PEIRCE AND WILLSON. — THERMAL CONDUCTIVITIES. 53 



Possiliferous Tennessee Marble. 



(Red with numerous white fossils.) 

 Thickness in centimeters, 2.40 



Temperatures of the faces of the glass plate, 82°. 3 and 63°. 2 



Temperatures of the faces of the marble slab, 43°.3 and 24°.4 



Ratio of the couductivities of the marble and the glass, 2.73 



Absolute conductivity of the marble, 0.00756 



American White Marble. 

 (Cream white.) 

 Thickness in centimeters, 2.68 



Temperatures of the faces of the glass plate, 83°. 6 and 64°. 6 



Temperatures of the faces of the marble .slab, 45°. 4 and 20°. 3 

 Ratio of the couductivities of the marble and the glass, 2.15 



Absolute conductivity of the marble, 0.00596 



Vermont Statuary Marble. 



(Snow white with coarse but uniform grain.) 

 Thickness in centimeters, 2.40 



Temperatures of the faces of the glass plate, 82°. 9 and 64°. 2 



Temperatures of the faces of the marble slab, 44° .7 and 21°. 7 



Ratio of the couductivities of the marble and the glass, 2.09 



Absolute conductivity of the marble, 0.00578 



Lisbon Marble. 

 (Light terra-cotta with darker veins.) 



Thickness in centimeters, 2.30 



Temperatures of the faces of the glass plate, 80°. 9 and 60°. 8 



Temperatures of the faces of the marble slab, 39°. 6 and 19°. 6 



Ratio of the conductivities of the marble and the glass, 2.47 



Absolute conductivity of the marble 0.00685 



St. Baume Marble. 



(Yellow, red, and yellowish white brecciated.) 

 Thickness in centimeters, 2.36 



Temperatures of the faces of the glass plate, 80°. 9 arid 61°. 2 



Temperatures of the faces of the marble slab, 40°. 3 and 22°. 1 



Ratio of the couductivities of the marble and the glass, 2.75 



Absolute conductivity of the marble, 0.00761 



