1. Noah’s Ark Make thee an ark of gopher wood; rooms shalt thou make in the ark; and shall pitch it within and without with pitch. And this is the fashion which thou shalt make it of; the length of the ark shall be three hundred, the breadth of it fifty, and the height of it thirty. Genesis 6: 14-15

2. Unit of Length Used in Genesis The length of your forearm. Cubit First recorded unit of length. Egyptian Cubit Rule Liverpool Museum

3. Leviticus Ye shall do no unrighteousness in judgment, in meteyard, in weight, or in measure. Just balances, just weights, a just ephah, and just hin, shall ye have.

4. Unit Stnds Established in the Magna Carta Agreed to by King John of England Runnymede, 1215

5. Clause 35 There shall be one measure of wine throughout our whole realm, and one measure of ale and one measure of corn -- namely, the London quart, and one width of dyed and russet and hauberk cloths -- namely, two ells below the selvage. (a textile’s selvage) London Quart Ell = a yard and a quarter

6. Unit Stnds Established in the US Constitution Section 8 … fix the Standard of Weights and Measures; …

7. Mars Climate Orbiter The Mars Climate Orbiter was intended to enter orbit at an altitude of 140.5–150 km (460,000-500,000 ft.) above Mars. However, a navigation error caused the spacecraft to reach as low as 57 km (190,000 ft.). The spacecraft was destroyed by atmospheric stresses and friction at this low altitude. The navigation error arose because the contractors for craft's thrusters did not use SI units to express their performance. The thrusters on the spacecraft, which were intended to control its rate of rotation, were controlled by a computer that underestimated the effect of the thrusters by a factor of 4.45. This is the ratio between a pound force (the standard unit of force in the imperial system) and a newton (the standard unit in the metric system). The software was working in pounds force, while the spacecraft expected figures in newtons; 1 pound force equals approximately 4.45 newtons. Wikipedia

8. Ancien Regime Weights and Measures 800 Unit Names 250,000 Different Units

9. Town Hall of Laon, France “T” for the Size of Barrels Ell for Cloth Gauge for Bricks Gauge for Roof Tiles

10. Origin of the Metric System 1790 French National Assembly requests the French Academy of Sciences to …deduce an invariable standard for all the measures and all the weights. Charles de Talleyrand-Périgord In place of a measure derived from history or the fiat of kings, he asked that the legislature derive its fundamental measure from nature, the common heritage of all mankind. Only a measure derived from nature, he declared, could be eternal because only such a standard could be reconstructed should its man-made embodiment suffer the ravages of time. The Measure of All Things Ken Adler

11. Delambre Mechain A Unit of Length 1790 meter Proposal One Millionth of the Distance Btwn the Pole and the Equator along a Meridian running through Paris

12. Provisional Meter of 1793 Borda, Lagrange, Laplace Estimate = 443.44 lignes (1 pied = 144 lignes)

13. Triangulation

14. Link btwn Mechain & Delambre’s Triangulations Head of the Statue of the Virgin Mary Rodez Cathederal

15. The final step was to embody the meter in a permanent physical standard. Copper Had been sufficient for the provisional meter, but for the definitive meter only ultimate Metal would do. Long despised as a contaminant by South American prospectors, Platinum was difficult to melt, difficult to purify, and nearly indestructable. For just That reason it had acquired a lustrous reputation among savants. It promised to outlast Time. … The Commission of Weights and Measures spent one fifth of its budget Buying and refining some one hundred pounds of pure platinum. In April 1799 [Lenoir] was supplied with the calculated value of the definitive meter And four bars of pure platinum, and told to shape four standards of precisely one Meter each. For this purpose he employed a “comparator” of his own invention, Which could gauge objects to within one millionth of a toise (0.0000072 inches). The task was “diabolically tricky.” Of the four bars, the one that came closest – within 0.001 percent of the proper length – was selected as the definitive meter. 1799 Meter The Measure of All Things Ken Adler

16. “Convention of the Meter” - 1875 15 years later the meter was forged. Made of a Platinum-Iridium Alloy.

17. 1963 Meter Krypton Gas Discharge 1,650,763.73 wavelengths of orange-red light, in a vacuum,produced By burning the element Kr-86.

18. 1983 Meter Distance light travels, in a vacuum, in 1/299.792,458 seconds.

19. Standard Kilogram US Prototype - 1889 Danish Prototype - 1949 A Unit of Mass

20. A Unit of Time The Second the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom Atomic Clocks at the Naval Observatory

21. A Unit of Temperature Triple Point Cells T = 273.16 Kelvin at the Triple Point of Water

22. A Unit of Amount Dozen GrossMole

23. The number of Carbon-12 atoms in a 12 gram sample of Carbon-12. Avogadro’s Number 6.02214179(30) x 10 +23

24. Units of Electric Current and Luminous Intensity Current Galvanometer for Measuring Current Luminous Intensity ampere candela