140 



TABLE 135.— THERMAL CONDUCTIVITY OF INSULATING MATERIALS 



(continued) 



Conductivity 



Density 

 Material g/cm 3 



Micanite 



Mineral wool 15 



" 30 



Paper, rice 



" blotting 



Paraffin wax 89 



Peat, dry 19 



" blocks 84 



Poreclain 



Rubber, rigid sponge, hard 09 



sponge, vulcanized 22 



commercial, 40% rubber. . . 

 92% " ... 



Sawdust 20 



Shellac 



Silk 



" scrap from spinning mill 10 



" 10 



" 10 



" 10 



Snow 25 



Steel wool 15 



" 08 



Wool, pure 09 



" very loose packing 04 



Woods : Ash i to grain 74 



" II " " 74 



Balsa 1 to grain 11 



Boxwood 90 



Cedar i to grain 48 



Cypress l to grain 46 



Fir i to grain 54 



" || to grain 54 



Lignum vitae 1.16 



" 1.16 



Mahogany, 1 to grain... .70 

 II to grain. . . .70 



Oak, x to grain 82 



" || to grain 82 



Pine, pitch, i to grain... 



" Virginia, ditto 55 



" white, ditto 45 



" || to grain 45 



Sprdce, 1 to grain 41 



Teak, l to grain 64 



" || to grain 64 



Walnut, 1 to grain 65 



Rocks : Basalt 



Chalk 



Granite 2.8 



Limestone, very variable.. 2.0 



Slate, i to cleavage , 



" || to cleavage 



Sandstone, air-dried 2.2 



freshly cut 2.3 



re 

 30 



30 



40 

 20 

 30 

 30 

 20 

 90 

 25 

 20 

 25 

 25 

 30 



■200 

 100 





 50 





 55 

 55 

 30 

 30 

 20 

 20 

 30 

 20 



30 

 20 

 20 

 20 

 100 

 20 

 20 

 15 

 15 

 30 

 30 

 60 

 60 



15 

 15 

 20 

 20 



20 

 95 

 95 

 20 

 20 



joule/ 



(cm 2 sec °C/ 



cm) 



.0021- 



.0042 



.00042 



.00052 



.00046 



.00063 



.0023 



.00052 



.0017 



.0104 



.00037 



.00054 



.0028 



.0016 



.00060 



.0023 



.00040 



.00023 



.00037 



.000495 



.00056 



.0016 



.00080 



.00090 



.00036 



.00042 



.0017 



.0031 



.00045 



.0015 



.0011 



.00096 



.0014 



.0035 



.0025 



.0030 



.0016 



.0031 



.0021 



.0036 



.0015 



.0014 



.0011 



.0026 



.0011 



.00175 



.0038 



.0014 



.020 



.0092 



.022 



.010 



.014 



.025 



.013 



.017 



cal/ 



(cm 2 sec °C/ 



cm) 



.00050- 



.00010 



.00010 



.00012 



.00011 



.00015 



.00055 



.00012 



.00041 



.0025 



.000088 



.00013 



.00067 



.00038 



.000143 



.0006 



.00010 



.000055 



.000088 



.000118 



.000134 



.00038 



.000191 



.00022 



.000086 



.00010 



.00041 



.00074 



.000084 



.00036 



.00027 



.00023 



.00033 



.00081 



.00060 



.00072 



.00038 



.00074 



.00050 



.00086 



.00036 



.00033 



.00026 



.00062 



.00026 



.00042 



.00091 



.00033 



.0048 



.0022 



.0053 



.0024 



.0033 



.0060 



.0031 



.0041 



(continued) 



SMITHSONIAN PHYSICAL TABLES 



