204 DE MORGANS ACCOUNT OF WRIGHTS SPECULATIONS 



1786. By various communications made by him to the 

 Gentleman's Magazine from 1744 upwards, it appears that 

 he was an observer, particularly of comets, a calculator of 

 their elements, etc. In his younger days he was employed 

 by Heath and Sisson as a maker of mathematical instru- 

 ments; and he wrote on navigation and taught it with a 

 reputation which procured him, in 1742, an offer of the 

 professorship of navigation in the Imperial Academy of St. 

 Petersburg. He was moreover an engraver, and even 

 executed the plates for some of his own works ; and as 

 the one which I have described has so many quarto plates, 

 effectively done in mezzotinto, and without the name of 

 any engraver attached, I conclude, in spite of " by the best 

 masters " in the title-page, they are of Wright's own work- 

 manship. He had some acquired scholarship, but not of 

 a very profound cast. 



I learn from Professor Chevallier, of the University of 

 Durham, to whom I am indebted for the references to the 

 Gentleman's Magazine, that when the library of Mr. Allan 

 of Darlington, the author of the memoir cited, was sold 

 by auction in London in 1822, it contained, as the memoir 

 states, the original copper of several of Wright's plates. 

 And further, that Wright appears to have been consulted 

 on matters of taste : for that in the chapter library of 

 Durham there is a design by him for some alterations in 

 the Cathedral, including an ornamented battlement with 

 finials upon the western towers ; which design was carried 

 into execution, as is to be seen. 



The works by Wright which are mentioned in the memoir, 

 are some calculations of eclipses (single leaves, I suppose, 

 descriptive of the phases, after the manner of the time) ; 

 the Pannauticon, a work on navigation, published in 1734; 

 Louthiana, a work on the antiquities of Ireland, of which 

 one volume only was published in 1748; the treatise 

 described in this article ; and others which I do not note, 

 as according to a common fashion of biographical memoirs, 

 there is a confusion between works " completed " and works 

 printed and published. Lalande mentions The Use of 

 the Globes, London, 1740, 8vo ; Clavis Caelestis, being the 

 explication of a diagram entitled A Synopsis of the Universe 

 , . . London, 1742, 4to ; and the work above described. 



It seems to me that Wright is entitled to have his 



