I 



1. Mean ELASTiciTr of Aqueous Vapoe at To- 



BONTO Observatory. 

 (The numbers show the height of a mercurial 



columQ in inches which the elastic force of 



vapor would support). 



If 



I 



is 

 i 

 i 



2 



iii 



lippliiiipiiliil^ 

 iiiiimiiiiiiiimm'l 



II. Meaj^ Humidity of Atmosphere at Toronto 

 Observatory. 



(The numbers shew the relative amount of moist- 

 ure, 00 being complete dryness ana 1.00 satura- 

 tion). 



m 



^m.-Si -86 -85 



1855. -83 -80 -81 



1856. -78 -76 '74 



1857. -89 -84 .77 

 18"v8.-78 77 -69 

 1859. -81 -79 -75 

 1860 -81 -81 -71 



1861. -88 -84 -80 



1862. -81 -84 -83 



1863. -85 -83 -78 



1864. -83 -83 -80 

 J815.-8] -83 -79 



1866. -83 -81 -77 



1867. -83 -81 -78 



1868. 83 -81 -74 

 18H9.-80 - 80 ■« 

 1870 -83 -80 -8 

 1871. -84 -77 -76 

 1873. -80 '79 -75 



80 -74 -74 



73 -65 -78 

 75 -71 '79 



74 -74 -77 

 66 -69 -69 

 63 67 -69 

 74 -76 -71 

 73 -69 -69 

 73 -65 -66 

 ■68 -69 -71 

 ■75 -75 -63 

 ■73 -69 70 

 65 -62 -73 

 •73 -73 

 •71 -75 



71 

 74 

 •67 •7t 



67 -63 

 •69 

 ■67 



•f2 



•73 



■71 '73 -79 



•79 ^74 79 



•69 -73 75 



•78 -77 -78 



■70 -70 -74 



■70 -70 -75 



•73 76 -74 



•73 -78 -79 



•73 -74 ^83 



•.. ^76 -75 



•66 -73 -75 



•65 -69 -75 



•73 •ra -78 



•69 ^70 -77 

 ■77 -76 -79 

 74 ^72 :79 



•74 -78 



■73 



■80 -80 

 •75 •Is 



1! •If, 



•83 ^79 

 •82 •SO 

 •80 -80 

 •80 ^78 

 •77 -77 

 ■75 -80 

 •73 -75 

 •77 :81 

 •78 'St 

 ■79 -79 

 •73 -76 

 •77 -76 



.. -79 

 80 79 



■so ^79 

 ■81 -73 

 •ST -74 

 •84 -77 

 •79 ^78 

 •83 -77 

 •83 ^77 

 •82 ^76 

 •79 75 

 •79 -75 

 •77 -74 

 •83 76 

 •83 -77 

 •83 •76 



Highest 

 ■89 -84 



•85 



■80 



■76 



•79 



•79 



•78 



•80 



•83 



•84 -87 



•79 



Lowest. 



78 ^76 



■69 



•63 



•63 



•63 



•60 



•68 



•71 



•73 



•74 ^77 



•73 



Mean. 



■83 'SI 



•77 



■71 



•69 



•73 



•71 



■73 



•7S 



•77 



•78 •SI 



.76 



la woodlands the soil is sheltered from the 

 sun, and is usually covered by a cushion of 

 decaying leaves. This tends to equalize the 

 temperature, making it -warmer in winter and 

 cooler in summer than in open fields. Being 

 cooler in summer, it requires less change of 

 temperature to bring the atmosphere to the 

 clear point, and hence the influence of wood- 

 lands upon rains. Besides this, when in 

 foliage the evaporation from the leaves due to 

 the vital action of the trees, and the drying off 

 of water from dews and rain, afford a direct 

 cooling process, from the well known law of 

 nature that nothing can pass from a denser to 

 a rarer form without losing heat. 



Being sheltered from the winds, the snows 

 lie uniformly upon the ground in a forest, and 

 wasting away more slowly, they tend to cool 

 the air around them, and thus prevent the in- 

 jury that very warm days in early spring 

 might otherwise cause to fruit. This retard- 

 ing of vegetation in spring is similar in its 

 effects to that from large bodies of water, on 

 the leeward side of which, as is well-known, 

 the best fruit districts in the country are 

 found. 



Besides these effects, woodlands sbade the 

 sources of rills, and are a screen against drying 

 winds. In fact, such is the amount of moist- 

 ure exhaled from a forest in full leaf that a 

 dry wind could not pass over a woodland of 

 considerable extent Avithout acquiring a de- 

 gree of humidity favorable to the cultivated 

 lands beyond. 



^Ye must probably admit, that less rain in 

 a shower reaches the earth in a forest than in 

 an open field, since much of it is intercepted 

 by the leaves, and in warm ■n-eather soon evap- 

 orated. But such as does reach the earth, 

 being in a damp and sheltered place, does not 

 run quickly off, gullying the hill sides and 

 washing the soil into tjie streams, as in an 

 open country, and inundating the valleys by 

 sudden freshets. It sinks into the earth to 

 reappear as springs, or is appropriated by the 

 tender and juicy vegetation of the under 

 growth, and the spongy and luxuriant growth 

 of the swamps. The soil being more pervious 

 to the water, in fact, absorbs much more than 

 the sun-baked surface of clay in an open field, 

 and hence we never hear of the drying up of 

 streams, until the country is cleared of its 

 forests. 



