67 



ANALYSIS OF THE OBSERVATORY RECORDS FOB 

 JULY, 1866, IN CONJUNCTION WITH THOSE OF 

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



The meteorological phenomena of this July have been so nicely balanced in 

 their effects on life, that the deaths were only one below the average of the 

 Dine previous .lulys. In 1805,— the healthiest July on record, —the mortality 

 ■was one-third lower ; nevertheless, it is remarkable, that the present month 

 had a smaller number of deaths under 45 years of age, than any one of the 

 preceding nine years, the death-rate being raised, altogether, by very infirm and 

 old people. The weather, still, was quite abnormal, as the following analysis 

 •will show : — 



Atmospheric-pressure mean, 30*100, was -H '242 above the 20 years' adopted 

 standard for July. Only two years out of the previous 25, had higher means, 

 — 1860 and 1850. Last year was less by — '053. The mouth's range was 1'106 

 inches. The maximum, 30 '460, having occurred on the 11th, and the mini- 

 mum, 29 354, on the 28th. This range is about that of the mean of the pre- 

 vious eleven yeais, though + "270 more than 1865 had. The greatest move- 

 ment of the barometer in any twenty-four hours, from 1 p.m. to 1 p.m., was a 

 fall of — 476 of an inch on the 28th. Last year's maximum was some what 

 more. The next highest was a fall of — "380 on the 5th, and the largest rise 

 was -f- '327 on the 30th, and another of -f '324 on the 9th. Altogether there 

 were eleven days on which the movement exceeded one-fifth of an inch. From 

 the 6th to the 1 1th inclusive, the barometer rose daily until the maximum of 

 the month was attained, and the deaths on these six days were more numerous 

 (14) than on any other consecutive six days in the month, 8 of the number 

 were from 60 to 71 years old, 4 from 28 to 58, and only 2 below 5 years old. 

 From the 18th to the 23rd, there were only 2 deaths, aged 52 and 76 respec- 

 tively, and this period was marked by the smallest daily barometical move- 

 ments, of any six days in the month.Old and hopelessly diseased people succumb 

 to variations of atmospheric pressure in this climate, much more readily thaa 

 to variations of temperature, or the lowest cold we are subject to. Out of the six 

 days of smallest mortality, there were four on which the minimum temperature 

 was at or below freezing point, and the two others had minima of 33 and 37 only. 



Wind-force was — 15 '87 lbs. below the July average of the previous nine 

 years, being only 23 "67 lbs. 1860 and 1861, howevei", had both a much smaller 

 amount, while last year had considerably more than double the aggregate 

 force. Nevertheless, a minute comparison of the frequency and force of the 

 winds from the eight points of the compass, gives the more favorable aspect 

 to the present month. North, north-east, east, and south-east were all below 

 the average, both in frequency and force ; south, soath-west, west, and north- 

 west were all above the average in frequency, but south and west alone were 

 above in force. Frequent and gentle breezes from these two points gave a 

 pleasant and healthy character to this month. The greatest wind pressure 

 recorded was 5"2l lbs. to the square foot, with a south wind at 7 a.m. on the 

 29th. On the 30th last year there was a storm from the south-west, which 

 added 15"621bs. to the month's force, and there were three other days on 

 which 5 "21 lbs. pressure was registered. The present month, moreover, had 

 only one entry of 2'60 lbs,, while last July had 7. The Calms, too, present a 

 remarkable contrast, for while last year had 55, the present year had only 

 36, being — 3 '82 less than the average of the previous eight years. Almost 

 constant but gentle serial movement, therefore, characterised this month in 

 this city ; while storms, causing numerous shipwrecks, prevailed on the sea- 

 board of the southern and eistem colonies of the Australian Continent. 



Temperature me?in, 4o'2'3 degrees, is the coldest on record since July 1854, 

 and is — 'SO of a degree below the 20 years' average. 1865 had a mean -f-1'86 

 degrees milder, and 1864 was four degrees warmer than the present July. The 

 self -registering maxima and minima thermometers gave or.ly the mean of 

 44 87 degrees. Thus for two months consecutively these thermometers have 

 given lower means than the observed ones. It is very rarely that any month 

 does this, but that two in succession should do so is without parallel. Last 

 year's self-registered mean was -}- 4 '28 degrees more than the present month's. 

 The extremes of temperature were 68 degrees or. +he 2nd, and 27 on the 12th. 

 The last is the lowest teniperature noted in the 26 years, during which regular 

 records have been kept. 29 "4 degrees, in June 1849, was previo\isly the 



