1 Jan., 1902.] QUEENSLAND AGRICULTURAL JOURNAL. 57 
Science. 
ARTIFICIAL COLD. 
We have received from Mr. G. Monks, One-mile, Gympie, a very instruc- 
tive and interesting paper read by Mr. John Falconer, C.E., at an agricultural 
conference held in Bundaberg in June, 1898. The subject is “ Artificial Cold,” 
and, as we are now approaching the hottest summer months, perhaps some of our 
readers might like to make a trial of the process as detailed by Mr. Falconer. 
The general idea is thus stated :—When by any process, a change is pro- 
duced in the form of matter, it undergoes certain developments; thus, 
when gas under pressure becomes liquified, it gives off a great amount of 
heat, and when it again is allowed to expand it takes up heat from its nearest 
surroundings. That is the principle in all plans or systems whereby artificial 
cold is produced. If, when air is compressed in a cylinder, it is surrounded by 
water, the temperature of the cylinder will be reduced; but when the air is 
released again, if it be conducted through a pipe surrounded by water, the 
latter will be frozen, as the air in expansion takes up as much heat as it had 
before it was cooled after being reduced, and it takes up heat from whatever it 
comes in contact with. Mr. Falconer exhibited a cylinder into which gas had 
been pumped with great force, until there was a pressure inside it of nearly 
300 Ib. per square inch. Now, if a small pipe were attached to this cylinder, 
and the pipe were conducted through a bucket of water, the expanding liquid 
gas would recover from the water all the heat it- had before it was condensed 
and liquified in the cylinder, and the expanding of the gas would cause the 
absorption of the heat surrounding the pipe and reduce the temperature of the 
water until it. became frozen. 
A. model of a safe was then shown. Of this safe the author said— 
“Mwenty years ago I designed and had constructed for a friend near 
Brisbane a dairy on the principle here shown, and on the hottest day in summer 
you could always be sure that the dairy was a cool place; it was constructed 
on the side of a hill, and is in use to the present day (1893). ‘The model was 
thus described:—A box haying the appearance of an ordinary safe. It is 
double, and between the inner and the outer boards there is a packing of saw- 
dust, which is a non-conductor of heat. It is airtight, except at the bottom. 
Jt stands in an open trough in which there is water, and around the bottom 
there is a casing of four plies of blanketing. At the side there is an air 
chimney, and under the elbow of the pipe is an ordinary kerosene lamp, the 
chimney of which enters the funnel through a small tube. The combustion of 
the air in the ea creates an expansion of the air in the funnel; if the lamp 
is turned up high, a roaring is heard in the funnel, caused by the rush of 
expanding air through it, for the heated air passing up the funnel causes a 
partial vacuum in the box, expanding the air in it, and causing a draught. The 
outer air having no inlet, except through the wet blanket, becomes rarified in 
its seco through the chamber, and the desired effect—z.e., cold storage—is 
produced, for the expanding air must get heat, and it gets it trom whatever it 
comes in contact with; in other words, the heat is drawn from whatever is in 
the chamber to supply the requirement of a natural law. If a larger lamp is 
need, the expansion becomes greater, and whatever is in the chamber will be 
‘ozen. 
