The effects of moisture on the thermal conductivity of soils: With a bibliography on the heating of cables

It has been appreciated for many years that the presence of moisture in the soil surrounding underground cable was of assistance in dissipating the heat generated within the cable. But little was definitely known, however, of the exact changes in the thermal conductivity of soils caused by the presence of moisture. The following article shows that moisture plays a predominant part. The relative thermal conductivity of various types of perfectly dry soils, such as sand, clay, gravel, etc., covers a range from only one to two, while the addition of moisture increases the range to five times or more that of dry soils. The article also includes a bibliography on the heating of underground cables, giving reference to 59 papers on the subject in English, French and German.