 #ahh4   piece of wood1 which 

is to be squared1 and each side of which
 square must     be an inch1 to find the
 diameter1 #acf4   pieces and cubes1    
representation of1 #ie4   pieces1       
representation of1 by cross-hatching1   
#gg1 #gh4  ,cylindrical pieces1         
representation of three1 one within the 
other1 by   cross-hatching1 #gh4        
pieces that join each other1            
representation of1 #hf4   pin           
line-shaded1 representation of1 #hf4    
,decagon1 a1 #fc4  ,degrees of a circle1
 #eb-ee4  ,diameter of a cylindrical    
piece of wood1 which is to be squared1  
and each     side of which square must  
measure an inch1 to find1 #acf4         
,diamond1 a1 #ei1 #fj4  ,different      
views1 arrangement of1 #id-aaa4         
,dimension figures in mechanical        
drawing1 #ia4  ,dimensions1 marking1    
#ia-ic4  ,distances1 relative from the  
eye1 representation of1 by line-shading1
 #hi4  ,dodecagon1 a1 #fc4  ,dotted     
lines1 use of1 #dh4  ,double eye1 or    
knuckle-joint1 pencil lines for1 #adf4  

or knuckle-joint1 with an offset1 #adg4 
,double thread1 #aef4  ,drawing board1  
#ag1 #ah4   fastening the drawing to1   
#bgh4   size of1 #ah4   small1 advantage
 of1 to student1 #ah4  ,drawing for     
engraver on wood1 #bfh4   gear wheels1  
#aic-bbb4  ,drawing instruments1 #bb-bf4
   parts of1 #cd4   selecting and       
testing1 #bb4  ,drawing paper1 #bf-bi4  
different qualities1 kinds and forms1   
#bf1 #bg4   location of on the drawing  
board1 #bh1 #bi4  ,drawing the curves   
for screw threads1 #aei4   to scale1    
making a1 #agg4  ,drawings for          
engraving1 necessity of conforming to   
the particular process     of1 #bff4    
for engravings by the wax process1 #bfh1
 #bfi4  ,drawings for photo-engraving1  
#bff4   for the blacksmith1 #agb4       
shading and coloring1 #bgg-bhh4         
,drilling machine1 a boiler1 #bfi1 #bgj4
   ,eccentric and strap1 #cja4   to find
 how much motion it will give to its    
rod1 #bbc4  ,edge view of a wheel1 to   
draw1 #bjc4  ,elevation1 #id4  ,ellipse1

 dimensions of1 how taken and           
designated1 #fc4   form of a true1 #ff4 
most correct method of drawing1 #gb4    
the1 #fc-ge4  ,elliptical figure1 whose 
proportion of width to breadth shall    
remain the     same1 whatever the length
 of the major axis1 #fi4  ,emery paper1 
use of on the lining pen1 #cg4          
,ennagon1 a1 #fb1 #fc4  ,engine work1   
examples of1 #bhi-cjc4  ,engine1 working
 drawings of a #ajj horse-power1 #bii4  
,engravings by the wax process1 drawings
 for1 #bfh1 #bfi4  ,examples for        
practice1 #afi-agg   in bolts1 nuts and 
polygons1 #aab-aea4   of engine work1   
#bhi-cjc4   of work with nine sides1    
#ace4   ,feed motion of a ,niles        
horizontal tool work boring mill1 #bji4 
,five-sided figure1 to draw1 #acb1 #acc4
  ,flanks of teeth to trace             
hypocycloides1 for1 #bjj4  ,foci of an  
ellipse1 #fd4  ,franklin ,institute or  
,united ,states ,standard for heads of  
bolts and of     nuts1 basis of1 #aah4  
,full stroke cam1 method of drawing or  

marking out a1 #bcg-bda4   ,gear1 part  
of1 showing the teeth in1 the remainder 
illustrated by     circles1 #bji4  ,gear
 teeth1 names of the curves and lines   
of1 #aic4  ,gear wheels1 drawing1       
#aic-bbb4   various examples for laying 
out1 #bad-bbb4  ,gearing oval1          
construction of1 #baj4  ,general view1  
#id4  ,geometrical terms1 simple        
explanation of1 #dh4  ,geometry1        
advantage of to the draughtsman1 #dh4   
,governor of an engine1 #bib1 #bic4     
,guide bolts from one pulley to another1
 arrangement of idle pulleys     to1    
#bfd4   ,heart cam1 to draw1 #ge1 #gf4  
,hexagon1 a1 #fb1 #fc4   head1          
representation of a piece with1 #if4    
head1 to draw the end view of1 #abe1    
#abf1 #abg4   headed screw1 to draw1    
#aac1 #aad4   radius across corners1    
#ach4  ,hexagonal form1 representation  
of1 #ih4  or hexagon heads of bolts1    
#aah1 #aai4  ,hole1 representation of by
 shade or shadow line1 #hc4  ,hollows in
 connection with round pieces1          

representations of1 #hg-hi4             
,hypocycloides for the flanks of teeth1 
to trace1 #bjj4   ,independent          
condenser1 #bhh4  ,india ink1 advantages
 of in drawing1 #cj4   difference       
between good and inferior1 #ca4   good1 
characteristics of1 #ca4  ,india ink1   
,higgins'1 #cj4   mixing1 #be4          
testing1 #ca1 #cb4   the two forms of1  
#cj4   to be used thick1 #cb4   use of1 
#cj4   use of on parchment1 #cb4  ,ink1 
applying1 to the bow pen1 #df4   for    
drawing1 #cj-cc4  ,instruments1         
preparation and use of1 #cd-dg4  ,iron  
planing machine1 representation of1     
#bhb4  ,iron1 wrought and cast1         
representation of by cross-hatching1    
#hb4   ,journal1 #bid4  ,journals of    
shafts1 #bgg4   ,key1 a1 drawn in       
perspective1 #ib1 #ic4   drawing of a1  
#ia4   marking the dimensions of on a   
drawing1 #ib4   representation of with a
 shade line1 #hd4  ,knuckle-joint1      
pencil eye for1 #adf4   with an offset1 
#adg4   ,large bow or circle pen1 joints

 of1 #bc4  ,lathe centre1 representation
 of1 #hf4  ,lathe feed motion1 drawing  
of a part of a1 #bjh4  ,lead pencils for
 drawing1 #bc4  ,lead1 representation of
 by cross-hatching1 #hb4  ,left-hand    
thread1 #aef4  ,lever1 a1 actuating a   
plunger in a vertical line1 to find how 
much a given     amount of motion of the
 long arm will actuate the plunger1     
#bbf4   and shaft1 drawing1 #ajc1 #ajd1 
#aje4   arm and cam1 in one piece on a  
shaft1 a shoe sliding on the line1 and  
held against the cam face by the rod1 to
 find the position of the face     of   
the shoe against the cam1 #bbh4         
example of the end of a1 acting directly
 on a shoe1 #bbe4   to find how much a  
given amount of motion of a long arm    
will move the   short arm of a lever1   
#bbd4  ,levers1 two1 upon their axles or
 shafts1 the arms connected by a link1  
and     one arm connected to a rod1     
#bbg4  ,light in shading1 #bhj4         
management of1 in mechanical drawing1   
#hb1 #hc4  ,line-shaded engravings1     

drawing for1 #bfd-bgf4  ,line-shading1  
#gg-ij4   and drawing for line-shaded   
engravings1 #bfd-bgf4   in perspective  
drawing of a pipe-threading stock and   
die1 #he4   mechanical drawing made to  
look better and show more distinctly by1
 #hb4   simplest form of1 #hb4  ,lines  
and curves1 #dh-gf4  ,lines in          
pencilling1 where to begin1 #bd1 #be4   
,lining pen1 #bb4  ,lining pen1 form of1
 #cd-cg4  ,lining pen1 use of with a ,t 
square1 #de1 #dg4  ,link introduced in  
the place of a roller1 to find the      
amount of motion of     the rod1 #bbf4  
quick return1 plotting out the motion of
 a shaper1 #bej-bec4  ,links1 pencilling
 for1 #ade1 #adf4  ,locomotive frame1   
#agd4   spring1 #afi4   ,machine screw1 
to draw1 #aab1 #aac4  ,main journal1    
#bid4  ,marking dimensions1 #ia-ic4     
,measuring rules1 draughtsman's1 #cc4   
,mechanical motions1 plotting1 #bbc-bfc4
  ,motion an eccentric will give to its 
rod1 to find1 #bbc4   a shaper link1    
quick return1 plotting out1 #bej-bec4   

imparted in a straight line to a rod1   
attached to an eccentric strap1 to      
find the amount of1 #bbi-bca4   which a 
crank imparts to a connecting rod1 #bdi1
 #bej4  ,motions1 plotting mechanical1  
#bbc-bfc4  ,moulding cutter1 finding the
 curves for1 #beg-bfc4   ,niles'        
horizontal tool work boring mill1 feed  
motion of a1 #bji4  ,nonagon1 a1 #fb4   
,nut1 a representation of the shade line
 on1 #hd4   cap1 to pencil in a1 #ade4  
to show the thread depth in the top or  
end view of a1 #aff4  ,nuts' and bolts1 
dimensions of ,united ,states ,standard1
 #aag4  ,nuts and polygons1 examples in1
 #aab-aea4   ,octagon1 a1 #fb1 #fc4     
,oil cup1 representation of1 #bhb1 #bhd4
  ,outline views1 #ig1 #ih4  ,oval      
gearing1 construction of1 #baj4   ,paper
 cutter1 the form of the end of1 #be4   
rules or scales1 #cb4  ,parabola1 to    
draw by lines1 #gd1 #ge4   to draw      
mechanically1 #gc1 #gd4  ,parallel      
lines1 #di4  ,parallelogram1 #ei1 #fj4  
,parchment1 use of ,india ink on1 #cb4  

,pen1 ,german1 regulated to draw lines  
of various breadths1 #hd1 #he4   lining1
 form of1 #cd-cg4  ,pen point1 forming  
the1 #ci1 #dj4   form of recently       
introduced1 #ci4  ,pen points1          
oil-stoning1 #cf4  ,pen1 with sapphire  
points1 #he4  ,pens1 circle1 #cg1 #ch4  
used in drawing1 #bb4  ,pencil holders  
for sticks of lead1 #bd4   lines in     
drawing1 #bc4   sharpening for fine     
work1 #bd4  ,pencilling for a link1     
having the hubs on one side only1 #ade4 
in a cap nut1 #ade4  ,penknife and      
rubber scratching out1 #be4  ,pentagon1 
a1 #fb1 #fc4  ,perimeter1 the1 #ej4     
,periphery1 #ej4  ,perpendicular line1  
#di4  ,perspective sketches to denote   
the shape of the piece1 #ic4            
,photo-engraving1 drawings for1 #bff1   
#bfg4  ,piece of work should1 in        
mechanical drawing1 be presented in as  
few views     as possible1 #id4  ,pillow
 block box1 #bid4  ,pin1 in a socket1 in
 section1 representation of1 #hg1 #hh4  
,pinion teeth1 to draw to the pitch of  

the inner and small end of1 #bjf4  ,pins
 and discs1 discrimination of1 in       
mechanical drawing1 #if4  ,pipe         
threading stock and die1 drawing of1    
#he4  ,pitch circle of the inner and    
small end of1 to draw1 #bjf4   to obtain
 a division of the lines that divide1   
#afg4  ,plan1 #id4  ,planing machine1 a 
cutting tool for1 #bfd-bff4  ,plotting  
mechanical motions1 #bbc-bfc4   out the 
motion of a shaper link quick return1   
#bej-bec4  ,point1 a1 #di4  ,points of  
drawing instruments1 #cd4  ,polished    
surfaces1 to show by shading1 #bhb4     
,polygon of twelve equal sides1 to draw1
 #abi1 #acj4  ,polygons1 bolts and nuts1
 examples of1 #aab-aea4   construction  
of1 #fa4   designation of the angles of1
 #fb4   names of regular1 #fb1 #fc4     
scales giving the lengths of the sides  
of1 #ace4  ,preparation and use of the  
instruments1 #cd-dg4  ,produced line1   
#ej4  ,projecting one view from another1
 #ajf4  ,projections1 #agh-aib4         
,protractors1 #ec4  ,pulley1 ,medart1   

shading a1 #bhj4  ,pulleys1 arrangement 
of idle1 to guide bolts from one pulley 
to     another1 #bfd4   ,quadrangle1    
quadrilateral or tetragon1 #ei4         
,quadrant of a circle1 #ej4  ,quick     
return motion1 ,whitworth1 plotting out1
 #bec-bef4   ,radius across corners of a
 hexagon1 #ach4  ,rankine's process for 
rectifying and subdividing circular     
arcs1 #baj4  ,reducing scales1 #age4    
,rectangle1 a1 #ei1 #fj4  ,rectangular  
piece1 a1 to draw in two views1 #ih1    
#ii4   requires two or three views1 #if1
 #ig4   representation of1 #if4  ,red   
ink1 marking dimensions of mechanical   
drawings in1 #ia4  ,rhomboid1 a1 #fj4   
,rhomb1 rhombus or diamond1 #ed1 #fj4   
,right line1 a1 #di4  ,ring with a      
hexagon cross section1 #ih4  ,rivet1    
side and end views of1 #di4  ,roller1   
example of a short arm having a1 acting 
upon a larger roller1 #bbe4  ,rod1      
attached to an eccentric strap1 to find 
the amount of motion imparted     in a  
straight line to a1 #bbi-bca4   end with

 a round stem1 #adh4  ,round stem1 a    
representation of1 #if4   top and bottom
 thread1 #aef4  ,rubber1 #be4   form of1
 #bf4   proper uses of1 #be4   sponge1  
#bf4   the use of1 #be4   to be used on 
,bristol board1 #bf4   velvet1 #bf4     
,rule1 steel1 #cb4   ,sapphire points1  
pen with1 #he4  ,scale for diameter of a
 regular polygon1 #adj4   of tooth      
proportions1 #aie4   triangular1 #cc4   
,scales1 for measurement and drawing1   
#cb4   reducing1 #age4  ,scratching out1
 #be4  ,screw machine1 to draw1 #aab1   
#aac4   thread1 ,united ,states         
standard1 to draw1 #aei-afj4   threads  
and spirals1 #aeb-afh4   threads1       
drawing the curves for1 #aei4   threads 
for small bolts1 with the angles of the 
threads drawn in1     #aeb-aee4         
threads of a large diameter1 #aef4      
,section lining or cross-hatching1      
#gg-hb4  ,sectional view of a section of
 a wheel1 for showing dimensions through
 arms     and hub1 #bjb4  ,sector of a  
circle1 #ea4  ,segment of a circle1 #ej4

  ,semicircle1 #ea4  ,shade curve1      
representation of1 #hg4   line produced 
for circles1 #hd4  ,shade line1 produced
 in straight lines1 #hd4   or shadow    
line1 #hb4  ,shading a ,medart pulley1  
#bhj4   and coloring1 points to be      
observed in1 #bgh4   brush1 #bha4   by  
means of lines to distinguish round from
 flat surfaces1 and denote     relative 
distances of surfaces1 #he4   example   
in1 of a ,blake's patent direct acting  
steam pump1 #bhd1 #bhe4   example of1 in
 an independent condenser1 #bhh4   light
 in1 #bhj4   simple1 #bgg4   to show by1
 that the surfaces are highly polished1 
#bhb4  ,shadow line1 #hb4   lines and   
line shading1 #gg-ij4  ,shaft for cam   
plate1 #cja4  ,shaper link1 quick       
return1 plotting out the motion of a1   
#bej-bec4  ,shoe against a cam1 to find 
the position of the face of1 #bbh4      
,side elevation1 drawing a1 #ajf4       
,sides or flats of work1 to find the    
lengths of1 #ace1 #acf4  ,slots not     
radiating from a centre1 to draw1 #aca1 

