As part of our ongoing programme to recatalogue GSA Library’s rare books, we’ve just discovered Plans et dessins tires de la belle architecture ou representations d’edifices executes ou projettes en cxv plances : avec les explications necessaires by Christian Ludwig Stieglitz (1756-1836), published in 1801 in Paris.
Although the Library has many 19th century French architectural books, this volume is particularly interesting in that its title page features dates from both the Gregorian calendar (1801) and the French Republication calendar (IX).
The French Republican, or Revolutionary, Calendar was in use for about 12 years after the French Revolution, from about 1792 to 1805, and was briefly resurrected for 18 days during the Paris Commune of 1871. The new Republic was keen to sweep away some of the legal, religious and societal orthodoxes of the ancien regime, and created a new system of measures (the metric system) and a new calendar, beginning at Year I (1792). Our volume dates to year IX (1801).
The calendar was created by a commission of astronomers, geographers, mathematicians and poets, and saw not only a new numbering system for years, but also new names for months, days and seasons. The 12 months were each divided into 3 10-day weeks called decades with the last day in each 10 replacing Sunday as the day of rest. Each month was named after an aspect of nature, for example Vendemiaire (grape harvest) and Frimaire (frost).
Days were divided into 10 hours, each with 100 decimal minutes, creating an hour that lasted a conventional 144 minutes. Traditional French saints days were replaced with days celebrating animals, tools, plants or minerals.
Update June 2014: Sadly this volume was lost in the Mackintosh Library fire.