141 



TABLE 135.— THERMAL CONDUCTIVITY OF INSULATING MATERIALS 



(concluded) 



Density 



Substance g/cm 3 



Asbestos fiber 201 



85% magnesia asbestos 216 



Cotton 021 



101 



Eiderdown 0021 



109 



Lampblack, Cabot number 5. .193 



Quartz, mesh 200 1.05 



Poplox, popped Na 2 Si0 3 093 



°C 

 500 



rioo 



1500 

 100 



150 



rioo 



\500 



500 



i 200 



1500 



kt 



cgs Substance 



.00019 Asbestos paper 



.00016 Blotting paper 



.00017 Portland cement 



.000111 Chalk 



.000071 Ebonite, t, 49° 



.00015 Glass, mean 



.000046 Ice 



.000074 Leather, cow-hide 



.000107 " chamois 



.00024 Linen 



.000091 Silk 



.000160 Caen stone, limestone. 

 Free stone, sandstone. 



kt 



cgs 



.00043 



.00015 



.00071 



.0020 



.00037 



.002 



.0057 



.00042 



.00015 



.00021 



.000095 



.0043 



.0021 



Substance 



Density 

 g/cm 3 



kt 



cgs 



at 20°C at 100°C 



Substance 



Density 



g/cm 3 



kt 

 cgs 



at 20°C at 100°C 



Brick, fire 1.73 



Carbon, gas .... 1.42 



Ebonite 1.19 



Fiber, red 1.29 



Glass, soda 2.59 



Silica, fused .... 2.17 



.00110 



.0085 



.00014 



.00112 



.00172 



.00237 



.00109 



.0095 



.00013 



.00119 



.00182 



.00255 



Boxwood 0.90 



Greenheart 1.08 



Lignumvitae .... 1.16 



Mahogany 0.55 



Oak 0.65 



Whitewood 0.58 



Conductivity 



.00036 

 .00112 

 .00060 

 .00051 

 .00058 

 .00041 



Substance g/cm 3 



Air-cell asbestos 231 



Cork, ground 168 



Diatomite 326 



Infusorial earth, natural 506 



" h'd pressed blocks. . . .321 



Magnesium carbonate 450 



Vitribestos 362 



.00041 

 .00110 

 .00072 

 .00060 

 .00061 

 .00045 



Safe 

 100°C 200°C 300°C 400°C 500°C temp. 



.00034 .00043 .00050 — — 320 



.00015 .00019 — — 180 



.00028 .00032 .00037 .00042 .00046 600 



.00034 .00032 .00040 — — 



.00030 .00029 .00033 .00036 — 400 



.00023 .00025 .00025 — — 300 



.00049 .00066 .00079 .00090 .00102 600 



TABLE 136.— THERMAL CONDUCTIVITY OF VARIOUS SUBSTANCES 



Material 

 Amorphous carbon. 



100 

 100 

 Concrete: 



insulating 250 



sand cement 400 



Graphite (artificial).. 100 



100 



2800 



500 



Limestone 40 



Description Sil 



Fireclay, pottery quality.... 56 



Fireclay, fine quality 56 



Aluminous 52 



Silica 95 



Tempera- k Tempera- k 



ture °C cgs Material Hire °C cgs 



37-163 .028-.003 Brick: carborundum . 150-1200 .0032-. 027 



360 .089 building 15-1100 .0018-. 0038 



842 .129 graphite 300-700 .024 



light diatomite. 200-600 .00025-00032 



750 .00045-. 00051 magnesia 50-1130 .0027-. 0072 



900 .0025-.0031 Glass silk: density 



390 .338 .055 15 .000096 



914 291 .083 17 .000092 



3200 .002 .16 9 .000071 



700 .31-.22 .21 10 .000075 



.0046-.0057 Granite 100 .0045-.0050 



Stoneware mixtures.. 70-1000 .0029-.0053 

 Percent composition 

 Tita- Cal- Mag- 

 nium Ferric cium nesium Alkali Density 



ica oxide Alumina oxide oxide oxide oxides g/cm 3 



46 1.84 36.79 2.58 .38 .60 1.24 2.0 



46 1.84 36.79 2.58 .38 .60 1.24 2.05 



2.7 41.3 2.5 — 2.0 



16 .57 1.46 .85 1.96 .08 .21 1.81 



k, 



cgs 

 .0025 

 .0020 

 .0028 

 .0036 



«* Griffiths, E., Journ. Inst. Fuel, vol. 15, p. Ill, 1942. 



SMITHSONIAN PHYSICAL TABLES 



