PALMER: THE DESIGNING OF CONE PULLEYS. 61 
At the left of the figure draw the circle arc A62, the center of 
which is quickly located thus: Draw X2, horizontal; 21 a 45°-line; 
140 a horizontal. Bisect 41 at 3, and mark O with O4—43. With 
O2 as radius draw the arc. 
If, now, instead of beginning the measurement of each | from 
the vertical AB we measure from this circle arc, then the straight 
line WD gives the values of 1 and the curve may be abandoned. 
The length 6U will now be the value of | for the origin in position 
A’. And so for any position of A’ the value of | is seen on the hor- 
izontal through the origin A’, and is the part of this horizontal in- 
cluded between the arc A62 and the straight line WUD. _ Both this 
arc and the straight line are readily located and drawn, so that we 
now have for crossed belts a treatment exactly corresponding to 
that for the case of open belts, and equally as simple and complete. 
THE FINAL DIACRAM. 
The essential portions of Fig. 6, constituting our useful working 
diagram, are shown in Fig. 7. 
All lines can be easily and quickly drawn from memory with the 
simple drafting instruments. The rectangle is first constructed with 
AB equal the distance between centers, in any convenient scale, 
and the length BC=zvd. Then with the T-square and 45°-triangle 
BE, AX, X2, 21, 10, are at once drawn. Then point 3, the mid- 
dle of 41 is marked, and O4 made equal 43, and the arc 26A struck. 
Then EW and XW are drawn, determining W, when WD may be 
drawn and the diagram is ready for use, just as the diagram for 
open belts is used, as already explained. 
