THE FORTHCOMING TRANSIT OF VENUS.

Evening Star, Issue 3350, 14 November 1873, Page 3

THE FORTHCOMING TRANSIT OF VENUS.

V e lately announced that permission had been given by the Government to erect stations on behalf of the American Government for the observation of the transit of Venus ; one to be erected at the southern part of New Zealand, and one on the Campbell or Auckland Islands, We have been enabled to gather the following particulars regarding this event, which is one of the highest importance to the science of astronomy, as it affords the best means of ascertaining the true distance of the sun from the earth. That distance, it will be understood, forms the grand measure from which astronomical measurements are made. These events are of extremely rare occurrence, Only two have been observed during the last century with any degree of accuracy to be of the least importance in a scientific sense—viz., that of 1761 and that of 1769. Tne next transit—the one for which preparations are being marie—will occur on the morning of Monday, Bth December, 1874. The next will take place on the 6th December, 1882, The succeeding one will leave the long interval of 122 years, its date being fixed for 7th June, 2004. The approaching transit has awakened deep interest throughout the whole scientific world. The different Governments and learned societies of Europe and America have entered into arrangements for carrying out their observations upon the most approved plan as respect location, and instruments of the highest possible perfection have been constructed. To j these we shall take occasion to refer on another occasion. Now comes the reason why New Zealand has been selected as one of the stations for observation. In northern latitudes the transit will just be over before a low December sun has risen above the horizon, so that observations, to be at all effective, must be taken from this quarter of the earth where the sun will be considerably elevated during the four hours the planet will occupy in crossing the sun’s disc. On the morning of Bth December, the day in which the forthcoming transit occurs, the sun rises m New Zealand at 4.38 a. m. According to the latest advices from Home, Lord Lindsay (one of the most accomplished and enthusiastic mvantt), with his astronomer Mr Gill, was actively engaged fitting up a photographic apparatus of both the reflecting and refracting kind, which they intended carrying with them to

the Mauritius, which station hia lordship had fixed upon for making his observations of the forthcoming transit. A great many observations are to be taken, the stations occupied by observers being as far as pospsible apart from each other other. By that means it is hoped that a comparison of results will have the effect of reducing possible errors of observation to a minimum. The transit of 17(59 excited considerable interest, and several European Governments fitted out expeditions to those parts of the world where the phenomenon was likely tobe seen to the best advantage. England fitted out an expedition to Otaheite, in the Pacific Ocean, the command of which was assigned to no less a personage than the celebrated Captain Cook. Observations were likewise taken in Lapland and California, Pekin, Manilla, Batavia, lakutsk, and every part of Europe. It is now well known that those observations were not made with such delicacy and accuracy as to enable mathematicians to determine with that precision which the present state of science demands the great problem upon which so much in astronomy depends. It is, therefore, generally believed that the forthcoming observations will considerably alter the interval between the earth and the grand central ruler of the solar system. It is expected that with the instruments which can now be employed and the skill and care of our observers, the horizontal parallax of the sun will be determined to within the two-hundredth part of a second. The possible error will not exceed that amount.