^90 Meteorological Observations for 1830-31 . 



sandth part of an inch, were observed and noted each day at 9 li. 

 80 m. A. M., and likewise at 8 li. 30 m. p. m., as recommended 

 by the Royal Society of Edinburgh; but the lowest temperatures 

 at night, shewn by a Register Thermometer, were observed and 

 noted only at 9 h. 30 m. a. m. In the year 1830 the extremes 

 of the lowest temperatures at night, viz. 22^° and 63% occurred 

 on 20th February and on 28th July, while those in 1831, viz. 

 11° and 61°, occurred on 1st February and on the 9th of both 

 July and August. 



By inspection of the above Table for the years 1830 and 

 1831, it will be observed that there is a marked difference be- 

 tween the mean temperatures, the mean atmospheric densities or 

 pressures, and the depths of rain, which occurred in the same 

 months of these two successive years ; that the mean tempera- 

 ture of 1831 commenced lower, rose to a greater elevation in 

 June, July, and August, ended higher, and exhibits a decidedly 

 higher annual mean than the corresponding mean temperature of 

 1830; that the monthly depths of rain for 1831 commenced 

 higher, but in June, July, and August, descended much lower, 

 ended lower, and exhibit a decidedly lower annual amount, than 

 the corresponding monthly depths and annual amount of rain for 

 1830 ; and that the mean barometric pressure, or atmospheric 

 density, appears in general to increase with an elevation of the 

 mean temperature, and to diminish with an increased depth of 

 rain, and, consequently, that the mean annual atmospheric den- 

 sity of 1830 was, as it should be, under the circumstances noted 

 in the Table, considerably less than that of 1831. 



The varying force and directions of the wind, the aurorae bo- 

 reales, solar and lunar halos, &c., entered in the register, are ne- 

 cessarily omitted in this general view of the phenomena. 



M. A. 



On the probable Origin of Mineral Springs. By C. E. Stifft, 

 formerly Mining Engineer to the Duke of Nassau. 



When it was the fashion to refer volcanic phenomena to 

 burning beds of coal or the decomposition of iron-pyrites, mi- 

 neral waters were considered, as a matter of course, to derive 

 their origin from the same source. Although, now-a-days, it 



