GEORGE GRAHAM. 163 



was the best general mechanic of his time, and had a complete 

 knowledge of practical astronomy ; so that he not only gave to 

 various movements for measuring time a degree of perfection 

 which had never before been attained, but invented several 

 astronomical instruments, by which considerable advances 

 have been made in that science ; he also effected great 

 improvements in those which had before been in use; and, 

 by a wonderful manual dexterity, constructed them with 

 greater precision and accuracy than any other person in the 

 world. 



A great mural arch in the Observatory at Greenwich was 

 made by Dr. Halley, under Mr. Graham's immediate inspection, 

 and divided by his own hand; and from this incomparable 

 original, the best foreign instruments of the kind are copies 

 made by English artists. The sector by which Dr. Bradley 

 first discovered two new motions in the fixed stars was of his 

 invention and fabrication. He comprised the whole planetary 

 system within the compass of a small cabinet, from which, as a 

 model, all the modern orreries have been constructed. And 

 when the French Academicians were sent to the north to make 

 observations for ascertaining the figure of the earth, Mr. Graham 

 was thought the fittest person in Europe to supply them with 

 instruments ; by which means they finished their operations in 

 one year, while those who went to the south, not being so well 

 furnished, were very much embarrassed and retarded in their 

 operations. 



Mr. Graham was many years a member of the Royal Society, 

 to which he contributed several ingenious and important dis- 

 coveries, chiefly on astronomical and philosophical subjects, 

 particularly a kind of horary alteration of the magnetic needle, 

 a quicksilver pendulum, and many curious particulars relating 



