134 CAPT. NEWBOLD ON THE TEMPERATURE OF THE SPRINGS, WELLS 



At Cassergode, on the west coast, lat.N. 12° 29', whose mean temperature is about 

 80°, the diurnal fluctuation amounted to only 1°'5 in cloudy weather. At Mangalore, 

 on the same coast, lat. N. 12° 53', it amounted on a clear day to 2°-75. The last ex- 

 periment was made, at my request, by my friend Mr. B. G. Maurice, Madras Medical 

 Service. In stiff clayey soils, at the depth of four feet from the surface, and sheltered 

 to the distance of six yards radius from the spot perforated, the temperature fluctuated 

 but little, and gave a tolerably correct mean of the air. In light sandy soils a greater 

 d^pth is necessary ; and at all times it is advisable to observe the temperature of the 

 perforation in the soil at the coldest and hottest periods of the day, which, with an 

 unclouded sky, will be found to occur at, or just before, sunrise, and from 2 to 3 p.m. 

 Such observations should, if possible, be compared with the temperature of a spring 

 or well of moderate depth, at from six to ten feet below the surface, bearing in mind 

 what has already been stated regarding the causes affecting the temperature of wells 

 and springs. 



