Great Telescopes | AdventAI

Seventh-day Adventist Publishing Association · Battle Creek, Mich. · Mar 18, 1873

Great Telescopes.

The United States boasts of the largest refracting telescope in the world, the object-glass of which they have recently purchased in England. It is a twenty-five-inch glass magnifying three thousand times and bringing our vision, to all intents and purposes, to within a distance of eighty miles from the moon. The construction of a lens of this size is a work of the most laborious and difficult nature, it being absolutely necessary that the glass should be of uniform density, perfectly pellucid, and free from even the smallest flaw. The telescope to which this glass belongs is made of steel, with an inner zinc tube, the whole mounted on a pillar twenty-nine feet in height, and weighing not less than nine tons. The next largest telescope is placed in the Observatory in Chicago, and has an object-glass eighteen inches and a half in diameter. The two next largest have object-glasses of fifteen and a half inches in diameter, and they are situated at Cambridge, Massachusetts, and at the Observatory of Pulkowa, in Russia. The most gigantic of telescopes, however, is still unfinished, though now rapidly approaching completion. The object-glass for this instrument will have a diameter of twenty-seven inches and will alone cost $50,000. It is being manufactured for the government of the United States, and will probably be placed on an astronomical station to be established by the Coast Survey Bureau on the Sierra Nevada mountains. It will thus be situated at a height of from seven to ten thousand feet above the level of the sea, in an atmosphere of wonderful purity and comparatively free from clouds. That the establishment of this great instrument will add greatly to our knowledge of physical astronomy cannot be doubted, but it may reasonably be doubted whether any telescope will enable us, as has been recently suggested, to settle by direct optical proof whether the moon is inhabited or not.