Engineering Drawing by Thomas E. French, 1947 edition. It has tons of amazing illustrations like this:
It has chapters on lettering,
but the only chapter I've made use of in my drawing yet is the one on applied geometry.
It tells you how to make perfectly parallel lines, perpendicular lines, all kind of regular polygons, ellipses and parabolas, find the centers of circles, and all sorts of things, with just a compass and straight edge!
This has been very helpful for my drafting, or draughting, (is there a difference?) by which I mean drawing things that have to be mathematically precise, which I mainly have to do with design, like this and such. Everybody these days seems to do such things with a computer, but I mostly don't and I like it that way. ^_^
Here are some of my drafting tools. My Ames guide is missing though. : ( St. Anthony, help!
To finish, here's a reason why I prefer traditional drafting to digital. Here's an in-process quatrefoil I made with traditional drafting methods and tools and geometry:
The interior flower-like cross won't be there with the final quatrefoil, but it's part of the process and it's beautiful.
Now here's a shot of the process of making a similar quatrefoil with a vector program: