372 Mr. nanso?i's Meteorological Journal for 1821. [IV^H^ 



The annual mean temperature of the past year is 51° ; being 

 about 2° above tlie average ; the mean of the tirst three months, 

 40-9°; second, 54-P; third, 61-9°; fourth, 48°; of the six 

 ijf inter months, 44*4° ; six summer months, 57*9°. The maxi- 

 mum, or hottest state of the year, was 81°, which occurred on 

 the memorable 19th of July, the Coronation of King George IV.; 

 the minimum or coldest state was 23°, which is only 9° below- 

 freezing ; this happened on the 4th January, making an annual 

 variation of 58°. From the above, the reporter is enabled to 

 draw the following comparison between the past and preceding- 

 year, viz. the average heat of the six summer months of 1821 

 was nearly one degree more than that of 1820, and the heat of 

 the six wmter months, 3° above the corresponding ones of the 

 preceding year, so that the temperature of 1821 has been more 

 mild than usual, and not marked by any very great extremes. 



The annual mean elevation of the barometer is nearly 29 

 inches and 7-lOths ; highest, 30-65, which v/as on January 23 ; 

 lowest, 28* 1(), which happened on December 28; the difference 

 of these extremes makes 2*49 inches : mean of the six summer 

 months, 29*75 ; of the six winter months, 29*63. The mean 

 daily movements of the barometrical surface measure near 48 

 inches: total number of changes, 105. The barometer through- 

 out the month of February was remarkably high and desultory 

 in its movements : on the contrary, in the month of December, 

 it oscillated most extraordinarily ; and towards the close of the 

 year very low ; the utmost depression was the minimum of the 

 year. 



Much has been said about the wetness of the past year. My 

 annual account scarcely amounts to 32 inches in depth, which is 

 certainly under the average for Manchester. Mr. John Black- 

 wall, of Crumpsall, makes his annual fall three inches more, and 

 Mr. John Dalton, for Ardwick, nearly eight inches more than 

 mine. On the contrary, Mr. Edward Stelfox, of Lymra, near 

 Warrington, has only registered a fall of 28 inches. The differ- 

 ences in our annual statements of rain, from places so near toge- 

 ther, are singular, and certainly require an attentive inquiry. The 

 only difference in our apparatus is, that Mr. Dalton's rain funnel 

 is larger : mine, Mr. Blackwall's, and Mr. Stelfox's, are made 

 alike, the same size, and of one material, which is that of copper. 

 Provided our calculations of the method of measuring the rain 

 collected in these funnel-areas be correct, and which I liave 

 every reason to conclude is the case; and provided their surfaces 

 are parallel with the horizon, and at sufficient distances from 

 trees, buildings, or any object that might obstruct a free access, 

 it must follow that there can be no error in our results. I have 

 noted down 180 days on which rain fell more or less, which 

 number is one less than last year. In the last five months of 

 l8'20, there were 85 wet days ; the number in the corresponding 



