Hello, everyone,
I was pleasantly surprised to learn that a form of sundial has an
important application in everyday life of Omani farmers, even in the
present day.
There is an article "The use of stars in agriculture in Oman" in the
Journal of Semitic Studies (Nash & Agius, Spring 2011, vol. LVI, iss. 1,
doi: 10.1093/jss/fgq063). The article describes how farmers cooperate by
sharing access to irrigation water flowing from a stream or spring,
using a system of time intervals called athars to manage the flow of
water to the fields. Each farmer is entitled to divert the irrigation
water to his fields for a certain number of athars each day. There are
48 athars in 24 hours: 24 during the day and 24 in the night.
The article addresses the night time measurements in some detail - a
sequence of star risings marks the passage of athars – but makes only
passing reference to the use of sundials for the daytime measurements.
There is, however, an accompanying photograph of one such dial showing
quite clearly that it consists of nothing more than a vertical rod
perhaps 2m high, plus a series of parallel straight lines scratched in
the ground. Presumably each line represents one athar. The dial is
crudely made and I imagine it has to be redrawn fairly frequently
because wind, animal hooves, and occasional desert rainstorms would
likely erase the scratches.
The lines are aligned North-South and and appear to be spaced more
widely if they are further away from the rod, suggesting a primitive
polar dial. However, the spacing does not appear to increase as much as
I think it should for a polar dial. As well, a polar dial ought to have
its face inclined to match the latitude but this dial is drawn on level
ground. Oman is at about 20N, so perhaps the discrepancies are small
enough to be acceptable and would be cancelled out after a few days - if
we assume the allocation of athars varies from day to day. Or perhaps
I'm mistaken in thinking of it as a polar dial.
Anyway, this fascinating application of a sundial leads to a question:
are there other examples of sundials being used even today, to measure
the passage of time for ‘real world’ purposes?
Steve Lelievre
Fredericton NB
Canada
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