14 BULLETIN 789, U. S. DEPARTMENT OF AGRICULTURE. 
At a distance of 6 feet from the top we can change to = rounds 
12’’ on center. 
EXAMPLE 4. 
Required: Vertical and lateral pressure at the bottom of a rec-;~ 
tangular bin 8 feet by 14 feet by 68 feet in height, walls to be of steel 
plates, bin to be used for storing barley weighing 40 pounds per 
cubic foot. 
8x14 
16+28 
Diameter of equivalent regular bin=4 x 2.55=10.2 feet. 
For barley in a steel bin we may select for y’ a value of 0.375 and 
for k a value of 0.4, then 
Ax Xp —404 x0 215 —0 oe: 
Hydraulic radius = = ST 
240.30 
D at 60 feet. 
At bottom = <4, for which = = 49. 08. 
V =49. 08 X17=835 pounds. 
For W=40 V= =o of 835=668 pounds per square foot. 
L=0. 4X 668 = 267 pounds per square foot. 
APPENDIX. 
Values of yw’, the coefficient of friction of grain on different sub- 
stances, and of k, the ratio of the lateral to the vertical pressure of 
grain, as determined by the experiments of different observers are 
presented herewith. 
Coefficients of friction of various kinds of grain on bin walls. 
From Airy, Wilfred. The pressure of grain, Institution of civil engineers. Minutes of proceedings. 
Vol. 131, p. 347-358. London, 1898. 
Weight Coefficient of friction. 
of e ubic 
oot 
is loosely | Grainon | Grain on | | Grain on Grain on | Grain on 
filledinto} grain. rough smooth iron. cement. 
mmieasure board. board. ; 7 
: Bu 5 a? B B 
Pounds. 
Wes Giri ee Ses we ee 49 0. 466 0. 412 0. 361 0. 414 0. 444 
Barloy:s:2-0 3 i. ee ee 39 . 507 . 424 3 376 - 452 
Oats 202 Sit See ee ee ee ee 28 BS y . 450 412 - 466 
Corn 38 3.423 2 ee ee ee 44 -521 . 344 308 374 - 423 
Beans? ssc oa. Sao n eee re ee eee ees .616 . 435 322 366 . 442 
eee ee a Se ee Rae eo 50 : 472 . 287 268 263 3 oS 
ME. ene | 41 456 »407 308 339 414 
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