Why Europeans invented their earliest clocks

Clepsydra (water clock)

image from Richard A. Paselk

from Wikipedia ...

Canonical hours are ancient divisions of time (also called "offices"), developed by the Christian Church, serving as increments between prayers.

The practice grew from the Jewish practice of reciting prayers at set times of the day: for example, in the book of Acts, Peter and John visit the temple for the afternoon prayers. Psalm 119:164 states: "Seven times a day I praise you for your righteous laws."

This practice is believed to have been passed down through the centuries from the Apostles. In 525, St. Benedict wrote the first official manual for praying the Hours, and the Vatican wrote the first official breviary in the 11th century.

Already well-established by the ninth century, these canonical offices consisted of eight daily prayer events and three (or four) nightly divisions (called "nocturnes", "watches," or "vigils"). Building on the recitation of psalms and canticles from Scripture, the Church has added (and, at times subtracted) hymns, hagiographical readings [chronicles of the Saints and Martyrs], and other prayers. The practice of observing canonical hours are maintained by many Churches, such as the Catholic, Orthodox, and Anglican communions.

The daily events were:

* (at dawn) Matins ("MATT'-inz") called "Orthros" in Eastern Churches

* (at dawn) Lauds ("lawds") later separate from Matins in the West; aka "Morning Prayer" or "The Praises."

* (at ~6 AM) Prime (the "first hour")

* (at ~9 AM) Terce (the "third hour")

* (at Noon) Sext (the "sixth hour")

* (at ~3 PM) Nones (the "ninth hour")

* (at sunset) Vespers (aka "Evensong" or "Evening Prayer")

* (at bedtime) Compline ("COMP'-lin", aka "Night Prayer")

Muslim prayers

["al-" is the Roman alphabet transliteration of the Arabic article for "the." The comparable Hebrew article is "el."]

Muslims still use a modified definition of canonical hours when they pray five times a day. Their prayer (salah) times are

* Salat al-Fajr -- Dawn

* Salat al-Zuhr -- Midday

* Salat al-Asr -- Afternoon (prayed silently)

* Salat al-Maghrib -- Sunset

* Salat al-Isha -- Night

I * II * III * IV * V * VI * VII * VIII * IX * X * XI * XII

from http://www.humboldt.edu/~rap1/EarlySciInstSite/Workshops/TimeClksMidAge.htm

The Development of the Clock
and the Concept of Time in the Middle Ages

by Richard A. Paselk
Department of Chemistry, Humboldt State University

It is thought that the mechanical clock was invented in Western Europe around 1300 CE. The exact date is difficult to establish because no clocks from this period are extant, and because the terms used to describe early clocks were also used to describe clepsydra or water-clocks. One of the most remarkable aspects of the clock is that some of the earliest known examples were also incredibly complex. An example is the Astrarium completed by Geovanni di Dondi, an Italian astrologer/physician in 1364. This clock is well known because di Dondi left detailed plans for its construction (at least three replicas exist: at the Science Museum, London; at the Smithsonian, Washington D.C.; and one owned by IBM Corp.). This clock had seven faces which displayed the positions of the stars (as on an astrolabe's face), the positions of various planets, the moon's position etc., it was a complex, multiple-display astronomical device. This device is unlikely to have arisen from nowhere. It turns out we now know that astronomical gearwork goes far back into antiquity (e.g. the Antikythera device, an astronomical computer of c. 50 BCE, a geared Byzantine Sundial/calendar of c. 520 CE, and various geared astrolabes of c. 1200-1300 CE).

But gearwork is only half of the problem of the origin of the clock-the other is the origin of the escapement. This mechanism truly seems to be a medieval invention. Are there again precedents? First alarm bells of medieval timers had an oscillating action. Second, we know the Chinese invented an escapement of a different sort (C. 1090), but there is no evidence of its diffusion, and indeed the technology was quickly lost in China itself.

We have been dealing with technical aspects of the clock's origins. What about need-who cared? First the Monastic orders: there were specific requirements for times of prayer. But these times were better measured with sundials or water clocks because they needed unequal hours, that is hours proportional to day length, which in Northern Europe varies significantly with the season! (Of course in Northern Europe the sun is often obscured by clouds and water clocks may freeze in the winter!) And, until the invention of the pendulum clock, water clocks were capable of greater accuracy! The second group would be astronomers and medical astrologers. They wanted equal hours, the hours of the planets and stars-God's hours. For them the clock was a conscious model of the solar system. It could then of course also become a valuable theological model once it was perfected.

The clock quickly became one of the great symbols of the medieval period. Building a clock was their equivalent of the Apollo Project: an incredibly expensive venture requiring the services of the most highly trained scientists and technicians of the culture and a large investment of material.