According to http://www.aticourses.com/international_system_units.htm :
The recommendations of the B.A. [British Association for the Advancement of
Science] committees were adopted by the First International Electrical
Congress in Paris in 1881. Five "practical" electrical units were defined as
certain powers of 10 of the CGS units: the ohm, farad, volt, ampere, and
coulomb. In 1889, the Second Congress added the joule, watt, and a unit of
inductance, later given the name henry.
According to http://en.wikipedia.org/wiki/Newton :
The newton was first used around 1904, but not until 1948 was it officially
adopted by the General Conference on Weights and Measures (CGPM) as the name
for the MKS unit of force.
It is not clear if the joule was "first used" before being officially
adopted by the congress, but given that Joule died the same year, it may
have been proposed then as a memorial.
--
John Hynes
San Francisco
Pat Naughtin wrote:
Dear All,
Can anyone give me the definitive date that the joule was introduced into
the SI as the unit for energy. I suspect that it was at the same time as
the newton, but I'm having trouble finding the right reference.
I have searched the BIPM web site but with no luck.
Cheers and thanks,
Pat Naughtin
Geelong, Australia
