Dear Frank
Sorry, but I'm pretty sure you can't use that trick because Italian and
Babylonian time are "local" in a way that modern hours are not. The modern
time at a location ninety degrees away is always a fixed amount before or
after the time you're interested in. For instance, for a wall in England
facing west of south, you could find a spot ninety degrees away in the South
Atlantic where, say, the modern time is always 2 hours earlier than in
England.

But, except at the equinoxes, that location's sunrise and sunset will not be
2 hours after yours. So, a horizontal dial showing correct Italian and
Babylonian hours for that location will not show the Italian and Babylonian
hours in England, even if you adjust the numbers by 2 hours.

This is because the Italian and Babylonian hours relate to the local
horizontal plane. So, whereas a sundial reading modern hours can be moved to
a new location and positioned so as still to work correctly, perhaps by
using a wedge to cant it, this is not true of an Italian/Babylonian sundial.
Such a dial can be used only at one latitude.

Chris Lusby Taylor
51.4N 1.3W



----- Original Message ----- 
From: "Frank Evans" <[email protected]>
To: "Sundial" <[email protected]>
Sent: Wednesday, March 31, 2010 2:01 PM
Subject: re how italian dials


> Greetings, fellow dialists,
> I'm starting to think that for a vertical dial in Italian hours it would
> be simplest to use the old dialist's trick of laying it out as a
> horizontal dial at ninety degrees away.
> Frank
>
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> https://lists.uni-koeln.de/mailman/listinfo/sundial
>

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