TABLE 584.— REFLECTING FACTOR OF BUILDING MATERIALS 553 



The radiation used to measure the reflecting factors for the wavelengths given was ob- 

 tained from the sun's radiation transmitted through selected filters. The radiation from a 

 "pointalight" transmitted through a thin gold filter may be used in place of the sun. 



Description (1.78/i) 



Magnesium carbonate 63 



Clay tiles 



Dutch : light red 68 



Machine-made : red 72 



red 55 



lighter red 52 



dark purple 22 



Hand-made : red 60 



red brown 55 



Concrete tiles 



Uncolored 37 



Brown 13 



Brown : very rough 08 



Black 06 



Slates 



Dark gray : smooth 09 



fairly rough 10 



rough 09 



Greenish gray : rough 16 



Mauve 14 



Blue gray 20 



Silver gray (Norwegian) 22 



Other roofing materials 



Asbestos cement : white 35 



red 33 



Enamelled steel : white 35 



green 26 



red 24 



blue 23 



Galvanized iron : new 58 



very dirty 10 



whitewashed 63 



Special roofing sheet : brown 20 



green 13 



Bituminous felt 10 



Aluminized felt 67 



Weathered asphalt 12 



Roofing lead : old 46 



Bricks 



Gault : cream 74 



Stock : light fawn 56 



Fletton : light portion 67 



dark portion 54 



Wire cut : red 56 



Sand-lime : red 41 



Mottled purple 33 



Stafford: blue 21 



Lime-clay (French) 57 



SMITHSONIAN PHYSICAL TABLES 



