Atmospheeic Pressure. 



281 



TABLE XIX. — Extreme Readings of the Barometer for each Month ; Extreme Mean Daily Heights 

 for each Month ; and Extreme Diurnal Ranges for each Month, together with the Ranges and 

 Means of the Extremes. 



Month. 



Extreme Readings. 



Extreme Daily Means. 



Extreme Diurnal Ranges. 





Highest. 



Lowest. 



Range. 



Mean. 



Hi 



ghest. 



Lowest. 



Range. 



Mean. 



Greatest. 



Least. 





d. 



h. 



in. 



d. 



h. 



in. 



in. 



in. 



d. 



in. 



d. 



in. 



in. 



in. 



d. 



in. 



d. 



in. 



January 



19 







30-196 



13 



2 



27-837 



2-359 



29-016 



19 



30-169 



13 



28-022 



2-147 



29-095 



9 



1-044 



2 



0-060 



February 



7 



2 



30-063 



3 



2 



28-770 



1-293 



29-416 



7 



30-026 



3 



28-914 



1-112 



29-470 



4 



0-660 



25 



0-047 



March 



8 







30-158 



30 



18 



28-969 



1-189 



29-563 



8 



30-125 



31 



29-063 



1062 



29-594 



30 



0-669 



8 



0-053 



April 



23 



20 



29-836 



1 



8 



28-953 



0-883 



29-395 



18 



29-791 



1 



29-026 



0-765 



29-408 



3 



0-509 



11 



0058 



May 



1 







30-200 



27 



6 



29-108 



1-092 



29-654 



1 



30-184 



27 



29-141 



1-043 



29-662 



0-400 



15 



0033 



June 



14 



20 



29-996 



8 



18 



28-618 



1-378 



29-307 



12 



29-983 



9 



28-838 



1-145 



29-410 



10 



0-597 



12 



0-021 



July 



11 



2 



30-030 



29 



6 



29-135 



0-895 



29-582 



11 



29-999 



29 



29-237 



0-762 



29-618 



17 



0-519 



13 



0-025 



August 



12 



10 



30-048 



22 



4 



29-065 



0-983 



29-556 



12 



30-022 



3 



29-130 



0-892 



29-576 



21 



0-510 



11 



0-034 



September 



22 



22 



30-368 



29 



18 



29-385 



0-983 



29-876 



23 



30-323 



30 



29-500 



0-823 



29-911 



11 



0-412 



7 



0-029 



October 



19 







30-161 



28 







28-415 



1-746 



29-288 



19 



30-105 



28 



28-586 



1-519 



29-345 



28 



0-724 



25 



0-030 



November 



29 



10 



30-165 



21 



20 



28-647 



1-518 



29-406 



14 



30-080 



22 



28-963 



M17 



29-521 



22 



0-655 



2 



0083 



December 



28 







30-207 



5 



4 



29-462 



0-745 



29-834 



18 



30-187 



5 



29-545 



0-642 



29-866 



4 



0-481 



18 



0-044 



Extremes of Atmospheric Pressure for 1843. 



Highest barometer occurred ••• September 22'i 22'' = 30-368 "l ^ ^ !f„, c.n^'^'r.n 



Lowest January W^ 2'— 27-837 j ^^^^e = 2-531, mean = 29-102. 



Highest daily mean occurred--- September 23*^ = 30-323 1 -p _ o qhi 001*70 



Lowest January 13^ ^ 28-022 P^''^'' - ^■'^"^' '"^^'^ - ^^'^'^^ 



January 



Highest monthly mean occurred December 

 Lowest January 



= 29-358 f -^^"^^ ~ 0-605, mean = 29-660. 



The greatest diurnal range of pressure occurred January 9^, = 1-044. 



Theleast June 12'i, =0-021. 



The greatest range of pressure for a month occurred Jamiary 13"^ — 19^, = 2-359. 



Theleast December, = 0-745. 



The greatest range of mean daily pressure for a month occurred January 13'' — 19'', = 2-147. 



Theleast December, = 0-642. 



The mean of the highest and lowest readings in the year is 0-507 in. less than the mean for the year ; the 

 mean of the highest and lowest daily means is 0-437 in. less than the mean for the year. If we compare 

 similarly the means of the highest and lowest readings and daily means in each month with the monthly means, 

 we obtain the following results : — 



Monthly/ Means minus Mean of Highest and Lowest Headings in each Month. 



Jan. Feb. March. April. May. June. July- Aug. Sept. Oct. Nov. Dec. 



in. in. in. in. in. in. in. in. in. in. in. iu. 



+ 0-341 +0-083 +0-099 +0-092 -0-034 +0-312 +0-053 +0-100 +0-059 -1-0-113 +0065 +0128 



Monthly Means minus Mean of Highest and Lowest Daily Means in each Month. 



Jan. Feb. March. April. May. June. July. Aug. Sept. Oct. Nov. Dec. 



in. in. in. in. in. in. in. in. in. in. in. in. 



+ 0-262 +0-029 +0-068 +0-079 -0-042 +0209 +0-017 +0-080 +0-024 +0-056 -0-050 +0-096 



MAG. AND MET. OBS. 1843. 4 B 



