366 Scientific Intelligence — Meteorology. 



The principal results of the observations may be briefly stated 

 as follows : — 



Each of the four series of observations shews, that the progress 

 of the temperature is not regular at all heights, but that at a cer- 

 tain height (varying on different days) the regular diminution be- 

 comes arrested, and for the space of about 2000 feet the tempera- 

 ture remains constant or even increases by a small amount : it 

 afterwards resumes its downward course, continuing for the most 

 part to diminish regularly throughout the remainder of the height 

 observed. There is thus, in the curves representing the progres- 

 sion of temperature with height, an appearance of dislocation, 

 always in the same direction, but varying in amount from 7° to 12°. 

 In the first two series, viz. Aug. 17 and 26, this peculiar inter- 

 ruption of the progress of temperature is strikingly coincident with 

 a large and rapid fall in the temperature of the devj-point. The 

 same is exhibited in a less marked manner on Nov. 10. On Oct. 

 21 a dense cloud existed at a height of about 3000 feet ; the tem- 

 perature decreased uniformly from the earth up to the lower sur- 

 face of the cloud, when a slight rise commenced, the rise continu- 

 ing through the cloud, and to about 600 feet above its upper sur- 

 face, when the regular descending progression was resumed. At 

 a short distance above the cloud the dew-point fell considerably, 

 but the rate of diminution of temperature does not appear to have 

 been affected in this instance in the same manner as in the other 

 series ; the phenomenon so strikingly shewn in the other three 

 cases being perhaps modified by the existence of moisture in a 

 condensed or vesicular form. 



It would appear on the whole that about the principal plane of 

 condensation heat is developed in the atmosphere, which has the 

 effect of raising the temperature of the higher air above what it 

 would have been had the rate of decrease continued uniformly from 

 the earth upwards. 



There are several instances of a second or even a third sudden 

 fall in the dew-point, but any corresponding variation in the tempera- 

 ture is not so clearly exhibited, probably owing to the total amount 

 of moisture in the air being, at low temperatures, so very small 

 that even a considerable change in its relative amount would pro- 

 duce but a small thermal effect. 



As the existence of the disturbance in the regular progression of 

 temperature now stated rendered it neccessary, in order to arrive 

 at any approximate value of the normal rate of diminution with 

 height, to make abstraction of the portion affected by the disturbing 

 cause, each series was divided into two sections, the first comprising 

 the space below the stratum in which the irregularity existed, and 

 the second commencing from the point where the regular diminu- 

 tion of temperature was resumed. It was then found that the 

 rate of diminution was nearly uniform within each section, but that 

 it was b me what greater in the lower than in the upper sections'. 



