— 165 — 
by multiplying tlie sectional area of tlio bars by the intensity of working stress, so 
that T^z 21.96 x 5 
M-- 
109.8 say 110 tons, therefore 
110x 13 
2x 10 
44.7 inch tons. 
. Consultiug Table XIV. we see a 4 ,7 pin will be required. We will use this 
size for the pins at the next panel points. 
For the pin at the first panel point we may take T = 8.70 x 5 ■= 43.8 say 44 
tons, making the horizon tul momeufc 
II 
44 x 5 
18.8 inch tons. 
asc ertain the value of T, Table YII. gives A = 4.74, and t is equal to 4 tons, 
^ 1 - 2 5 ,/ and dt = 1 為" = 1.31", therefore 
12 .1 inch tons. 
Consequently 
M =： 1/* て 1J3.8 ) 2 + ( 12.1 ) 2 = 18.4 inch tons 
r respon c ]i U g to a diameter of 8". 
t may be well to increase this to 3士" so as lo correspond witli tlie diameter of 
s ioe pin, which we must assume of this dimension, so as to allow for the un* 
ain P u U on each channel of the strut acting with a lever arm of three inches. 
も Of course there will be an intermediate bearing used for this pin. W e can in- 
polute the size of tl:e other bottom chortl pins as diameter. 
1 °'v let us pass to the liip pin. Tlie bearing must be at least equal to that 
given 
by the equation 
B 
26.25 
i = 1.6" 
the ^ x 12 - 
6 V ^ lue °； 1 being obtained from Table XVI. 
. 1 this value will make the lever arm l for the diagonal stress 
ßa y 2 ナ 0.8) = 1.2" and that for the liip vertical stress i (1.6 -|- 1.25) + 0.8=»2.28 
16 tons, and (F), that in a 
The stress (S) in one diagonal is approximately 
hip ^'tical, 1x^74 = 9i5 tons； 
maklUg tlle inclined moment, 16 x 1.2 = 19.2 iucli tons, 
an d the vertical moment, 9.5 x f 二 21.4 inch tons. 
tons 町) 11 ® these off to scale we find the resultant moment to be about 44.5 inch 
仙 8 ’ C0lle8 P°nding nearly to a 3g" pin, tlie smaller diameter being chosen, because 
^ethod gives an excess of strength. 
ail( j g パ 11 g may now be checked by finding by scale the resultant of twice 16 
tons ° U P 0ri 山6 diagonal and kip vertical respectively. It proves to be about 40 
XV ： we find that for this stress and a pin 8| 7/ diameter, a 
0 of 1 8’’ will be required, showing that the assumed lever arms are ample. 
