49 



<)r surpassed the present month's mean, being respectively, 30*082., 30*008. 



The movements of the Barometer, too, were both extensive and frequent. 

 The extreme range of the month was, 1*262 inches. In the previous seven years 

 — 1859 only, had a greater range, i.e., 1'275 inches. The minimum 29*187 

 occurred on the 11th ; the maximum^30*449 on the 22nd. The latter has only 

 been thrice higher in May during the previous 23 years, i.e., 1852, 30*482 ; 1847, 

 30*467; 1845, 30*492. There were many lower minima. The greatest move- 

 ment of the Barometer within any 24 hours, was a rise of +.680 on the 28th ; 

 a fall of — '539 took place on the 11th, followed by a rise on the Tith of + '493 ; 

 altogether, there were perturbations exceeding one-fifth of an inch on 10 days. 

 The high mean pressure, and great fluctuations, were very obnoxious to 

 invalids ; as the death records in diseases of the brain, and organs of circula- 

 tion, and respu-ation, testify. 



Windfo7xe, 91*62 lbs,, was +48*32 lbs. more than the average of the previous 

 seven years, and much higher than any one May of the whole seven. S. W., 

 W., and N.W. prevailed at 73 out of the 93 observations, and had 78*35 lbs. 

 of the total force. From all other points of the compass, the winds were below 

 the average in number, and in force also, except E., which had + '06 only 

 above. The strongest wind had a pressure to the square foot of 10*42 lbs., and 

 was noted twice. So much serial movement had a very purifying effect on the 

 air and was beneficial to healthy persons, either young or old, but combined 

 with the high and varying pressure, and wide fluctuations of temperature, it 

 proved very fatal to invalids. Calms, 31, singularly enough, were within a 

 fraction of the average for May. 



Mean temperature was 52*14 degrees, which is +1*63 above the 20 years' 

 average ; last year, however, May's mean, was + "21 warmer. The mean, 

 deduced from the maxima and minima thermometers, is 53*19, The maximum 

 was 70 on the 5th, the minimum 33 on the 29th. Only in 1857, during the last 

 nine years, did the temperature fall so low. The month's range, 37 degrees, 

 exceeded any of the three preceding years' Mays. 



The daily range temx)erature mean, was 17*16 degrees, which is +1*86 

 degrees above the May average, and nearly as much above May last year. 

 On the 29th and 30th the maximum range, 28th, was noted ; but on eight other 

 days a range of 20, or above occurred. The minimum range was 8 degrees, 

 on the 16th. These fluctuations of temperature were injurious to persons 

 weakened by chronic diseases. 



Solar temperature had a mean of 8529 degrees, being +4*4.5, above the 

 average of the previous eight years. This is very remarkable, as the cloud 

 mean was also above the average. The maximum of the sun thermometer 

 was 100 ^degrees, on the 5th, and this is higher than was noted for any May of 

 the previous five years. The minimum was 63, on the 18th. This hot sunshine 

 with great atmospheric pressure, &c,, wide range of temperature, and strong 

 winds, probably accounts for the increase of deaths from apoplexy and other 

 diseases of the brain and nervous systern. 



Terrestrial radiation had a mean of 41*13 degrees, which is +1*97 above 

 the average of the previous eight years. The maximum was 50*5 on the 5th ; 

 the minimum 28*5 on the 29th. 



The total deposit of rain was only *84 of an inch, being — 1*01 less than the 

 20 years' mean fall for this month. It is also below that of any year since 1857, 

 when it was only '19 of an inch. Last year's May had nearly three times aa 

 much as the present. There were 12 days on which rain fell, but on only two 

 of them, the 11th and 17th, was it sufficient to cause the street channels to 

 run. The average wet days for May is + •32. 3 higher. For the eight days, 

 20th to 27th, not a sprinkle of rain took place. Strong dry southerly winds 

 well charged with ozone abounded in this period, and made catarrhs very pre- 

 valent, though without any deaths resulting therefrom. 



Snow fell on Mount Wellington on the 17th, and remained on the 18th, but 

 could not be seen on the following day. Another fall took place on the 28th, 

 and continued on the mountain until the month expired. 



Spontaneous Evaporation exceeded precipitation being 1*27 inches. 



Elastic-force of Vapor mean, was 298, which is — 11 below the 20 years' 

 average. 



Humidity mean was 76, being —3 below the 20 years' mean. 

 • (Xoud mean was O'OO, which is +'30 above the 20 years' average for May. 

 ■ Ozone had a mean of 7*40, which is + "90 above the 7 years' avei-age, and 

 higher than any one of the seven. The maximum was 10, and the minimum 5. 



Electricity had 17 positive imdications, with a maximum tension of 6 ; and 

 44 negative, with maximum of 5 '5, " Nil" record was only made once, at 

 the sunset observation of the 14th. Lightning was recorded on the evenings 

 of the 11th and 27th. 