#acb4   radiating from a centre1 #aca4  
,spiral spring1 to draw1 #aff4  ,spiral 
wound round a cylinder1 whose end is cut
 off at an angle1 #agh4  ,spirals and   
screw threads1 #aeb-afh4  ,sponge1      
rubber1 #bf4  ,spring bow pencil1 for   
circles1 #bb4   pen1 for circles1 #bb1  
#bc4  ,spring1 spiral1 to draw1 #aff4   
,spur wheel teeth1 how to draw1 #aid4   
,square1 a1 #ei1 #fj4   body1 which     
measures one inch on each side1 to find 
what it measures     across the corners1
 #acf4  ,square part1 a representation  
of1 #if4   parts1 use of a cross to     
designate1 #ie1 #if4   thread1 to draw  
a1 #afb-afd4  ,steam boiler1 horizontal1
 for stationary engine1 #bif4   chest   
and valves1 #cja4   chest side1 and     
horizontal cross section of cylinder1   
#cja4   pump1 ,blake's patent direct    
acting1 #bhd1 #bhe4  ,steel1            
representation of1 #bgg4                
representation of by cross-hatching1    
#hb4   square1 improved1 with pivoted   
blade1 #ai4  ,steps1 to draw a piece    

containing1 #ii-aja4  ,stock and die1   
pipe-threading1 drawing of1 #he4        
,straight line in geometry termed a     
right line1 #di4   or lining pen1 use of
 with a ,t square1 #de1 #dg4  ,stud1 to 
draw a1 #adb4  ,stuffing-box and gland1 
#afi4  ,surface of the paper1 condensing
 after rubbing out1 #be4  ,surfaces1    
highly polished1 to show by shading1    
#bhb4   ,tacks for drawing paper1 #bg1  
#bh4  ,tangent1 #ea4  ,taper or conical 
hole1 to denote in drawing1 #ajb4       
sides in a drawing1 #ajb1 #ajc4  ,tees1 
#ahj4  ,teeth of wheels1 rules for      
drawing1 #bjc4   pinion1 to draw the    
pitch of the inner and small end of1    
#bjf4   spur wheel1 how to draw1 #aid4  
to trace hypocycloides for the flanks   
of1 #bjj4  ,template for drawing the    
curves of thread1 #afe4  ,templates     
called curves1 #ba4  ,t square1 #ah1    
#ai4  ,t squares1 different kinds of1   
#ai4  ,tetragon1 a1 #ei1 #fb1 #fc4      
,thread1 a double1 #aef4   a round top  
and bottom1 #aef4   depth in the top or 

end view of a nut1 to show1 #aff4   left
 hand1 #aef4   square1 to draw a1       
#afb-afd4   ,whitworth1 #aef4  ,threads 
of a large diameter1 #aef4  ,thumb tacks
 for drawing paper1 #bg4  ,tint1 to     
graduate the depth of1 for a cylindrical
 surface1 #bgi4  ,tooth face1 how to    
find the curve for1 #aih4   proportions1
 ,willis' scale of1 #aie4  ,tracing     
cloth1 #bi4   paper1 #bi4  ,trammel1 use
 of in drawing an ellipse1 #gb4         
,trapezium1 #fj4  ,trapezoid1 a1 #fj4   
,triangle1 equilateral1 #eh1 #ei4       
isosceles1 #eh1 #ei4   obtuse1 #eh4     
right angle1 #eh4   scalene1 #ei4   use 
of in dividing circles1 #abi4   use of  
in drawing polygons1 #abi1 #acj4   use  
of to draw slots radiating from a       
centre1 #aca4  ,triangles1 #ai-ba1      
#eh-fj4   requirements in use of1 #bj1  
#ba4   to draw1 #acc4   using with the  
square1 #bj4  ,triangular scale1 #cc4   
,trigon1 a1 #fb1 #fc4  ,true ellipse1 a 
near approach to the form of1 #fi-gb4   
,united ,states standard bolts and nuts1

 #aad-aah4   standard thread1 to draw1  
#aei1 #afj4   ,valve of an engine1      
#bij-bib4  ,valves1 #cja4  ,vertex1 the1
 #ei4  ,views1 different arrangement of1
 #id-aaa4   of a piece of work1         
designations of1 #ajc1 #ajd4   of a     
piece1 two systems of placing1 #ajf-aaa4
   ,washer1 a1 representation of the    
shadow side of1 #hc4  ,wax process1     
drawings for engravings by1 #bfh1 #bfi4 
engraving from a print from a wood      
engraving1 #bfi4  ,wedge-shaped piece1  
representation of a1 #ig4  ,wheel1 edge 
view of a1 to draw1 #bjc4   sectional   
view of a section of a1 #bjb4  ,wheels1 
construction1 to find the curves of1    
#bjd4   to draw the arcs for the teeth  
of1 #bje4  ,whitworth thread1 #aef4     
quick return motion1 plotting out1      
#bec-bef4  ,willis' scale of tooth      
proportions1 #aie4   application of1    
#aig4  ,wood engraving1 drawing for1    
#bfh4  ,wood1 representation of by      
cross-hatching1 #hb4   representation   
of1 regular and irregular shade lines   

in1 #ij4  ,wrought iron1 representation 
of1 #bgg4   representation of by        
cross-hatching1 #hb4     ,,catalogue    
,,of  ,practical and ,scientific ,books 
,,published ,,by  ,,henry ,,carey       
,,baird  ,,co4  ,,industrial            
,,publishers1 ,,booksellers ,,and       
,,importers1  #haj ,walnut ,street1     
,philadelphia4  ,illustration3 ,pointing
 ,finger ,any of the ,books comprised in
 this ,catalogue will be sent by mail1  
free of postage1 to any address in the  
world1 at the publication prices4       
,illustration3 ,pointing ,finger ,a     
,descriptive ,catalogue1 #if pages1     
#hvo41 will be sent free and free of    
postage1 to any one in any part of the  
world1 who will furnish his address4    
,illustration3 ,pointing ,finger ,where 
not otherwise stated1 all of the ,books 
in this ,catalogue are bound in muslin4 
,,amateur ,,mechanics' ,,workshop3  ,a  
treatise containing plain and concise   
directions for the manipulation of ,wood
 and ,metals1 including ,casting1       

,forging1 ,brazing1 ,soldering and      
,carpentry4 ,by the author of the ,lathe
 and ,its ,uses4 ,third edition4        
,illustrated4 #hvo4 #c4jj  ,,andres4--,a
 ,practical ,treatise on the            
,fabrication of ,volatile and ,fat      
,varnishes1 ,lacquers1 ,siccatives and  
,sealing ,waxes4  ,from the ,german of  
,,erwin ,,andres1 ,manufacturer of      
,varnishes and ,lacquers4 ,with         
additions on the ,manufacture and       
,application of ,varnishes1 ,stains for 
,wood1 ,horn1 ,ivory1 ,bone and         
,leather4 ,from the ,german of ,,dr4    
,,emil ,,winckler and ,,louis ,e4       
,,andes4 ,the whole translated and      
edited by ,,william ,t4 ,,brannt4 ,with 
#aa illustrations4 #abmo4 #b4ej         
,,arlot4--,a ,complete ,guide for ,coach
 ,painters3  ,translated from the       
,french of ,m4 ,,arlot1 ,coach ,painter2
 for eleven years ,foreman of ,painting 
to ,m4 ,eherler1 ,coach ,maker1 ,paris4 
,by ,a4,a4 ,,fesquet1 ,chemist and      
,engineer4 ,to which is added an        

,appendix1 containing ,information      
respecting the ,materials and the       
,practice of ,coach and ,car ,painting  
and ,varnishing in the ,united ,states  
and ,great ,britain4 #abmo4 #a4be       
,,armengaud1 ,,amoroux1 ,,and           
,,johnson4--,the ,practical             
,draughtsman's ,book of ,industrial     
,design1 and ,machinist's and           
,engineer's ,drawing ,companion3        
,forming a ,complete ,course of         
,mechanical ,engineering and            
,architectural ,drawing4 ,from the      
,french of ,m4 ,armengaud the elder1    
,prof4 of ,design in the ,conservatoire 
of ,arts and ,industry1 ,paris1 and     
,,mm4 ,armengaud the younger1 and       
,amoroux1 ,civil ,engineers4 ,rewritten 
and arranged with additional matter and 
plates1 selections from and examples of 
the most useful and generally employed  
mechanism of the day4 ,by ,,william     
,,johnson1 ,assoc4 ,inst4 ,c4,e4        
,illustrated by fifty folio steel       
plates1 and fifty wood-cuts4 ,a new     

edition1 #dto41 half morocco      #aj4jj
  ,,armstrong4--,the ,construction and  
,management of ,steam ,boilers3  ,by ,r4
 ,,armstrong1 ,with an ,appendix by     
,,robert ,,mallet1 ,c4,f41 ,f4,r4,s4    
,seventh ,edition4 ,illustrated4 #a vol4
 #abmo4 #ge4jj                          
,,arrowsmith4--,paper-,hanger's         
,companion3  ,a ,treatise in which the  
,practical ,operations of the ,trade are
 ,systematically laid down3 with        
,copious ,directions ,preparatory to    
,papering2 ,preventives against the     
,effect of ,damp on ,walls2 the various 
,cements and ,pastes ,adapted to the    
,several ,purposes of the ,trade2       
,observations and ,directions for the   
,panelling and ,ornamenting of ,rooms1  
etc4 ,by ,,james ,,arrowsmith4 #abmo41  
cloth #a4be  ,,ashton4--,the ,theory and
 ,practice of the ,art of ,designing    
,fancy ,cotton and ,woollen ,cloths from
 ,sample3  ,giving full instructions for
 reducing drafts1 as well as the methods
 of spooling and making out harness for 

cross drafts and finding any required   
reed2 with calculations and tables of   
yarn4 ,by ,,frederic ,t4 ,,ashton1      
,designer1 ,west ,pittsfield1 ,mass4    
,with fifty-two illustrations4 ,one vol4
 folio       #aj4jj                     
,,auerbach--,,crookes4--,anthracen3     
,its ,constitution1 ,properties1        
,manufacture and ,derivatives1 including
 ,artificial ,alizarin1 ,anthrapurpurin1
 etc41 with their applications in       
,dyeing and ,printing4 ,by ,g4          
,,auerbach4 ,translated and edited from 
the revised manuscript of the ,author1  
by ,,wm4 ,,crookes1 ,f4,r4 ,s41         
,vice-,president of the ,chemical       
,society4 #hvo4     #e4jj               
,,baird4--,miscellaneous ,papers on     
,economic ,questions4 ,by ,henry ,carey 
,baird4 7,in preparation47              
,,baird4--,the ,american ,cotton        
,spinner1 and ,manager's and ,carder's  
,guide3  ,a ,practical ,treatise on     
,cotton ,spinning2 giving the           
,dimensions and ,speed of ,machinery1   

,draught and ,twist ,calculations1 etc42
 with notices of recent ,improvements3  
together with ,rules and ,examples for  
making changes in the sizes and numbers 
of ,roving and ,yarn4 ,compiled from the
 papers of the late ,,robert ,h4        
,,baird4 #abmo4       #a4ej             
,,baird4--,standard ,wages ,computing   
,tables3  ,an ,improvement in all former
 ,methods of ,computation1 so arranged  
that wages for days1 hours1 or fractions
 of hours1 at a specified rate per day  
or hour1 may be ascertained at a glance4
 ,by ,t4 ,,spangler ,,baird4 ,oblong    
folio #e4jj  ,,baker4--,long-,span      
,railway ,bridges3  ,composing          
,investigations of the ,comparative     
,theoretical and ,practical ,advantages 
of the various ,adopted or ,proposed    
,type ,systems of ,construction2 with   
numerous ,formulae and ,tables4 ,by ,b4 
,,baker4 #abmo4 #a4ej  ,,baker4--,the   
,mathematical ,theory of the            
,steam-,engine3  ,with ,rules at length1
 and ,examples worked out for the use of

 ,practical ,men4 ,by ,t4 ,,baker1      
,c4,e41 with numerous ,diagrams4 ,sixth 
,edition1 ,revised by ,prof4 ,j4,r4     
,,young4 #abmo4 #ge4jj  ,,barlow4--,the 
,history and ,principles of ,weaving1 by
 ,hand and by ,power3  ,reprinted1 with 
,considerable ,additions1 from          
,engineering1 with a chapter on         
,lace-making ,machinery1 reprinted from 
the ,journal of the ,society of ,arts4  
,by ,,alfred ,,barlow4 ,with several    
hundred illustrations4 #hvo41 #ddc pages
 #aj4jj  ,,barr4--,a ,practical         
,treatise on the ,combustion of ,coal3  
,including descriptions of various      
mechanical devices for the ,economic    
,generation of ,heat by the ,combustion 
of ,fuel1 whether solid1 liquid or      
gaseous4 #hvo4 #b4ej  ,,barr4--,a       
,practical ,treatise on ,high ,pressure 
,steam ,boilers3  ,including ,results of
 ,recent ,experimental ,tests of ,boiler
 ,materials1 together with a            
,description of ,approved ,safety       
,apparatus1 ,steam ,pumps1 ,injectors   

and ,economizers in actual use4 ,by     
,,wm4 ,m4 ,,barr4 #bjd ,illustrations4  
#hvo4 #c4jj  ,,bauerman4--,a ,treatise  
on the ,metallurgy of ,iron3            
,containing ,outlines of the ,history of
 ,iron ,manufacture1 ,methods of ,assay1
 and ,analysis of ,iron ,ores1          
,processes of ,manufacture of ,iron and 
,steel1 etc41 etc4 ,by ,h4 ,,bauerman1  
,f4,g4,s41 ,associate of the ,royal     
,school of ,mines4 ,fifth ,edition1     
,revised and ,enlarged4 ,illustrated    
with numerous ,wood ,engravings from    
,drawings by ,j4,b4 ,,jordan4 #abmo4    
#b4jj  ,,bayles4--,house ,drainage and  
,water ,service3  ,in ,cities1 ,villages
 and ,rural ,neighborhoods4 ,with       
,incidental ,consideration of ,certain  
,causes ,affecting the ,healthfulness of
 ,dwellings4 ,by ,,james ,c4 ,,bayles1  
,editor of ,the ,iron ,age and ,the     
,metal ,worker4 ,with numerous          
illustrations4 #hvo4 cloth1 #c4jj       
,,beans4--,a ,treatise on ,railway      
,curves and ,location of ,railroads3    

,by ,e4,w4 ,,beans1 ,c4,e4 ,illustrated4
 #abmo4 ,tucks #a4ej  ,,beckett4--,a    
,rudimentary ,treatise on ,clocks1 and  
,watches and ,bells3  ,by ,sir ,,edmund 
,,beckett1 ,bart41 ,,ll4 ,d41           
,q4,c4,f4,r4,a4,s4 ,with numerous       
illustrations4 ,seventh ,edition1       
,revised and ,enlarged4 #abmo4 #b4be    
,,bell4--,carpentry ,made ,easy3  ,or1  
,the ,science and ,art of ,framing on a 
,new and ,improved ,system ,with        
,specific ,instructions for ,building   
,balloon ,frames1 ,barn ,frames1 ,mill2 
,frames1 ,warehouses1 ,church ,spires1  
etc4 ,comprising also a ,system of      
,bridge ,building1 with ,bills1         
,estimates of ,cost1 and valuable       
,tables4 ,illustrated by forty four     
plates1 comprising nearly #bjj figures4 
,by ,,william ,e4 ,,bell1 ,architect and
 ,practical ,builder4 #hvo4 #e4jj       
,,bemrose4--,fret-,cutting and          
,perforated ,carving4  ,with fifty three
 practical illustrations ,by ,w4        
,,bemrose1 ,,jr4 #a vol4 quarto4 #c4jj  

,,bemrose4--,manual of ,buhl-work and   
,marquetry4 ,with ,practical            
,instructions for ,learners1 and ninety 
colored designs ,by ,w4 ,,bemrose1 ,,jr4
 #a vol4 quarto4 #c4jj                  
,,bemrose4--,manual of ,wood ,carving4  
,with ,practical ,illustrations for     
,learners of the ,art1 and ,original and
 ,selected ,designs4 ,by ,,william      
,,bemrose1 ,,jr4 ,with an ,introduction 
by ,,llewellyn ,,jewitt1 ,f4,s4,a41 etc4
 ,with #abh illustrations1 #dto4 #c4jj  
,,billings4--,tobacco  ,its ,history1   
,variety1 ,culture1 ,manufacture1       
,commerce1 and ,various ,modes of ,use4 
,by ,e4,r4 ,,billings4 ,illustrated by  
nearly #bjj engravings4 #hvo4 #c4jj     
,,bird4--,the ,american ,practical      
,dyers' ,companion4  ,comprising a      
,description of the ,principal ,dye     
,stuffs and ,chemicals used in ,dyeing1 
their ,natures and ,uses1 ,mordants1 and
 ,how ,made1 with the best ,american1   
,english1 ,french and ,german processes 
for ,bleaching and ,dyeing ,silk1 ,wool1

 ,cotton1 ,linen1 ,flannel1 ,felt1      
,dress ,goods1 ,mixed and ,hosiery      
,yarns1 ,feathers1 ,grass1 ,felt1 ,fur1 
,wool1 and ,straw ,hats1 ,jute ,yarn1   
,vegetable ,ivory1 ,mats1 ,skins1 ,furs1
 ,leather1 etc41 etc4 ,by ,wood1        
,aniline1 and other ,processes1 together
 with ,remarks on ,finishing ,agents1   
and ,instructions in the ,finishing of  
,fabrics1 ,substitutes for ,indigo1     
,water ,proofing of ,materials1 ,tests  
and ,purification of ,water1            
,manufacture of ,aniline and other ,new 
,dye ,wares1 ,harmonizing ,colors1 etc41
 etc41 embracing in all over #hjj       
,receipts for ,colors and ,shades1      
accompanied by #agj ,dyed ,samples of   
,raw ,materials and ,fabrics ,by ,f4,j4 
,,bird1 ,practical ,dyer1 ,author of    
,the ,dyers' ,hand ,book4 #hvo4 #aj4jj  
,,blinn4--,a ,practical ,workshop       
,companion for ,tin1 ,sheet-,iron1 and  
,copper-plate ,workers4  ,containing    
,rules for describing various kinds of  
,patterns used by ,tin1 ,sheet ,iron1   

and ,copper plate ,workers1 ,practical  
,geometry2 ,mensuration of ,surfaces and
 ,solids1 ,tables of the ,weights of    
,metals1 ,lead pipe1 etc41 ,tables of   
,areas and ,circumferences of ,circles1 
,japan1 ,varnishes1 ,lackers1 ,cements1 
,compositions1 etc41 etc4 ,by ,,leroy   
,j4 ,,blinn1 ,master ,mechanic4 ,with   
over ,one ,hundred ,illustrations4      
#abmo4 #b4ej  ,,booth4--,marble         
,worker's ,manual4  ,containing         
,practical ,information respecting      
,marbles in general1 their ,cutting1    
,working and ,polishing1 ,veneering of  
,marble1 ,mosaics1 ,composition and ,use
 of ,artificial ,marble1 ,stuccos1      
,cements1 ,receipts4 ,secrets1 etc41    
etc4 ,translated from the ,french by    
,m4,l4 ,,booth4 ,with an ,appendix      
concerning ,american ,marbles4 #abmo1   
cloth #a4ej  ,,booth and ,,morfit4--,the
 ,encyclopaedia of ,chemistry1          
,practical and ,theoretical4  ,embracing
 its application to the ,arts1          
,metallurgy1 ,mineralogy1 ,geology1     

