An Introduction to Practical Astronomy

Автор: Elias Loomis
Издательство: harper & Brothers, Publishers
Страниц: 516
Год: 1884
Размер: 25,4 МБ

THE rapid advance in the cultivation of Practical Astronomy which has recently been made in the United States is one of the most encouraging features of the age. It is less than twenty-five years since the first refracting telescope, exceeding those of a portable size, was imported into the United States, and the introduction of meridional instruments of the large class is of still more recent date. "We may now boast of two Observatories, liberally equipped with instruments of the best class, and provided with a permanent corps of observers, as also a considerable number of other establishments more or less complete, and a still larger number of telescopes of dimensions adequate to be employed in original research...