148 SIMSON. 



one of his pupils (Dr. Traill) submitted to him some 

 propositions, which he regarded as porisms, Dr. Sim- 

 son would neither admit nor deny that they were such, 

 but said with some pleasantry, "they are propositions." 

 One of them, however, he has given in his work as a 

 porism, and with a complimentary reference to its 

 ingenious and learned author. 



Thus his life wore away without completing this 

 great work, at least without putting it in such a con- 

 dition as satisfied himself. It was left among his MSS., 

 and by the judicious munificence of a noble geometri- 

 cian, the liberal friend of scientific men, as well as the 

 successful cultivator of science, Earl Stanhope,* it 

 was, after his death, published, with his restoration of 

 Apollonius' treatise De Sectione determinata, a short 

 paper on Logarithms, and another on the Method of 

 Limits geometrically demonstrated, the w 7 hole forming 

 a very handsome quarto volume ; of which the Porisms 

 occupies nearly one-half, or 277 pages. 



This work is certainly the master-piece of its distin- 

 guished author. The extreme difficulty of the subject 

 was increased by the corruptions of the text that re- 

 mains in the only passage of the Greek geometers which 

 has reached us, the only few sentences in which any 

 mention whatever is made of porisms. This passage is 

 contained in the preface or introduction to the seventh 

 book of Pappus, which we have already had occasion 

 to cite. But this was by far the least of the difficulties 

 which met the inquirer after the hidden treasure, the 

 restorer of lost science, though Albert Girard thought 

 or said, in 1635, that he had restored the Porisms of 

 Euclid. As we have seen, no trace of his labours k 

 left; and it seems extremely unlikely that he should 

 have really performed such a feat and given no proofs 

 of it. Halley, the most learned and able of Dr. Sim- 

 son's predecessors, had tried the subject, and tried it 



* Grandfather of the present Earl, whose father also was a successful 

 cultivator of natural science, mechanical especially. 



