Near and Far, Together
View through the eyepiece, both near and far, together.
Post-Script: I've seen samples of the See and Draw Copier online in much better condition, but none would have the quality of memories as this one particular specimen. As for grandpa's mechanical calculators, I'll have to ask my oldest brother if he has any in his possession, and will post an article accordingly.
Here's a wikipedia article about the Camera Lucida.
Typecast via Remington Ten Forty (whose ribbon vibrator has taken on a decidedly clanky mechanical sound this week), photos via Lumix G5.