Curator Thierry Lalande discusses which decimal-based units succeeded in the longterm.
Background: While decimal-based weights, measures, and currency were eventually adopted in France, decimal time and the French Republican calendar failed. In September 1805, Napolean Bonaparte declared that in 1806 France would resume using the Gregorian calendar. Several scholars point to his desire to reconcile with the Church, as the Revolutionaries had used the 10-day "week" to divert attention away from traditional Sunday activities. The Republican calendar lasted about 12 years, but mandatory use of decimal time lasted only 197 days, from September 22, 1794 to April 7, 1795.
Why? Decimal time was approved by the State (some towns installed decimal clocks that continued to run after the 10-hour day was no longer mandatory) and using the state-sanctioned measures was a sign of support. But unlike standardized weights and measures, or decimal currency, decimal time didn't solve a widespread problem.
Beyond the inherent appeal of base-10 mathematics to decision-makers of the time, decimal time made it easier to know exactly how much of the day had passed. But these two advantages weren't enough to justify the hassle of new notation and the expense of new mechanical devices. Though official, decimal time was used only by a few people for specialized areas, notably the mathematician Jean-Pierre Laplace.
We marvel at the Musée's pieces for different reasons. Some for the precision and craftsmanship achieved hundreds of years ago, like the meter standards that are only 0.2mm different from our current meters. Others, like the locks and keys, are more beautiful examples of what has become commonplace and produced in a large scale. Others are early examples of technology, like the giant fax machine or the working Vélibe bicycle dock. The decimal clocks illustrate another aspect of history: a different approach to measuring time.