[19] 



1887, on Dinby statioo, north of Baradine, 408 miles north of Sydney, situ- 

 ated in a densely timbered country, the mean rainfall was 32'66 inehes 

 against 38'92 at the neighboring station in the open. On the other hand, 

 in the very dry year of 1888, Dinby figured for 11-73 inches with 15-52 

 inches at the above stations. Elevation, however, seems to have a benefi- 

 cial influence on rainfall, as the average of fourteen years at WoUongong, 

 half a mile from the sea, at a height of sixty-seven feet is 38'84 inches, and 

 at Cordeaux, near the same place, six miles from the sea, it is 55-53 inches 

 for seventeen years, at an elevation of about 1,200 feet." The foregoing 

 extract is given for what it may be worth as indicating whether it is the 

 presence of the timber which influences precipitation, or elevation, merely, 

 which has a favorable effect in increasing rainfall. There are other points 

 in Consul Cameron's excellent report that I shall call attention to, 

 namely, the amount of moisture taken up by evaporation by different soils 

 and situations, but more particularly the difference between sod-covered 

 soil and bare earth and water surface. The test was made by Mr. H. C. 

 BuBsell, B. A. C. M. G. F. R. 8., the government astronomer for New 

 South Wales. The tests were secured by the use of pans eight inches deep, 

 and surfaces of four square feet and the records made when practicable 

 through the twelve months of the wettest season recorded, which showed 

 a mean temperature of 63-1°, the total rainfall was 81-418 inches in one 

 hundred and eighty four days of the year, on many of which evaporation 

 did not take place, the water running over the test pans. The total evap- 

 oration from the square in grasses was 35-960 inches; from the water surface 

 31-027 inches; from the garden soil, which, though sandy, hardened when 

 dry, it was 25-476 inches, showing, by a difference of nearly ten Hnd a half 

 inches, that either the inherent heat of the live grass, the increase of ex- 

 posed surface by the grass blades, or the sponge-like absorbtion of the bare 

 earth, made this difference. It is probable all three agencies were operative , 

 but there is a difference between the grass and the water surfaces. The 

 grass giving off 4-933 inchess more than the water. This indicates an effect 

 of absorbtion of heat by the broken surface and color of the grass, and per- 

 haps a reflection of heat from the surface of the water, an effect I claim as 

 one reason why a solid snowbank will lie longer in the open air unmelted 

 than in thick timber or brush near by, an effect that every one familiar 

 with the mountains can often see. Other influences are present, namely it 

 is warmer in dense timber in the winter season than in the open, and while 

 it is cooler in the timber during the daylight in summer when the sun is 

 shinning; it is warmer within a timber belt on a summer night than in the 

 open. This is proven by the fact that cold given off from the bodies of 

 snow during the night in the summer months often causes water to freeze 

 in the open, when it does not do so in the nearby timber. There is an- 

 other and very important fact indicated by the difierenee of ten and a hall 



