vni. 



is^OTES ON THE METEOROLOGY AND MORTALITY OF 



THE HOBART TOWN REGISTRATION DISTRICT DURING 



THE MONTH OF MAY, 1872. 



By E. Swarbreck Hall. 



The total deaths this month exceeded that of any IMay in the previous 

 15 years. Great fluctuations in atmospheric pressure, and very great <laily 

 variations of temi)erature, seem to have been the i^rincipal agents in causing 

 the high death rate in previously diseased and debilitated persons. Deaths 

 from zymotic and acute inflammatory alfectious were very small, and of 

 youDg persons below 20 years ohl the deaths were at a minimum. 



Atmospheric pressure mean, 21)'905, only exceeded the 30 years' average for 

 May by +'094 of an inch. The maximum, 30 '421, occurred on the 7th; 

 the minimum, 29"302, on the 17th, being an extreme range in the month of 

 1*119 inches. But the daily fluctuations were very great, the highest recorded 

 being a rise of x '505 on the 21st, and on 13 other days there were movements 

 of the barometer above one-fiftli of an inch. In all respects atmospheric 

 jjressure differed much from what it was in May, 1871. 



Wind force.— loial 45'241bs., was + 12*25 above the average, and nearly 

 three times as much as IMay, 1871, had. Out of the 93 observations 60 were 

 from the Nortk-ivcst, with nearly one-half of the total force. Soath-toest came 

 next, both in frequency and force, being 12 of the former, 10*661bs. of 

 the latter. The strongest winds hatl only 2'60Ibs. pressure to the square foot, 

 and were registered 7 times. Calms were registered at 20 of the observations, 

 being 22*80 below the May average. Constant moderate winds prevailing 

 principally from the quarter least favourable to health was therefore the 

 wind character of the month. 



Temperature mean 51.19 degrees was only +0*57 above the 30 years' 

 average, and — 1*29 less than in May, 1871. The maximum high-day tempe- 

 rature by the self-registering thermometer was 70 degrees on the 2Gth, and 

 the mean of all the maxima was 62*06. The minimum of the low-night 

 temperature was 32 degrees (freezing point) in the night of the 3i-d. The mean, 

 of all the minima was 41*77 degrees. The Wet-Bulb Thermometer mean of 

 the self-registering thermometers was 46*77 degrees. 



Daily Range of Temperature had the mean of 20*29 degrees, being -f4'94 

 above the 30 years' average. Only May, 1857, exceeded this, being 22*40. 

 May, 1871, had only 16*32. The greatest range in any 24 hours was 34 degrees 

 registered both on the 3rd and 7th. 



Solar Liiensiiy mean was 79*50 degrees, being 2*66 less than the average. 

 The maximum was 93 degrees on the 5th and 13th. 



Terrestrial Radiation mean 37*21 degrees, was — 2*77 below the average. 



The minimum was 29 degrees in the night of the 28th. In 6 other nights 

 it was below freezing point. In May, 1871, this thermometer never fell below 

 freezing point, the minimum being 43 degi*ees. 



Elastic force of vapour mean 294, was — 10 below the average. 



Humidity mean 78, was —2 below the average, notwithstanding the excess 

 in rain-fall. 



Rain-fall total was 2.64 inches, being -f '87 above the average. It was 

 recorded on 15 days, which is -f 2*25 above the average. Snoio appeared on 

 ;Mount AVellington on the 19th, and never disappeared during the rest of the 

 month, but received some additions. 



Spontaneous Evaporation amounted to 1*39 inches only. 



Cloud mean, 6*58, was + 1*08 above the average. 



Ozone mean, 7*05, was + 20 more than the average. Saturation (10) was 

 recorded 8 times out of the 26 observations. 



Electricity. There were 15 positive with tension from 3 to 6 ; negatives 31 

 T^dth tenrsion from 1 to 4, and 16 nils. No lightninr/ seen or thunder heard. 

 Aurora- Australia visible on the nights of the 28th and 29th. 



The Deaths were 51 in number, being -\- 11 1-15 above the May average of 

 the previous 15 years, one more than May, 1857, had, and 18 more than in May, 

 1871. The third week had the most deaths, 16 ; the first week the fewest, 6 ; 

 the second and fourth weeks each 13 ; the last 3 days 3 ; on 3 days there were 

 no deaths} on the IGth, 17th, 25th, there were four deaths each day. The 



