Bill
All we need now is a good clock to control the mechanism which compensates for
the EoT?
Brian Albinson
----- Original Message -----
From: Bill Gottesman
To: Robert Bargalló
Cc: sundial@uni-koeln.de
Sent: Sunday, September 27, 2009 10:24 AM
Subject: Re: Fwd: Direct reading time.
I like it. I would like to hear the story of how it was designed and
fabricated. Is it located at a residence or a public place?
-Bill Gottesman
Burlington, VT
Robert Bargalló wrote:
---------- Forwarded message ----------
From: Robert Bargalló <bargallorob...@gmail.com>
Date: 2009/9/17
Subject: Direct reading time.
To: Robert Bargalló <bargallorob...@gmail.com>
Hello All,
When an inexperienced person examine a well constructed Sundial, often
underestimate the instrument because it is not marking the official time and
having to make some “antipathetic” corrections of the indicated time. That is
the main reason we have built a sundial that gives civil time accurately,
enough to adjust the minute a non solar clock that it has stopped. In a word,
in our quadrant needless resort to the equation of time or to the local
position versus the Meridian corresponding to the time zone. No arithmetic
corrections are needed.
Descriptively, the device is a horizontal sundial with a gnomon consisting
in thin thread nylon. The mechanism presents a 48 teeth gear, powered by an
endless screw, which allows the entire clock to rotate some degrees around an
axis parallel to the Earth rotation axis (around the gnomon). In other words,
the mobile set plays like a hypothetical sundial indicating the exact civil
time is elsewhere, in another position but in the same geographic parallel. As
to the accuracy, the quadrant presents marks of all the minutes from the 5 h 45
a.m. until the 8 h 15 p.m. The single need featuring the device is that one or
twice a week requires adjusts a rotatable knob to indicate the current date.
This disc, of course, acts on the endless screw and, for that reason, on the
rotation.
Really, the rotation movement compensates not only the equation of the
time, but also the error caused for the geographic longitude position of the
instrument.
For the same method we can use the sundial giving 3 types of time: the
local solar time, the standard time, or the daylight savings.
Since we installed it, from November 2006 to date, it has indicated time
with an error that in no case exceeded one minute.
Happy Dialling!
Robert Bargalló
More information at next blog
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