,medicine and ,pharmacy4 ,by ,,james ,c4
 ,,booth1 ,melter and ,refiner in the   
,united ,states ,mint1 ,professor of    
,applied ,chemistry in the ,franklin    
,institute1 etc41 assisted by ,,campbell
 ,,morfit1 author of ,chemical          
,manipulations1 etc4 ,seventh ,edition4 
,complete in one volume4 royal #hvo41   
#igh pages1 with numerous wood cuts and 
other illustrations4 #e4jj              
,,bramwell4--,the ,wool ,carder's       
,vade-,mecum4  ,a ,complete ,manual of  
the ,art of ,carding ,textile ,fabrics4 
,by ,w4,c4 ,,bramwell4 ,third ,edition1 
revised and enlarged4 ,illustrated pp4  
#djj4 #abmo4 #b4ej  ,,brannt4--,a       
,practical ,treatise on the ,raw        
,materials and the ,distillation and    
,rectification of ,alcohol1 and the     
,preparation of ,alcoholic ,liquors1    
,liqueurs1 ,cordials1 ,bitters1 etc43   
,edited chiefly from the ,german of ,dr4
 ,k4 ,stammer1 ,dr4 ,f4 ,elsner1 and ,e4
 ,schubert4 ,by ,,wm ,t4 ,,brannt4      
,illustrated by thirty one engravings4  

#abmo4 #b4 #ej  ,,brannt--,,wahl4--,the 
,techno-,chemical ,receipt ,book4       
,containing several thousand ,receipts  
covering the latest1 most important1 and
 most useful discoveries in ,chemical   
,technology1 and their ,practical       
,application in the ,arts1 and the      
,industries4 ,edited chiefly from the   
,german of ,drs4 ,winckler1 ,elsner1    
,heintze1 ,mierzinski1 ,jacobsen1       
,koller and ,heinzerling with additions 
by ,,wm4,t4 ,,brannt and ,,wm4,h4       
,,wahl1 ,,ph4 ,d4 ,illustrated by #gh   
engravings4 #abmo4 #die pages4 #b4jj    
,,brown4--,five ,hundred and ,seven     
,mechanical ,movements4  ,embracing all 
those which are most important in       
,dynamics1 ,hydraulics1 ,hydrostatics1  
,pneumatics1 ,steam ,engines1 ,mill and 
other ,gearing1 ,presses1 ,horology and 
,miscellaneous ,machinery1 and including
 many movements never before published1 
and several of which have only recently 
come into use4 ,by ,,henry ,t4 ,,brown4 
#abmo4 #a4jj  ,,buckmaster4--,the       

,elements of ,mechanical ,physics4  ,by 
,j4,c4 ,,buckmaster4 ,illustrated with  
numerous engravings4 #abmo4 #a4ej       
,,bullock4--,the ,american ,cottage     
,builder4  ,a ,series of ,designs1      
,plans and ,specifications1 from #bjj to
 #bj1jjj1 for ,homes for the ,people1   
together with ,warming1 ,ventilation1   
,drainage1 ,painting and ,landscape     
,gardening4 ,by ,,john ,,bullock1       
,architect and ,editor of ,the          
,rudiments of ,architecture and         
,building1 etc41 etc4 ,illustrated by   
#ge engravings4 #hvo4 #c4ej             
,,bullock4--,the ,rudiments of          
,architecture and ,building4  ,for the  
use of ,architects1 ,builders1          
,draughtsmen1 ,machinists1 ,engineers   
and ,mechanics4 ,edited by ,,john       
,,bullock author of ,the ,american      
,cottage ,builder4 ,illustrated by #bej 
,engravings4 #hvo4 #c4ej                
,,burgh4--,practical ,rules for the     
,proportions of ,modern ,engines and    
,boilers for ,land and ,marine          

,purposes4  ,by ,n4,p4 ,,burgh1         
,engineer4 #abmo4 #a4ej  ,,burns4--,the 
,american ,woolen ,manufacturer3  ,a    
,practical ,treatise on the ,manufacture
 of ,woolens1 in two parts4 ,part ,first
 gives full and explicit instructions   
upon ,drafting1 ,cross-,drawing1        
,combining ,weaves1 and the correct     
arrangement of ,weights1 ,colors and    
,sizes of ,yarns to produce any desired 
fabric4 ,illustrated with diagrams of   
various weavings1 and twelve samples of 
cloth for explanation and practice4     
,part ,second is fully supplied with    
extended ,tables1 ,rules1 ,examples1    
,explanations1 etc42 gives full and     
practical information1 in detailed      
order1 from the stock department to the 
market1 of the proper selection and use 
of the various grades and staples of    
wool1 with the admixture of waste1      
cotton and shoddy2 and the proper       
application and economical use of the   
various oils1 drugs1 dye stuffs1 soaps1 
belting1 etc4 ,also1 the most approved  

method for ,calculating and ,estimating 
the ,cost of ,goods1 for all ,wool1     
,wool ,waste and ,cotton and ,cotton    
,warps4 ,with ,examples and             
,calculations on the ,circular motions  
of ,wheels1 ,pinions1 ,drums1 ,pulleys  
and ,gears1 how to speed them1 etc4 ,the
 two parts combined form a whole work on
 the ,american way of manufacturing more
 complete than any yet issued4 ,by      
,,george ,c4 ,,burns4 #hvo4             
,,byles4--,sophisms of ,free ,trade and 
,popular ,political ,economy ,examined4 
,by a ,,barrister 7,,sir ,,john         
,,barnard ,,byles1 ,judge of ,common    
,pleas74 ,from the ,ninth ,english      
,edition1 as published by the           
,manchester ,reciprocity ,association4  
#abmo4 #a4be  ,,bowman4--,the ,structure
 of the ,wool ,fibre in its ,relation to
 the ,use of ,wool for ,technical       
,purposes3  ,being the substance1 with  
additions1 of ,five ,lectures1 delivered
 at the request of the ,council1 to the 
members of the ,bradford ,technical     

,college1 and the ,society of ,dyers and
 ,colorists4 ,by ,f4,h4 ,,bowman1 ,d4   
,sc41 ,f4,r4,s4,e41 ,f4,l4,s4           
,illustrated by #cb engravings4 #hvo4   
#f4ej  ,,byrn4--,the ,complete          
,practical ,distiller3  ,comprising the 
most perfect and exact ,theoretical and 
,practical ,description of the ,art of  
,distillation and ,rectification2       
including all of the most recent        
improvements in distilling apparatus2   
instructions for preparing spirits from 
the numerous vegetables1 fruits1 etc2   
directions for the distillation and     
preparation of all kinds of brandies and
 other spirits1 spirituous and other    
compounds1 etc4 ,by ,m4 ,,la ,,fayette  
,,byrn1 ,m4,d4 ,eighth ,edition4 ,to    
which are added ,practical ,directions  
for ,distilling1 from the ,french of    
,th4 ,fling1 ,brewer and ,distiller4    
#abmo4  ,,byrne4--,hand-,book for the   
,artisan1 ,mechanic1 and ,engineer3     
,comprising the ,grinding and           
,sharpening of ,cutting ,tools1         

,abrasive ,processes1 ,lapidary ,work1  
,gem and ,glass ,engraving1 ,varnishing 
and ,lackering1 ,apparatus1 ,materials  
and ,processes for ,grinding and        
,polishing1 etc4 ,by ,,oliver ,,byrne4  
,illustrated by #ahe wood engravings4   
#hvo4 #e4jj  ,,byrne4--,pocket-,book for
 ,railroad and ,civil ,engineers3       
,containing ,new1 ,exact and ,concise   
,methods for ,laying out ,railroad      
,curves1 ,switches1 ,frog ,angles and   
,crossings2 the ,staking out of work2   
,levelling2 the ,calculation of         
,cuttings2 ,embankments2 ,earthwork1    
etc4 ,by ,,oliver ,,byrne4 #ahmo41 full 
bound1 pocket-book form4 #a4ge          
,,byrne4--,the ,practical               
,metal-,worker's ,assistant3            
,comprising ,metallurgic ,chemistry2 the
 ,arts of ,working all ,metals and      
,alloys2 ,forging of ,iron and ,steel2  
,hardening and ,tempering2 ,melting and 
,mixing2 ,casting and ,founding2 ,works 
in ,sheet ,metal2 the ,processes        
,dependent on the ,ductility of the     

,metals2 ,soldering2 and the most       
,improved ,processes and ,tools employed
 by ,metal-,workers4 ,with the          
,application of the ,art of             
,electro-,metallurgy to ,manufacturing  
,processes2 collected from ,original    
,sources1 and from the works of         
,holtzapffel1 ,bergeron1 ,leupold1      
,plumier1 ,napier1 ,scoffern1 ,clay1    
,fairbairn and others4 ,by ,,oliver     
,,byrne4 ,a new1 revised and improved   
edition1 to which is added an ,appendix1
 containing ,the ,manufacture of        
,russian ,sheet-,iron4 ,by ,,john       
,,percy1 ,m4,d41 ,f4,r4,s4 ,the         
,manufacture of ,malleable ,iron        
,castings1 and ,improvements in         
,bessemer ,steel4 ,by ,a4,a4 ,,fesquet1 
,chemist and ,engineer4 ,with over ,six 
,hundred ,engravings1 ,illustrating     
every ,branch of the ,subject4 #hvo4    
#g4jj  ,,byrne4--,the ,practical ,model 
,calculator3  ,for the ,engineer1       
,mechanic1 ,manufacturer of ,engine     
,work1 ,naval ,architect1 ,miner and    

,millwright4 ,by ,,oliver ,,byrne4      
#hvo41 nearly #fjj pages4 #d4ej         
,,cabinet ,,maker',s ,,album ,,of       
,,furniture3  ,comprising a ,collection 
of ,designs for various ,styles of      
,furniture4 ,illustrated by ,forty-eight
 ,large and ,beautifully ,engraved      
,plates4 ,oblong1 #hvo4 #c4ej           
,,callingham4--,sign ,writing and ,glass
 ,embossing3  ,a ,complete ,practical   
,illustrated ,manual of the ,art4 ,by   
,,james ,,callingham4 #abmo4 #a4ej      
,,campin4--,a ,practical ,treatise on   
,mechanical ,engineering3 ,comprising   
,metallurgy1 ,moulding1 ,casting1       
,forging1 ,tools1 ,workshop ,machinery1 
,mechanical ,manipulation1 ,manufacture 
of ,steam-,engines1 etc4 ,with an       
,appendix on the ,analysis of ,iron and 
,iron ,ores4 ,by ,,francis ,,campin1    
,c4,e4 ,to which are added1             
,observations on the ,construction of   
,steam ,boilers1 and ,remarks upon      
,furnaces used for ,smoke ,prevention2  
with a ,chapter on ,explosions4 ,by ,r4 

,,armstrong1 ,c4,e41 and ,,john         
,,bourne4 ,rules for ,calculating the   
,change ,wheels for ,screws on a        
,turning ,lathe1 and for a              
,wheel-cutting ,machine4 ,by ,j4 ,,la   
,,nicca4 ,management of ,steel1         
,including ,forging1 ,hardening1        
,tempering1 ,annealing1 ,shrinking and  
,expansion2 and the ,case-hardening of  
,iron4 ,by ,g4 ,,ede4 #hvo4 ,illustrated
 with twenty-nine plates and #ajj wood  
engravings4 #e4jj  ,,carey4--,a ,memoir 
of ,henry ,c4 ,carey4  ,by ,,dr4 ,,wm4  
,,elder4 ,with a portrait4 #hvo41 cloth 
4#ge  ,,carey4--,the ,works of ,henry   
,c4 ,carey3  ,harmony of ,interests3    
,agricultural1 ,manufacturing and       
,commercial4 #hvo4 #a4ej  ,manual of    
,social ,science4 ,condensed from       
,carey's ,principles of ,social         
,science4 ,by ,,kate ,,mckean4 #a vol4  
#abmo4 #b4be  ,miscellaneous ,works4    
,with a ,portrait4 #b vols4 #hvo4 #f4jj 
,past1 ,present and ,future4 #hvo4 #b4ej
  ,principles of ,social ,science4 #c   

volumes1 #hvo4 #aj4jj  ,the             
,slave-,trade1 ,domestic and ,foreign2  
,why it ,exists1 and ,how it may be     
,extinguished 7#ahec74 #hvo4 #b4jj  ,the
 ,unity of ,law3 ,as ,exhibited in the  
,relations of ,physical1 ,social1       
,mental and ,moral ,science 7#ahgb74    
#hvo4 #c4ej  ,,clark4--,tramways1 their 
,construction and ,working3  ,embracing 
a ,comprehensive ,history of the        
,system4 ,with an exhaustive analysis of
 the various modes of traction1         
including horse-power1 steam1 heated    
water and compressed air2 a description 
of the varieties of ,rolling stock1 and 
ample details of cost and working       
expenses4 ,by ,d4 ,,kinnear ,,clark4    
,illustrated by over #bjj wood          
engravings1 and thirteen folding plates4
 #b vols4 #hvo4 #ab4ej  ,,colburn4--,the
 ,locomotive ,engine3  ,including a     
,description of its ,structure1 ,rules  
for ,estimating its ,capabilities1 and  
,practical ,observations on its         
,construction and ,management4 ,by      

,,zerah ,,colburn4 ,illustrated4 #abmo4 
#a4jj  ,,collens4--,the ,eden of ,labor2
 or1 the ,christian ,utopia4  ,by ,t4   
,,wharton ,,collens1 author of          
,humanics1 ,the ,history of ,charity1   
etc4 #abmo4 ,paper cover1 #a4jj2 ,cloth 
#a4be  ,,cooley4--,a ,complete          
,practical ,treatise on ,perfumery3     
,being a ,hand-book of ,perfumes1       
,cosmetics and other ,toilet ,articles4 
,with a ,comprehensive ,collection of   
,formulae4 ,by ,,arnold ,j4 ,,cooley4   
#abmo4 #a4ej  ,,cooper4--,a ,treatise on
 the use of ,belting for the            
,transmission of ,power4  ,with numerous
 illustrations of approved and actual   
methods of arranging ,main ,driving and 
,quarter ,twist ,belts1 and of ,belt    
,fastenings4 ,examples and ,rules in    
great number for exhibiting and         
calculating the size and driving power  
of ,belts4 ,plain1 ,particular and      
,practical ,directions for the          
,treatment1 ,care and ,management of    
,belts4 ,descriptions of many varieties 

of ,beltings1 together with chapters on 
the ,transmission of ,power by ,ropes2  
by ,iron and ,wood ,frictional ,gearing2
 on the ,strength of ,belting ,leather2 
and on the ,experimental ,investigations
 of ,morin1 ,briggs1 and others4 ,by    
,,john ,h4 ,,cooper1 ,m4,e4 #hvo4 #c4ej 
,,craik4--,the ,practical ,american     
,millwright and ,miller4  ,by ,,david   
,,craik1 ,millwright4 ,illustrated by   
numerous wood engravings and two folding
 plates4 #hvo4 #e4jj  ,,cristiani4--,a  
,technical ,treatise on ,soap and       
,candles3  ,with a ,glance at the       
,industry of ,fats and ,oils4 ,by ,r4,s4
 ,,cristiani1 ,chemist4 ,author of      
,perfumery and ,kindred ,arts4          
,illustrated by #agf engravings4 #eha   
pages1 #hvo4 #g4ej                      
,,cristiani4--,perfumery and ,kindred   
,arts3  ,a ,comprehensive ,treatise on  
,perfumery1 containing a ,history of    
,perfumes from the remotest ages to the 
present time4 ,a complete detailed      
description of the various ,materials   

and ,apparatus used in the ,perfumer's  
,art1 with thorough ,practical          
,instruction and careful ,formulae1 and 
advice for the fabrication of all known 
preparations of the day1 including      
,essences1 ,tinctures1 ,extracts1       
,spirits1 ,waters1 ,vinegars1 ,pomades1 
,powders1 ,paints1 ,oils1 ,emulsions1   
,cosmetics1 ,infusions1 ,pastilles1     
,tooth ,powders and ,washes1 ,cachous1  
,hair ,dyes1 ,sachets1 ,essential ,oils1
 ,flavoring ,extracts1 etc42 and full   
details for making and manipulating     
,fancy ,toilet ,soaps1 ,shaving ,creams1
 etc41 by new and improved methods4     
,with an ,appendix giving hints and     
advice for making and fermenting        
,domestic ,wines1 ,cordials1 ,liquors1  
,candies1 ,jellies1 ,syrups1 ,colors1   
etc41 and for ,perfuming and ,flavoring 
,segars1 ,snuff and ,tobacco1 and       
,miscellaneous ,receipts for various    
useful ,analogous ,articles4 ,by ,r4,s4 
,,cristiani1 ,consulting ,chemist and   
,perfumer1 ,philadelphia4 #hvo4 #e4jj   

,,cupper4--,the ,universal              
,stair-,builder3  ,being a new ,treatise
 on the ,construction of ,stair-,cases  
and ,hand-,rails2 showing ,plans of the 
various forms of ,stairs1 method of     
,placing the ,risers in the ,cylinders1 
general method of describing the ,face  
,moulds for a ,hand-,rail1 and an       
expeditious method of ,squaring the     
,rail4 ,useful also to ,stonemasons     
constructing ,stone ,stairs and         
,hand-,rails2 with a new method of      
,sawing the ,twist ,part of any         
,hand-,rail square from the face of the 
plank1 and to a parallel width4 ,also1 a
 new method of forming the ,easings of  
the ,rail by a gauge2 preceded by some  
necessary ,problems in ,practical       
,geometry1 with the ,sections of        
,prismatic ,solids4 ,illustrated by #bi 
plates4 ,by ,r4,a4 ,,cupper1 ,architect1
 author of ,the ,practical              
,stair-,builder's ,guide4 ,third        
,edition4 ,large #dto4  ,,davidson4--,a 
,practical ,manual of ,house ,painting1 

