LIVEEPOOL AND WIHEAL. 



quarry, at a depth of about fifty feet from the surface, one of 

 which measured upwards of thirty feet in length, and covered 

 an area of about three hundred superficial feet." 



In the observations upon the climate of Liverpool we avail 

 ourselves of the results obtained by Mr. Hartnup, at the 

 Liverpool Observatory, between the years 1846-50 inclusive, 

 seeing that no series of observations can exceed these in 

 minuteness and accuracy ; besides, they are reduced to a com- 

 mon standard. 



During the years referred to, the mean reading of the baro- 

 meter, corrected for index error and reduced to 32° Fahr., was 

 29-860 inches, the extremes being 30-862 inches and 28*382 

 inches, respectively on February 11th, 1849, and December 

 6th, 1847. The instrument not being self- registering these 

 extremes were obtained at the ordinary times of reading off; 

 and that they cannot be implicitly trusted in, is proved by the 

 fact stated by Mr. Hartnup, that at 10 p.m. on the latter 

 occasion the mercury fell to 28-154 inches. This, however, is 

 of little moment in the present inquiry, as it is the mean 

 pressure more than extremes, which seldom occur, that co- 

 operates in exerting an influence upon the local Flora. 



Temperature is a much more powerful agent than atmos- 

 pheric pressure, and the mean reading of the thermometers, 

 corrected for index errors and diurnal range, was 49*9° Fahr. ; 

 the highest of a self-registering thermometer being 82*3°, on 

 the 19th June, 1846, and the lowest of a self-registering in- 

 strument being 20*8°, on the 29th January, 1848. The mean 

 daily range of temperature was 8*8°, and the extreme range 

 for the five years amounted to 61*5. The least mean range 

 takes place in January, when it amounts to 5-7°; and the 

 maximum occurs in May and June, when it equals 11*8°. 



The mean temperature of the dew-point, or point at which 

 invisible moisture is deposited from the atmosphere, was 44*9°, 

 i.e., 5° below the mean temperature of the air. The mean 

 elastic force of vapour, or the average amount of water dif- 



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