54 PROCEEDINGS OP THE AMERICAN ACADEMY. 



Rose Ivory Marble. 



(From Djebel-er-Roos, Algiers. White with very sUght piukish tinge. Very fine 



in grain.) 



Thickness in centimeters, 2.64 



Temperatures of the faces of the glass plate, 80°. 3 and 60° .2 



Temperatures of the faces of the marble slab, 39°. 8 and 19°.0 



Ratio of the conductivities of the marble and the glass, 2.7C 



Absolute conductivity of the marble, 0.00756 



Italian Egyptian Marble. 

 (Breccia. Slate colored witli oclire-yellow and white veins.) 

 Thickness in centimeters, 2.55 



Temperatures of the faces of the glass plate, 83°. and 63°. 3 



Temperatures of the faces of the marble slab, 43°. 1 and 19°. 2 



Ratio of the conductivities of the marble and the glass, 2.25 



Absolute conductivity of the marble, 0.00623 



Mexican Onyx. 



(Alabaster white, translucent.) 

 Thickness in centimetres, 2.29 



Temperatures of the faces of the glass plate, 82°.9 and 63°. 8 



Temperatures of the faces of the onyx slab, 43°.l and 19°. 8 

 Ratio of the conductivities of the onyx and the glass, 2.01 



Absolute conductivity of the oynx, 0.00556 



Vermont Dove Colored Marble. 



(Dove colored witli light and dark striaj.) 

 Thickness in centimeters, 2.19 



Temperatures of the faces of the glass plate, 80°.5 and 59°. 3 



Temperatures of the faces of the marble slab, 39°. 1 and 18°.9 



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



Absolute conductivity of the marble, 0.00684 



Bardiglio Marble. 



(From the Seravazza quarries. Cloudy white, with network of distinct dark lines.) 

 Thickness in centimeters, 2.44 



Temperatures of the faces of the glass plate, 81°. 8 and 61°. 3 



Temperatures of the faces of the marble plate, 41°. 1 and 19°. 3 



Ratio of the conductivities of the marble and the glass, 2.45 



Absolute conductivity of the marble, 0.00680 



