I would strongly recommend
"Sundials their theory and construction."
, if you are interested in
making moondials or sundials, as it has far more on different types of
dial than I could ever fit onto this page, but here is a summary of what
you need to know:
The simplest type of moondial is a sundial. This can only be used
at full moon,(I have only ever
made the horizontally mounted sort, but all designs of sundial
can be adapted as moondials)
Simply read 12.00 as midnight rather than midday.
The moons shadow will lose 48 minutes for every day after
full moon and will be equivalently fast before full moon. Some sundials have a table
of corrections to allow them to be used as moondials.
Here are the corrections that have to be made during the weeks before and after
Days from full moon: 0.....1.....2.....3.....4.....5.....6.....7
amount of correction
(hours:minutes):.........0:0 0:48 1:36 2:24 3:12 4:0 4:48 5:36
Alternatively, you could make a dial
specially, with different scales
for different days of the month. For example, a 7-day moondial should look
something like this (not to scale)
The moon casts a strong
enough shadow for
a few days before and after full moon. If you live in a city where there
are a lot of streetlights,the period of the month during which you can use
will be shorter. In remote rural areas, it may be possible to use a moondial
for up to half of the month. Moondials can be designed accordingly.
I make sun and moondials out of sheet copper, with
designs and hour markings etched on. The plinth can be obtained from your
local garden centre, where they will usually have suitable ornamental
pillars, or something similar. Often, if you ask they will be able to
supply you with the base from a bird bath,
or know of a wholesaler who could supply you with any number of interesting
pieces of reject stoneware . Don't worry if you don't have the equipment or
enthusiasm for metalwork, the possibilities are endless. You
could turn your entire garden into a moondial, by planting flowerbeds in
concentric circles around a central post, tree or piece of topiary.
ornamental cabbages and lettuces,
moon daisies**, moon carrots, Hawthorn,
willow, vines, cucumbers, melons and many other plants are traditionally
associated with the
has a more comprehensive list of lunar
plants***. See also the link
For more on lunar gardening,
If you click here you will find the
angles for the hour markings for a sundial designed for your latitude.
These measurements for the sundial can be used for the full moon scale,
and scales for the other days of the month can be calculated by adding or
removing 48 minutes to each hour marking on the
full moon/sun scale, for each day before or after full moon and arranging the
scales concentrically, in order, from
the earliest date before full moon to the latest date after full moon.
(e.g the scale for two days before full moon should be identical to the full
moon scale, except that every hour mark will be shifted out by 96 minutes
from the equivalent mark on the full moon scale)If you are
lucky enough to live in an area where the moonlight is unsullied by neon,
you may find yourself requiring quite a large dial, in order to accomodate
all of the scales
(if you assume that 48 minutes
are 48/60ths of the separation between two hour markings, you won't be
100% accurate, but it shouldn't make any difference except on an extremely
The size of the gnomond
is not crucial either: If it is too big, the tip of the shadow will be off
the edge of the dial, and if it's too small, it will not reach all the way
to the hour markings, but as the elevation of the sun and moon changes from
summer to winter, the length of the shadow will also vary. The average
elevation of the sun is equal to 90 degrees minus your latitude, The moon's
elevation varies even more than the sun's, but on average is about the same.
On a horizontal sundial, the angle of the gnomond to the dial should be
equal to your latitude.(this applies equally to horizontal or south facing
vertical wall mounted dials)
(N.B. astronomy is not really my strong point, if I have got anything badly
wrong here, please E-MAIL ME and tell me. My methods produce reasonably
accurate sun and moondials, but you should be aware that the time which
watches and clocks show often deviates considerably from that shown on sun
and moondials, especially around the equinoxes. This is because conventional
clocks only aproximate astronomical time. Sun and moondials will not, of
course show British Summer Time, daylight saving time or other local
interference by central government. Moondials also have many curious
eccentricities and innacuracies of their own)
There is also apparently another sort of moondial,used for black magic
rather than timekeeping. Click here
to find out more.
*"How the pale Phoebe, hunting in a grove,
First the boy Endymion, from whose eyes
She took eternal fire that never dies;
How she conveyed him softly in a sleep,
His temples bound with poppy to the steep
Head of old Latmos, where she stoops each night,
Gilding the mountain with her brothers light,
To kiss her sweetest"
Fletcher, The Faithful Shepherdess.
Endymion was identified with
The man in the moon 
** The word "daisy" means literally "day's eye", because of the resemblance
between the flower and the sun (click here for
more on the symbolism of the eye ). Common daisies close their flowers at night,
I think that the moon daisy, ox-eye daisy or Marguerite does not, and this may be one reason
why it has aquired its
name. The similar May weed certainly stays open at night.
In ancient times the moon-daisy was sacred to the moon goddess Artemis,
and was prescribed for period pains.
Later it was associated with Mary Magdalane, and was known as the Maudlin daisy.
In Somerset it was connected with the Thunder God and was called the Dun Daisy
. In parts of Africa
there is a shrub with large daisy-like flowers, known as Fleur Marguerite.
I pressed one of the flowers as a souvenir on a visit to
Cameroon. The plant is associated with mirages, and is apparently named after
the goddess Margara, who seems to be The White Goddess
. I was completely
unaware of this at the time, and it was pure synchronicity that I chose to press
the flower between the pages of
"The White Goddess" by Robert Graves.
In "Masquerade" by Kit Williams, the violinist says, after the eclipse:
"I shall play the Song of the Sun. The Sun is the eye of day, and as long as I play this tune, the day's eye cannot close again."
The man played the Song of the Sun so sweetly that it
made the happy daisies grow."
In the picture, the violinist is seated on a huge sow which has
daisies growing out of it, and
there are cut cabbages in
***The BBC Gardeners Question Time Panel were asked what plants
they would take to the moon. They suggested Paper moon iris, moon
daisy, honesty, epiphylum cactus, rocket (groan), runner beans
(because they are so useful and productive, but a
vine seems appropriate),
(double groan), bindweed and hairy bittercress
(to be left there!)[back]
Links to other sites on the Web
Sundials on the internet
A flower loved and hated
A fascinating article about Daisies (no honestly!)
A great moondial page
Gothic gardening: potpourri
Moondials and nocturnals
North American Sundial Society Homepage
A very comprehensive site about sundials with lots of links
Seeds for a moongarden
The Moon Watch
Attractive watch showing the phases of the moon
Sundials, clocks and castles
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