I found Mario's explanations on Roman and European hour systems most fascinating: thank you.
I have a tangentially related question or questions; Mario mentioned that different times were appropriate to different people (country or city dwellers, perhaps). I understand (largely from "Heavenly Clockwork" by Needham et al.) that the Chinese may also have inherited their system of equal hours from the Babylonians. Like the Romans, the Chinese reckoned the boundary of the day at midnight. Some centuries BC the Chinese were using unequal hours, but around 200 BC their double hour system was perfected and became the only one for official use. In this, twelve equal "double hour" periods are named during the day (nychthemeron). Each has two halves and so each half is equal to one of our modern hours. The midpoint of one of these double hours was midnight, so the double hours straddle our times of 0000, 0200, 0400, 0600 ... 2200 and the boundaries between them are at 0100, 0300, 0500 ... 2300. However, a system of unequal hour night watches continued alongside the use of equal double hours until the 19th century. So: Were unequal daytime hours also used for everyday purposes, as opposed to official ones, during this 2000 year period (from around 200 BC onwards)? I am not familiar with Chinese sundials but the only old ones I recall are equatorial and clearly appropriate for official use. I imagine that they are marked for equal (double) hours. Is this correct? Were there also - or are there still existing - old Chinese sundials which show unequal daytime hours, or were equal hours the only time shown? Andrew James PRI Limited, PRI House, Moorside Road Winchester, Hampshire SO23 7RX United Kingdom Tel: +44 (0) 1962 840048 Fax: +44 (0) 1962 841046 www.pri.co.uk PRI Limited is a company registered in England and Wales with company number 2199653 Measure - Inform - Empower This correspondence is confidential and is solely for the intended recipient(s).If you are not the intended recipient, you must not use, disclose, copy, distribute or retain this message or any part of it. If you are not the intended recipient please delete this correspondence from your system and notify the sender immediately. This message has been scanned for viruses by MailControl. --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial