272 A. BOYD. 
The jointed wheels were cast in two halves, and were 
united by a simple flanged joint consisting of two rather 
heavy rectangular lugs cast on the inside of the rim with 
a single 2inch bolt passing through them. The two halves 
of the boss were also united by rectangular flanges, two # 
inch bolts passing through each pair of flanges at a distance 
of 1°8 inches from the centre of the wheel, This joint was 
made of the simplest possible construction in order to 
simplify any calculations that may be made. Hach casting 
was very carefully set up on the planing machine and the 
face of junction planed truly level and to the desired 
dimensions. The bolt holes were then drilled to such a 
size that the bolts had to be lightly hammered in, by this 
means any slackness in the joint was obviated. 
Table of Dimensions of Rim Joint. 
Radial /|Circum. Dist. icht 
Position | breadth | length | Depth | of bolt | ts eeeeens 
Wheel. of of flange | of two in from 
joint. (mean | lugsin/inches.| inside | Two | Bolt. 
inches.) | inches. edge. | Lugs. 
Four armed, jointed; bay A. | 1°088 | 1-520} 1:150| 0°50 | 0°479 | 0-123 
between arms. | bay C. | 1°100 | 1°490| 1°150/ 0°50 | 0-482 | 0-123 
Four armed, jointed) arm AB.| 1:044 | 1°520/ 1150} 0°45 | 0°458 | 0:123 
along arms. armCD.| 1:034 | 1550] 1:150| 0°50 | 0°469 | 0:123 
In the case of the wheel jointed at the centres of the 
bays the diameter of the boss measured across the flanges 
was 4°7 inches, and the thickness of the pair of flanges 
was 1°95 inches. The corresponding measurements for the 
wheel jointed along the arms were 4°8 and 1°91 inches. 
Weights of rotating parts :— 
Spindle ee ae Ba ade oo.) OOeiGen 
Pulley, key, and collar ... wee. bee, 2 
Cross-bar and set-screws sea Soe» 2a 
Shackles with nuts each... ue ... OT tees 
——_—__. —__ 
Total 2.: ee oe oe ‘2 15° 23alies 
