XX. Ml 



volume. This task was undertaken from friendship to the late 

 Professor Boole. The difficulty of preparing unfinished papers for 

 the press is obvions ; and it is not surprising that, as he once men- 

 tioned to the writer, it should have cost him some months of hard 

 work. 



Dr. Todhunter has left a treatise on Elasticity, which was very 

 nearly finished. The time and labour he spent over this work 

 injured his eyesight, and probably led to his final illness. These 

 MSS. had been sent to Professor Cayley to report on ; and we learn 

 from Professor Mayor's pamphlet that the investigation shows that 

 they are of the same class as the history of the Theory of Attraction, 

 and seem fairly complete. 



Another result of the labours of his latter years is a treatise on 

 Arithmetic. Such a work when perfected would have smoothed the 

 way for the young beginner over many difficulties. It is greatly to be 

 regretted that he did not undertake it sooner. 



lu the summer of 1880 Dr. Todhunter first began to suffer from 

 his eyesight, and from that date he gradually and slowly became 

 weaker. But it was not until September, 1883, when he was at 

 Hunstanton, that the worst symptoms came on. He then partially 

 lost by paralysis the use of the right arm, and, though he afterwards 

 recovered from this, he was left much weaker. In January of the 

 next year he had another attack, and on the 1st of March, 1884, he 

 died at his own residence in Cambridge, surrounded by his dearest 

 relatives. It was a fit ending to an honourable and respected life 

 spent in the advancement of that science which he loved so well. 



E. J. R. 



April, 1884. 