,graining1 ,marbling1 and               
,sign-,writing3  ,containing full       
information on the processes of ,house  
,painting in ,oil and ,distemper1 the   
,formation of ,letters and ,practice of 
,sign-,writing1 the ,principles of      
,decorative ,art1 a ,course of          
,elementary ,drawing for ,house         
,painters1 ,writers1 etc41 and a        
,collection of ,useful ,receipts4 ,with 
nine colored illustrations of ,woods and
 ,marbles1 and numerous wood engravings4
 ,by ,,ellis ,a4 ,,davidson4 #abmo4     
#c4jj  ,,davies4--,a ,treatise on       
,earthy and ,other ,minerals and        
,mining3  ,by ,d4,c4 ,,davies1          
,f4,g4,s41 ,mining ,engineer1 etc4      
,illustrated by #gf ,engravings4 #abmo4 
#e4jj  ,,davies4--,a ,treatise on       
,metalliferous ,minerals and ,mining3   
,by ,d4,c4 ,,davies1 ,f4,g4,s41 ,mining 
,engineer1 ,examiner of ,mines1         
,quarries and ,collieries4 ,illustrated 
by #adh engravings of ,geological       
,formations1 ,mining ,operations and    

,machinery1 drawn from the practice of  
all parts of the world4 #b;d ,edition1  
#abmo41 #dej pages4 #e4jj  ,,davies4--,a
 ,treatise on ,slate and ,slate         
,quarrying3  ,scientific1 ,practical and
 ,commercial4 ,by ,d4,c4 ,,davies1      
,f4,g4,s41 ,mining ,engineer1 etc4 ,with
 numerous illustrations and folding     
plates4 #abmo4 #b4ej  ,,davis4--,a      
,practical ,treatise on the ,manufacture
 of ,bricks1 ,tiles1 ,terra-,cotta1     
etc43  ,including ,common1 ,pressed1    
,ornamentally ,shaped1 and ,enamelled   
,bricks1 ,drain-,tiles1 ,straight and   
,curved ,sewer-,pipes1 ,fire-,clays1    
,fire-,bricks1 ,terra-,cotta1           
,roofing-,tiles1 ,flooring-,tiles1      
,art-,tiles1 ,mosaic ,plates1 and       
,imitation of ,intarsia or ,inlaid      
,surfaces2 comprising every important   
,product of ,clay employed in           
,architecture1 ,engineering1 the        
,blast-,furnace1 for ,retorts1 etc41    
with a ,history and the ,actual         
,processes in ,handling1                

,disintegrating1 ,tempering1 and        
,moulding the ,clay into ,shape1 ,drying
 ,naturally and ,artificially1 ,setting 
and ,burning1 ,enamelling in ,polychrome
 ,colors1 ,composition and ,application 
of ,glazes1 etc42 including ,full       
,detailed ,descriptions of the most     
modern ,machines1 ,tools1 ,kilns1 and   
,kiln-,roofs used4 ,by ,,charles        
,,thomas ,,davis4 ,illustrated by #bbh  
,engravings and #f ,plates4 #hvo41 #dgb 
pages #e4jj  ,,davis4--,the ,manufacture
 of ,leather3  ,being a description of  
all of the ,processes for the ,tanning1 
,tawing1 ,currying1 ,finishing and      
,dyeing of every kind of ,leather2      
including the various ,raw ,materials   
and the ,methods for ,determining their 
,values2 the ,tools1 ,machines1 and all 
,details of ,importance connected with  
an ,intelligent and ,profitable         
,prosecution of the ,art1 with ,special 
,reference to the ,best ,american       
,practice4 ,to which are added ,complete
 ,lists of all ,american ,patents for   

,materials1 ,processes1 ,tools1 and     
,machines for ,tanning1 ,currying1 etc4 
,by ,,charles ,,thomas ,,davis4         
,illustrated by #cjb engravings and #ab 
,samples of ,dyed ,leathers4 ,one vol41 
#hvo41 #hbd pages #aj4jj                
,,dawidowsky--,,brannt4--,a ,practical  
,treatise on the ,raw ,materials and    
,fabrication of ,glue1 ,gelatine1       
,gelatine ,veneers and ,foils1          
,isinglass1 ,cements1 ,pastes1          
,mucilages1 etc43  ,based upon ,actual  
,experience4 ,by ,f4 ,,dawidowsky1      
,technical ,chemist4 ,translated from   
the ,german1 with extensive additions1  
including a description of the most     
,recent ,american ,processes1 by        
,,william ,t4 ,,brannt1 ,graduate of the
 ,royal ,agricultural ,college of       
,eldena1 ,prussia4 #ce ,engravings4     
#abmo4 #b4ej  ,,de ,,graff4--,the       
,geometrical ,stair-,builders' ,guide3  
,being a ,plain ,practical ,system of   
,hand-,railing1 embracing all its       
necessary ,details1 and ,geometrically  

,illustrated by twenty-two ,steel       
,engravings2 together with the use of   
the most approved principles of         
,practical ,geometry4 ,by ,,simon ,,de  
,,graff1 ,architect4 #dto4 #b4ej  ,,de  
,,koninck--,,dietz4--,a ,practical      
,manual of ,chemical ,analysis and      
,assaying3  ,as applied to the          
,manufacture of ,iron from its ,ores1   
and to ,cast ,iron1 ,wrought ,iron1 and 
,steel1 as found in ,commerce4 ,by      
,l4,l4 ,,de ,,koninck1 ,dr4 ,sc1 and ,e4
 ,,dietz1 ,engineer4 ,edited with       
,notes1 by ,,robert ,,mallet1 ,f4,r4,s41
 ,f4,s4,g41 ,m4,i4,c4,e41 etc4 ,american
 ,edition1 ,edited with ,notes and an   
,appendix on ,iron ,ores1 by ,a4,a4     
,,fesquet1 ,chemist and ,engineer4      
#abmo4 #b4ej  ,,duncan4--,practical     
,surveyor's ,guide3  ,containing the    
necessary information to make any person
 of common capacity1 a finished land    
surveyor without the aid of a teacher4  
,by ,,andrew ,,duncan4 ,illustrated4    
#abmo4 #a4be  ,,duplais--,a ,treatise on

 the ,manufacture and ,distillation of  
,alcoholic ,liquors3  ,comprising       
,accurate and ,complete ,details in     
,regard to ,alcohol from ,wine1         
,molasses1 ,beets1 ,grain1 ,rice1       
,potatoes1 ,sorghum1 ,asphodel1 ,fruits1
 etc42 with the ,distillation and       
,rectification of ,brandy1 ,whiskey1    
,rum1 ,gin1 ,swiss ,absinthe1 etc41 the 
,preparation of ,aromatic ,waters4      
,volatile ,oils or ,essences1 ,sugars1  
,syrups1 ,aromatic ,tinctures1          
,liqueurs1 ,cordial ,wines1             
,effervescing ,wines1 etc41 the ,ageing 
of ,brandy and the improvement of       
,spirits1 with ,copious ,directions and 
,tables for ,testing and ,reducing      
,spirituous ,liquors1 etc41 etc4        
,translated and ,edited from the ,french
 of ,,mm4 ,,duplais1 ,aine et ,jeune4   
,by ,m4 ,,mckennie1 ,m4,d4 ,to which are
 added the ,united ,states ,internal    
,revenue ,regulations for the           
,assessment and ,collection of ,taxes on
 ,distilled ,spirits4 ,illustrated by   

fourteen folding plates and several wood
 engravings4 #gdc pp4 #hvo4 #aj4jj      
,,dussauce4--,a ,general ,treatise on   
the ,manufacture of ,vinegar3           
,theoretical and ,practical4 ,comprising
 the various ,methods1 by the ,slow and 
the ,quick ,processes1 with ,alcohol1   
,wine1 ,grain1 ,malt1 ,cider1 ,molasses1
 and ,beets2 as well as the ,fabrication
 of ,wood ,vinegar1 etc41 etc4 ,by      
,prof4 ,h4 ,,dussauce4 #hvo4 #e4jj      
,,dussauce4--,practical ,treatise on the
 ,fabrication of ,matches1 ,gun ,cotton1
 and ,fulminating ,powder4  ,by         
,professor ,h4 ,,dussauce4 #abmo4 #c4jj 
,,dyer ,,and ,,color-,,maker',s         
,,companion3  ,containing upwards of two
 hundred ,receipts for making ,colors1  
on the most approved principles1 for all
 the various styles and fabrics now in  
existence2 with the ,scouring ,process1 
and plain ,directions for ,preparing1   
,washing-off1 and ,finishing the ,goods4
 #abmo4 #a4be  ,,edwards4--,a ,catechism
 of the ,marine ,steam-,engine1  ,for   

the use of ,engineers1 ,firemen1 and    
,mechanics4 ,a ,practical ,work for     
,practical ,men4 ,by ,,emory ,,edwards1 
,mechanical ,engineer4 ,illustrated by  
sixty-three ,engravings1 including      
examples of the most modern ,engines4   
,third edition1 thoroughly revised1 with
 much additional matter4 #abmo4 #dad    
pages #b4jj  ,,edwards4--,modern        
,american ,locomotive ,engines1  ,their 
,design1 ,construction and ,management4 
,by ,,emory ,,edwards4 ,illustrated     
#abmo4 #b4jj  ,,edwards4--,modern       
,american ,marine ,engines1 ,boilers1   
and ,screw ,propellers1  ,their ,design 
and ,construction4 ,showing the ,present
 ,practice of the most ,eminent         
,engineers and ,marine ,engine ,builders
 in the ,united ,states4 ,illustrated by
 #cj large and elaborate plates4 #dto4  
#e4jj  ,,edwards4--,the ,practical      
,steam ,engineer's ,guide  ,in the      
,design1 ,construction1 and ,management 
of ,american ,stationary1 ,portable1 and
 ,steam ,fire ,engines1 ,steam ,pumps1  

,boilers1 ,injectors1 ,governors1       
,indicators1 ,pistons and ,rings1       
,safety ,valves and ,steam ,gauges4 ,for
 the use of ,engineers1 ,firemen1 and   
,steam ,users4 ,by ,,emory ,,edwards4   
,illustrated by #aai engravings4 #dbj   
pages4 #abmo4 #b4ej                     
,,elder4--,conversations on the         
,principal ,subjects of ,political      
,economy4  ,by ,dr4 ,,william ,,elder4  
#hvo4 #b4ej  ,,elder4--,questions of the
 ,day1  ,economic and ,social4 ,by ,dr4 
,,william ,,elder4 #hvo4 #c4jj          
,,elder4--,memoir of ,henry ,c4 ,carey4 
,by ,dr4 ,,william ,,elder4 #hvo4 cloth4
 4#ge  ,,erni4--,mineralogy ,simplified4
  ,easy ,methods of ,determining and    
,classifying ,minerals1 including ,ores1
 by means of the ,blowpipe1 and by      
,humid ,chemical ,analysis1 based on    
,professor von ,kobell's ,tables for the
 ,determination of ,minerals1 with an   
,introduction to ,modern ,chemistry4 ,by
 ,,henry ,,erni1 ,a4,m41 ,m4,d41        
,professor of ,chemistry4 ,second       

,edition1 rewritten1 enlarged and       
improved4 #abmo4 #c4jj                  
,,fairbairn4--,the ,principles of       
,mechanism and ,machinery of            
,transmission  ,comprising the          
,principles of ,mechanism1 ,wheels1 and 
,pulleys1 ,strength and ,proportions of 
,shafts1 ,coupling of ,shafts1 and      
,engaging and ,disengaging ,gear4 ,by   
,,sir ,,william ,,fairbairn1 ,bait4     
,c4,e4 ,beautifully illustrated by over 
#aej wood-cuts4 ,in one volume1 #abmo4  
#b4ej  ,,fitch4--,bessemer ,steel1      
,ores and ,methods1 ,new ,facts and     
,statistics ,relating to the ,types of  
,machinery in ,use1 the ,methods in     
,vogue1 ,cost and ,class of ,labor      
employed1 and the ,character and        
,availability of the ,ores utilized in  
the ,manufacture of ,bessemer ,steel in 
,europe and in the ,united ,states2     
together with opinions and excerpts from
 various accepted authorities4 ,compiled
 and arranged by ,,thomas ,w4 ,,fitch4  
#hvo4 #c4jj  ,,fleming4--,narrow ,gauge 

,railways in ,america4  ,a ,sketch of   
their ,rise1 ,progress1 and ,success4   
,valuable ,statistics as to ,grades1    
,curves1 ,weight of ,rail1 ,locomotives1
 ,cars1 etc4 ,by ,,howard ,,fleming4    
,illustrated1 #hvo4 #a4ej               
,,forsyth4--,book of ,designs for       
,headstones1 ,mural1 and other          
,monuments3  ,containing #gh ,designs4  
,by ,,james ,,forsyth4 ,with an         
,introduction by ,,charles ,,boutell1   
,m4,a4 #d to41 cloth #e4jj              
,,frankel--,,hutter4--,a ,practical     
,treatise on the ,manufacture of        
,starch1 ,glucose1 ,starch-,sugar1 and  
,dextrine3  ,based on the ,german of    
,,ladislaus ,,von ,,wagner1 ,professor  
in the ,royal ,technical ,high ,school1 
,buda-,pest1 ,hungary1 and other        
authorities4 ,by ,,julius ,,frankel1    
,graduate of the ,polytechnic ,school of
 ,hanover4 ,edited by ,,robert ,,hutter1
 ,chemist1 ,practical ,manufacturer of  
,starch-,sugar4 ,illustrated by #eh     
engravings1 covering every branch of the

 subject1 including examples of the most
 ,recent and ,best ,american ,machinery4
 #hvo41 #cdd pp4 #c4ej   ,,gee4--,the   
,goldsmith's ,handbook3  ,containing    
full instructions for the ,alloying and 
,working of ,gold1 including the ,art of
 ,alloying1 ,melting1 ,reducing1        
,coloring1 ,collecting1 and ,refining2  
the ,processes of ,manipulation1        
,recovery of ,waste2 ,chemical and      
,physical ,properties of ,gold2 with a  
,new ,system of ,mixing its ,alloys2    
,solders1 ,enamels1 and other ,useful   
,rules and ,recipes4 ,by ,,george ,e4   
,,gee4 #abmo4 #a4ge   ,,gee4--,the      
,silversmith's ,handbook3  ,containing  
full instructions for the ,alloying and 
,working of ,silver1 including the      
different modes of ,refining and        
,melting the ,metal2 its ,solders2 the  
,preparation of ,imitation ,alloys2     
,methods of ,manipulation2 ,prevention  
of ,waste2 ,instructions for ,improving 
and ,finishing the ,surface of the      
,work2 together with other ,useful      

,information and ,memoranda4 ,by        
,,george ,e4 ,,gee1 ,jeweller4          
,illustrated4 #abmo4 #a4ge   ,,gothic   
,,album ,,for ,,cabinet-,,makers3       
,designs for ,gothic ,furniture4        
,twenty-three plates4 ,oblong #b4jj     
,,greenwood4--,steel and ,iron3         
,comprising the ,practice and ,theory of
 the ,several ,methods ,pursued in their
 ,manufacture1 and of their ,treatment  
in the ,rolling-,mills1 the ,forge1 and 
the ,foundry4 ,by ,,william ,,henry     
,,greenwood1 ,f4,c4,s4 ,asso4           
,m4,i4,c4,e41 ,m4,i4,m4,e41 ,associate  
of the ,royal ,school of ,mines4 ,with  
#ig ,diagrams1 #ecf pages4 #abmo4 #b4jj 
,,gregory4--,mathematics for ,practical 
,men3  ,adapted to the ,pursuits of     
,surveyors1 ,architects1 ,mechanics1 and
 ,civil ,engineers4 ,by ,,olinthus      
,,gregory4 #hvo41 plates4 #c4jj         
,,grier4--,rural ,hydraulics3  ,a       
,practical ,treatise on ,rural          
,household ,water ,supply4 ,giving a    
full description of ,springs and ,wells1

 of ,pumps and ,hydraulic ,ram1 with    
,instructions in ,cistern ,building1    
,laying of ,pipes1 etc4 ,by ,w4,w4      
,,grier4 ,illustrated #hvo4 4#ge        
,,grimshaw4--,modern ,milling3  ,being  
the substance of two addresses delivered
 by request1 at the ,franklin           
,institute1 ,philadelphia1 ,january     
#aith2 and ,january #bgth1 #ahha4 ,by   
,,robert ,,grimshaw1 ,ph4 ,d4 ,edited   
from the ,phonographic ,reports4 ,with  
#bh ,illustrations4 #hvo4 #a4jj         
,,grimshaw4--,saws3  ,the ,history1     
,development1 ,action1 ,classification1 
and ,comparison of ,saws of all kinds4  
,with ,copious ,appendices4 ,giving the 
details of ,manufacture1 ,filing4       
,setting1 ,gumming1 etc4 ,care and ,use 
of ,saws2 ,tables of ,gauges2           
,capacities of ,saw-,mills2 ,list of    
,saw-,patents1 and other valuable       
information4 ,by ,,robert ,,grimshaw4   
,second and greatly enlarged edition1   
with ,supplement1 and #ced              
,illustrations4 ,quarto #d4jj           

