Got it. My problem was that I was expecting the line to snap to the object as I was drawing it. But I had to place it approximately, then select it and then it would snap to the middle of a bounding box side or corner.

Thanks.

I'm new to Inkscape and I've been reading The Book of Inkscape. My problem is with snapping from the middle of a bounding box edge. Here's what I'm doing 1. Make the snap control bar visible with View>Show/Hide>Snap Controls Bar. 2. Enable snapping with View>Snap or %. 3. Create two boxes. 4. Select...