The Voyage of the Discovery Volume 1

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ...reader may well wonder why so much trouble should be taken to ascertain small differences in the earth's magnetism, and he could scarcely be answered in a few words. Broadly speaking, the earth is a magnet, and its magnetism is constantly changing; but why it is a magnet, or why it changes, or indeed what magnetism may be, is unknown, and obviously the most hopeful road to the explanation of a phe nomenon is to study it. For many reasons the phenomenon of magnetism could be recorded in few more useful places than our winter station in the Antarctic. These record strips were a source of great interest to us all when Bernacchi showed them from time to time. They varied much in character; sometimes the lines would run with long gradual waves, at others they were distinctly jerky and unsettled, and occasionally, there were magnetic storms when they would fly off the paper altogether. There was a fourth line, which I have not yet mentioned; this was the line of temperature, and was necessary for the correction of the others. It was this that gave Bernacchi most of his trouble and drew to an alarming extent on our oil supply. The desire was to keep a constant temperature inside the hut, but with the frequent change outside this was most difficult to do, and although attempts were made to regulate the burning of a heating lamp within, the variations were at first very great MAGNETIC HUTS 209 though they were lessened when we could get a sufficient supply of soft snow to bank the house up thoroughly outside. Besides the magnetic variometers the larger hut contained another instrument of importance in the seismograph, which also kept a continuous record on a long roll of sensitised paper. I do not know that we had any good reason for so thinking,...