302 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



would traverse in one hour a plate of the given material one 

 square foot in area, one inch thick, and with its surfaces main- 

 tained at temperature differing by one degree. 



C. 



Air i6 



Hairfelt 32 



Cotton Wool 323 



Mineral Wool 38 



Canvas, Hemp .420 



Compressed Cork .47 



Mill Shavings 65 



F'ii* 75 



Oak 1.70 



Water 4.41 



Iron 476.0 



Copper 3^92.0 



Lumber. 



Estimated average life of treated and untreated lumber in 

 the United States when set under conditions subjecting it to 

 decay : 



Untreated Treated 



Species Years Years 



Redwood* 14 — 



Cypress* 14 — 



Red Cedar* 14 — 



White Cedar* 13 — 



Chestnut* 12 — 



Douglas Fir 10 20 



White Oak 3 20 



White Pine 8 18 



Yellow Pine 8 20 



Elm 7 20 



Western Yellow Pine 6 20 



Sugar Pine 6 18 



Spruce 6 17 



