| a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
| Herschel (hûr'shəl) Pronunciation Key
Family of British astronomers led by Sir William Herschel (1738-1822), who discovered Uranus (1781) and cataloged more than 800 binary stars and 2,500 nebulae. His sister Caroline Herschel (1750-1848) discovered eight comets and several nebulae and star clusters, and published at least two astronomical catalogs which are still currently used. His son Sir John Frederick William Herschel (1792-1871) discovered 525 nebulae and pioneered celestial photography. Our Living Language : Brother and sister William Herschel and Caroline Herschel began their professional careers as musicians. Born in Germany, they moved to England, where Caroline became a soprano soloist in performances conducted by her brother. William's background in music spurred him to study mathematics and astronomy, which he then taught his sister, and they each went on to produce a string of important scientific discoveries. William was the first astronomer to study binary stars and, while searching for comets in 1781, he discovered Uranus, the first new planet to be discovered since ancient times. He also discovered two satellites of Uranus (Titania and Oberon, 1787), and two of Saturn (Mimas and Enceladus, 1789-90). Caroline observed her first comet in 1786 and eventually discovered seven others, as well as nebulae and star clusters. King George III appointed William his Astronomer Royal in 1787, and Caroline was made assistant astronomer. After William's death, Caroline returned to Germany and published a catalog of 2,500 nebulae, for which the (British) Royal Astronomical Society awarded her its gold medal in 1828. |