ASTRAL BODIES

Wanganui Chronicle, Volume 73, Issue 314, 11 July 1930, Page 11

ASTRAL BODIES

PUTTING ON SPEED VONDERFUL PLANETARIUM CHICAGO, May 20. Images of more stars than one can sec in the firmament on a clear night with the unaided eye will be projected upon the artificial sky of the Adler Planetarium when it is opened to the public. This latest 1,000,000 dollar gift to the city, on its newest “made island” Lake Michigan, is a building without precedent in the United States, not duplicating the function of any observatory. Most visitors therefoiu will have a wholly new experience when they enter the inner room of the planetarium, watch the dome become velvety dark and vague like the night heavens, then see the stars come out and the planets move along their courses. Above the roof of the planetarium the actual heavenly bodies will be shining—brightly, too, because the island is sufficiently far out in the clean air of the lake to escape the Jimming lights and smoke of the cityThen why attempt to duplicate the wonders of the night sky! This question is answered when audiences are made aware of the accomplishments of the strange big optical instrument that by means of scores of * 4 lantern slides ’ ’ in motion, produces the effect of natural sky indoors. This remarkable machine, invented in Germany by Dr W. Bauersfeld and made by Carl Zeiss, Jena, is a projector of amazing powers. Its lens ‘‘eyes” number more than 100, and they arc so constructed that they operate in co-ordinated motion. Through these lenses at many different angles the images of the planet family, the sun, moon and stars are thrown upon the dome, an inverted bowl 72 feet in diameter. But their actual motions are reproduced with speed so heightened that in the course of a lecture hour an audience may witness revolutions that would take perhaps thousands of years in the slow, stately process of nature. To aid the lecturer, a flaming arrow flashes on at his will to point out the particular spot in the sky he is discussing. Thus an astronomer can bring his lofty subject within the comprehension of the public. To groups of about 500 seated in the auditorium he can show the movement of the planets, even those that are the most complicated, the machine projecting the heavenly bodies in their proper space and light relationship. Moreover, with an adjustment of this surprising instrument, he can span the centuries, letting his audience gaze upon the celestial bodies in tne exact positions they held when the Psalmist meditated upon “the moon and the stars, which thou hast ordained.” Or if he chooses he can reveal them as they will appear 26,000 years in the future. Astronomers themselves find the representation helpful. Dr J. Jackson, vice director of the Greenwich Observatory, England, wrote of the device: 4 4 Even the scientist is charmed to see an optical presentation of what he knows so well—Mercury and Venus chasing each other around the sun and the outer planets describing loops which can only be seen in the sky by months or years of observation.”