MAGAZINE OF SCIENCE AND ART. 
123 
introductory to the reports which I shall probably have 
occasion to make to this society, when the meteorolo¬ 
gical observatories, now established or about shortly to 
be established, shall have produced the valuable and 
reliable results which may with justice be expected 
from them. 
In the first place let me congratulate this society, 
and the colony in general, on what I believe to be the 
fact, namely, that the important work of registering 
meteorological phenomena has been entered on more 
systematically bv the goverpieuts of this and of the ad-' 
joining colony than by any of the governments of Europe. 
In other countries the work is being performed by 
individuals, by societies, in private houses, and in dis 
connected observatories; hut in Australia it is a 
national undertaking; and not only so, but I am glad 
to be able to state of the Australian colonics, so far as 
my own limited observation can be relied on, that 
although they do not at present possess a very formi¬ 
dable army of philosophers, although from peculiar 
and well known courses they are somewhat in arrears 
in the education of their inhabitants, yet there does 
seem to exist, amongst a very great number of those 
inhabitants, an intelligent desire for the promotion of 
science, far more than 1 have met with amongst per¬ 
sons of the same class in England. 
This thirst after knowledge so elevating in its opera¬ 
tion and in its results it 13 the duty of every govern¬ 
ment to encourage, and in tho performance of this duty 
the government of N. S. Wales may claim a high 
position amongst the nations of the earth. 
Our little observatories scattered about the colony, 
besides collecting data on which the future Newton of 
meteorology may, perhaps, ground his grand harmony 
of the winds and clouds, besides distinguishing between 
the characteristics of different localities in such a man¬ 
ner as to guide the sickly in his search for a climate 
suitable to his constitution, the engineer in providing 
the water supply for our towns and cities, tho agricul¬ 
turist and gardener in the cultivation of particular crops 
and plants, will do something also towards tho encou¬ 
raging a habit of thought, and promoting the pursuit of 
science in the colony. In many cases we may hope 
vague wonder will be succeeded by curiosity, curiosity 
will begin enquiry, and thought, and some useful 
lessons may be derived from those strange looking 
pigeon houses, as the boys in the country irreverently 
call our thermometer stands. 
I will now proceed to give a short account of ■what is 
about to be done for meteorology in this country. 
The places at present selected for observatories are 
Deniliqnin, Albury, Cooma, Goulbum, Bathurst, Par- 
Tamatta, Sydney, Maitland, Armidale, and light houses 
at Gabo Island, Newcastle, and Moreton Island. I 
have also reason to hope for the valuable assistance of 
an amateur observer on the Liverpool Plains. 
These thirteen places, though they do not represent 
all the various climates of New South "Wales, yet, go 
far towards attaining that object. 
Deniliquin may be considered a type of the extensive 
dry flats of the Murray Kiver. The country round 
Albury though not much higher, is yet of a very 
different character, consisting principally of a series of 
ranges of no great elevation. Goulburn and Bathurst 
about the same height, and bearing considerable resem¬ 
blance to each other, yet differ in being situated on 
different sides of the Blue Mountain range, where we 
may expect to meet with a great difference in their 
meteorological characters. 
Cooma and Armidale represent the elevated plains 
ofMauerooaud New England. Maitland and Parra¬ 
matta, the low lauds nearly on a level with the .sea, yet 
sufficiently removed from it to differ considerably in 
moisture and extremes of temperature from the places 
more immediately under its influence, as Sydney and 
the three light houses. There seems some doubt at 
present whether, owing to the separation of the Moreton 
Bay district, an observatory will be established at 
.Moreton Island or not. 
The observatory first completed, and the only one 
from which I have as yet received any monthly returns 
is at the Lunatic Asylum, Parramatta, where tho 
observer, Mr. Statham, has Gntered most zealously on 
and takes great interest in his duties. 
The instruments employed were all made by Messrs. 
Negretti and Zarabra, anil selected and compared with' 
the Greenwich standards, by Mr. Glaisher, secretary of 
the meteorological society. Tho result of their com¬ 
parison w r as highly satisfactory: of 72 thermometers 
51 are without error, and in tho remaining 21 the cor¬ 
rection in no case exceeds 1-10 of a degree. The 
barometers are provided with a screw by which the 
mercury in tho cistern is adjusted to tho zero point, 
and the vernier reads to -002 of an inch. The tube is 
contracted near the lower end so as to hinder the free 
passage of the mercury, and so to diminish the risk of 
breakage; notwithstanding this precaution, however, 
two of them, though most carefully packed by tho 
makers, were broken on the voyage. Warned by this 
circumstance I adopted additional precautions in pack¬ 
ing them for the country, and I consider myself fortunate 
in the fact, that four out of the five that I have ex¬ 
amined arrived safely at their destinations. 
In the fifth tho glass cistern is broken, which is not 
to be wondered at when it is considered that the dray 
in which it was conveyed -was upset four times, and un¬ 
loaded eight times, on the road. 
The thermometers have nothing peculiar in their 
construction, excepting, perhaps, the mercurial maxi¬ 
mum thermometer, patented by tho makers, which 
seems the best instrument of the kind that has yet been 
produced. Its peculiarity consists in a great contrac¬ 
tion of the tube a little above tiro bulb, so that when tho 
thermometer is placed in a horizontal position the 
mercury will not recede with a diminuition of tempera¬ 
ture, but remains at its maximum height until caused 
to return by being placed in a vertical position. The 
instrument whoso indications will perhaps excite the 
greatest interest is that known as Mason's hygrometer, or 
the dry and wet bulb thermometers. The difference be¬ 
tween the readings of the two thermometers depending 
on the rapidity of evaporation from the moistened bulb 
enables us to determine with considerable accuracy the 
amount of moisture in the air at different times and 
stations, a matter of great importance in a sanitary 
point of view; and I am not without hopes, that by a 
series of experiments we may be able to determine a 
simple relation between the indications of this 
hygrometer, and the amount of evaporation from water 
exposed to the air. 
. That such a relation exists is evident from the con¬ 
sideration that the depression of the wet bulb ther¬ 
mometer is due to tho quantity of heat rendered latent 
by evaporation, and must, therefore, under similar 
circumstances of atmospheric pressure and temperature 
be directly proportional to the quantity of wator eva¬ 
porated. 
According to Dalton’s experiments the evaporation is 
proportional to the difference between the elastic forces 
of vapour at the temperature of evaporation, and of the 
vapour actually present in the air : now this difference 
of elastic forces is (for a given barometric pressure) pro¬ 
portional to the depression of the wet bulb thermometer, 
so that Dalton’s rule agrees with that which I have 
proposed to a great extent; there is this objection, 
however, to Dalton's rule, that it makes tho evaporation 
proportional to the atmospheric pressure, as well as to 
the depression of the wet bulb thermometer, a result 
which seems by no means possible. 
In the introduction to a volume of Madras meteoro¬ 
logical observations,! find it stated, that the evaporation 
er minute in inches of water, is not only proportional 
ut exactly equal to tho difference in inches of mercury , 
between tho elastic forces of vapour at the air tempera¬ 
ture and at the dew point. This result is, to say the 
least, very remarkable, and I have been unable to 
ascertain on what principle or series of experiments it 
rests. 
