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XX. Remarlis on the IVeather during the Quarter ending 

 December 31, 1847. By James Glaisher, Esq.^ of the 

 Royal Observatory, Greenwich'''^. 



THE quarterly meteorological returns for the past quarter, 

 furnished to the Registrar-General, have been obtained 

 from twenty- eight different places in England and one in 

 Ireland. Upon every subject of investigation in these reports, 

 and with almost every gentleman from whom they have been 

 received, I have been in frequent correspondence ; I know 

 therefore, in most cases, the character of the instruments, and 

 the circumstances under which the observations have been 

 made. 



Every return has been examined by myself, and each result 

 checked by comparison with others made in neighbouring 

 places; and in every case where suspicion seemed to rest, I 

 have immediately had the observations examined; and in all 

 cases where the numbers did not stand this examination, they 

 have not been printed. 



The whole of the observations were then reduced to mean 

 places and discussed by myself, and the results form a body of 

 meteorological facts of which I can speak with much confi- 

 dence. In the course of their reduction, the character of the 

 period over which the observations extend came forcibly under 

 my notice ; and I found it to be one remarkable in many re- 

 spects, and such as would interest many of the readers of the 

 Philosophical Magazine, who would not otherwise see the 

 account in the Registrar- General's report itself; and its publi- 

 cation in the Philosophical Magazine will have the effect of 

 bringing these valuable reports to the notice of persons inter- 

 ested in meteorology. 



The daily temperatures of the air, evaporation and dew- 

 point, during the whole quarter, with the exceptions of the 

 period between Nov. 17 and Nov. 21, and between Dec. 20 

 and Dec. 31, have been above the average for the season, and 

 at times these departures have been very great. 



It perhaps may tend to clearness if I speak of each subject 

 of investigation separatel}'. 



The mean temperature of the air at Greenwich — 



For the month of October was 52'^-9, which is 4!°-l, l^'o, 

 4.°-9, 3°-4, 2°-7, and 2°-4 above that in the years 1841 to 1846 

 respectively. The high temperature in this month is very 

 remarkable. 



For the month of November was 46°'9, which is 4°*2, 4°*1, 

 3"1, 2"-9, l^-l, and 0°9 above that of the years 1841 to 1846 

 res})ectively. 



* (.'ornniuiiicali'd l)y the Author. 



