B. TERRESTRIAL PHYSICS AND METEOROLOGY. 121 



in the Indian Ocean, had it not happened that this one seems 

 to have passed directly over the island of Mauritius, famous 

 in meteorological science as the residence of Meldrum, and 

 the place of operation of that meteorological society which 

 lias done so much to increase our knowledge of these terri- 

 ble atmospheric disturbances. Indications of the late hurri- 

 cane were observed on the 22d of March, at Port Louis, in a 

 falling barometer and a rising wind, which increased until it 

 reached its height on the 27th and 28th. Its greatest force 

 was 11 on the Beaufort scale, and the barometer sank as low 

 as 28.57 inches. The town itself presented a very sad ap- 

 pearance after the storm was over, the roofs and debris of 

 fallen houses, and broken trees innumerable, partially ob- 

 structing all of the main streets. There were very few 

 houses but were more or less injured; the museum of the 

 Royal College was unroofed, many cellars were inundated 

 and valuable goods destroyed, and many lives were lost. 12 

 yl,X., 15. 



THE TEMPERATURE OF RAIN-WATER. 



The temperature of falling rain in thunder-storms has been 

 observed for four years by Breitenlohner. He finds that, 

 during this interval, from one third to one fourth of the total 

 rain-fall occurs in connection with thunder and lightning. 

 The table showing his results explains many views on the 

 various relations between the temperature of the air and the 

 rain. The average of the observations shows that the falling 

 rain belonging to storms that come from the northern por- 

 tions of the horizon is generally colder, the differences dimin- 

 ishing as we turn to the west or east; while the rain-fall 

 coming from the southwest is decidedly warmer. The great- 

 est number of thunder-storms comes to his station in Austria 

 from the northwest, and the next most numerous class of 

 storms come from the southwest and the northeast. Com- 

 paring the quantity of rain-fall and the temperatures, it seems 

 that the greatest rain-fall corresponds nearly to the colder 

 temperatures, the least rain-fall to the warmer. The region 

 of greatest number of storms is also the region of greatest 

 rain-fall. Ordinarily the rain is more or less nearly the tem- 

 perature of the air itself, and varies therefrom, at most, only 

 a few tenths of a degree. From the study of the observa- 



F 



