Pros:
The dial can relatively accurately tell the time during daylight hours (it can inaccurately tell the time during the night).
It can fold up into a flat disc for portability, which is a massive bonus for the times.
It is exquisitely beautiful.
Cons:
It's no Casio chronograph accuracy-wise (however as it was developed in the 17th century we can let that one slide).
Moonlight can't replace sunlight, thus one must tell the time during the night via level of sleepiness.
It doesn't have an alarm clock.
Don't be late for your 3pm with Rene Descartes, buy a Universal Equinoctial Ring Dial!
Nicholas Avery
Oh and I've forgotten another (vital) con: The dial needs to be aligned with celestial north pole, so you need a compass to use it! Later on somebody invented the swiss army knife version successfully combining the two.
ReplyDeleteNicholas Avery