CHAPTER IX. 



Middle Life. — Summer of his Life. — Acton Square. — 

 Welcomes Mathematical A ssistance. — Comparative Rest. — 

 Amalgams. — Air Engine. — Joint Research with TJiom- 

 son. — Vice - President of the Society. — Visit of Sir 

 William Thomson. — BirtJi of his Daughter. — Royal 

 Medal. — Death of his Wife. — Return to Oakfield. — 

 Honours. — Electrical Welding. — Joint Research Resumed. 

 — Memoir of Sttirgeon. — Thermo-dynamical Properties of 

 Solids. — Council of Royal Society. — Railway Accident. — 

 Work at Oakfield.— Thomclijfe. — His Experiments Stopped. 

 — President of the Society. — Honours. — Visits. — Small 

 Scale Researches. — Determination of Mechanical Equiva- 

 lent of Heat from the Thermal Effects of Electricity. — 

 Propagation of Joule's Views. — Hirns Verifications. 



The end of 1849 finds Joule, then 31 years of age, 

 already commencing the short summer of his life. His 

 regular attendance at the meetings of the British Asso- 

 ciation since 1842, and the office of secretary to the 

 Chemical Section, to which he was elected at the meeting 

 in Cambridge in 1845, have secured him a large acquaint- 

 ance amongst the leaders of science who attended these 

 meetings. He has also made the acquaintance of Professor 

 Bunsen, who called on him at Oakfield with Sir Lyon 

 Playfair in 1845, an d he has paid several visits to London 

 to see Sir Lyon Playfair, and Faraday, or to stay with his 



