STUDY OF HOT SPRINGS

Nelson Evening Mail, Volume LXX, 21 December 1936, Page 3

STUDY OF HOT SPRINGS

NOTED SCIENTIST'S VISIT INVESTIGATIONS AT ROTORUA A world authority ori hot springs and geysers and one of America’s most distinguished physicists, Dr. A. L. Day, director of the geophysical laboratory, Of th<i Carnegie Institution, Washington, arrived from Sydney- by the Awatea (says the “N.Z. Herald”). He will spend a considerable time in Ne wZealand studying the thermal district, and wili also visit White Island. The probable relationship between hot springs and voleanism—the natural process resulting in the formation of volcanoes—is a subject that has .occupied Dr Day’s attention for some time, and having spent seven years in an in vestigalibn of the hot springs at Yellowstone National Park, he now intends to compare the activity there with that of the springs in the Rotorua thermal region. ROTORUA’S SPECIAL FEATURE “New Zealand’s remarkable geysers and hot springs are known all over the world,” said Dr. Day. “There are only three locations in the world With phenomena of this kind—lceland, Yellowstone and New Zealand. The situa-

tion at Rotorua is somewhat unique because, a number of years ago there was a volcanic, outbreak in the midst of the region. Therefore there must be a close relationship between hot springs and voleanism.

.“The opportunity to study this relationship is better at Rotorua than anywhere else in the world. It will bo interesting to see whether such a relationship really exists.” After being an instructor in physics at Yale University and a physical geologist' with the United States Geological Survey, Dr. Day became director of the geophysical laboratory of the Carnegie Institution upon its foundation in 1907. Ho explained yesterday that the work of the laboratory con-

sisted of studying and experimenting with rock formations. Rocks were actually made in the laboratory under conditions that enabled changes in temperature and other natural processes to be noted and measured. The Carnegie institution was the first to study rock formations in this way, and its work was conducted all over the world.

A GREAT ACHIEVEMENT An outstanding achievement on the part of Dr. Day in recent vearg has been to assist in the successful casting, after one failure, of the 2GO-inch telescopic mirror Which is to be mounted in the Mount Wilson Observatory, California. Speaking of this mirror, Dr. Day said it was the largest piece of glass in the world, being 17ft in diameter. It was rather remarkable because it had a grid structure on the back to reduce the weight without losing rigidity. This was the first astronomical mirror to be made in such a way. Dr. Day explained that solid glass discs could not be made to an inde-

finite size, and when the casting cl a 200-incl) solid disc was proposed, it was thought that the shape would not be retained. Therefore the mirror was made about half the weight of the solid disc by means of the grid structure. So far it seemed to be a perfect success and there had been practically no stress. Dr. Day, who is accompanied by Mrs Day, left yesterday afternoon for Wellington, where he will lecture under tiie auspices of the W ellington Philosophical Society. He will return to Auckland to take part in the proceedings of the congress of the Australian Association for the Advancement of Science, which will be held early next month.