At 12:23 PM 4/5/2009, David Beierl wrote...
>First, I learned electricity in the '50s.  Yes, 
>I know I was only eight...<shrug>.  The Systeme 
>Internationale did not exist prior to 1960 and 
>wasn't taught to the trade until long after;

How very hypocritical of you to further a 
discussion of SI units for electricity after 
asking me not to (in pmail - "please -- let's 
leave SI out of it...this stuff is scary enough 
as it is...").  But, since you have, metrology is 
one of my hobbies, and it irks me when someone gets it wrong.

Technically the Systeme Internationale started in 
1960, because that year saw a change in name, but 
the basis for international electrical standards existed long before.

The coulomb, going back to its first definition 
by the 1st IEC in 1881, has always been a derived 
unit. The British Association for the Advancement 
of Science at Edinburgh in 1892, defined the 
ampere as that unvarying current that would 
deposit 0.001 118 000 grams of silver per second 
from a solution of silver nitrate in water. The 
coulomb was derived from this, being the amount 
of charge delivered by 1 ampere in 1 second.

By the 1950's, the ampere was included in the 
International System of Electric and Magnetic 
Units as a fundamental unit of electricity. In 
1950, the ampere was defined by US Law as a 
fundamental unit, and the same law shows that the 
coulomb is a derivation. (15 USC Sec. 223) 
http://uscode.house.gov/uscode-cgi/fastweb.exe?getdoc+uscview+t13t16+988+1++

The 9th CGPM (1948) adopted the ampere for the 
unit of electric current, following a definition 
proposed by the CIPM (1946, Resolution 2), the 
same definition which is used in the SI: "The 
ampere is that constant current which, if 
maintained in two straight parallel conductors of 
infinite length, of negligible circular 
cross-section, and placed 1 metre apart in 
vacuum, would produce between these conductors a 
force equal to 2 x 10�7 newton per metre of 
length." - source BIPM, 
http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf

That definition of the ampere became an official 
base unit of the "mks" system, along with the 
kelvin and the candela, at the 10th CGPM, in 
1954. The "mksA" system then went on to be renamed as the SI in 1960.