XV 111 



of his last effort, presently noticed, was tlie immediate cause of his death. 

 He became a Fellow of the Eoyal Society in 1844. In the * Transactions' 

 for 1848, 1850, 1858 appear his papers on Differential Equations, on 

 Linear Equations of Differentials and of Differences, and on the Problem of 

 Three Bodies, the first of which received a Royal Medal. His other com- 

 munications are to the Philosophical Magazine, 1847-1864. One separate 

 and posthumous work, ' An Essay on the Kesolution of Algebraic Equa- 

 tions,' 1866, 8to (printed for private circulation), demands notice. This spe- 

 culation especially refers to equations of the fifth degree, or qiiintics. Mr. 

 Hargreave believed himself to have arrived at a solution in the same sense 

 and manner as the cubic has long been solved. The solution of the cubic 

 is not quite pure. An expression having nine values, or three triplets, 

 gives in each triplet the three roots of one of three cubics, which only 

 differ in containing different cube roots of unity. Mr. Hargreave alleges 

 that he produces five similarly associated quintics, of which the five quin- 

 tuplets of roots can be given in an expression of the 25th degree. The 

 complexity of the analysis, compared with that of a quadratic, is pro- 

 bably in even a higher ratio than the complexities of the discriminants 

 (p. 9) of a quintic and a quadratic ; and there will be very few readers. 

 The result cannot yet be pronounced upon ; but assuredly the thought and 

 the skill employed will remain the subjects of lasting admiration. 



His old teacher, Mr. De Morgan, informs us that the most remarkable 

 point, though not the greatest, about Mr. Hargreave was the change in his 

 handwriting. From sixteen to eighteen years of age he wrote in a manner 

 which almost required a microscope to decipher ; his examination-papers 

 put the proof of the binomial theorem into the area of a visiting card. He 

 emerged from his legal studies with a round Roman hand of more than 

 average size, and much more than average legibility. 



On the 22nd January, 1867, died at Plymouth Sir William Snow 

 Harris, Kt., in his seventy-fifth year. He was the only son of Thomas 

 Harris of Plymouth, Solicitor, whose family had settled in that town as 

 early as the year 1600. He was educated first at the Grammar School at 

 Plymouth, after which he entered the medical profession, and completed 

 his studies in Edinburgh. Harris commenced the practice of his pro- 

 fession as a militia surgeon, and afterwards became a general practitioner 

 in Plymouth ; but his love of science, especially of electricity, interfered 

 with his practice. 



In 1820 he invented a system of lightning-conductors, by which he 

 became more generally known than by his discoveries. This system had 

 reference chiefly to the defence of the Royal Navy from the destructive 

 effects of lightning, and its pecuharity consisted in permanently fixing 

 sufficiently massive copper bands in the masts, and in leading these copper 

 lines along the ship's timbers to the copper sheathing, so as to afford the 



