A note on materials: I am an inveterate "recycler"
and the materials used for the instruments I construct often
reflect what I have on hand at the moment. Thus, although brass
is the most common traditional metal for instruments, and has
the best working/use qualities, a number of instruments are fabricated
from copper because I was given a large sheet of 14 G copper.
I have also used bronze (from cast plaques) because it was available,
though in this case I also find it exceptionally attractive and
easy to work. If you are purchasing metal brass is generally
your best choice. If you are on a budget, I strongly recommend
periodic trips to your local salvage yard, building up a stock
of metal as you find it.
Astrolabes are probably the the
sini qua non of ancient instruments. They have been collected
for centuries, and forgeries have been made for centuries, though
genuine, working, astrolabes were made in Islamic countries up
through the nineteenth century. For background information on
astrolabes a number of books are available. Some which I have
used extensively are listed among the references
for this site. The Astrolabe
site on the Internet provides a brief essay on the astrolabe,
museums having astrolabe collections, a history
of the astrolabe, and finally, astrolabe
links, references, and reproductions, including a "personal
astrolabe" available for a fee made by that site's creator.
the classic universal instrument of the Middle Ages. A complex
project requiring many hours and high skill to do well.
Astrolabe: claimed to be Christopher Columbus' own instrument.
Probably derived from large wood measuring instruments used by
astronomers, which were derived in turn by simplifying the planispheric
astrolabe to its measurement basics. An intermediate level project,
much simpler than the planispheric astrolabe, but still challenging.
Mariner's Astrolabe: the classic form of the navigator's
astrolabe as used by the Portuguese and the Spanish in the 16th
and 17th century. Somewhat more difficult than the transitional
instrument above if fabricated, as here. A realistic model should
be made of very heavy stock, and would be better as a casting.
Armillary Sphere: this
was a teaching/demonstration instrument representing a Ptolomaic
model of the universe. Such models were characteristic of the
late Middle ages and up into the 17th century. This is a difficult
and time consuming project, involving fabrication with a number
of different media: metal, wood, and stone.
Torquetum or turquet: this
is a complex and sophisticated instrument characteristic of Medieval
astronomy and the Ptolemaic tradition. This recreation is based
on contemporary diagrams, descriptions in the literature, and
the requirements for a functional instrument. It is not intended
to replicate any specific instrument, but rather to be made in
the spirit of the period - it could have been made by a scholar/cratsman
of the 13th or 14th century. This is a difficult and time consuming
project, involving fabrication and shaping of metal and wood,
along with extensive scale division.
modeled after a dial found in the walls of Canterbury Cathedral
during repair work in the 1930's. Thought to be 9h or 10th century.
This is a relatively simple metal project which I have done as
a fabrication from bronze plate, and in a simple workshop project
in aluminum. It would also be excellent as a casting.
Simple Quadrant: this
is a measuring instrument used from the early middle ages through
the Renaissance. Frequently other scales were added to make it
into a timekeeping instrument. This is one of the least demanding
of the projects listed, requiring some woodworking (or you could
substitute cardboard), paper, and ink. I have also used the quadrant
as a workshop project using plywood. A bronze version is in progress.
Kamal: used by Arab sailors
since time immemorial, this very simple instrument shares the
same principle as the cross-staff, but here the cross piece is
replaced by a card, and the staff by a piece of cord. This is
a beginning level project, requiring little skill or time.
Cross staff: one of the
most popular navigation instruments of the Renaissance and Age
of Exploration, it was derived from a larger astronomical instrument
invented in the 14th century. The cross-staff largely substituted
for the mariners astrolabe in Northern Europe. This can be a
simple or an intermediate level woodworking project. In addition
to the original project illustrated, a workshop version based
on half-inch dowel is also described.
Dry-Card Box Compass
Dry-card Compass: modeled after a 13th-15th century Italian
compass. This is a relatively straight-forward project for those
with a wood lathe and some lathe experience.