From a set of engravings known as Urania’s Mirror or a View of the Heavens published in around 1825. The set of thirty-two astronomical star-chart cards were enormously popular — and probably very helpful to amateur astronomers learning to read the heavens. Each card is pierced with holes corresponding in size to the magnitudes of the brightest stars, meaning that when held the card up to the light it would shine with the constellation pattern. (Source: Rawpixel / Library of Congress)