COMMITTEES ON BEHALF OF THE GOVERNMENT Bis 
COMMITTEE TO PRESCRIBE AND PUBLISH SPECIFICATIONS 
FOR THE PRACTICAL APPLICATION OF THE DEFINITIONS 
OF THE AMPERE AND VOLT. 1894 
It will be recalled that the Academy sent delegates in 1884 to 
the International Congress of Electricians at Paris. At this 
congress the “legal ohm” or “ congress ohm” was established, 
having for its determination the resistance of a column 
of mercury 106 centimeters long. It was considered both at 
that time and subsequently that this length was not the proper 
one and for the further consideration of this and other matters 
connected with electrical units an international electrical congress 
was held in Chicago in 1893. On this occasion the ohm known as 
the “international ohm” was determined upon, having as its 
basis the resistance of a column of mercury 106.3 centimeters 
long. The“ volt,” “ ampere,” “ henry ” and other units were also 
fixed. 
In the year following an act was passed by the Congress of 
the United States, defining the various units in accordance with 
the decisions of the electrical congress. ‘These comprised the 
ohm, the ampere, the volt, the coulomb, the farad, the joule, the 
watt and the henry; the last, as is well known, named in honor of 
Joseph Henry, the first Secretary of the Smithsonian Institution 
and second President of the National Academy of Sciences. 
The act referred to, which was approved on July 12, 1894,'" 
contained the following provision: 
“Sec. 2. That it shall be the duty of the National Academy of Sciences to 
prescribe and publish, as soon as possible after the passage of this Act, such 
specifications of details as shall be necessary for the practical application of the 
definitions of the ampere and volt hereinbefore given, and such specifications 
shall be the standard specifications herein mentioned.” 
For some reason which is not apparent, the Act did not come 
to the attention of the President until the last day of October.*” 
On November 6, he applied to the Secretary of State for an 
authentic copy, and received the same on November 9. 
* Stat. at Large, vol. 28, p. ror, 53d Congress, 2d Session, chap. 131. See also Rep. Nat. 
Acad. Sci. for 1894, p. 39; also for 1895, p. 7. 
*™ See Rep. Nat. Acad. Sci. for 1894, p. 40. 
