494 SIMSON. 



his thoughts. After some time a sudden light broke 

 in upon him ; it seemed at length as if he could descry 

 something of a path, slippery, tangled, interrupted, but 

 still practicable, and leading at least in the direction 

 towards the object of his research. He eagerly drew 

 a figure on the stump of a neighbouring tree with a 

 piece of chalk ; he felt assured that he had now the 

 means of solving the great problem ; and although he 

 afterwards tells us that he then had not a sufficiently 

 clear notion of the subject (eo tempore Porismatum 

 naturam non satis compertain habebam),* yet he accom- 

 plished enough to make him communicate a paper 

 upon the discovery to the Royal Society, the first 

 work he ever published (Phil. Trans, for 1723). He 

 was wont in after life to show the spot on which the 

 tree, long since decayed, had stood. If peradventure 

 it had been preserved, the frequent lover of Greek 

 geometry would have been seen making his pilgrimage 

 to a spot consecrated by such touching recollections. 

 The graphic pen of Montucla, which gave such interest 

 to the story of the first observation of the transit of 

 Venus by Horrox in Lancashire, and to the Torricellian 

 experiment, f is alone wanting to clothe this passage 

 in colours as vivid and as unfading. 



This great geometrician continued at all the inter- 

 vals of his other labours intently to investigate the 

 subject on which he thus first threw a steady light. 



His first care upon having made this discovery was to 

 extend the particular propositions until he had obtained 



* Op. Rel. 320. I Hist, de Math. vol. i. 



