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358 Scientific Intelligence—Meteorology. 
This agrees well enough with the rest of the scale, but there is no 
need to employ a conjectural quantity ; and if the rate of absorption 
corresponding to the above be computed, so close an agreement will 
be found, as may entitle the numbers to be looked on as something 
better than mere estimates,—as the results, indeed, of a species of 
observation, 
The mean of the whole shews a loss of ‘0610 in passing through 
one mile of atmosphere; with the barometer at 27-0 inches (that 
being about the average height of my stations), but reduced to 30-0 
inches, the quantity will be 0671. 
Hence the loss of light in passing from the zenith through a homo- 
geneous atmosphere of 5:2 miles will be -303, or only about one per 
cent. less than Professor Forbes’s result. And as my air was con- 
siderably drier than his (the mean humidity being not much above 
‘30 instead of ‘56), this will probably account for the difference ; 
and, at any rate, the agreement is much closer than could have been 
expected. 
I once mentioned this matter to Captain Waugh, the present 
Surveyor-General of India, then my fellow-assistant ; but he not 
only had not noticed the thing, but did not even apprehend my mean- 
ing. He assented to my remark on the loss of light in passing 
through the atmosphere, but asserted that the aperture should vary 
as the distance, thus allowing for no loss! 0:1 inch per mile answered, 
he said, for all distances that he had tried! So it might answer for 
the distances most usually occurring on the Survey; for 4 inches 
would be proper for 40 miles, and-2 inches not much too bright 
at 20, and it is not often that these limits would be passed. Yet it 
is hardly possible to conceive that he should not have noticed the 
different intensity of the lights; had not his opportunities been per- 
haps rather unfavourable, as his work lay chiefly in plains, where, 
as mentioned above, the light of a grazing ray is very much re- 
duced, and the atmospheric effect would therefore be mixed up with 
disturbing local causes. 
I myself was much astonished at first discovering that the air had 
so great absorbent powers, and many ideas are suggested by the 
fact. We see at once how easily many of the planets may be ren- 
dered habitable to beings like ourselves. Mars, e. g., may enjoy a 
temperature little inferior to our own, by having a less absorbent 
envelope; and Venus may be kept as cool as we are, by having 
one more so.—(Proceedings of Roy. Soc. Edin., vol. ii., No. 36.) 
METEOROLOGY. 
2. Climate of Australia. By John Gould, Esq., F.R.S., F.G.S., 
&c.—In a country of such vast extent as Australia, spreading over 
so many degrees of latitude, we might naturally expect to find much 
