Year 2003

Article of the month April

What are all these bands called?

The figure below shows an armillary dial or a Sphaera Armillaris Gnomonica in the Northern Hemisphere.

What are the names of all the circular bands we see in its construction?
This page lists all their designations.
Note that number 13 is the east-west band through the poles, and not the style or polos.
One will not always find all bands on every armillary dial.

1	Polus Arcticus
2	Circulus Arcticus
3	Tropicus Cancri
4	Linea Equinoctiorum
5	Tropicus Capricorni
6	Circulus Antarcticus
7	Polus Antarcticus
8 and 9	Ecliptica or Zodiacus
10	Circulus Horizontalis
11	Primus Verticalis
12	Meridianus or Colorus Solstitiorum
13	Colorus Aequinoctiorum

Fer de Vries.

English translation: RH