NOTES ON THE METEOROLOGY AND MORTALITY OF 



THE HOIJART TOWN REGISTRATION DISTRICT DURING 



THE MONTH OF DECEMBER, 1871. 



By Dr. E. Swarbkeck Hall. 



The hot and very dry character of this month, together with the ex- 

 cessive daily variations of temperature, might have been expected to cause a 

 death-rate largely above the December average, but the excess was only 

 tritliiig, three-fourths of the deaths being above 15 yeais old, children's 

 deaths under the a-^e forming an unusually small proportion of the total 

 deaths, while those above GO years old were more than one-third of tho 

 whole. 



Atmonplieric pres.iior mean, 20790, was only + 45 above the average. 

 The maximum was :^0'174 on the 1st, the minimum, 20 262, on the 12th ; 

 the extreme range of the month therefoi-e being "912 of an inch. The 

 greatest movement of the barometer in any twenty-four hours was a fall of 

 — 'SLS on the 30th. There were, however, 12 other days on which the 

 variations exceeded one-fifth of an inch. 



Wind-farce total, 96-51 lbs., was + 9'O0 above the average. Winds from 

 the north loest greatly exceeded those from any other point of the compass 

 both in frequency and force. Many of them, however, were no doubt 

 deflected west winds. Two of them were hot winds. West winds were the 

 next in point of strength, but south-east in regard to number. The strongest 

 winil of the month was on the 31st, when a gale from the west was recorded 

 as having a pressure of 10*42 lbs. to the square foot. There were only 7 

 calms being — 5 '80 below the avera.^e. 



Temperature Mean was 65 05 degrees, being -1- 4'83 above the average. 

 Only one December in the previous 30 years was hotter, i.e. 185.5, when the 

 mean was 67. The extremes were 08 degrees on the 4th, and 42 degrees 

 in the nights of the 13th and 27th. The wet-bulb thermometer had the mean 

 of 57 '35, being -t- 2*37 above the average. 



Daily range of temperature, 23 13 degrees, was + 3*22 above the average, 

 and was only exceeded in the previous 30 years by December 1857, when 

 25*50 was recorded. The greatest range of any twenty-four hours was 41 

 degrees on the 30th. 



Solar Intensity mean, 107*74 deg., was -f 3*77 above the average, and only 

 once exceeded. The hottest record was 132 deg. on the 4th. In December 

 1850 one deg. higher was registered. The highest ever recorded here for any 

 month was in February 1857, when it was 143 deg. 



Terrestrial Radiafinn mean, 48 44 deg., was only -f *20 above the average. 

 The minimum was 36 5 in the night of the 27th. It is one of the pleasant 

 jteculiarities of the weather in Tasmania, that cool nights generally prevail 

 even when the days are unusually hot. 



Elastic-force of vapour mean, 380, was + 28 above the mean, and higher 

 than any December since 1860 when it was 302. It ranged from maximum 

 580 on the evening observation of the 8th, to minimum 165 on the morning of 

 the 25th. This range was unusually great. 



Humidity mean, 50, was— below the average— only in the first year 

 (1841) of the 30 years' series of meteorological records was humidity less, 

 i.e., 56. 



Rainfall, '53 of an inch, was— 1*20 below the average. In five Decembers 

 out of the preceding 30 there have been less rainfalls than in this, and in one 

 the same. On only one day, the 8th, was there rain enough to flush the 

 drains, &c. - a thunderstorm. The rain fell on 5 days being — 7 below the 

 average. No snow on Mount Wellington during the month. 



Spontaneous Evaporation was 3 '00 inches. 



(iioud mean, 5 82, was + •21 above the average. 



Ozone mean, 7*22, was -f* 03 above the average showing, in the absence of 

 the usual faU of rain, that many of the winds recorded noith west were really 

 ozone-boaring winds fiom the sea, and so maintaining a punty of fcJie atmos- 

 I'here counteracting other atmospheric phenomena adverse to health and 

 life. 



JiUctricity had 20 positive indications, with tension ranging from 3 to 8 j 



