Abstract
THE PERMANENCE OF MARKINGS ON VENUS.—In Bulletin No. 12 de l' Academic Royale des Sciences de Belgique, Dr. Terby contributes a paper entitled, “Facts demonstrating the permanence of the dark spots on Venus, and the slowness of their motion of rotation.” Dr. Terby made a series of observations of Venus between April and August 1887, and sent some of the results, in a sealed packet, to the Academy in the same year. A similar series of observations was made by M. Perrotin from May to September 1890, and the results were communicated to the Paris Academy (Comptes rendus, October 27, 1890). The object of the present paper is to call attention to the fact that the drawing made by M. Perrotin in 1890 agrees in every respect with those made by Dr. Terby in 1887. Each observer made drawings of two types of markings, and in each case the change from one type to the other took place about two months after the first observation. A comparison shows that Venus occupied very nearly the same position in her orbit during the time that the drawings were made by the two observers. The earth's position was also little different in both cases. This agreement between independent observers seems therefore to justify the following conclusions:—
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Our Astronomical Column. Nature 43, 427–428 (1891). https://doi.org/10.1038/043427a0
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DOI: https://doi.org/10.1038/043427a0