BULLETIN 537, U. S. DEPARTMENT OF AGRICULTURE. 



ft) 



o 



< 







a 



o 



cc 



J 



^ 



to 















t p* 





fc> 















ISiOf"* 



c Wft « 





o W) p 





E=15 





o t> 





O 







to m 



■A -• 









si 













H 







oo t^. 



T) en 









c3 a> 





W a 











00 •->&! 



"8.2 * 









£S p 



^-~ 



" o o 





a 





c jj 



Cl CN to 







o a> 



^tOCOi-t 



t. £ 





CDlM 





PH O 





1 U 







13 







<5S 



ft) 



^ 





J3 , o • 





•SffeSo 







£ o- 



ft) 



Crushing 

 strength, 

 pounds 



per 

 square 

 inch. 





















03 





































o> 





















a 



1 









s 





o 













o 



s| 



s 



s 



3 © 



^3 



03 



£S 



s 

















=i 











02 03 



03 



t>> 























a 





ja 







3 

 o 





03 



a> 







^^ 



& d c 







Sgilx) 













>-. 03 









Mft) 



















[>> 





^ 



x 















CD 



£ 



M 





? 



CO 



O 







fl 





55 !=^3 







f- 





TO ^^, 









3* 





I* 







oooo 













<-< N(N^lOO'rOi.-OOCliO-*O^Q-l"-COOX''tO!DiOIOL': 



CO NOlNr^iOI-OOOit'NlON^OOI^l-I'MtOMr^CONNt'- 

 O _^o6 TjHh^OOOO OO 00 r~ CO!-' CO O O0 ION 00 I- O0 I~ 00 CO Q0 I- CO CO OO 



O00 CO'OOll^OO CJOM »-t CO tHOOOO CN 00 r-lt^OS^ 



oo r* ^to oo oo oo oo ,_"5 i^ t~ ^oi co ^o ©to co t^ ^^t~ -* CO 'O 



OO tO t^ lO CO 00 Wt^»C © ^ TfcJilO IOH OCO^HTJ^ 



lO Ol ^^I> ^^-^•^^_^t^OiO^_ N CjicO ^^"^ »Ot^ CO U0 IOCCON 



~H-*t<COC0tOCN'-HCOr~CO'-*<MlOO00cOC>0r~COt0r~COC0C0O00CJiCO 

 N N 00 O CO - 'O to CO lO IC rH N M CO lO lO ■*[•- C CC CI CI t- Lt CO lO to 



OOOCN-ch" '»-) "rH *i-4 



OJiOMiO(Ni001COcOC5 0C'0]CONtO«CONCJr^OIOOONOiiO'*CO 



to -}* to »o i^ — r — cc cr -j: cc or. cc y. cc cc _ c vc cr ~ r - cc x cc cc i ~ i~ co 



co-r 



■3g i 7t •? O 



« 5 * 3 S « 



8lgia| 



§ . © c 2 2 2 • '.2 '.2U-2 S.2 '• • '§.2 



O O.S 



"3.2 



— J:; b 



CB CU ~ 



(- b '/, 



C3 C3 d 



f- 1 CO CO 

 Efl 01 w 



0; <U o 



111 



— oopoo^^o 



r*CJ u u uu 



a 1 



ooooo^-o^ at 



•r-o3o3o3o3c3^o3 



tr-OOOOOE-O 



s t;- 1 s 



; cv a; 



1<K 



£^fe- 



O 03 



siHjl" 



'0? S C ?< 03, 

 2 g O S^ o3S 2^' 



^« ■ 4- n jj o 52 

 <i<! .-<rfsOl-303«- 



;oiio wi-r. -i-criHcoNi-cicooyj^NOOOHOi t- oc c?j 

 : ~. -r — — -r '0 tc -r <" »o ■- — < ci ct c-i r-> c-i t - i - r / s. v_ v c/ v: 

 ■ ^ '^ '— ■ — c± cQcocdcpcdtp4«^'4««mMn»eonMn 

 JOogooooooooooocoooooooooo 



