A GREAT INVENTION

Evening Post, Volume CVII, Issue 143, 18 June 1924, Page 6

A GREAT INVENTION

Th©: opening of an international^ conference of -authorities t: on ■■ re-' frigeration serves^ among' other: things, the good purpose of' awakening attention to a modern' miracle that suffers from .the oblivion that arises from familiarity, but should be_ redognised as one of the world's. greatest inyer/ tions. Everyone knows that food is carried round the world,frozen: and most people who think of the matter at all.have a vague idea of, the economic importance of the invention, of -refrigeration to many countries, of which New Zealand is one...'Mr; Sidney Webb,, in:welcoming the delegates to the confer^ ence, pointed' out that refrigeration is really 'of vital importance' to Britain, because half her foodstuffmust be imported from overseas. It is i refrigeration which has endowed. New Zealand with a truly' phenomenal' export trade in meat and dairy ; produce, and . which is gradually increasing the facility with which such perishables as fruit and vegetables can be preservedl and transported in the fresh state. But_ of the proeess\ of artificial refrigeration the average man" knows little. It is a strange thing that ,the cold-.atmosphere required for chilled 'or frozen storage is produced by burning coal—and that heat is used' for abstraction of heat from the goods to be frozen. The method of freezifig is,' in principle, very simple. When a bicycle pump'is energetically used it becomes hot.1 This ,is due not to the friction of the internal parts, but' .to'the fact that, air, when compressed, becomes, hot. If ? now, the compressed and heated air is cooled while' under pressure, and then allowed to expand, it will, immediately demand the restoration of the abstracted heat, and wiJLJ become correspond-

ingly cola. This is precisely what occurs in all refrigerating .machines ; their varieties and complications are the result of practical' mechanical evolution and the use of., gases ..which give higher . effiencies than air. The same process^ carefully repeated, enables those who wish to do so> to liquefy, gases,■■ and, by a further paradox, to popularise the use of, such' intense heat1 as is by the oxy-acetyiene flame. . ■: ' The parent /of all refrigerating, machines was produced.in 1834 by John Hague, front1 the designs |of Jacob , Perkins. In 1856 and 18p7, improved machines were made^oy James Harrison, of Geelong, Victoria, and though some of these machines are said to have been made in New South Wales in. 1859, the first Harrison ;machin!e; put to industrial (use '.■ was /installed 'in England in IS6I for chilling oil to* extract-, the /paraffin, from it. Refrigerating engineering advanced by leaps -.and bounds when the transport of meat in chilled holds| began, and ■ apparatus of' remarkable efficiency and singular beauty was rapidly developed, driven 'by steam engines of large power; and capable of producing fifteen^ tons or more,of ice for each ton of coal consumed by the plant. The history of the; frozen meat trade is also the history of" the freezing machine. Australian meat was •first landed in London,' frozen by the Harrison machines, in 1873; it was a failure; but four years later the process had become a 'practical, success.. In 1882, the first big con-' signment of New Zealand /meat, : 5000 carcasses, reached England] No doubt this charige in the British dietary has hastened' the disappearance of the' stately sailing ship from the world's great trade' routes, for the ship that carried meat could carry wool and other non-perishable produce goods as well, but a, sailing ;ship, could not easily* transport frozen cargoes.'