Tracing the history of medieval astronomy
With the quadrant itself pretty much complete (aside from the scale), it was time to start working on something to mount it on. So today we started with the central column which was assembled from plywood to make a 5″ box that was 8′ tall.
Continue reading “Instrumentation – The Great Quadrant: Day 5”
With the lattice finished the goal today was to put the edging and scale on and clean things up.
To start, we inserted some additional horizontal supports along the outer arms:
Continue reading “Instrumentation – The Great Quadrant: Day 4”
Previously, we rough cut the beams for the lattice. Today’s goal was to get them notched and assembled. To do so, we used a special blade for the table saw that cut wide chunks out instead of a narrow line.
Continue reading “Instrumentation – The Great Quadrant: Day 3”
From the full scale plans we started cutting out pieces today.
First we cut out the arcs which will hold the scale. As noted previously, the idea was to have several to choose from so we could see which had the smoothest arc. If nothing else, it just reduced the amount of plywood we had laid out.
Continue reading “Instrumentation – The Great Quadrant: Day 2”
Work began today on the prototype of the great quadrant. I’d drawn up a set of plans for the quadrant arm last week (each box = 1″) so that’s where we started today (we being my father and I since he does construction and contracting professionally and has a workshop we can use).
To begin, we used a sheet of plywood to draw out a full sized set of blueprints. Mathematically, the most important parts of the entire structure is the arc which will display the scale, and that the pivot around which it rotates and from which the plum bob will hang is exactly in the center of the circle the arc lies on.
So to start, we measured the box in the upper left corner on the plywood, found the center, and screwed a long wood arm in the center. Holes were drilled in that arm at 36″ and 34″ from the center to draw the arc 2″ wide.
Continue reading “Instrumentation – The Great Quadrant: Day 1”
As the long term goal of my project is to collect measurements in order to produce a star catalog and determine planetary orbits, this will obviously require some way to collect these measurements.
The master instrumentationalist whose data Kepler used was Tycho Brahe. He had numerous devices and their meticulous crafting and exceptionally large sizes allowed for the most accurate measurements of the age.
But for me, one stood out: Tycho’s Great Quadrant which is the one I’ll be modeling my own after.
Continue reading “Instrumentation – The Great Quadrant: Alignment”