MAWSON EXPEDITION

Taranaki Daily News, 19 December 1929, Page 7

MAWSON EXPEDITION

MUCH RESEARCH WORK A STRANGE INSTRUMENT. VOYAGE OF THE DISCOVERY. The Discovery, with the Mawson Expedition, which .is now on its way .to the Antarctic to conduct scientific research, carries highly developed instruments for oceanographic observations. With' these the party can study the depths, temperature, composition, and current movements and life of the sea traversed. , The Discovery, writes Sir Douglas Mawson in the Adelaide Observer, is fitted with three devices to test the depths of the sea. . . Firstly, ■ a Kelvin sounding machine driven by electro-motor, is supplied for use in shallow water and is of special value for navigation purposes when steaming close to . land. It can be operated while the ship is in motion. A glass tube sealed at the lipper end and attached to a strong multipie strand wire is carried to the bottom by a heavy weight.' The depth reached is jalculated from the degree of .compression to which the air in the tube has oecn. subjected owing to the pressure of the water lying above it. For- deeper water, a machine is installed on the forecastle head. The drum carries 5000 fathoms of wire of 0.028 inch diameter, with a breaking strain of 2401 b. .. . , * j "For the present voyage there is used a new instrument, by the use of which the depth of the ocean, even when it’ amounts' to several thousand fathoms, can at any time be ascertained in a few seconds * ■ ■ - /The .measure of the . depths, depends , upon' the time interval taken for a sound to travel to the bottom of the sea and buck again. The sound waves communicated to the water are made by an hydraulic hammer located in a sealed metal tank set in the bottom of the vessel at the forward end. The- ‘-returning sound waves echoed from; the floor of the’sea are recorded in a' delicately constructed, and care- , fully' tuned, . electrically-recording receiverAsynchronised with the dispatch mechanism mid set in the hull near the of the vessel. ' ; It is- anticipated that by the aid of these instruments the contour and nature of the sea-floor along the route to be traversed by the ship will be revealed.

TEMPERATURE OF SEA WATER. The body, of the ocean is composed of many-lay era vof water, each quite distinct so far as temperature and salinity are concerned. These separate ■ water strata have each‘their own independent movement, just as have the various layers of the atmosphere. The current movements in each of these layers is, therefore, a further subject for study. The temperature of the surface waters will be recorded continuously as a graph, drawn on a c.liarj by an electricallyoperated- distance-thermometer set in the hull of the ship. In the case of the deeper waters, records will be obtained at as many stations as possible, observing at frequent intervals from the surface to the bottom. Tho water samples from various depths are examined quantitatively in regard to the more important constituents contained therein. Dr. Stanley Kemp’s observations in the neighbourhood of South Georgia have shown ..that, where nitrogen and phosphorus are abundant in the surface waters these fertilising constituents are just as stimulating to plant life in the seas as they are valuable o the farmers crops on the land. With the increase of microscopic plant forms in the sea waters, there results in turn a vast crustacean life which constitutes the principal food of the southern vyhales. Therefore, waters abnormally, rich in nitrogen and phosphorus are potential whaling grounds. . The most interesting departnient of oceanography is that dealing with, the living contents of the waters. This is usually considered in two main groups, fhe life bn the sea bottom and the life of the surface and intermediate waters. The trawls loaded with spoil from the sea floor are landed on a special dredgt ing platform at the stern of the vessel. The biological material captured by these various methods is dealt with in tho deck laboratory.

FUR AND FEATHER. The zoologists will also have a busy and interesting time collecting and recording the abundant seal and bird life of the far south. All these creatures support both internal and external paiasites, consequently they have a secondary interest Ho less important than that of the hosts themselves. They are not merely subjects for the. taxidermist, but offer, interesting possibilities for the parasitologist. The sub-antarctic islands, besides teeming with creatures of fur and feather" also support an appreciable amount and variety of plant life, an opportunity not affoixLu on the Antarctic mainland. ... . . , The inclusion in the equipment ot a small aeroplane greatly increases our range of observation, a provision which wilf be valuable in plotting the distribution of the pack ice and in locating land. By frequent ascents to heights of 10,000 ft/ and more, it is also expected that the aviators will furnish the meteorologist with valuable upper-air data. , Not least in importance of the instrument equipment is the photographic section, which amply provides for the taking of moving and still pictures of all objects and incidents worthy of record. .The medical oflicer is to conduct bacteriological studies and inquiries into problems connected with metabolism as affected by the unusual conditions of food and life in' Antarctica. A useful item of the medical equipment is an Xray apparatus, which will be invaluable should any bones be broken m the conduct of the exploration by land, sea, or air.