COMETS AND THEIR WAYS.

New Zealand Herald, Volume XLVI, Issue 14142, 18 August 1909, Page 5

COMETS AND THEIR WAYS.

THE RETURN OF HALLEY'S.

To .interest a mixed audience in such a subject as that of " Comets" requires the special gifts which were displayed by Professor H. W. Segar, M.A., of the Auckland University, on Monday evening when handling this subject. The professor treated his subject with considerable ingenuity, and, while be imparted a good deal of solid instruction to those present, he never allowed the subject to become '- heavy. With the aid of fine limelight views he made his points perfectly clear to the audience, and was followed with close attention throughout. After referring to the wonder with which comets had always been regarded and the speculation their appearance ■ had always provoked, the professor went on to say that many comets had been remark- 7 able for special reasons, and, after giving the circumstances under which Salley predicted the return of- the comet which now- bears his name, went.on to refer-to the historic associations connected with the J appearances of " the'" comet. ' - The "sword" which hung over Jerusalem in: 66 was Halley's comet; The great' comet that appeared at the time of the Norman invasion of England was again Halley's comet. In England it was looked upon as s a presage of the ..success of the Normans, but William the Conqueror reassured his courtiers, who were ■• also anxious, by saying that such a comet appeared only when a kingdom wanted a king. A 'famous panel of the Bayeur tapestry showed Harold quaking on his throne and a group gazing at the comet. The appearances of Halley's comet had varied considerably. In 1066' it. was-"a remarkable object,'creating dread throughout Europe. At its appearance in 1835 it was visible to the naked eye during the. whole of October. This return was remarkable on account of the rapid changes visible in the comet. The nucleus appeared to be in a state of great activity and ejected streams of water in various directions with apparent violence. There were a number of lateral tails or brushes making various angles with the main tail. At one time the comet lost its tail. Continuing, Professor Segar said the prospects for the approaching visit were bright for the southern hemisphere, despite •what appeared to be a necessary deduction that the mass of a comet was less after each visit to the sun. The circumstances of the coming visit were very similar to those existing in 1066, when the comet was a grand object even in the northern hemisphere. According to . the American astronomer, the comet would be nearest to the sun on May 10, 1910, and would then soon reach its greatest brilliancy. It would be a morning star at this time, and' and must be seen before sunrise. Owing to the comet lying near the ecliptic, and to the fact that in these latitudes at that time of the year and before sunrise the ecliptic cut the horizon at a large angle or. lay high, the comet rising some hour and a-half before the sun would be up in the sky before the sun rose, and would be seen for some time without much interference from twilight. In the northern hemisphere the reverse would be the case] the ecliptic lying low, and the sun rising very soon after the comet. About June 1 the comet would probably be at its greatest apparent magnitude. These dates were based on the assumption that Mr. Seagrave's calculations were correct, but if the investigations of the English astronomers, Cowell and Crommelius, were correct the comet would be about a month earlier. On any hypothesis the comet was bound.to be observed by photography within the next two months .. *

There would in May be a total eclipse of the sun, visible at the edge of Tasmania, and if it turned out that these two could be seen in conjunction, they would be the eight of a lifetime. Owing to the fact that the sun's light wouT3 be hidden the comet would be seen at its best. The professor suggested that the shipping companies should give people facilities for making the trip to Tasmania to witness this remarkable sight. The lecture was listened to, with the keenest attention, and at the close' Professor Segar was accorded a hearty vote of thanks.