Named for the Earl of Orrery who,
at the beginning of the 18th
Cent. in Ireland, had one made for his personal
collection of scientific apparatus. Orreries are
three dimensional models of how celestial bodies
orbit the Sun in our solar system.
They may be exceedingly complex or very simple,
finished with precious stones and gold, or made
from wood and paper.
They featured in the collector’s cabinets
of the 18th
and 19th Century. Some were made for Kings,
heads of State and wealthy patrons. Itinerant
philosophers carrying orreries travelled through
the educated and enlightened world of the time.
“The wise man looks into space and
does not regard the small as too little
nor the great as too big, for he knows that
there is no limit to dimensions.”
Since the age of fourteen Brian has been making
telescopes and observing the sky.
He was fortunate in having an Uncle who built
a 300 mm diameter. reflecting telescope
and an observatory to house it.
In effect Brian became the sorcerer's apprentice.
An abiding interest in antique scientific instruments
also began at this time and continued through
a life-time spent in design, development and research
into military hardware in England, Canada and
Since his retirement in 1990 he has devoted his
time once more to the sky above, and the antique
instruments used in telling its secrets.
He is an accomplished public speaker and has
appeared on Good Morning Australia and radio.
The author of numerous articles on astronomy he
has spent the last 4 years on research for a book
about the Great Melbourne Telescope and the history
of astronomy in Victoria, visiting Ireland, England
and Europe in the process.
His book “Halley’s
comet over Australia” published in 1986
sold over 60,000 copies and was entered in the
Guinness book of records as being the fastest
book ever published in Australia.
What did Brian make for Sydney Observatory?
Brian made 2 astronomical models for the Sydney
Observatory. These were designed to be powered
and operated around the clock by visitors of all
ages. In order to stand up to this heavy workload,
the gears had to be made especially thick.
Brian Greig's Electric Tellurian at Sydney Observatory
The first model was a hybrid Tellurian / Lunarium
- an elaborate Sun/Earth/Moon system. It is a
Tellurion (sometimes also spelt Tellurium) because
it shows the Earth rotating anti-clockwise on
its axis as it revolves anti-clockwise around
The sun includes a lamp which lights up the side
of the Earth facing the sun, thus demonstrating
day and night and how the sun rises in the east
and sets in the west. The apparent motion of the
stars can also be understood via the rotation
and revolution of the Earth.
The model is also a Lunarium...
The north and south poles of the Earth are on
a constant tilt as the Earth revolves around the
sun, demonstrating the position of the north and
south celestial poles, the significance of the
zodiac and the occurence of seasons.
The model is also a Lunarium because it shows
the moon revolving anti-clockwise around the Earth.
This coupled with the light from the sun shows
the phases of the moon - full moon (as viewed
from Earth) when the Earth is between the sun
and the moon, and new moon when the moon is between
the sun and the Earth.
The moon's orbit is on a tilt, which explains
why we do not get a lunar and solar eclipse every
full moon and new moon respectively, but only
when a full or new moon occurs as the moon is
crossing one of the nodes - the points halfway
up or halfway down the tilting orbit.
The angle of the tilt can be adjusted manually
every year by the exhibitors to correct for the
clockwise recession of the nodes.
The second model was a standard Brian Greig Orrery
featuring all of the planets out to Saturn with
no gearing for the moons. Brian made some improvements
in design, to help it withstand the stresses of
How does Brian create an Orrery?
An Orrery can take Brian anywhere from 6 weeks
to 6 months to make. Although Brian has now made
more than a dozen of these clockwork models, the
process still requires great patience and precision.
Potential customers are invited to see photos
of Brian's orreries.
The customer may request certain features to be
added to previously created designs. They may
request additional planets or revolving moons
etc. Brian then spends a few weeks considering
the implications of the new design requirements
before he puts together a quote. The quote
includes time estimates for design, new tool sourcing,
construction and components.
Don't forget to view the exquisite orrery
catalogue with items that are for sale.
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