late Professor of Practical Astronomy in Glasgmv. 289 



fended, by screwing to the socket a hemispherical cap. At the 

 other end of the case which environed the stem, there was sol- 

 dered a tube of brass, wide enough to admit a scale of proper di- 

 mensions, before which there was an opening in the tube, de- 

 fended by glass. 



The utmost range of the scale he determined by the points, 

 where the thermometer was found to be stationary when the ball 

 and a certain part of the stem were immersed in water, boiling 

 under the greatest variations of pressure which the climate af- 

 forded. The interval so found, he subdivided by other observa- 

 tions into degrees, which corresponded to inches of the barome- 

 ter, and which were so denominated upon the scale. 



In the year 1756, the College of Glasgow, upon the death of 

 Dr ALEXANDER MACFARLANE of Jamaica, a great lover of, and 

 proficient, in the sciences, received a legacy of a valuable collec- 

 tion of astronomical instruments, which that gentleman had got 

 constructed at London by the best artists, and had carried out 

 with him to Jamaica, with a view of cultivating astronomy in 

 that island. The College, upon this, soon built an observatory 

 for their reception, which, by medals placed under the founda- 

 tion, was called by the name of their generous benefactor ; and 

 Mr WILSON was immediately thought of by the members of the 

 Faculty, as a proper person for taking charge of it, and making 

 the astronomical observations. At this juncture his Grace AR- 

 CHIBALD, Duke of Argyle, who had all along continued his pa- 

 tronage to Mr WILSON, more especially since he had brought the 

 art of letter-founding into Scotland, used his influence with Go- 

 vernment, and procured his Majesty's presentation, nominating 

 and appointing him Professor of Practical Astronomy and Ob- 

 server in the College, with an annual salary of fifty pounds, pay- 

 able out of the Exchequer; and, accordingly, in 1760, he was 

 admitted to this new office by the unanimous and most cordial 

 welcome of all the members of the Faculty. 



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