,,grimshaw4--,a ,supplement to ,grimshaw
 on ,saws3  ,containing additional      
practical matter1 more especially       
relating to the ,forms of ,saw-,teeth1  
for special material and conditions1 and
 to the ,behavior of ,saws under        
particular conditions4 #abj             
,illustrations4 ,by ,,robert ,,grimshaw4
 ,quarto4 #b4jj  ,,griswold4--,railroad 
,engineer's ,pocket ,companion for the  
,field3  ,comprising ,rules for         
,calculating ,deflection ,distances and 
,angles1 ,tangential ,distances and     
,angles1 and all ,necessary ,tables for 
,engineers2 also the ,art of ,levelling 
from ,preliminary ,survey to the        
,construction of ,railroads1 intended   
,expressly for the ,young ,engineer1    
together with ,numerous ,valuable ,rules
 and ,examples4 ,by ,w4 ,,griswold4 #ab 
mo41 tucks #a4ge  ,,gruner4--,studies of
 ,blast ,furnace ,phenomena3  ,by ,m4,l4
 ,,gruner1 ,president of the ,general   
,council of ,mines of ,france1 and      
lately ,professor of ,metallurgy at the 

,ecole des ,mines4 ,translated1 with the
 author's sanction1 with an ,appendix1  
by ,l4,d4 ,b4 ,,gordon1 ,f4,r4,s4,e41   
,f4,g4,s4 #hvo4 #b4ej                   
,,guettier4--,metallic ,alloys3  ,being 
a ,practical ,guide to their ,chemical  
and ,physical ,properties1 their        
,preparation1 ,composition1 and ,uses4  
,translated from the ,french of ,a4     
,,guettier1 ,engineer and ,director of  
,founderies1 author of ,la ,fouderie en 
,france1 etc41 etc4 ,by ,a4,a4          
,,fesquet1 ,chemist and ,engineer4      
#abmo4 #c4jj  ,,haserick4--,the ,secrets
 of the ,art of ,dyeing ,wool1 ,cotton1 
and ,linen1  ,including ,bleaching and  
,coloring ,wool and ,cotton ,hosiery and
 ,random ,yarns4 ,a ,treatise based on  
,economy and ,practice4 ,by ,e4,c4      
,,haserick4 ,illustrated by #cbc ,dyed  
,patterns of the ,yarns or ,fabrics4    
#hvo4 #be4jj  ,,hats ,,and ,,felting3   
,a ,practical ,treatise on their        
,manufacture4 ,by a ,practical ,hatter4 
,illustrated by ,drawings of ,machinery1

 etc4 #hvo4 #a4be  ,,henry4--,the ,early
 and ,later ,history of ,petroleum3     
,with ,authentic ,facts in regard to its
 ,development in ,western ,pennsylvania4
 ,with ,sketches of the ,pioneer and    
,prominent ,operators1 together with the
 ,refining ,capacity of the ,united     
,states4 ,by ,j4,t4 ,,henry4            
,illustrated #hvo4  ,,hoffer4--,a       
,practical ,treatise on ,caoutchouc and 
,gutta ,percha1  ,comprising the        
,properties of the ,raw ,materials1 and 
the manner of ,mixing and ,working them2
 with the ,fabrication of ,vulcanized   
and ,hard ,rubbers1 ,caoutchouc and     
,gutta ,percha ,compositions1           
,water-proof  ,substances1 ,elastic     
,tissues1 the ,utilization of ,waste1   
etc41 etc4 ,from the ,german of         
,,raimund ,,hoffer4 ,by ,w4,t4 ,,brannt4
 ,illustrated #abmo4 #b4ej              
,,hofmann4--,a ,practical ,treatise on  
the ,manufacture of ,paper in all its   
,branches3  ,by ,,carl ,,hofmann1 ,late 
,superintendent of ,paper-,mills in     

,germany and the ,united ,states2       
recently ,manager of the ,public ,ledger
 ,paper ,mills1 near ,elkton1 ,maryland4
 ,illustrated by #aaj wood engravings1  
and five large ,folding ,plates4 #dto41 
cloth2 about #djj pages4 #ej4jj         
,,hughes4--,american ,miller and        
,millwright's ,assistant3  ,by ,,william
 ,,carter ,,hughes4 #abmo4 #a4ej        
,,hulme4--,worked ,examination          
,questions in ,plane ,geometrical       
,drawing3  ,for the ,use of ,candidates 
for the ,royal ,military ,academy1      
,woolwich2 the ,royal ,military         
,college1 ,sandhurst2 the ,indian ,civil
 ,engineering ,college1 ,cooper's ,hill2
 ,indian ,public ,works and ,telegraph  
,departments2 ,royal ,marine ,light     
,infantry2 the ,oxford and ,cambridge   
,local ,examinations1 etc4 ,by ,f4      
,,edward ,,hulme1 ,f4,l4,s41 ,f4,s4,a41 
,art-,master ,marlborough ,college4     
,illustrated by #cjj examples4 ,small   
quarto4 #c4ge  ,,jervis4--,railroad     
,property3  ,a ,treatise on the         

,construction and ,management of        
,railways2 designed to afford useful    
knowledge1 in the popular style1 to the 
holders of this class of property2 as   
well as ,railway ,managers1 ,officers1  
and ,agents4 ,by ,,john ,b4 ,,jervis1   
late ,civil ,engineer of the ,hudson    
,river ,railroad1 ,croton ,aqueduct1    
etc4 #abmo41 cloth #b4jj  ,,keene4--,a  
,hand-,book of ,practical ,gauging3     
,for the ,use of ,beginners1 to which is
 added a ,chapter on ,distillation1     
describing the process in operation at  
the ,custom-,house for ascertaining the 
,strength of ,wines4 ,by ,,james ,b4    
,,keene1 of ,h4,m4 ,customs4 #hvo4 #a4be
  ,,kelley4--,speeches1 ,addresses1 and 
,letters on ,industrial and ,financial  
,questions3  ,by ,,hon4 ,,william ,d4   
,,kelley1 ,m4,c4 #edd pages1 #hvo4 #c4jj
  ,,kellogg4--,a ,new ,monetary ,system3
  ,the only means of ,securing the      
respective ,rights of ,labor and        
,property1 and of ,protecting the       
,public from ,financial ,revulsions4 ,by

 ,,edward ,,kellogg4 ,revised from his  
work on ,labor and other ,capital4 ,with
 numerous additions from his manuscript4
 ,edited by ,,mary ,,kellogg ,,putnam4  
,fifth edition4 ,to which is added a    
,biographical ,sketch of the ,author4   
,one volume1 #abmo4  ,paper cover4 #a4jj
  ,bound in cloth4 #a4ej                
,,kemlo4--,watch-,repairer's            
,hand-,book3  ,being a ,complete ,guide 
to the ,young ,beginner1 in ,taking     
,apart1 ,putting ,together1 and         
,thoroughly ,cleaning the ,english      
,lever and other ,foreign ,watches1 and 
all ,american ,watches4 ,by ,f4 ,,kemlo1
 ,practical ,watchmaker4 ,with          
,illustrations4 #abmo4 #a4be            
,,kentish4--,a ,treatise on a ,box of   
,instruments1  ,and the ,slide ,rule2   
with the ,theory of ,trigonometry and   
,logarithms1 including ,practical       
,geometry1 ,surveying1 ,measuring of    
,timber1 ,cask and ,malt ,gauging1      
,heights1 and ,distances4 ,by ,,thomas  
,,kentish4 ,in one volume1 #abmo4 #a4be 

,,kerl4--,the ,assayer's ,manual3  ,an  
,abridged ,treatise on the ,docimastic  
,examination of ,ores1 and ,furnace and 
other ,artificial ,products4 ,by ,,bruno
 ,,kerl1 ,professor in the ,royal       
,school of ,mines2 ,member of the ,royal
 ,technical ,commission for the         
,industries1 and of the ,imperial       
,patent-,office1 ,berlin4 ,translated   
from the ,german by ,,william ,t4       
,,brannt1 ,graduate of the ,royal       
,agricultural ,college of ,eldena1      
,prussia4 ,edited by ,,william ,h4      
,,wahl1 ,ph4 ,d41 ,secretary of the     
,franklin ,institute1 ,philadelphia4    
,illustrated by sixty-five engravings4  
#hvo4 #c4jj  ,,kingzett4--,the ,history1
 ,products1 and ,processes of the       
,alkali ,trade3  ,including the most    
,recent ,improvements4 ,by ,,charles    
,,thomas ,,kingzett1 ,consulting        
,chemist4 ,with #bc illustrations4 #hvo4
 #b4ej  ,,kinsley4--,self-,instructor on
 ,lumber ,surveying3  ,for the ,use of  
,lumber ,manufacturers1 ,surveyors1 and 

,teachers4 ,by ,,charles ,,kinsley1     
,practical ,surveyor and ,teacher of    
,surveying4 #abmo4 #b4ej  ,,kirk4--,the 
,founding of ,metals3  ,a ,practical    
,treatise on the ,melting of ,iron1 with
 a ,description of the ,founding of     
,alloys2 also1 of all the ,metals and   
,mineral ,substances used in the ,art of
 ,founding4 ,collected from original    
sources4 ,by ,,edward ,,kirk1 ,practical
 ,foundryman and ,chemist4 ,illustrated4
 ,third edition4 #hvo4 #b4ej            
,,kittredge4--,the ,compendium of       
,architectural ,sheet-,metal ,work3     
,profusely ,illustrated4 ,embracing     
,rules and ,directions for ,estimates1  
,items of ,cost1 ,nomenclature1 ,tables 
of ,brackets1 ,modillions1 ,dentals1    
,trusses1 ,stop-,blocks1 ,frieze        
,pieces1 etc4 ,architect's              
,specification1 ,tables of              
,tin-,roofing1 ,galvanized ,iron1 etc41 
etc4 ,to which is added the ,exemplar of
 ,architectural ,sheet-,metal ,work1    
containing details of the ,centennial   

,buildings1 and other important         
,sheet-,metal ,work1 ,designs and       
,prices of ,architectural ,ornaments1 as
 manufactured for the ,trade by the     
,kittredge ,cornice and ,ornament       
,company1 and a ,catalogue of ,cornices1
 ,window-,caps1 ,mouldings1 etc41 as    
manufactured by the ,kittredge ,cornice 
and ,ornament ,company4 ,the whole      
supplemented by a full ,index and ,table
 of ,contents4 ,by ,a4,o4 ,,kittredge4  
#hvo41 #efe pages4  ,,landrin4--,a      
,treatise on ,steel3  ,comprising its   
,theory1 ,metallurgy1 ,properties1      
,practical ,working1 and ,use4 ,by      
,m4,h4,c4 ,,landrin1 ,jr41 ,civil       
,engineer4 ,translated from the ,french1
 with ,notes1 by ,a4,a4 ,,fesquet1      
,chemist and ,engineer4 ,with an        
,appendix on the ,bessemer and the      
,martin ,processes for ,manufacturing   
,steel1 from the ,report of ,abram ,s4  
,hewitt1 ,united ,states ,commissioner  
to the ,universal ,exposition1 ,paris1  
#ahfg4 #abmo4 #c4jj  ,,larden4--,a      

,school ,course on ,heat3  ,by ,w4      
,,larden1 ,m4,a4 #cba pp4 #abmo4 #b4jj  
,,lardner4--,the ,steam-,engine3  ,for  
the ,use of ,beginners4 ,by ,,dr4       
,,lardner4 ,illustrated4 #abmo4 4#ge    
,,larkin4--,the ,practical ,brass and   
,iron ,founder's ,guide3  ,a ,concise   
,treatise on ,brass ,founding1          
,moulding1 the ,metals and their        
,alloys1 etc42 to which are added       
,recent ,improvements in the            
,manufacture of ,iron1 ,steel by the    
,bessemer ,process1 etc41 etc4 ,by      
,,james ,,larkin1 late ,conductor of the
 ,brass ,foundry ,department in ,reany1 
,neafie  ,co4's ,penn ,works1           
,philadelphia4 ,fifth edition1 revised1 
with extensive additions4 #abmo4 #b4be  
,,leroux4--,a ,practical ,treatise on   
the ,manufacture of ,worsteds and       
,carded ,yarns3  ,comprising ,practical 
,mechanics1 with ,rules and             
,calculations applied to ,spinning2     
,sorting1 ,cleaning1 and ,scouring      
,wools2 the ,english and ,french        

,methods of ,combing1 ,drawing1 and     
,spinning ,worsteds1 and ,manufacturing 
,carded ,yarns4 ,translated from the    
,french of ,,charles ,,leroux1          
,mechanical ,engineer and               
,superintendent of a ,spinning ,mill1 by
 ,,horatio ,,paine1 ,m4,d41 and ,a4,a4  
,,fesquet1 ,chemist and ,engineer4      
,illustrated by twelve large ,plates4   
,to which is added an ,appendix1        
containing ,extracts from the ,reports  
of the ,international ,jury1 and of the 
,artisans selected by the ,committee    
appointed by the ,council of the        
,society of ,arts1 ,london1 on ,woolen  
and ,worsted ,machinery and ,fabrics1 as
 exhibited in the ,paris ,universal     
,exposition1 #ahfg4 #hvo4 #e4jj         
,,leffel4--,the ,construction of        
,mill-,dams3  ,comprising also the      
,building of ,race and ,reservoir       
,embankments and ,head-,gates1 the      
,measurement of ,streams1 ,gauging of   
,water ,supply1 etc4 ,by ,,james        
,,leffel  ,,co4 ,illustrated by #eh     

engravings4 #hvo4 #b4ej                 
,,leslie4--,complete ,cookery3          
,directions for ,cookery in its ,various
 ,branches4 ,by ,,miss ,,leslie4        
,sixtieth thousand4 ,thoroughly revised1
 with the addition of ,new ,receipts4   
,in #abmo41 cloth #a4ej                 
,,lieber4--,assayer's ,guide3  ,or1     
,practical ,directions to ,assayers1    
,miners1 and ,smelters1 for the ,tests  
and ,assays1 by ,heat and by ,wet       
,processes1 for the ,ores of all the    
principal ,metals1 of ,gold and ,silver 
,coins and ,alloys1 and of ,coal1 etc4  
,by ,,oscar ,m4 ,,lieber4 #abmo4 #a4be  
,,love4--,the ,art of ,dyeing1          
,cleaning1 ,scouring1 and ,finishing1 on
 the ,most ,approved ,english and       
,french ,methods3  ,being ,practical    
,instructions in ,dyeing ,silks1        
,woolens1 and ,cottons1 ,feathers1      
,chips1 ,straw1 etc4 ,scouring and      
,cleaning ,bed and ,window ,curtains1   
,carpets1 ,rugs1 etc4 ,french and       
,english ,cleaning1 any ,color or       

,fabric of ,silk1 ,satin1 or ,damask4   
,by ,,thomas ,,love1 a ,working ,dyer   
and ,scourer4 ,second ,american         
,edition1 to which are added ,general   
,instructions for the use of ,aniline   
,colors4 #hvo4 #cdc pages #e4jj         
,,lukin4--,amongst ,machines3           
,embracing ,descriptions of the various 
,mechanical ,appliances used in the     
,manufacture of ,wood1 ,metal1 and other
 ,substances4 #abmo4 #a4ge              
,,lukin4--,the ,boy ,engineers3  ,what  
,they ,did1 and ,how ,they ,did ,it4    
,with #cj plates4 #ahmo4 #a4ge          
,,lukin4--,the ,young ,mechanic3        
,practical ,carpentry4 ,containing      
,directions for the ,use of all kinds of
 ,tools1 and for ,construction of       
,steam-,engines and ,mechanical ,models1
 including the ,art of ,turning in ,wood
 and ,metal4 ,by ,,john ,,lukin1 ,author
 of ,the ,lathe and ,its ,uses1 etc4    
,illustrated4 #abmo #a4ge  ,,main and   
,,brown4--,questions on ,subjects       
,connected with the ,marine             

,steam-,engine3  ,and ,examination      
,papers2 with ,hints for their          
,solution4 ,by ,,thomas ,j4 ,,main1     
,professor of ,mathematics1 ,royal      
,naval ,college1 and ,,thomas ,,brown1  
,chief ,engineer1 ,r4,n4 #abmo41 cloth4 
#a4ej  ,,main and ,,brown4--,the        
,indicator and ,dynamometer3  ,with     
their ,practical ,applications to the   
,steam-,engine4 ,by ,,thomas ,j4 ,,main1
 ,m4,a4,f4,r41 ,ass't ,s4 ,professor    
,royal ,naval ,college1 ,portsmouth1 and
 ,,thomas ,,brown1 ,assoc4 ,inst4       
,c4,e41 ,chief ,engineer ,r4,n41        
attached to the ,r4,n4 ,college4        
,illustrated4 #hvo4 #a4ej  ,,main and   
,,brown4--,the ,marine ,steam-,engine4  
,by ,,thomas ,j4 ,,main1 ,f4,r4 ,ass't  
,s4 ,mathematical ,professor at the     
,royal ,naval ,college1 ,portsmouth1 and
 ,,thomas ,,brown1 ,assoc4 ,inst4       
,c4,e41 ,chief ,engineer ,r4,n4         
,attached to the ,royal ,naval ,college4
 ,with numerous illustrations4 #hvo4    
#e4jj  ,,martin4--,screw-,cutting       

