SENSITIVE FLAME.

Star (Christchurch), Volume LXVI, Issue 20296, 4 May 1934, Page 4

SENSITIVE FLAME.

Strange Demonstrations by Scientists. A flame sensitive to noise, liquid air, and a battery wireless that ran off gas mains and without batteries were amongst the novelties seen at Canterbury College yesterday afternoon, when the Canterbury College Scientific So ciety held its triennial conversazione Visitors were greeted on their entrance to the department of physics by an electrically illuminated sign spelling “welcome” in red letters. The word flashed on as each person entered. It was not, as many thought, worked from the floor. A beam of light was directed on to a selenium cell, and the momentary interruption of this beam each time a visitor passed it at the enntrance dooi caused the electric light to flash in the overhead sign. In the physics department many experiments were in progress in connec tion with light, heat and electricity. A specially shaped flame burned from a gas burner and it was proved that it was peculiarly sensitive to noise of all kinds. When a large tuning fork was struck the flame became forked and when a shrill whistle was blown it leapt suddenly into a tall, slim shape. Another demonstration was concerned with a battery wireless set which ran off gas mains and entirely without batteries. Here also, the “Blattnerphone” for recording speech was demonstrated. It was explained that this instrument is used by the 8.8. C. for recording and transmitting the Empire short wave programmes and important speeches such as those made by the Fw.ng.

A demonstration which attracted a great deal of attention was that of the “liquid air” plant. Air is first compressed to 150 times its ordinary pressure and is then directed to expand through a very fine nozzle from which it emerges as liquid. Its temperature at this stage is 200 degrees Centigrade below zero. A rubber tubing placed into some of this “air” will freeze icehard and will splinter and break if it is struck with anything hard or heavy. A peculiar feature of the demonstration is that the freezing property of the “air” is lost when it touches the human skin. This, it was explained, is because‘the heat of the human body keeps a film of warm air between the skin and the new liquid. Many demonstrations of commercial processes of a chemical nature were given in the chemistry department. The testing of intelligence, of manual dexterity and ability of various kinds, was demonstrated in the psychology department. The apparatus displayed was that commonly used for stich tests as vocational guidance tests In the zoology department and the botany department, many animal and vegetable specimens were shown. Habits of life of various organisms were illustrated by specimens and microscopic slides. Mimicry in butterflies was illustrated by some interesting collections. Exhibits in connection with the work of the forestry and geology departments were shown in the laboratories of those departments. Demonstrators in the various departments gave descriptive accounts of the experiments with which they were concerned. Lecturettes were delivered in the evening by the professors of the various subjects.