Non-Magnetic Ship Data

Hokitika Guardian, 27 April 1921, Page 4

Non-Magnetic Ship Data

TI-IE CARNEGIE’S EXPERIMENTS. • SAN FRANCISCO, March 29. ; New Zealand and Australia will lie considerably interested in the comple.tion by the Carnegie Institute of Washington of what might be termed an X-ray of the earth’s atmosphere, forwarded from San Francisco, giving all j data in regard to the experiment, which was made through the use of the non- ' magnetic ship Carnegie, which arrived , from the South Seas at the Golden Gate recently.

The X-ray was in the form of observations of compass and other magnetic variations on all of the earth’s oceans, these variations being traced in the atmosphere hv two specially designed in struments called a deflector and magnometer. These tracings later will ha shown on a chart, which . might be likened to the X-ray plate; this chart will be made available to every navy and merchant marine on the earth as a

guide to navigation, as nearly exact as it is humanly possible to make such a guide. So intensively and penetratingly did the instruments work, aided by t'*o utter absence of magnetic attraction by everything else oil the vessel, that certain degrees of longitude in the Indian Ocean were found recently to bs radically different from the best charts and projections available up to that time. In some, instances these differences amounted to.several minutes. There is a constant play of these variations over the magnetic fields, and the cause of this play or change, although exhaustively theorised upon, never has been exactly explained, the Carnegie scientists say. Those magnetic changes make the utilisation of the non-magnetic ship and its instruments, and the preparation of new ehnrts, constantly necessary. For instance, a mariner using a magnetic chart prepared by the institution ten ’years ago could not steer as accurately as though he consulted a chart prepared hut a year ago. The magnetic ship made an absolute myth out of the general belief that the compass always points directly north. It added convincing proof to the scientific theory that there are only two longitudinal lines, one of them extremely irregular, where such a thing occurs. Whenever a ship crosses one of these lines the compass will get the direct polaric influence. Everywhere else it will point either east of north or west of north.

In tho taking of these figurative X-rays and the compilation of its data, sometimes interestingly geographical as well as magnetic, the Carnegie has travelled more than 300,000 miles since she was launched on June 121 li, 1909. She is, the only vessel credited with having circumnaviated the globe in the subAntarctic regions. In this voyage, entirely within the confines of the Great Southern Ocean, which has coma to tie the scientific name for the Antarctic, she stopped but once, that being at the Island of Georgia, a whaling station in the South Pacific.