,tables1 for the ,use of ,mechanical    
,engineers3  ,showing the ,proper       
,arrangement of ,wheels for ,cutting the
 ,threads of ,screws of any ,required   
,pitch2 with a ,table for ,making the   
,universal ,gas-,pipe ,thread and ,taps4
 ,by ,w4,a4 ,,martin1 ,engineer4 #hvo4  
4#ej  ,,michell4--,mine ,drainage3      
,being a ,complete and ,practical       
,treatise on ,direct-,acting            
,underground ,steam ,pumping ,machinery4
 ,with a ,description of a large number 
of the best known ,engines1 their       
,general ,utility and the ,special      
,sphere of their ,action1 the ,mode of  
their ,application1 and their ,merits   
compared with other ,pumping ,machinery4
 ,by ,,stephen ,,michell4 ,illustrated  
by #acg engravings4 #hvo41 #bgg pages4  
#f4jj  ,,molesworth4--,pocket-,book of  
,useful ,formulae and ,memoranda for    
,civil and ,mechanical ,engineers4  ,by 
,,guilford ,l4 ,,molesworth1 ,member of 
the ,institution of ,civil ,engineers1  
,chief ,resident ,engineer of the       

,ceylon ,railway4 ,full-bound in        
,pocket-book form #a4jj  ,,moore4--,the 
,universal ,assistant and the ,complete 
,mechanic3  ,containing over one million
 ,industrial ,facts1 ,calculations1     
,receipts1 ,processes1 ,trades ,secrets1
 ,rules1 ,business ,forms1 ,legal       
,items1 ,etc41 in every occupation1 from
 the ,household to the ,manufactory4 ,by
 ,r4 ,,moore4 ,illustrated by #ejj      
,engravings4 #abmo4 #b4ej               
,,morris4--,easy ,rules for the         
,measurement of ,earthworks3  ,by means 
of the ,prismoidal ,formula4            
,illustrated with ,numerous ,wood-,cuts1
 ,problems1 and ,examples1 and concluded
 by an ,extensive ,table for finding the
 ,solidity in cubic yards from ,mean    
,areas4 ,the whole being adapted for    
convenient use by ,engineers1           
,surveyors1 ,contractors1 and others    
needing ,correct ,measurements of       
,earthwork4 ,by ,,elwood ,,morris1      
,c4,e4 #hvo4 #a4ej  ,,morton4--,the     
,system of ,calculating ,diameter1      

,circumference1 ,area1 and ,squaring the
 ,circle3  ,together with ,interest and 
,miscellaneous ,tables1 and other       
information4 ,by ,,james ,,morton4      
,second ,edition1 enlarged1 with the    
,metric ,system4 #abmo4 #a4jj           
,,napier4--,manual of                   
,electro-,metallurgy3  ,including the   
,application of the ,art to             
,manufacturing ,processes4 ,by ,,james  
,,napier4 ,fourth ,american1 from the   
,fourth ,london edition1 revised and    
enlarged4 ,illustrated by engravings4   
#hvo4 #a4ej  ,,napier4--,a ,system of   
,chemistry ,applied to ,dyeing4  ,by    
,,james ,,napier1 ,f4,c4,s4 ,a ,new and 
,thoroughly ,revised ,edition4          
,completely brought up to the present   
state of the ,science1 including the    
,chemistry of ,coal ,tar ,colors1 by    
,a4,a4 ,,fesquet1 ,chemist and          
,engineer4 ,with an ,appendix on ,dyeing
 and ,calico ,printing1 as shown at the 
,universal ,exposition1 ,paris1 #ahfg4  
,illustrated4 #hvo4 #dbb pages #e4jj    

,,neville4--,hydraulic ,tables1         
,coefficients1 and ,formulae1 for       
finding the ,discharge of ,water from   
,orifices1 ,notches1 ,weirs1 ,pipes1 and
 ,rivers3  ,third ,edition1 with        
,additions1 consisting of ,new ,formulae
 for the ,discharge from ,tidal and     
,flood ,sluices and ,siphons2 general   
information on ,rainfall1               
,catchment-,basins1 ,drainage1          
,sewerage1 ,water ,supply for ,towns and
 ,mill ,power4 ,by ,,john ,,neville1    
,c4,e4,m4,r4 ,i4,a42 ,fellow of the     
,royal ,geological ,society of ,ireland4
 ,thick #abmo4 #c4ej                    
,,newbery4--,gleanings from ,ornamental 
,art of every style3  ,drawn from       
,examples in the ,british1 ,south       
,kensington1 ,indian1 ,crystal ,palace1 
and other ,museums1 the ,exhibitions of 
#ahea and #ahfb1 and the best ,english  
and ,foreign works4 ,in a series of #ajj
 exquisitely drawn ,plates1 containing  
many hundred examples4 ,by ,,robert     
,,newbery4 #dto4 #ab4ej                 

,,nicholls4--,the ,theoretical and      
,practical ,boiler-,maker and           
,engineer's ,reference ,book3           
,containing a variety of ,useful        
,information for ,employers of ,labor1  
,foremen and ,working ,boiler-,makers1  
,iron1 ,copper1 and ,tinsmiths1         
,draughtsmen1 ,engineers1 the ,general  
,steam-using ,public1 and for the ,use  
of ,science ,schools and ,classes4 ,by  
,,samuel ,,nicholls4 ,illustrated by    
sixteen plates1 #abmo4 #b4ej            
,,nicholson4--,a ,manual of the ,art of 
,bookbinding3  ,containing full         
instructions in the different ,branches 
of ,forwarding1 ,gilding1 and           
,finishing4 ,also1 the ,art of ,marbling
 ,book-edges and ,paper4 ,by ,,james ,b4
 ,,nicholson4 ,illustrated4 #abmo41     
cloth #b4be  ,,nicolls4--,the ,railway  
,builder3  ,a ,hand-,book for           
,estimating the ,probable ,cost of      
,american ,railway ,construction and    
,equipment4 ,by ,,william ,j4 ,,nicolls1
 ,civil ,engineer4 ,illustrated1 full   

bound1 pocket-book form4 #b4jj          
,,normandy4--,the ,commercial ,handbook 
of ,chemical ,analysis3  ,or ,practical 
,instructions for the ,determination of 
the ,intrinsic or ,commercial ,value of 
,substances used in ,manufactures1 in   
,trades1 and in the ,arts4 ,by ,a4      
,,normandy4 ,new ,edition1 ,enlarged1   
and to a great extent rewritten4 ,by    
,,henry ,m4 ,,noad1 ,ph4,d41 ,f4,r4,s41 
thick #abmo4 #e4jj  ,,norris4--,a       
,handbook for ,locomotive ,engineers and
 ,machinists3  ,comprising the          
,proportions and ,calculations for      
,constructing ,locomotives2 ,manner of  
,setting ,valves2 ,tables of ,squares1  
,cubes1 ,areas1 etc41 etc4 ,by          
,,septimus ,,norris1 ,m4,e4 ,new        
edition4 ,illustrated1 #abmo4 #a4ej     
,,north4--,the ,practical ,assayer3     
,containing ,easy ,methods for the      
,assay of the ,principal ,metals and    
,alloys4 ,principally designed for      
explorers and those interested in       
,mines4 ,by ,,oliver ,,north4           

,illustrated4 #abmo4  ,,nystrom4--,a    
,new ,treatise on ,elements of          
,mechanics3  ,establishing ,strict      
,precision in the ,meaning of ,dynamical
 ,terms3 accompanied with an ,appendix  
on ,duodenal ,arithmetic and ,metrology4
 ,by ,,john ,w4 ,,nystrom1 ,c4,e4       
,illustrated4 #hvo4 #b4jj               
,,nystrom4--,on ,technological          
,education and the ,construction of     
,ships and ,screw ,propellers3  ,for    
,naval and ,marine ,engineers4 ,by      
,,john ,w4 ,,nystrom1 late ,acting      
,chief ,engineer1 ,u4,s4,n4 ,second     
edition1 revised1 with additional       
matter4 ,illustrated by seven           
engravings4 #abmo4 #a4ej                
,o',,neill4--,a ,dictionary of ,dyeing  
and ,calico ,printing3  ,containing a   
brief account of all the ,substances and
 ,processes in use in the ,art of       
,dyeing and ,printing ,textile ,fabrics2
 with ,practical ,receipts and          
,scientific ,information4 ,by ,,charles 
,o',,neill1 ,analytical ,chemist4 ,to   

which is added an ,essay on ,coal ,tar  
,colors and their application to ,dyeing
 and ,calico ,printing4 ,by ,a4,a4      
,,fesquet1 ,chemist and ,engineer4 ,with
 an appendix on ,dyeing and ,calico     
,printing1 as shown at the ,universal   
,exposition1 ,paris1 #ahfg4 #hvo41 #dia 
pages4 #e4jj  ,,orton4--,underground    
,treasures3  ,how and ,where to ,find   
,them4 ,a ,key for the ,ready           
,determination of all the ,useful       
,minerals within the ,united ,states4   
,by ,,james ,,orton1 ,a4,m41 ,late      
,professor of ,natural ,history in      
,vassar ,college1 ,n4,y42 ,cor4 ,mem4 of
 the ,academy of ,natural ,sciences1    
,philadelphia1 and of the ,lyceum of    
,natural ,history1 ,new ,york2 author of
 the ,andes and the ,amazon1 etc4 ,a    
,new ,edition1 with ,additions4         
,illustrated4 #a4ej  ,,osborn4--,the    
,metallurgy of ,iron and ,steel3        
,theoretical and ,practical in all its  
,branches2 with special reference to    
,american ,materials and ,processes4 ,by

 ,h4,s4 ,,osborn1 ,,ll4 ,d41 ,professor 
of ,mining and ,metallurgy in ,lafayette
 ,college1 ,easton1 ,pennsylvania4      
,illustrated by numerous large folding  
plates and wood-engravings4 #hvo4 #be4jj
  ,,overman4--,the ,manufacture of      
,steel3  ,containing the ,practice and  
,principles of ,working and ,making     
,steel4 ,a ,handbook for ,blacksmiths   
and ,workers in ,steel and ,iron1 ,wagon
 ,makers1 ,die ,sinkers1 ,cutlers1 and  
,manufacturers of ,files and ,hardware1 
of ,steel and ,iron1 and for ,men of    
,science and ,art4 ,by ,,frederick      
,,overman1 ,mining ,engineer1 ,author of
 the ,manufacture of ,iron1 etc4 ,a new1
 enlarged1 and revised ,edition4 ,by    
,a4,a4 ,,fesquet1 ,chemist and          
,engineer4 #abmo4 #a4ej                 
,,overman4--,the ,moulder's and         
,founder's ,pocket ,guide3  ,a ,treatise
 on ,moulding and ,founding in          
,green-sand1 ,dry-sand1 ,loam1 and      
,cement2 the ,moulding of ,machine      
,frames1 ,mill-gear1 ,hollow-ware1      

,ornaments1 ,trinkets1 ,bells1 and      
,statues2 ,description of ,moulds for   
,iron1 ,bronze1 ,brass1 and other       
,metals2 ,plaster of ,paris1 ,sulphur1  
,wax1 etc42 the ,construction of        
,melting ,furnaces1 the ,melting and    
,founding of ,metals2 the ,composition  
of ,alloys and their ,nature1 etc41 etc4
 ,by ,,frederick ,,overman1 ,m4,e4 ,a   
new ,edition1 to which is added a       
,supplement on ,statuary and ,ornamental
 ,moulding1 ,ordnance1 ,malleable ,iron 
,castings1 etc4 ,by ,a4,a4 ,,fesquet1   
,chemist and ,engineer4 ,illustrated by 
#dd engravings4 #abmo4 #b4jj  ,,painter1
 ,,gilder1 ,,and ,,varnisher',s         
,,companion3  ,containing ,rules and    
,regulations in everything relating to  
the ,arts of ,painting1 ,gilding1       
,varnishing1 ,glass-,staining1          
,graining1 ,marbling1 ,sign-,writing1   
,gilding on ,glass1 and ,coach ,painting
 and ,varnishing2 ,tests for the        
,detection of ,adulterations in ,oils1  
,colors1 etc42 and a ,statement of the  

,diseases to which ,painters are        
peculiarly liable1 with the ,simplest   
and ,best ,remedies4 ,sixteenth         
,edition4 ,revised1 with an ,appendix4  
,containing ,colors and                 
,coloring--,theoretical and ,practical4 
,comprising descriptions of a great     
variety of ,additional ,pigments1 their 
,qualities and ,uses1 to which are      
added1 ,dryers1 and ,modes and          
,operations of ,painting1 etc4 ,together
 with ,chevreul's ,principles of        
,harmony and ,contrast of ,colors4      
#abmo4 ,cloth #a4ej  ,,pallett4--,the   
,miller's1 ,millwright's1 and           
,engineer's ,guide4  ,by ,,henry        
,,pallett4 ,illustrated4 #abmo4 #c4jj   
,,pearse4--,a ,concise ,history of the  
,iron ,manufacture of the ,american     
,colonies up to the ,revolution1 and of 
,pennsylvania until the present time4   
,by ,,john ,b4 ,,pearse4 ,illustrated   
#abmo4 #b4jj  ,,percy4--,the            
,manufacture of ,russian ,sheet-,iron4  
,by ,,john ,,percy1 ,m4,d41 ,f4,r4,s41  

,lecturer on ,metallurgy at the ,royal  
,school of ,mines1 and to ,the ,advance 
,class of ,artillery ,officers at the   
,royal ,artillery ,institution1         
,woolwich2 ,author of ,metallurgy4 ,with
 ,illustrations4 #hvo41 paper #ej cts4  
,,perkins4--,gas and ,ventilation3      
,practical ,treatise on ,gas and        
,ventilation4 ,with ,special ,relation  
to ,illuminating1 ,heating1 and ,cooking
 by ,gas4 ,including ,scientific ,helps 
to ,engineer-students and others4 ,with 
,illustrated ,diagrams4 ,by ,e4,e4      
,,perkins4 #abmo41 cloth #a4be          
,,perkins ,,and ,,stowe4--,a ,new ,guide
 to the ,sheet-iron and ,boiler ,plate  
,roller3  ,containing a ,series of      
,tables showing the ,weight of ,slabs   
and ,piles to ,produce ,boiler ,plates1 
and of the ,weight of ,piles and the    
,sizes of ,bars to produce ,sheet-iron2 
the ,thickness of the ,bar ,gauge in    
decimals2 the ,weight per foot1 and the 
,thickness on the ,bar or ,wire ,gauge  
of the fractional parts of an inch2 the 

,weight per sheet1 and the ,thickness on
 the ,wire ,gauge of ,sheet-iron of     
various dimensions to weigh #aab lbs4   
per bundle2 and the conversion of ,short
 ,weight into ,long ,weight1 and ,long  
,weight into ,short4 ,estimated and     
collected by ,g4,h4 ,,perkins and ,j4,g4
 ,,stowe4 #b4ej                         
,,powell--,,chance--,,harris4--,the     
,principles of ,glass ,making4  ,by     
,,harry ,j4 ,,powell1 ,b4,a4 ,together  
with ,treatises on ,crown and ,sheet    
,glass2 by ,,henry ,,chance1 ,m4,a4 ,and
 ,plate ,glass1 by ,h4,g4 ,,harris1     
,asso4 ,m4 ,inst4 ,c4,e4 ,illustrated   
#ahmo4 #a4ej  ,,proteaux4--,practical   
,guide for the ,manufacture of ,paper   
and ,boards4  ,by ,a4 ,,proteaux4 ,from 
the ,french1 by ,,horatio ,,paine1      
,a4,b41 ,m4,d4 ,to which is added the   
,manufacture of ,paper from ,wood1 by   
,,henry ,t4 ,,brown4 ,illustrated by six
 plates4 #hvo4  ,,proctor4--,a          
,pocket-,book of ,useful ,tables and    
,formulae for ,marine ,engineers4  ,by  

