20 



ANALYSIS OF THE OBSERVATORY RECORDS FOR 

 MARCH, 1866, IN CONJUNCTION WITH THOSE OF 

 BIRTHS, DEATHS, &c. By E. Swarbeeck Hall. 



In the mortality-rato for tlxo twelve months of tlio year — on the average 

 of the previous nine years — March stands the third on the list, February and 

 July both liaving a higher mean of deaths. Tlio mean is 56 3-9, the present 

 month had 57 deaths, and six out of the previous nine, had each between 50 and 

 CO. The extremes were 73 in 1864, and 48 in 1859. After the short but 

 violent storm of wind and rain on the morning of the 8th the deaths diminished 

 largely, one third of all the deaths of the month having occurred during the 

 first week, and principally from the bowel-complaints which had originated 

 in the previous month, 



Atmospltcric pressure mean, 30"017, was unusually high, being -f "160 

 above the 20 years' adopted standard mean for March. Only two years out 

 of the previous 25 had a higher mean, i.e.-. — 1864, 30*109; the most fatal 

 March on record, and 1858, 30.021, — when the second heaviest death-rate 

 took place ; the present month occupying the third place in both respects. The 

 range of pressure, moreover, during the present month, exceeded both those 

 years, or indeed any March since 1857, being 1'252 inches. The minimum, 

 29 "196, was registered at sunset on the 3rd ; the maximum, 30*448, at 7 a.m. 

 on the 22nd. In 1864 the latter rose higher, but the former was much less. 

 In 1858 the maximum differed but little from that of the present month, but 

 the minimum did not fall nearly so low. The greatest movement of the 

 barometer on any day, was a fall of —"628 of an inch on the 3rd, and on the 

 14th there was a rise of almost as great an amount. Altogether there were 

 16 days on which the pressure varied above one-fifth of an inch. Last year's 

 March had only 9. Atmospheric pressure, therefore, was more inimical to 

 health and life this month than usual. 



The Winds, too, this month, were not on the whole favorable to health and 

 life. The total force was only 49 "13 lbs., being — 5'53 lbs. less than the four 

 years' table, and nearly as much less than the mean of the last nine years. 

 From every point of the compass except north-west and south-west, the winds 

 were below the average in frequency, and only west and north-west had more 

 than the average force. North-west winds were greatly in excess, and they 

 are always least propitious to health and life, having the least ozone. There 

 was a '^ixonghot loind on the 13th, and a feeble oae on the 25th. The strongest 

 winds recorded had only a pressure of 5"21 lbs. to the square foot, and were 

 registered three times, on the 4th, 5th, and 13th. Had the wind been guaged 

 between 3 and 6 a.m. of the 8th, 1 am sure, from personal experience of it, a 

 strength of more than double the above would have been noted. At the usual 

 hour of observation, 7 a.m., it had sunk to 2.60. 



Temperature menn, by the observed thermometers, was 60" 25 degrees, being 

 so near the 20 years' average for March, that it only exceeded it by + 00 '27 

 of a degree. 1865 had a mean nearly 1^ degrees colder. By the self- 

 registering maxima and minima thermometers, the moan was 61 "56 degrees. 

 The extremes were 88 with the hot wind on the 13th, and 39 in the cold night 

 of the 2nd. No year since 1856 has had so low a minimum, and no year since 

 1861 so high a maximum. The extreme range of the month, 49 degi-ees, was 

 eight degrees beyond that of last year, and considerably greater than any other 

 March since 1861, when the range was 54 degrees. The mean of all the maxima 

 was 73'03, while last year's was nearly two degrees less. The mean of aU the 

 minima was 50*03, being more than half an inch lower than last year ; so that 

 the present month had on the whole warmer days and colder nights than March 

 1865 had. 



Daily range of temperature had a mean, which has only been exceeded in 

 the last 25 years, by March, 18.57, and 1856, being exactly 23*00 degrees, while 

 the two exceptional years were about half and three quai'ters of a degree more. 

 The 20 years' mean for March is only 20*04 degrees. The greatest range of 

 temperature in any twenty-four hours was 33 degrees on the 29th ; last year's 

 was the same, and many years have had more. The smallest range on any 

 day was 12 degrees ; last year's was 6. There have therefore been constant 

 but moderate daily-ranges. The diseases popularly ascribed to variations of 



