ASTRONOMY OF THE NINETEENTH CENTURY. 429 



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Herschel, was born at Slough in 1792. His academical education 

 was completed at St. John's College, Cambridge, and in iS^Q he was 

 Senior Wrangler and also Smith's Prizeman. His first scientific paper, 

 published in 1816, was an account, of observations of rrrtrltjple stars; / ' 

 and in the period between 1823 and 1828 he published sever^l-qata- 

 logues, comprising nearly 1,000 such stars. Again; #1^330 he c / on> / 

 piled catalogues of the positions of 1,500 stars. In 1834 he/proceeded /' ' 

 to the Cape of Good Hope, and remained there for four years fdr the 

 purpose of studying the heavens of the Southern Hemisphere, himself 

 defraying all the expenses. In 1836 the gold medal of the Royal 

 Astronomical Society was awarded to him for his catalogue of nebulse. 

 At the same time that he was carrying on these astronomical labours, 

 he engaged also in elaborate investigations in several departments of 

 physical science, as the papers attest that from time to time appeared 

 in the scientific journals. He was also the author of systematic trea- 

 tises on Sound and on Light published in the " Encyclopaedia Metro- 

 politana," and these are esteemed as among the best treatises on the 

 subjects. In 1830 appeared from his pen " A Preliminary Discourse 

 on the Study of Natural Philosophy/' which formed the first volume 

 of Lardner's " Cabinet Cyclopaedia." This work unites in an extraor- 

 dinary degree elegance of style and clearness of exposition, with power 

 of logic and range of thought. A small octavo of 360 pages, in every 

 respect adapted for popular reading, it is yet the best introduction to 

 the study of physical science that can be put into the hands of an in- 

 telligent student. "A Treatise on Astronomy" was also contributed 

 to Lardner's " Cyclopaedia " by Sir John Herschel, who wrote besides a 

 larger work on the same subject entitled "The Outlines of Astronomy." 

 These works and the more recent publication, " Familiar Lectures on 

 Scientific Subjects," are admirable examples of scientific literature. 

 Sir John Herschel was made Master of the Mint in 1850, and died 

 full of years and honours in 1871. 



The study of double stars, in which Sir William Herschel first aroused 

 the interest of astronomers, received, as we have seen, much attention 

 from Sir John Herschel. The number of nebulas with which Halley 

 was acquainted in 1714 was but six, but by the beginning of the 

 present century the number had increased to several thousands. Sir 

 W. Herschel furnished catalogues of no fewer than 2,500, which he 

 had observed. These all belonged to the northern heavens, for at the 

 beginning of the present century astronomers were acquainted with no 

 other nebulae of the southern hemisphere than those observed by 

 Halley and Lacaille (page 261). In 1828 Mr. Dunlop communicated 

 to the Royal Society a list of 629 nebulas and star clusters which he 

 had observed with a Newtonian reflector of 9 inches diameter. In 

 1833 Sir John Herschel gave the results of his observations of nebulas 

 in the northern heavens. These observations extended over eight 

 years, and were made with a 2o-feet reflector. His catalogue embraces 



