PEIRCE AND WILLSON. — THERMAL CONDUCTIVITn]S. 55 



sienna Marble. 



(Yellowish white with blue veins.) 



Thickness in centimeters, 2.48 



Temperatures of the faces of the glass plate, 81 ".5 and 60°. 9 



Temperatures of the faces of the marble plate, 40°. 9 and 18°. 6 



Ratio of the conductivities of the marble and the glass, 2.44 



Absolute conductivity of the marble, 0.00676 



St. Anne Marble. 

 (Brown black with white patches.) 



Thickness in centimeters, 2.34 



Temperatures of the faces of the glass plate, 80°. 9 and 60°. 1 



Temperatures of the faces of the marble plate, 38°. 8 and 19°. 7 



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



Absolute conductivity of the marble, 0.00755 



American Black Marble. 



(Dark slate.) 

 Thickness in centimeters, 2.43 



Temperatures of the faces of the glass plate, 81°. and 61°.l 



Temperatures of the faces of the marble slab, 40°. 1 and 19°. 2 

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



Absolute conductivity of the marble, 0.00685 



Vermont Cloudy Marble. 



(Cloudy white with darker patches.) 

 Thickness in centimeters, 2.55 



Temperatures of the faces of the glass plate, 82°. 3 and 62°. 1 



Temperatures of the faces of the marble slab, 41°. 8 and 19°. 4 

 Ratio of the conductivities of the marble and the glass, 2.46 



Absolute conductivity of the marble, 0.00681 



Knoxville Marble 



(Pink with occasional dark serrated veins.) 

 Thickness in centimeters, 2 37 



Temperatures of the faces of the glass plate, 81 °.6 and 61°. 



Temperatures of the faces of the marl>le .slab, 38°.9 and 20°.l 



Ratio of the conductivities of the marble and the glass, 2.62 



Absolute conductivity of the marble, 0.00757 



