The Semper Opera five-minute clock (1841)

The clock above the proscenium of the Semper Opera today: the hour in Roman numerals on the left, the minutes in steps of five on the right. This is the third clock on the site, installed for the reopening of 1985; the first burned in 1869 and the second in 1945.Photograph: Andreas Praefcke, public domain · Wikimedia Commons

The need: Gottfried Semper’s opera house needed a clock the whole auditorium could read in the half-dark, without hands too small to see from the gallery.
Made by: Johann Christian Friedrich Gutkaes, clockmaker to the Saxon court, with his partner and future son-in-law Ferdinand Adolph Lange. Commissioned in 1838, started with the house on 12 April 1841.
What was new: Two cloth-covered drums about 160 cm across, with numerals about 40 cm high, showing through two apertures: hours I to XII on the left, minutes 5 to 55 on the right, advancing silently every five minutes. On the hour the right-hand aperture stayed blank.
Worth knowing: The clock was destroyed with the house in 1869 and rebuilt by Gutkaes’s apprentice Ludwig Teubner; destroyed again on 13 February 1945 and replaced with an electrically driven clock for the reopening of 13 February 1985. Teubner’s 1:10 model of 1896 is in the Mathematisch-Physikalischer Salon in Dresden.
Where it is now: Semperoper, Dresden, above the stage; the 1896 model in the Mathematisch-Physikalischer Salon, Staatliche Kunstsammlungen Dresden.

Historian’s noteThe Semperoper’s own account names Gutkaes as the maker; A. Lange & Söhne says Lange “participated”. The link to the big date of 1994 is a deliberate quotation by the modern house, down to the blank left-hand window for the first nine days of the month.

SourcesSemperoper, 180 years of the clock (PDF) · A. Lange & Söhne, The time in five-minute increments · Staatliche Kunstsammlungen Dresden, the 1896 model