Page:Popular Science Monthly Volume 1.djvu/739

Rh Governments, that it might be observed from widely-distant quarters of the globe. These went to Cape Wardhus, Kola, Cajaneburg, Otaheite, Fort Prince of Wales on the northwest of Hudson's Bay, St. Joseph and Santa Anna in California. The ingress of the planet was seen at almost all the observatories of Europe, the egress at Petersburg, Yakutsk, Uanilla, Batavia, Pekin, and Orenburg.

One of the principal observers, and perhaps the astronomer whose published observations were most highly valued, was David Rittenhouse. He, too, became an astronomer in boyhood, and used to calculate eclipses on the fences and on his plough-beam, when he stopped to rest in the field.

He, too, expectantly awaited the phenomenon, studying the theories and deductions that it involved by day and dreaming of them by night. He was assigned by the American Philosophical Society to Norriton, Pennsylvania, as his place of observation.

Rittenhouse possessed a highly-imaginative and sensitive nature; and when he saw, on the calm June day, the planet like a shadow, creeping, as it were, slowly along the edge of the solar disk, he became for some moments unconscious, overawed by the sublimity of the vision.

The transit of Venus, in 1874, occurs after an interval of one hundred and five and a half years.

Venus, being the second planet from the sun, and the larger of the two inferior planets having their orbits within that of the earth, appears to the earth the most luminous of all the planetary stars, her light at the period of her greatest splendor being so intense as to cast a shadow. She is seen in her full orbit beauty in regions under the equator at the period of her greatest elongation. Her telescopic appearance is interesting, lofty mountains breaking her luminous circle. During her transits her atmosphere is distinctly visible.

Extensive preparations are making, in England and on the Continent, for observing the transit in 1874 and 1882, which will afford the means of the most careful and accurate results.