SOUR ECLIPSE

Auckland Star, Volume LXVII, Issue 296, 14 December 1936, Page 8

SOUR ECLIPSE

TO-DAY'S EVENT.

SCIENTISTS AT WORK.

RESEARCH AT PUKEKOHE.

SUCCESSFUL OBSERVATIONS.. Stand by. Here she comes. Up a little, whoa, whoa. Half a minute to go. Up a little. Sun please. Shutter. Stand by for Bailey's Beads Shutter. "VVe got it. We've got it again. Interest was as intense as at the benches of a wool sale. Men sprawled full length on the ground, like tribesmen of the twilight ages making obeisance to an unknown god. They gazed into weird cannon-like instruments making mystic signs and talking in strange tongues. The scene was the top of Rooseville Park Hill, Pukekohc, and the occasion was the annular eclipse of the sun. As in the normal course of events it will be some 300 years before an eclipse, annular or total, will be seen in the same track, the observations were of great importance to the; official astronomical party at Pukekohe. The leader of the party, Mr. C. B. Micliie, of Kaitaia, said the primary object of his experiment was for the purpose of testing his -instruments and gaining general experience for the expedition to Phoenix' Islands next year.' The total eclipse occurring next June will be visible, for land observers from the Phoenix Islands locality only. The instruments used at Pukekohe, which were lent by the Greenwich Observatory, England, will be taken by warship to Phoenix Islands. Mr. Michie explained that careful timing of the eclipse was also being undertaken this morning with a chronometer, which was corrected by frequent time signals from Wellington. The party took a number of exposures during the partial phases of the morning eclipse, and these will, be worked up at the observatory in Wellington by Mr. I. L. Thomsen, acting Government astronomer, who was among the party. Visual work was carried out by Mr. M. Geddes, who discovered the Geddes comet in Otago in 1932, with a sin telescope. Observations were made also in diminution of light! throughout the eclipse by means of photographing with a small camera, a colourscreen laid on the ground. Coloured and white strips were laid on a black background, and after the films are developed the density of the imagery will be measured. A complete range of- soil temperatures at a i half and one inch below the ground were taken by Mr. A. W. B. Powell, who was also in charge of the wet and dry bulb, barograph, thermograph and hydrograph readings. A 19-foot coronagraph was controlled by Mr. Thomsen, assisted by Mr. W. Rose at the celeostat. The latter instrument, comprising of a large mirror, was manoeuvred to catch and deflect the rays along a long; tube at the end of which was a recording camera. Mr. Michie also had a 78in camera designed by himself. Among those assisting were Mr. A. H. R. Diggle, Mr. W. B. Marshall and Mr. Hinton. Mr. Geddes used his own telescope. There was a large number of onlookers, the majority of whom were equipped with smoked glass. Early Conditions Ideal. The party took up their positions at 8.30 a.m. About 9.15 a.m. the first contact was seen, when a minute fragment was chipped off the edge of the sun's disc. Conditions were then ideal, the sky was nearly cloudless and there was strong, bright sunshine. About 10.30 only the narrow crescent of the disc remained. In fact, it looked just like a new moon, and the landscape took on strange colours, due to the difference in the quality of the. light. The sky darkened visibly, as though twilight was descending, and the greener trees changed to a yellowish colour. Tiny points of light shining on the ground through foliage became crescent-shaped. The sky itself was a different blue, while the usual white clouds were dark in colour. The most interesting phase was the annular one, which started about 10.51 and lasted for a little over seven minutes. The crescent, which had decreased in width to a mere strip, rapidly grew into a ring of light. J.lie moon's edge at the narrowest portion of the crescent broke up into beads ol lio-ht. This phenomenon, known as Bailey's Beads, is eagerly sought by astronomers, as even with total eclipses it is rarely seen. There were shouts of triumph from the party and exposures were taken. The beads of light are caused by the sun shining through the valleys and depressions on the edge of the lunar disc.

Party Satisfied. At the end of the annular phase the ring became a crescent again, and gradually increased in size until about 1 o'clock, when the disc was once more 1 complete. The cloudy skies made the later stages of the observation much ! more difficult, but members of the party were highly satisfied with tlieir observations. ° Mr. Micliie said tliey had -not been able to see any shadow bands, while there was some uncertainty whether radial brushes from the cusps of the sun were definitely observed. There were a number of small sunspots, and these wei e |Ittsed for timing the eclipse by Mr. \ Geddes, wlio noticed the instant that the llsjutCspots were occulted by the moon. jltMr. Geddes was also very gratified to be yteable to see the mountains of the moon d ,™g;out against the upper. edge r of the crescent. '

The Final Stages. Successful observations were made- of the filial stages of the eclipse, including the last contact, and the party is hopeful that good photographs were obtained.

The party had all the more reason to be gratified, as when the instruments were in Japan last year no photographs were obtained, owing to clouds completely obscuring the sun. By the time of the last contact, approximately 12.4~> p.m., the colour of the sky and cloiuls had become normal. The party and onlookers then dispersed. "I will sec you in 100 years or so at the next one," remarked one observer, facetiously. The instruments were dismantled later in the afternoon, when there was little or nothing to show that the hill-top for. a few hours to-day had been the site of astronomical history.