68 



lowest. The extreme range, 41 degrees, is the greatest ever registered in the- 

 26 years. The meau of all the maxima, or high-day temperatures, was only 

 54'4r) degi-ees, while kst year's was +4 10 more. The mean of all the minima, 

 or low-night temperatures, was only 35*30 degrees, being — 4 45 less than .luly 

 1865 had. On eleven nights in the mouth, the minimum thermometer de- 

 scended to and below freezing point, i.e,, from the lUth to the 13th ; the 17tl> 

 to the "iuth ; the 23rd to 25th. Ice on ponds four feet deep, attained more 

 than an inch of thickness, and bore walking over. Neither in intensity, nor 

 duration, was ever so much frost before recorded in this city and neighbor- 

 hood. It is probable, however, that in the winter of I83G there was more. At 

 that time the Great Lake was so hermetically sealed by ice, that the fish 

 perished for want of fresh air,and loaded bullock carts were driven across the 

 lake to save the ordinary detours by the route on its margins. No minute and 

 accurate data, unfortunately, exist, for the meteorological phenomena at that 

 period, therefore, no reliably minute comparison can be made, I only write 

 from memory on this point. In the very cold period of 16 days from the loth 

 to the 23rd inclusive, 22 deaths only occurred, while in the other 15 days, 32 

 deaths took place ; so that the influence of cold, merely, on mortality, is not 

 here marked as it is said to be in England and elsewhere. 



Daily Ramje of Temperature had the mean of 1916 degrees,being + 3'81 

 degrees above the 20 years' average, but only — '35 of a degree less than 186.5' 

 had. The greatest range on any day was 27 degrees on the 2nd and 3rd, and 

 25th. The two first days had a heavier mortality (iO) than any other two coi>' 

 secutive days in the month, the next highest having only 6. The smallest- 

 range on any day was 9 degrees on the 29th, and on this day 4 deaths took place. 



The Solar Thermometer gave a mean for the month of 75*i)0 degrees, being 2 

 less than 1865 had, and also — "51 of a degree below the average of the pre- 

 vious tea years. The maximum record was 92 degrees on the first ; the 

 minimum, 52 on the 29th. The corresponding records last year were 92 and 50. 



The Terrestrial Radiation thermometer had a mean of 35 .50 degrees, 

 which is— 3'26 below that of 1865, and — 2"05 less than the average of the 

 previous ten years. The extremes were, 44 '5 on the 1st, 27*5 on the 19th. On 

 the 12th, when the self-registering minima air thermometer, elevated four 

 feet above the ground and under cover, fell to the lowest minimum ever re- 

 corded, 27 ; Terrestrial-radiation thermometer, on the grass and exposed to 

 the sky, was one dejrree higher. 



The aggregate i2a»i-/a^^ of the month was, 2*52 inches, being + '79 of an 

 inch above the 20 years mean, and + '92 of an inch more than July 1865 

 had. It fell on 15 days, which is + 1'27 more than the average of the pre- 

 vious eleven years. In the first fourteen days of the month, there were only 

 4 days on which rain fell, and the total amount was only '11 of an inch, 

 barely sufficient to moisten the surface of the ground. On the 15th, there was 

 guaged '24 of an inch, and there was a moderate run in the surface channels. 

 On the 20th, 21st, 22nd, there was rain in small quantities. The last six 

 days ot the month were all wet, and 1'86 of an inch was guaged. The greater 

 part of this fell on the 29t;h and 30th, and surface channels, sewers, and 

 rivulet, were thoroughly flushed, Snoxo was never absent from Mt. "Welling- 

 ton during the whole month, and received several copious additional deposits. 



Humidity had a mean of 83, whieh is only — "05 less than the 20 years*^ 

 mean, but + 4 above last year's. It ranged from minimum of 147 at 7 a m. on 

 the 19th, to maximum of 372 at 1 p.m. on the 2nd. The corresponding re, 

 cords for 1865 wei-e, 174 and 318. 



Spontaneous- Evaporation amounted to only 1'42 inches, being, as might be 

 expected from the low temperature, little sunshine, and moderate wind-force 

 of the month, much below rain -fall. Last year spontaneous evaporation ex- 

 ceeded rain -fall in amount. 



Cloud mean was 5'49, being -f "22 more than the 20 years' average for July, 

 though "41 less than 1865 had, notwithstanding the greater number of rainy 

 days and rain-fall in the present month. 



Ozone mean, 7 '00, is '09 less than the average of the previous nine years, 

 and — 1'55 less than 1865 had, showing how much serial movement increases the 

 purity of the air, above what mere washing of it by rain efltects. In the pre- 

 sent month the point of saturation (10), was never obtained, 9 being the 

 maximimi, though frequently recorded. The lowest register was 5, and vsry 

 frequently entered, i.e., 15 times out of the 62 records. 



