SCIENTIFIC AND TECHNICAL LABOURS TO 1860. 239 



labours had so far progressed that I was able to come 

 before the public with the proposal to adopt as unit 

 the resistance of a column of mercury of 1 metre in 

 length and 1 square millimetre in cross section at 

 C. . and to publish my method of producing this 

 mercury unit. The paper, which appeared in Poggen- 

 dorff s Annalen, was entitled: "Proposal for a repro- 

 ducible standard of resistance." 



Although Mr. Mathiessen in London violently 

 opposed the adoption of my unit and recommended 

 instead as empirical unit a wire of gold and silver 

 alloy with about the same resistance as Weber's unit, 

 my proposal was soon generally adopted , and the 

 Vienna International Telegraph Conference of the year 

 1868 made the mercury unit the legal unit of tele- 

 graphy. Nevertheless the English physicists continued 

 their efforts to introduce as international standard the 

 centimetre-gramme-second-system of resistance proposed 

 by Sir William Thomson and adopted by the British 

 Association -- the so-called c. g. s. unit a resistance 

 ten times as great as that of Weber's absolute unit. 

 The British Association appointed a special committee, 

 to which Sir William Thomson and also my brother 

 William belonged, which carried on a lively agitation 

 for the general adoption of the British Association 

 unit, although there had as yet been no really exact 

 representation of the same. Reliance was placed, 

 however, on the expected progress in electrical methods 

 of measurements, and it was justly urged that the 

 adoption of a theoretically fixed standard of resistance, 



