EQUIVALENT FROM ELECTRIC ACTION. 151 



whose health caused much anxiety, and whose funeral Joule 

 attended, March 3rd, 1864. Joule and his family spent July 

 at Mr. Tuppenden's, Eatton Court, Turnham Green. In 

 January, 1865, he spent a week at Greenock, during which 

 he delivered an address on the occasion of the opening of the 

 Watt monument. In the summer of 1866 he and his family 

 were at Portrush, and in the autumn of 1867 at Port Erin. 



In 1868, Joule, having sold his house in Old Trafford, 

 removed, J 6th October, to No. 5, Cliff Point, Lower 

 Broughton, Manchester. 



In 1 861, Joule was a Vice-President of the British 

 Association, in 1864, Member of the Philosophical Society of 

 Halle, and in 1867, Fellow of the Royal Society of Edinburgh. 



In 1864, Joule's portrait, by G. Patten, from which the 

 engraving accompanying this memoir has been taken, was 

 presented to the Society by E. W Binney and other members. 



Although in 1861 Joule was prevented continuing the 

 experiments on steam, or requiring steam, he still managed 

 to do a great deal of experimental work, mostly the im- 

 provement of thermometers, barometers, instruments for 

 measuring magnetic declination, and horizontal magnetic 

 intensity, and tangent galvanometers. On these subjects, 

 and on observations of certain natural phenomena, he com- 

 municates twenty papers to this Society between 1859 and 

 1868. 



In 1867 he makes experiments for the "Determination 

 of the Mechanical Equivalent of Heat from the Thermal 

 Effects of the Electric Currents," for the Committee on 

 Standards of the British Association. What Joule under- 

 took to determine was, not the Mechanical Equivalent of 

 Heat, but, the heat produced by a definite current in a 

 definite time when traversing a conductor of definite 



