50 



Terrestrial-radiation mean was 38 "56 degrees, which is —'83 of a degree 

 below the average of the previous nine 5'ears, and — 2*57 degrees less than 

 May 18G4 had. The extremes were 49 ou the 27th ; SO-5 on the 21st. 



i?a/n fell on 14 days to the aggregate amount of 1"88 inches, which only 

 differs from the 20 years' average for May, by + '03 above. At the same 

 time, the number of wet days is — I'lO less than the average of the previous ten 

 years. Until the 12th day of the month, no rain fell sufficient to scour the 

 surface drains, but on that day, and again on the 1.5th, 29th and 30th, this 

 effect, so important to the sanitary condition of the city, was produced. Fre- 

 quent deposits of Snow took place on Mount Wellington, but it was not 

 persistent throughout the month. Last year, less than one-half of the present 

 month's rain fell in May. In the mortality comparisons of months, the rain-fall 

 is always an important condition in Tasmania. 



Spontaneous evaporation, notwithstanding the hot sun and free Sbrial moy©- 

 meut, did not equal the rain precipitated, being only 1"G3 inches. In May 

 last year it was the reverse. 



Elastic force of vapor mean, 283, was — 26 below the 20 years' average. The 

 previous May was only — 11 less. 



Humidity mean was 79, being exactly that of the 20 years' standard. 

 1864 was —3 below this. ' 



May 



Cloud mean was 6*47 being + '77 more than the 20 years' average, and +*47 

 above May 18rf4. 



Ozone mean, 8.18, was +1.56 above the ayerage of the previous eight years' 

 Mays, and the highest of any of them. It is also +.78 more than May 1864 

 had. Being accompanied with a moist state of air, and little elastic force of 

 vapor, it did not, as otherwise it is apt to do, produce inflammatory affections 

 of the air passages — catavrah, bronchitis, &c. Never was a month so free from 

 deaths, from acute, or zymotic diseases. 



The electrometer recorded 16 positive indications with maximum tension of 

 6. The negatives were 41, with maximum tension of 6. Nil was recorded 5 

 times. In May 1864 there was one more positive with same maximum tension, 

 three more negatives, with maximum tension half a degi-ee higher, and only 

 one nil record. 



The deaths in May 1865 were 43 in number, being +31 more than the 

 average of the preceding eight years, but — 5 less than May 1864 had. The 

 tables following will show, that the conclusions deduced from the analysis of 

 the meteorological conditions of the month, are accurately substantiated. 



The deaths, under five years of age, 7, are less than half the average of the preced- 

 ing eight years, as also of May 1864. Moreover, they are less than those in any 

 one of the eight Mays tabled. They are also lessthan one-sixth of the total deaths 

 at all ages. At 5 to 20 deaths were above the average and were only exceeded by 

 one year of the eight, 1861. At " 20 to 4.5," the deaths were below the average, 

 and only three years had fewer. At " 45 to 60," the eight years' average 

 was greatly exceeded, and only May, 1864, had as many deaths. At "all ages 

 above 60" the mortality was more than double the average, and uo one of the 



