650 FHILOSOPHICAL TRANSACTIONS. [anNO IjQl. 



happen on the dth of June, 1761. In consequence of this resolution, they ap- 

 pointed Messrs. Maskelyne and Waddington to go to the island of St. Helena, 

 and Messrs. Mason and Dixon to go to Bencoolen, a settlement belonging to 

 the East India Company on the island of Sumatra. Two reflecting telescopes of 

 '2 feet focal length each, with an object glass micrometer of 40 feet focus adapted 

 to one of them, an astronomical clock, and an equal altitude instrument, were 

 ordered by the Society for each of those places. The munificence of his late and 

 present majesty, patrons of the r. s. defrayed the expence. 

 ^' Mr. Maskelyne and his assistant arrived at St. Helena in the month of April 

 1761 ; but Mr. Mason and his assistant, being detained at Plymouth by an ac- 

 cident, on their arrival at the Cape of Good Hope in the month of April 1761, 

 found it was too late to reach Bencoolen, and therefore resolved to stay at the 



and at the earnest intreaties of his relations, attended the divinity hall, and in 1731 passed his trials 

 to fit him for a preacher in the church of Scotland. Soon after this however the mind of our young 

 artist began to revolt against the idea of a profession so little suited to his talents ; and having had oc- 

 casion to attend a course of Mr. Maclaurin's mathematical class in the college, he there so much dis- 

 tinguished himself, that the professor took great notice of hira, and invited him often to his house, 

 where he had an opportunity of knowing more fully the extent of his capacity. In 1732, Mr. M, 

 kindly permited Mr. S. to make use of his rooms in the college for his apparatus, where he began to 

 work in his new profession of telescope making, under the eye of his eminent master and patron; 

 who, in a letter about 2 years after to Dr. Jurin, mentions the proficiency made by Mr. Short in con- 

 structing reflecting telescopes in these words : " Mr. Short, who had begun with making glass spe- 

 cula, is now employing himself to improve the metallic. By taking care of the figure, he is enabled 

 to give them larger apertures than others have done 3 and, upon the whole, they surpass in perfec- 

 tion all that 1 have seen of other workmen." Ihe figure which Mr. S. gave to his great specula was 

 parabolical : which he did however not by any rule or canon, but by practice and mechanical devices. 

 Mr. S. continued from this time to practise his art as a regular profession, with great success; so that 

 when, in the year 1736, he was called up to London, at the desire of queen Caroline, to give in- 

 structions in mathematics to William, Duke of Cumberland, he had cleared the sum of 3001. by the 

 profits of his business. Towards the end of the same year he returned again to Edinburgh; and 

 having made several useful improvements in his art during his stay in England, he now prosecuted it 

 with fresh vigour and success. In 1739, being then again at Ixjiidon, the Earl of Morton took Mr. 

 S. with him on a tour to the Orkney isles, and engaged him there to adjust the geography of that part 

 of Scotland. He returned to London with the Earl, and finally established himself there in the line 

 of his profession. In 1743 he was employed by Lord Thomas Spencer, to make a reflector of 12 

 feet focus, the largest that he ever constructed, except those for the king of Spain, and some others 

 of the same focal distance, with great improvements and higher magnifiers. The telescope for the 

 king ot Spain was finished in the year 1752, which, with its whole apparatus, cost 12001. But the 

 instrument made for Lord Thomas Spencer, having fewer accompaniments, was purchased for 600 

 guineas. From the great profits and success of his trade, Mr. S. left at his death a fortune 

 of 20,0001. 



Mr. S. was a good general scholar, and well skilled in optics and mathematical learning. He was 

 a ver)' useful member of the r. s. and wrote a number of excellent papers in the Philos. Trans. 

 And his determination of the sun's parallax at about 8^", from his ingenious calculations on the tran- 

 sit of Venus, in the above Memoir, has been pretty generally adopted by astronomers. 