,,frank ,,proctor4 ,second ,edition1    
,revised and ,enlarged4 ,full bound     
pocket-book form4 #a4ej                 
,,regnault4--,elements of ,chemistry4   
,by ,m4,v4 ,,regnault4 ,translated from 
the ,french by ,t4 ,,forrest ,,betton1  
,m4,d41 and edited1 with ,notes1 by     
,,james ,c4 ,,booth1 ,melter and        
,refiner ,u4,s4 ,mint1 and ,,william ,l4
 ,,faber1 ,metallurgist and ,mining     
,engineer4 ,illustrated by nearly #gjj  
wood engravings4 ,comprising nearly     
#a1ejj pages4 ,in two volumes1 #hvo41   
cloth #g4ej  ,,riffault1 ,,vergnaud1 and
 ,,toussaint4--,a ,practical ,treatise  
on the ,manufacture of ,colors for      
,painting3  ,comprising the ,origin1    
,definition1 and ,classification of     
,colors2 the ,treatment of the ,raw     
,materials2 the best ,formulae and the  
,newest ,processes for the ,preparation 
of every description of ,pigment1 and   
the ,necessary ,apparatus and           
,directions for its ,use2 ,dryers2 the  
,testing1 ,application1 and ,qualities  

of ,paints1 etc41 etc4 ,by ,,mm4        
,,riffault1 ,,vergnaud1 and ,,toussaint4
 ,revised and ,edited by ,m4,f4         
,,malepeyre4 ,translated from the       
,french1 by ,a4,a4 ,,fesquet1 ,chemist  
and ,engineer4 ,illustrated by ,eighty  
engravings4 ,in one vol41 #hvo41 #fei   
pages4 #g4ej  ,,roper4--,a ,catechism of
 ,high-,pressure1 or ,non-,condensing   
,steam-,engines3  ,including the        
,modelling1 ,constructing1 and          
,management of ,steam-,engines and      
,steam ,boilers4 ,with valuable         
illustrations4 ,by ,,stephen ,,roper1   
,engineer4 ,sixteenth edition1 revised  
and enlarged4 #ahmo41 tucks1 gilt edge4 
#b4jj  ,,roper4--,engineer's            
,handy-,book3  ,containing a full       
,explanation of the ,steam-,engine      
,indicator1 and its ,use and ,advantages
 to ,engineers and ,steam ,users4 ,with 
,formulae for ,estimating the ,power of 
all ,classes of ,steam-,engines2 also1  
,facts1 ,figures1 ,questions1 and       
,tables for ,engineers who wish to      

qualify themselves for the ,united      
,states ,navy1 the ,revenue ,service1   
the ,mercantile ,marine1 or to take     
charge of the ,better ,class of         
,stationary ,steam-,engines4 ,sixth     
edition4 #afmo41 #fij pages1 tucks1 gilt
 edge4 #c4ej  ,,roper4--,hand-,book of  
,land and ,marine ,engines3  ,including 
the ,modelling1 ,construction1 ,running1
 and ,management of ,land and ,marine   
,engines and ,boilers4 ,with            
illustrations4 ,by ,,stephen ,,roper1   
,engineer4 ,sixth edition4 #abmo41      
tucks1 gilt edge4 #c4ej                 
,,roper4--,hand-,book of the            
,locomotive3  ,including the            
,construction of ,engines and ,boilers1 
and the ,construction1 ,management1 and 
,running of ,locomotives4 ,by ,,stephen 
,,roper4 ,eleventh edition4 #ahmo41     
tucks1 gilt edge4 #b4ej                 
,,roper4--,hand-,book of ,modern ,steam 
,fire-,engines4  ,with illustrations4   
,by ,,stephen ,,roper1 ,engineer4       
,fourth edition1 #abmo41 tucks1 gilt    

edge4 #c4ej  ,,roper4--,questions and   
,answers for ,engineers4  ,this little  
book contains all the ,questions that   
,engineers will be asked when undergoing
 an ,examination for the purpose of     
procuring ,licenses1 and they are so    
plain that any ,engineer or ,fireman of 
ordinary intelligence may commit them to
 memory in a short time4 ,by ,,stephen  
,,roper1 ,engineer4 ,third edition4     
#c4jj  ,,roper4--,use and ,abuse of the 
,steam ,boiler4  ,by ,,stephen ,,roper1 
,engineer4 ,eighth edition1 with        
illustrations4 #ahmo41 tucks1 gilt edge4
 #b4jj  ,,rose4--,the ,complete         
,practical ,machinist3  ,embracing      
,lathe ,work1 ,vise ,work1 ,drills and  
,drilling1 ,taps and ,dies1 ,hardening  
and ,tempering1 the ,making and ,use of 
,tools1 ,tool ,grinding1 ,marking out   
,work1 etc4 ,by ,,joshua ,,rose4        
,illustrated by #cef engravings4        
,thirteenth edition1 thoroughly revised 
and in great part rewritten4 ,in one    
vol41 #abmo41 #dci pages4 #b4ej         

,,rose4--,mechanical ,drawing           
,self-,taught3  ,comprising             
,instructions in the ,selection and     
,preparation of ,drawing ,instruments1  
,elementary ,instruction in ,practical  
,mechanical ,drawing1 together with     
,examples in ,simple ,geometry and      
,elementary ,mechanism1 including ,screw
 ,threads1 ,gear ,wheels1 ,mechanical   
,motions1 ,engines and ,boilers4 ,by    
,,joshua ,,rose1 ,m4,e41 ,author of ,the
 ,complete ,practical ,machinist1 ,the  
,pattern-maker's ,assistant1 ,the       
,slide-valve4 ,illustrated by #ccj      
engravings4 #hvo41 #cac pages4 #d4jj    
,,rose4--,the ,slide-,valve ,practically
 ,explained3  ,embracing simple and     
complete ,practical ,demonstrations of  
the operation of each element in a      
,slide-valve ,movement1 and illustrating
 the effects of ,variations in their    
,proportions by examples carefully      
selected from the most recent and       
successful practice4 ,by ,,joshua       
,,rose1 ,m4,e41 ,author of ,the         

,complete ,practical ,machinist1 ,the   
,pattern-maker's ,assistant1 etc4       
,illustrated by #ce engravings4 #a4jj   
,,ross4--,the ,blowpipe in ,chemistry1  
,mineralogy and ,geology3  ,containing  
all ,known ,methods of ,anhydrous       
,analysis1 many ,working ,examples1 and 
,instructions for ,making ,apparatus4   
,by ,,lieut4-,,colonel ,w4,a4 ,,ross1   
,r4,a4,f41 ,g4,s4 ,with #abj            
,illustrations4 #abmo4 #a4ej            
,,shaw4--,civil ,architecture3  ,being a
 ,complete ,theoretical and ,practical  
,system of ,building1 containing the    
,fundamental ,principles of the ,art4   
,by ,,edward ,,shaw1 ,architect4 ,to    
which is added a ,treatise on ,gothic   
,architecture1 etc4 ,by ,,thomas ,w4    
,,silloway and ,,george ,m4 ,,harding1  
,architects4 ,the whole illustrated by  
#ajb quarto plates finely engraved on   
copper4 ,eleventh edition4 #dto4 #aj4jj 
,,shunk4--,a ,practical ,treatise on    
,railway ,curves and ,location1 for     
,young ,engineers4  ,by ,,william ,f4   

,,shunk1 ,civil ,engineer4 #abmo4 ,full 
bound pocket-book form4 #b4jj           
,,slater4--,the ,manual of ,colors and  
,dye ,wares4  ,by ,j4,w4 ,,slater4      
#abmo4 #c4ge  ,,sloan4--,american       
,houses3  ,a variety of ,original       
,designs for ,rural ,buildings4         
,illustrated by twenty-six colored      
,engravings1 with ,descriptive          
,references4 ,by ,,samuel ,,sloan1      
,architect1 author of the ,model        
,architect1 etc4 etc4 #hvo4 #a4ej       
,,sloan4--,homestead ,architecture3     
,containing ,forty ,designs for ,villas1
 ,cottages1 and ,farm-houses1 with      
,essays on ,style1 ,construction1       
,landscape ,gardening1 ,furniture1 etc41
 etc4 ,illustrated by upwards of #bjj   
engravings4 ,by ,,samuel ,,sloan1       
,architect4 #hvo4 #c4ej                 
,,smeaton4--,builder's                  
,pocket-,companion3  ,containing the    
,elements of ,building1 ,surveying1 and 
,architecture2 with ,practical ,rules   
and ,instructions connected with the    

subject4 ,by ,a4,c4 ,,smeaton1 ,civil   
,engineer1 etc4 #abmo4 #a4ej            
,,smith4--,a ,manual of ,political      
,economy4  ,by ,e4 ,,peshine ,,smith4 ,a
 new ,edition1 to which is added a full 
,index4 #abmo4 #a4be  ,,smith4--,parks  
and ,pleasure-,grounds3  ,or ,practical 
,notes on ,country ,residences1 ,villas1
 ,public ,parks1 and ,gardens4 ,by      
,,charles ,h4,j4 ,,smith1 ,landscape    
,gardener and ,garden ,architect1 etc41 
etc4 #abmo4 #b4jj  ,,smith4--,the       
,dyer's ,instructor3  ,comprising       
,practical ,instructions in the ,art of 
,dyeing ,silk1 ,cotton1 ,wool1 and      
,worsted1 and ,woolen ,goods2 containing
 nearly #hjj ,receipts4 ,to which is    
added a ,treatise on the ,art of        
,padding2 and the ,printing of ,silk    
,warps1 ,skeins1 and ,handkerchiefs1 and
 the various ,mordants and ,colors for  
the different styles of such work4 ,by  
,,david ,,smith1 ,pattern ,dyer4 #abmo4 
#c4jj  ,,smyth4--,a ,rudimentary        
,treatise on ,coal and ,coal-,mining4   

,by ,,warrington ,w4 ,,smyth1 ,m4,a41   
,f4,r4,g41 ,president ,r4,g4,s4 of      
,cornwall4 ,fifth edition1 revised and  
corrected4 ,with numerous illustrations4
 #abmo4 #a4ge  ,,snively4--,a ,treatise 
on the ,manufacture of ,perfumes and    
,kindred ,toilet ,articles4  ,by ,,john 
,h4 ,,snively1 ,phr4 ,d41 ,professor of 
,analytical ,chemistry in the ,tennessee
 ,college of ,pharmacy4 #hvo4 #c4jj     
,,snively4--,tables for ,systematic     
,qualitative ,chemical ,analysis4  ,by  
,,john ,h4 ,,snively1 ,phr4 ,d4 #hvo4   
#a4jj  ,,snively4--,the ,elements of    
,systematic ,qualitative ,chemical      
,analysis3  ,a ,hand-book for           
,beginners4 ,by ,,john ,h4 ,,snively1   
,phr4 ,d4 #afmo4 #b4jj  ,,stewart4--,the
 ,american ,system3  ,speeches on the   
,tariff ,question1 and on ,internal     
,improvements1 principally delivered in 
the ,house of ,representatives of the   
,united ,states4 ,by ,,andrew ,,stewart1
 late ,m4,c4 from ,pennsylvania4 ,with a
 ,portrait1 and a ,biographical ,sketch4

 #hvo4 #c4jj  ,,stokes4--,the           
,cabinet-,maker and ,upholsterer's      
,companion3  ,comprising the ,art of    
,drawing1 as applicable to ,cabinet     
,work2 ,veneering1 ,inlaying1 and       
,buhl-,work2 the ,art of ,dyeing and    
,staining ,wood1 ,ivory1 ,bone1         
,tortoise-,shell1 etc4 ,directions for  
,lackering1 ,japanning1 and ,varnishing2
 to make ,french ,polish1 ,glues1       
,cements1 and ,compositions2 with       
numerous ,receipts1 useful to workmen   
generally4 ,by ,j4 ,,stokes4            
,illustrated4 ,a ,new ,edition1 with an 
,appendix upon ,french ,polishing1      
,staining1 ,imitating1 ,varnishing1     
etc41 etc4 #abmo4 #a4be  ,,strength     
,,and ,,other ,,properties ,,of         
,,metals3  ,reports of ,experiments on  
the ,strength and other ,properties of  
,metals for ,cannon4 ,with a            
,description of the ,machines for       
,testing ,metals1 and of the            
,classification of ,cannon in service4  
,by ,officers of the ,ordnance          

,department1 ,u4,s4 ,army4 ,by authority
 of the ,secretary of ,war4 ,illustrated
 by #be large steel plates4 ,quarto4    
#aj4jj  ,,sullivan4--,protection to     
,native ,industry4  ,by ,sir ,,edward   
,,sullivan1 ,baronet1 author of ,ten    
,chapters on ,social ,reforms4 #hvo4    
#a4ej  ,,syme4--,outlines of an         
,industrial ,science4  ,by ,,david      
,,syme4 #abmo4 #b4jj  ,,tables ,,showing
 ,,the ,,weight ,,of ,,round1 ,,square1 
,,and ,,flat ,,bar ,,iron1 ,,steel1     
,,etc41  ,by ,measurement4 ,cloth4 #fc  
,,taylor4--,statistics of ,coal3        
,including ,mineral ,bituminous         
,substances employed in ,arts and       
,manufactures2 with their ,geographical1
 ,geological1 and ,commercial           
,distribution and ,amount of ,production
 and ,consumption on the ,american      
,continent4 ,with ,incidental           
,statistics of the ,iron ,manufacture4  
,by ,r4,c4 ,,taylor4 ,second edition1   
revised by ,s4,s4 ,,haldeman4           
,illustrated by five ,maps and many wood

 engravings4 #hvo41 cloth4 #aj4jj       
,,templeton4--,the ,practical           
,examinator on ,steam and the           
,steam--,engine3  ,with ,instructive    
,references relative thereto1 arranged  
for the ,use of ,engineers1 ,students1  
and others4 ,by ,,william ,,templeton1  
,engineer4 #abmo4 #a4be                 
,,thausing4--,the ,theory and ,practice 
of the ,preparation of ,malt and the    
,fabrication of ,beer3  ,with especial  
reference to the ,vienna ,process of    
,brewing4 ,elaborated from personal     
experience by ,,julius ,e4 ,,thausing1  
,professor at the ,school for ,brewers1 
and at the ,agricultural ,institute1    
,moedling1 near ,vienna4 ,translated    
from the ,german by ,,william ,t4       
,,brannt4 ,thoroughly and elaborately   
edited1 with much ,american matter1 and 
according to the latest and most        
,scientific ,practice1 by ,a4 ,,schwarz 
and ,,dr4 ,a4,h4 ,,bauer4 ,illustrated  
by #adj ,engravings4 #hvo41 #hae pages4 
#aj4jj  ,,thomas4--,the ,modern         

,practice of ,photography3  ,by ,r4,w4  
,,thomas1 ,f4,c4,s4 #hvo4 4#ge          
,,thompson4--,political ,economy4 ,with 
,especial ,reference to the ,industrial 
,history of ,nations3  ,by ,,robert ,e4 
,,thompson1 ,m4,a41 ,professor of       
,social ,science in the ,university of  
,pennsylvania4 #abmo4 #a4ej             
,,thomson4--,freight ,charges           
,calculator3  ,by ,,andrew ,,thomson1   
,freight ,agent4 #bdmo4 #a4be           
,,turner',s 7,,the7 ,,companion3        
,containing ,instructions in            
,concentric1 ,elliptic1 and ,eccentric  
,turning2 also various ,plates of       
,chucks1 ,tools1 and ,instruments2 and  
,directions for using the ,eccentric    
,cutter1 ,drill1 ,vertical ,cutter1 and 
,circular ,rest2 with ,patterns and     
,instructions for working them4 #abmo4  
#a4be  ,,turning3 ,specimens of ,fancy  
,turning ,executed on the ,hand or      
,foot-,lathe3  ,with ,geometric1 ,oval1 
and ,eccentric ,chucks1 and ,elliptical 
,cutting ,frame4 ,by an ,amateur4       

,illustrated by #cj exquisite           
,photographs4 #dto4 #c4jj               
,,urbin--,,brull4--,a ,practical ,guide 
for ,puddling ,iron and ,steel4  ,by    
,,ed4 ,,urbin1 ,engineer of ,arts and   
,manufactures4 ,a ,prize ,essay1 read   
before the ,association of ,engineers1  
,graduate of the ,school of ,mines1 of  
,liege1 ,belgium1 at the ,meeting of    
#ahfe-f4 ,to which is added ,a          
,,comparison ,,of ,,the ,,resisting     
,,properties ,,of ,,iron ,,and ,,steel4 
,by ,a4 ,,brull4 ,translated from the   
,french by ,a4,a4 ,,fesquet1 ,chemist   
and ,engineer4 #hvo4 #a4jj              
,,vaile4--,galvanized-,iron             
,cornice-,worker's ,manual3  ,containing
 ,instructions in ,laying out the       
,different4 ,mitres1 and ,making        
,patterns for all kinds of ,plain and   
,circular ,work4 ,also1 ,tables of      
,weights1 ,areas and ,circumferences of 
,circles1 and other ,matter calculated  
to ,benefit the ,trade4 ,by ,,charles   
,a4 ,,vaile4 ,illustrated by twenty-one 

plates4 #dto4 #e4jj  ,,ville4--,on      
,artificial ,manures3  ,their ,chemical 
,selection and ,scientific ,application 
to ,agriculture4 ,a series of ,lectures 
given at the ,experimental ,farm at     
,vincennes1 during #ahfg and #ahgd-ge4  
,by ,m4 ,,georges ,,ville4 ,translated  
and ,edited by ,,william ,,crookes1     
,f4,r4,s4 ,illustrated by thirty-one    
engravings4 #hvo41 #dej pages4 #f4jj    
,,ville4--,the ,school of ,chemical     
,manures3  ,or1 ,elementary ,principles 
in the ,use of ,fertilizing ,agents4    
,from the ,french of ,m4 ,,geo4 ,,ville1
 by ,a4,a4 ,,fesquet1 ,chemist and      
,engineer4 ,with ,illustrations4 #abmo4 
#a4be  ,,vogdes4--,the ,architect's and 
,builder's ,pocket-,companion and       
,price-,book3  ,consisting of a ,short  
but ,comprehensive ,epitome of          
,decimals1 ,duodecimals1 ,geometry and  
,mensuration2 with ,tables of ,united   
,states ,measures1 ,sizes1 ,weights1    
,strengths1 etc41 of ,iron1 ,wood1      
,stone1 ,brick1 ,cement and ,concretes1 

,quantities of ,materials in given      
,sizes and ,dimensions of ,wood1 ,brick 
and ,stone2 and full and complete ,bills
 of ,prices for ,carpenter's ,work and  
,painting2 also1 ,rules for ,computing  
and ,valuing ,brick and ,brick ,work1   
,stone ,work1 ,painting1 ,plastering1   
with a ,vocabulary of ,technical ,terms1
 etc4 ,by ,,frank ,w4 ,,vogdes1         
,architect1 ,indianapolis1 ,ind4        
,enlarged1 revised1 and corrected4 ,in  
one volume1 #cfh pages1 full-bound1     
pocket-book form1 gilt edges4 #b4jj     
,cloth #a4ej  ,,wahl4--,galvanoplastic  
,manipulations3  ,a ,practical ,guide   
for the ,gold and ,silver ,electroplater
 and the ,galvanoplastic ,operator4     
,comprising the ,electro-,deposition of 
all ,metals by means of the ,battery and
 the ,dynamo-,electric ,machine1 as well
 as the most approved ,processes of     
,deposition by ,simple ,immersion1 with 
,descriptions of ,apparatus1 ,chemical  
,products employed in the ,art1 etc4    
,based largely on the ,manipulations    

