VIII. Meteorological Abstract for the Years 1797, 1798, 

 and 1799. Communicated by John Platfair, F. R. S. 

 Edin. and Profejfor of Mathematics in the Univerfity of 

 Edinburgh. 



[Read at the Meetings in Jan. 1798, 1799, & 1800.] 



IN drawing up this abftracT, I have fomewhat enlarged the 

 plan followed in thofe formerly communicated to the So- 

 ciety. In order to reprefent more accurately the progrefs of 

 the feafons, every month is here divided into three parts, and 

 the flate of the barometer and thermometer is given for each 

 of thefe divifions. 



In the tables, therefore, that follow, the firft column contains 

 the greateft height of the barometer for each of the above divi- 

 fions ; the fecond the lead ; the third the mean ; and the fourth 

 the temperature of the air in the room where the barometer is 

 kept ; the fifth and fixth columns mew the greateft height of 

 the thermometer in the air that was obferved during the ten 

 days to which the numbers refer ; the next three give the mean 

 heights as obferved at three different times every day, viz. at 8 

 in the morning, 10 in the evening, and, as nearly as can be judg- 

 ed, when the day is warmeft, that is, fome time between mid-day 

 and 3 in the afternoon. The mean of all thefe three is taken 

 for the mean temperature of the day, which being computed 

 for each day, the mean of all thefe mean temperatures is fet 

 down as the medium temperature of the air for every one of the 



thirty-fix 



