XCV.The temperature variation of the thermal conductivity of pyrex glass

Abstract

The thermal conductivity of pyrex glass has been investigated over the temperature range from −180°C. to 250°C. The variation of conductivity may be satisfactorily represented by the relation K=A+b.log₁₀ T., where A and b are constants having the values −0·00352₃ and 0·00245₄ respectively. K is expressed in cal. cm.⁻¹ sec.⁻¹ deg.⁻¹, and T is the absolute temperature. The following table indicates how closely this relation satisfies the experimental observations:—