In last week's entry about the pointed drafting divider, I explained how it can be used to find the midpoint of a line without measuring.
Reader Ethan commented:
You know that there's a much easier way to find the exact midpoint of any line, right?
Set your tool to be obviously larger than the halfway point. Place one end at one end of your line. Mark an arc that crosses the original line and extends far enough on either side that when you make the same arc from the other end of the line, you get two points of intersection (like a venn diagram). The line connecting those two points of intersection will always go straight through the exact midpoint of your line. Geometrically. Without guess-and-check.
In my comment back to him I replied that I did know about it and that for various reasons I didn't include it in that entry, but I thought about it some more and came to 2 conclusions: 1, maybe others don't know it, and the point of this blog is to tell people about stuff they might not know. And 2, even though I have some issues with this method, other people with different working methods or different needs might find it way better, just like people like inks I don't like and pens I don't like.
So thanks to Ethan, and I hope this helps someone out!
Set your tool to be obviously larger than the halfway point. Place one end at one end of your line. Mark an arc that crosses the original line and extends far enough on either side that when you make the same arc from the other end of the line, you get two points of intersection (like a venn diagram). The line connecting those two points of intersection will always go straight through the exact midpoint of your line. Geometrically. Without guess-and-check.
In my comment back to him I replied that I did know about it and that for various reasons I didn't include it in that entry, but I thought about it some more and came to 2 conclusions: 1, maybe others don't know it, and the point of this blog is to tell people about stuff they might not know. And 2, even though I have some issues with this method, other people with different working methods or different needs might find it way better, just like people like inks I don't like and pens I don't like.
So thanks to Ethan, and I hope this helps someone out!