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ANALYSIS OF THE OBSERVATORY RECORDS FOR JANUARY, 



1865, IN CONJUNCTION WITH THOSE OF BIRTHS, DEATHS, 



&o. By E. Swarbeeck Hall, 



One thousaud eight hundred and sixty-five has commenced with weather of 

 an abnormal character, though so favorable to life, that the mortality for 

 January is considerably less than the average for the previous eight years. 

 Nevertheless, January 1804 had greatly the superiority in this respect, not 

 only over all other Januaries, but in comparison with any month of the twelve 

 in a year of the eight years now tabled. By the seven years' standard January 

 stands next to February for being the most fatal to life of the months of a year. 

 Atmospheric pressure, though continuously high and in a constant state of 

 oscillation, had no veiy extensive fluctuation on any day, and the whole range 

 of the month was only -711 of an inch, being considerably less than that of 

 any January of the previous twenty -four years recorded. 1846 had the nearest 

 approximation, but even its range was "779 of an inch. 1857 had the widest 

 range, being 1'492 inches. The mean of the present month was 29"855, being 

 -M40 above the twenty years' adopted standard mean for January. Last 

 year the mean was almost identical with that of the twenty years. The extremes 

 of the present month were — maximum, 30"175, on the 3rd ; minimum, 29 464, 

 on the 17th, Last year the maximum was nearly as high, but the minimum 

 very much lower. In fact, there is not on record so high a minimum for 

 January as that of the present month. The greatest movement of the 

 barometer on any day was a fall of — "428 of an inch on the 8th, The 

 greatest rise was + "329 of an inch on the 18th, Altogether there were daily 

 movements exceeding one-fifth of an inch only nine times. 



Wind force, 71*79 lbs., though almost identical with the four years' average 

 in Mr. Abbott's "Twenty Years' Meteorological Tables," is nevertheless — 7 "31 

 lbs. below the average of January for the last eight years. At the same time 

 the present month had greatly the predominance in winds blowing from the 

 quarters most propitious to health. The frequency and strength of the south- 

 west winds is without parallel in the month of January, The strongest wind 

 noted had a pressure to the square foot of 5 '21 lbs., and was registered on the 

 2nd, 6th, and 10th, two of the three being N,W, and one S.W. The calms 

 were only 13, being 4 4-7thsbelow the seven years' average. 



Temperature mean, 59 '53, was only a few decimals higher than that of the 

 previous month of December, and — 4 "04 degrees lower than the 20 years' 

 mean for January. It was also nearly two degrees less than January 1864 

 had, January 1853 had the lowest mean 57,67,-1852, I860, 1849, were 

 nearly the same as the present month, but no other January in the last twenty • 

 four years has had a mean below 60 degrees. The 14 years' records at the 

 Royal Observatory give a mean of 61 "24 degrees, and with the six subsequent 

 years, the mean is 63*57 degrees. By the self -registering maxima and minima 

 thermometers, the mean of the present month is 60*11 degrees, a much 

 smaller variation from the foregoing than is usual. The maximum temperature 

 78 degi-ees on the 30th, is the lowest in the past 24 years, and three degrees 

 below the maximum of January last year. The minimum temperature was 43 

 degrees, and noted on the 20th and 21st, 1862 had as low a minimum, and 1857 

 1856, 1855 each one degree lower. The extreme range of temperature, 35 

 degrees, exceeded that of January 1864 by two degrees, but was less than any 

 other January of the previous 24 years, The mean of all the maxima was 

 69*48 degrees, and of its minima 50*74. 



The dailg range of temperature had a mean of 18*74 degrees, being — 1*90 

 less than that of the 20 years, though + 1.61 degrees higher than January 

 1864 had. To this more variable temperature of the present mouth is princi- 

 pally to be ascribed the difference in mortality between the two months. The 

 greatest range on any day was, 29 degrees on the 21st, being two degrees above 

 that of last year's January. The smallest range was 9 degrees on the 30th. 



Solar-Intensity had a mean of 104*45 degrees, being more than three degrees 

 below January 1864, and— 5,77 less than the mean of nine years. The 

 maximum, 122 degrees, was on the 16th, and one degree less than that of last 

 year. The minimum was 70 degrees on the 1st. 



Terrestrial Radiation xaQdiQ. W2i% 47*51 degrees, being — 4*15 degrees below 

 the mean of the previous nine years, and less than any one of them. The 

 maximum was 53, on the oth and 28th, and the minimum 40*5 on the 20th 



