What are these parts of an old drawing compass?

I have an old Tacro drawing tool kit that is comprised of a compass and two accessories. One is a stylus to be used with dipped ink. The appears to be a handle of some sort. It’s smooth, probably enameled black, with a silver tip with threads inside. It’s about 1/2 the length of the compass. How would it be used?

My old compass had the stylus tip you mention along with a handle that could hold the stylus, letting it be used as a ruling pen. Will the stylus tip fit in the handle?

Yes, the stylus should fit into the black handle, if you want to create things other than circles, with the same line thickness.

And, if that ruling nib is the kind that looks like a kind of tweezer with an adjustment knob, then do not dunk it.

like this one

I remember my drafting teacher in high school explaining that one should never dip those ruling pens. You should carefully place a drop of ink between the pinchers with an eyedropper.

The tweezer is a pen nib for the compass. The handle is an attachment to “draw” with the pen nib. I have a set of drafting tools lying around here somewhere (dives through years of accumulated kruft) with exactly the same features.

Old ink bottles had a cap with a built-in dropper for filling pens like this.

I’m not that sorry that drafting like this has disappeared. It was tedious and mistake-prone.

Now you’ve got me remembering my old Rapidograph set, something I’d rather forget.

And when you want really nice lettering, time to get out the good old Leroy lettering set.