,hydroplastiques of ,,alfred ,,roseleur4
 ,by ,,william ,h4 ,,wahl1 ,ph4 ,d4     
7,heid71 ,secretary of the ,franklin    
,institute4 ,illustrated by #ahi        
engravings4 #hvo41 #fef pages4 #g4ej    
,,walton4--,coal-,mining ,described and 
,illustrated3  ,by ,,thomas ,h4         
,,walton1 ,mining ,engineer4            
,illustrated by #bd large and elaborate 
,plates1 after ,actual ,workings and    
,apparatus4 #e4jj  ,,ware4--,the ,sugar 
,beet4  ,including a ,history of the    
,beet ,sugar ,industry in ,europe1      
,varieties of the ,sugar ,beet1         
,examination1 ,soils1 ,tillage1 ,seeds  
and ,sowing1 ,yield and ,cost of        
,cultivation1 ,harvesting1              
,transportation1 ,conservation1 ,feeding
 ,qualities of the ,beet and of the     
,pulp1 etc4 ,by ,,lewis ,s4 ,,ware1     
,c4,e41 ,m4,e4 ,illustrated by ninety   
engravings4 #hvo4 #d4jj  ,,warn4--,the  
,sheet-,metal ,worker's ,instructor3    
,for ,zinc1 ,sheet-,iron1 ,copper1 and  
,tin-,plate ,workers1 etc4 ,containing a

 selection of ,geometrical ,problems2   
also1 ,practical and ,simple ,rules for 
,describing the various ,patterns       
required in the different branches of   
the above ,trades4 ,by ,,reuben ,h4     
,,warn1 ,practical ,tin-,plate ,worker4 
,to which is added an ,appendix1        
containing ,instructions for            
,boiler-,making1 ,mensuration of        
,surfaces and ,solids1 ,rules for       
,calculating the ,weights of different  
,figures of ,iron and ,steel1 ,tables of
 the ,weights of ,iron1 ,steel1 etc4    
,illustrated by thirty-two ,plates and  
thirty-seven ,wood ,engravings4 #hvo4   
#c4jj4  ,,warner4--,new ,theorems1      
,tables1 and ,diagrams1 for the         
,computation of ,earth-work3  ,designed 
for the use of ,engineers in            
,preliminary and ,final ,estimates1 of  
,students in ,engineering1 and of       
,contractors and other non-professional 
,computers4 ,in two parts1 with an      
,appendix4 ,part ,i4 ,a ,practical      
,treatise2 ,part ,,ii4 ,a ,theoretical  

,treatise1 and the ,appendix4           
,containing ,notes to the ,rules and    
,examples of ,part ,i42 ,explanations of
 the ,construction of ,scales1 ,tables1 
and ,diagrams1 and a ,treatise upon     
,equivalent ,square ,bases and          
,equivalent ,level ,heights4 ,the whole 
illustrated by numerous original        
engravings1 comprising explanatory cuts 
for ,definitions and ,problems1         
,stereometric ,scales and ,diagrams1 and
 a series of ,lithographic ,drawings    
from ,models3 ,showing all the          
,combinations of ,solid ,forms which    
occur in ,railroad ,excavations and     
,embankments4 ,by ,,john ,,warner1      
,a4,m41 ,mining and ,mechanical         
,engineer4 ,illustrated by #ad ,plates4 
,a new1 revised and improved edition4   
#hvo4 #d4jj  ,,watson4--,a ,manual of   
the ,hand-,lathe3  ,comprising ,concise 
,directions for ,working ,metals of all 
kinds1 ,ivory1 ,bone and ,precious      
,woods2 ,dyeing1 ,coloring1 and ,french 
,polishing2 ,inlaying by ,veneers1 and  

various methods practised to produce    
,elaborate work with ,dispatch1 and at  
,small ,expense4 ,by ,,egbert ,p4       
,,watson1 ,author of ,the ,modern       
,practice of ,american ,machinists and  
,engineers4 ,illustrated by #gh         
engravings4 #a4ej  ,,watson4--,the      
,modern ,practice of ,american          
,machinists and ,engineers3  ,including 
the ,construction1 ,application1 and    
,use of ,drills1 ,lathe ,tools1 ,cutters
 for ,boring ,cylinders1 and            
,hollow-work generally1 with the most   
,economical ,speed for the same2 the    
,results verified by ,actual ,practice  
at the ,lathe1 the ,vise1 and on the    
,floor4 ,together with ,workshop        
,management1 ,economy of ,manufacture1  
the ,steam-,engine1 ,boilers1 ,gears1   
,belting1 etc41 etc4 ,by ,,egbert ,p4   
,,watson4 ,illustrated by eighty-six    
engravings4 #abmo4 #b4ej                
,,watson4--,the ,theory and ,practice of
 the ,art of ,weaving by ,hand and      
,power3  ,with ,calculations and ,tables

 for the ,use of those connected with   
the ,trade4 ,by ,,john ,,watson1        
,manufacturer and ,practical            
,machine-,maker4 ,illustrated by large  
,drawings of the best ,power ,looms4    
#hvo4 #g4ej  ,,watt4--,the ,art of ,soap
 ,making3  ,a ,practical ,hand-book of  
the ,manufacture of ,hard and ,soft     
,soaps1 ,toilet ,soaps1 etc41 including 
many ,new ,processes1 and a ,chapter on 
the ,recovery of ,glycerine from ,waste 
,leys4 ,by ,,alexander ,,watt4 ,ill4    
#abmo4 #c4jj  ,,weatherly4--,treatise on
 the ,art of ,boiling ,sugar1           
,crystallizing1 ,lozenge-making1        
,comfits1 ,gum ,goods1  ,and other      
processes for ,confectionery1 etc41 in  
which are explained1 in an easy and     
familiar manner1 the various ,methods of
 ,manufacturing every ,description of   
,raw and ,refined ,sugar ,goods1 as sold
 by ,confectioners and others4 #abmo4   
#a4ej  ,,wedding4--,elements of the     
,metallurgy of ,iron4  ,by ,dr4         
,,hermann ,,wedding1 ,royal ,privy      

,counsellor of ,mines1 ,berlin1         
,prussia4 ,translated from the second   
revised and rewritten ,german edition4  
,by ,,william ,t4 ,,brannt1 ,graduate of
 the ,royal ,agricultural ,college at   
,eldena1 ,prussia4 ,edited by ,,william 
,h4 ,,wahl1 ,ph4 ,d41 ,secretary of the 
,franklin ,institute1 ,philadelphia4    
,illustrated by about #bej engravings4  
#hvo41 about #ejj pages 7,in            
preparation47                           
,,weinhold4--,introduction to           
,experimental ,physics1 ,theoretical and
 ,practical4  ,including directions for 
,constructing ,physical ,apparatus and  
for ,making ,experiments4 ,by ,,adolf   
,f4 ,,weinhold1 ,professor in the ,royal
 ,technical ,school at ,chemnitz4       
,translated and edited1 with the        
author's sanction1 by ,,benjamin        
,,loewy1 ,f4,r4,a4,s41 with a preface1  
by ,g4,c4 ,,foster1 ,f4,r4,s4           
,illustrated by three colored plates and
 #djd wood-cuts4 #hvo41 #hdh pages #f4jj
  ,,wightwick4--,hints to ,young        

,architects3  ,comprising ,advice to    
those who1 while yet at school1 are     
destined to the ,profession2 to such as1
 having passed their pupilage1 are about
 to travel2 and to those who1 having    
completed their education1 are about to 
practise4 ,together with a ,model       
,specification involving a great variety
 of instructive and suggestive matter4  
,by ,,george ,,wightwick1 ,architect4 ,a
 new edition1 revised and considerably  
enlarged2 comprising ,treatises on the  
,principles of ,construction and        
,design4 ,by ,g4 ,,huskisson            
,,guillaume1 ,architect4 ,numerous      
,illustrations4 ,one vol4 #abmo4 #b4jj  
,,will4--,tables of ,qualitative        
,chemical ,analysis4  ,with an          
,introductory ,chapter on the ,course of
 ,analysis4 ,by ,professor ,,heinrich   
,,will1 of ,giessen1 ,germany4 ,third   
,american1 from the eleventh ,german    
edition4 ,edited by ,,charles ,f4       
,,himes4 ,ph4 ,d41 ,professor of        
,natural ,science1 ,dickinson ,college1 

,carlisle1 ,pa4 #hvo4 #a4ej             
,,williams4--,on ,heat and ,steam3      
,embracing ,new ,views of ,vaporization1
 ,condensation1 and ,explosion4 ,by     
,,charles ,,wye ,,williams1 ,a4,i4,c4,e4
 ,illustrated #hvo4 #c4ej  ,,wilson4--,a
 ,treatise on ,steam ,boilers3  ,their  
,strength1 ,construction1 and           
,economical ,working4 ,by ,,robert      
,,wilson4 ,illustrated #abmo4 #b4ej     
,,wilson4--,cotton ,carder's ,companion3
  ,in which is given a description of   
the manner of ,picking1 ,baling1        
,marketing1 ,opening1 and ,carding      
,cotton2 to which is added a list of    
valuable ,tables1 ,rules1 and ,receipts1
 by ,,foster ,,wilson4 #abmo4 #a4ej     
,,wilson4--,first ,principles of        
,political ,economy3  ,with ,reference  
to ,statesmanship and the ,progress of  
,civilization4 ,by ,professor ,w4,d4    
,,wilson1 of the ,cornell ,university4  
,a new and revised edition4 #abmo4 #a4ej
  ,w,oe,h,l,e,r4--,a ,hand-book of      
,mineral ,analysis4  ,by ,f4            

,w,oe,h,l,e,r1 ,professor of ,chemistry 
in the ,university of ,goettingen4      
,edited by ,,henry ,b4 ,,nason1         
,professor of ,chemistry in the         
,renssalaer ,polytechnic ,institute1    
,troy1 ,new ,york4 ,illustrated #abmo4  
#c4jj  ,,worssam4--,on ,mechanical      
,saws3  ,from the ,transactions of the  
,society of ,engineers1 #ahfi4 ,by      
,s4,w4 ,,worssam1 ,,jr4 ,illustrated by 
eighteen large plates4 #hvo4 #b4ej      
99       99       99       99       99  
,,recent ,,additions4  ,,anderson--,the 
,prospector's ,hand-,book3  ,a ,guide   
for the ,prospector and ,traveler in    
,search of ,metal ,bearing or other     
,valuable ,minerals4 ,by ,j4,w4         
,,anderson4 #eb ,illustrations4 #abmo4  
#a4ej  ,,bilgram4--,slide-,valve ,gears3
  ,a new1 graphical method for          
,analyzing the ,action of               
,slide-,valves1 moved by ,eccentrics1   
,link ,motions1 and ,cut-off ,gears1    
offering easy means for properly        
designing ,valves and ,valve-,gears1 and

 for establishing the comparative merits
 of their various constructions4 ,by    
,,hugo ,,bilgram1 ,m4,e4 ,illustrated4  
#afmo4 #a4jj  ,,crew4--,a ,practical    
,treatise on ,petroleum3  ,comprising   
its ,geographical ,distribution1 its    
,geology1 ,chemistry1 ,mining1          
,refining1 ,preparation1 and ,uses4     
,together with a ,description of ,gas   
,wells and the ,application of ,gas as  
,fuel1 etc4 ,by ,,benjamin ,j4 ,,crew4  
,illustrated4 #hvo4 7,in preparation47  
,,crookes4--,select ,methods in         
,chemical ,analysis 7,chiefly           
,inorganic73  ,by ,,william ,,crookes1  
,f4,r4,s41 ,v4,p4,c4,s4 #b;d edition1   
re-written and greatly enlarged4        
,illustrated by #cg wood-cuts4 #gbe pp4 
#hvo4 #i4ej  ,,davis4--,a ,treatise on  
,steam-,boiler ,incrustation and        
,methods for ,preventing ,corrosion and 
the ,formation of ,scale3  ,by ,,charles
 ,t4 ,,davis4 ,illustrated by #fe       
engravings4 #hvo4 #b4jj  ,,davis4--,the 
,manufacture of ,paper3  ,being a       

,description of the various ,processes  
for the ,fabrication1 ,coloring and     
,finishing of every kind of ,paper1     
,including the ,different ,raw          
,materials and the ,methods for         
,determining their ,values1 the ,tools1 
,machines and ,practical ,details       
connected with an intelligent and a     
profitable prosecution of the art1 with 
special reference to the best ,american 
,practice4 ,to which are added a        
,history of ,paper1 complete ,lists of  
,paper-,making ,materials1 ,list of     
,american ,machines1 ,tools and         
,processes used in treating the ,raw    
,materials1 and in ,making1 ,coloring   
and ,finishing ,paper4 ,by ,,charles ,t4
 ,,davis4 ,illustrated by #aef          
engravings4 #ejj pages1 #hvo4 #f4jj     
,hand-,book of ,useful ,tables for the  
,lumberman1 ,farmer and ,mechanic3      
,containing ,accurate ,tables of ,logs  
,reduced to ,inch ,board ,measure1      
,plank1 ,scantling and ,timber ,measure2
 ,wages and ,rent1 by ,week or ,month2  

,capacity of ,granaries1 ,bins and      
,cisterns2 ,land ,measure1 ,interest    
,tables1 with ,directions for ,finding  
the ,interest on any sum at #d1 #e1 #f1 
#g and #h per cent41 and many other     
,useful ,tables4 #cb mo41 boards4 #ahf  
pages 4#be  ,,makins4--,a ,manual of    
,metallurgy3  ,by ,,george ,,hogarth    
,,makins1 ,m4,r4,c4,s4,s4,c4,s4         
,illustrated by #ajj engravings4 ,second
 edition rewritten and much enlarged4   
#hvo41 #eib pages4 #c4jj                
,,roper4--,instructions and ,suggestions
 for ,engineers and ,firemen3  ,by      
,,stephen ,,roper1 ,engineer #b4jj      
,,roper4--,the ,steam ,boiler3 ,its     
,care and ,management3  ,by ,,stephen   
,,roper1 ,engineer4 #abmo41 tuck1 gilt  
edges4 #b4jj  ,,roper4--,the ,young     
,engineer's ,own ,book3  ,containing an 
,explanation of the ,principle and      
,theories on which the ,steam ,engine as
 a ,prime ,mover is ,based4 ,by         
,,stephen ,,roper1 ,engineer4 #afj      
illustrations1 #cfc pages4 #ahmo41 tuck 

#c4jj  ,,rose4--,modern ,steam-,engines3
  ,an ,elementary ,treatise upon the    
,steam-,engine1 written in ,plain       
language2 for ,use in the ,workshop as  
well as in the ,drawing ,office4 ,giving
 ,full ,explanations of the             
,construction of ,modern                
,steam-,engines3 ,including ,diagrams   
showing their ,actual operation4        
,together with ,complete but ,simple    
,explanations of the operations of      
,various ,kinds of ,valves1 ,valve      
,motions1 and ,link ,motions1 etc41     
thereby ,enabling the ,ordinary         
,engineer to ,clearly ,understand the   
,principles ,involved in their          
,construction and ,use1 and to ,plot out
 their ,movements upon the ,drawing     
,board4 ,by ,,joshua ,,rose1 ,m4,e41    
,author of ,the ,complete ,practical    
,machinist1 ,the ,pattern ,maker's      
,assistant1 ,the ,slide ,valve and      
,mechanical ,drawing ,self-,taught4     
,illustrated by over #djj engravings4   
,in one volume1 #dto1 #cbj pages4 #f4jj 

,a ,great ,repository of ,practical and 
,scientific ,information4        99     
99       99       99       99  ,one of  
the ,fullest1 ,freshest and ,most       
,valuable ,hand-books of the ,age4      
,indispensable to ,every ,practical     
,man4  ,,just ,,ready4  ,,price1 #b4jj  
,,free ,,of ,,postage ,,to ,,any        
,,address ,,in ,,the ,,world4  ,,the    
,,techno-,,chemical ,,receipt ,,book3   
,,containing  ,several ,thousand        
,receipts1 covering the ,latest1 ,most  
,important and ,most ,useful            
,discoveries in ,chemical ,technology1  
and their ,practical ,application in the
 ,arts and the ,industries4  ,edited    
chiefly from the ,german of ,drs4       
,winckler1 ,eisner1 ,heintze1           
,mierzinski1 ,jacobsen1 ,koller1 and    
,heinzerling1  ,,with ,,additions ,,by  
,,william ,t4 ,,brannt1 ,graduate of the
 ,royal ,agricultural ,college of       
,eldena1 ,prussia1 ,,and ,,william ,h4  
,,wahl1 ,,ph4 ,d4 7,heid471 ,secretary  
of the ,franklin ,institute1            

,philadelphia2 author of ,galvanoplastic
 ,manipulations4  ,illustrated by       
,seventy-eight ,engravings4  ,in one    
volume1 xxxii1 #die pages1 #abmo41      
closely printed1 containing an immense  
amount and a great variety of matter4   
,price #b4jj1 free of postage to any    
address in the world4  ,the above or any
 of our books sent by mail1 free of     
postage1 at the publication price1 to   
any address in the world4  ,our ,new and
 ,enlarged ,catalogue of ,practical and 
,scientific ,books1 #if pages1 #hvo41   
and our other ,catalogues1 the whole    
covering every branch of ,science       
applied to the ,arts1 sent free and free
 of postage to any one1 in any part of  
the world1 who will furnish his address4
  ,,henry ,,carey ,,baird  ,,co41       
,industrial ,publishers1 ,booksellers   
and ,importers1     #haj ,walnut        
,street1 ,philadelphia1 ,pa41 ,u4,s4,a4 
,transcriber's ,notes3 ,opening quote on
 folio page #baj was eliminated due to  
ambiguity of the extent of the quote3   

,quote3 ,but these circular arcs4444    
,conventional text emphasis coding 444  
used for bolded text4