The astonishing feat of photographing the bones of the living animal within the tissues soon rendered the Rontgen rays indispensable in surgery and directed an army of investigators to their study.
Since the middle of the 19th century the system of photographing the heavenly bodies has been introduced, step by step, so that it bids fair to supersede eye observations in many of the determinations of astronomy.
Draper of New York in 1840; but it was not possible to do much in this direction until the more sensitive process of photographing on glass was introduced instead of the daguerreotype.
In 1860 De la Rue took the photoheliograph to Spain for the purpose of photographing the total solar eclipse which occurred on the 18th of July of that year.
The method adopted consisted in photographing the spectrum on a film which was kept in rapid motion by being attached to the front of a rotating disk.