16 Life and Letters of Frcmcls Galton 



makes to experiment'. The second son of Erasmus the elder, Erasmiis 

 the younger, seems to have been in character moi-e Hke his nepliew 

 Erasmus Alvey Darwin, the brother of Charles and friend of Thomas 

 Carlyle and his wife. He is reported to have been interested in 

 statistics, and although we do not lay much stress on this point, it 

 deserves notice with regard to later developments of ability in the 

 Darwin family. Erasmus Darwin the elder seems to have had distinct 

 mechanical ability, and physical tastes ; he was ingenious in mechanisms 

 — as perhaps the sketch of his ferry at Derby, taken from a brief 

 autobiography of his son, Sir Francis Sacheverel Darwin, will indicate 

 (see Plate V). He was also in constant touch with a number of men 

 working with distinction at mechanical problems. He invented a wind- 

 mill to grind colours" for his friend Wedgwood, which after approval by 

 Watt was not only used, but continued to be used till a steam-engine 

 by Boulton and Watt replaced it. To Darwin again Watt first imparted 

 under pledge of secrecy his plan for improving the steam-enginel In- 

 directly also we find Darwin intelligently interested in astronomical and 

 physical matters, such as the returns of comets predicted by Halley, 

 the nearest approach of comets to the earth as discussed by Bode, or 

 the experiments on mixing colours and on the nature of primary 

 colours by his friend Samuel Galton — his grandson's paternal grand- 

 father. On the whole we see in Erasmus Darwin most of the scientific 

 tastes which have been developed with greater thoroughness by his 

 children, grandchildren and great-grandchildren. 



When we look at these four generations of scientific workers, 

 the variable nature of their work — medical, biological, mathematical, 

 mechanical — the wonder is not that ability has been maintained, but 



' Erasmus himself, in 1788 {Botanic Garden, Part n, p. 262), certainly approves the 

 attribution of the memoir to Dr Robert Darwin. The paper dealing with "ocular 

 spectra " is an interesting one, the earliest as far as I know which drew attention to 

 the " contrast colour " seen by an eye fatigued by looking at a given colour. 



^ Meteyard, Life of Josiah Wedgwood, Vol. n, pp. 29 and 447. 



^ Owing to the kindness of Mr Darwin Wilmott I have been able very fully to 

 examine the commonplace book of Erasmus Darwin ; it gives the reader a far more 

 favourable opinion of Erasmus than his poems — designs for various mechanisms altei'nate 

 with accounts of medical cases, and with suggestions for experimental treatment. It is 

 a most interesting and valuable book from both tlie historical and social aspects. His 

 originality was shown in )iis attempt to inoculate against measles ; this made his son 

 Robert very ill, and his daughter Elizabeth is reported by some to have died as a result. 



