Microscopic Views of a 4M Sappphire Stylus

[VintageTechnologies]

I have used microscopes to evaluate the condition of diamond and sapphire styluses for almost 50 years, but never until now had a feasible way to take pictures. I finally cobbled up a solution from parts found on eBay and took pictures of various styluses to try my system out.

The 4-minute sapphire stylus on an Edison reproducer (such as H or K) is so tiny that most folks have a poor idea what one even looks like. The pictures that I show here were taken of a rare N-56 reproducer. The higher magnification is about 75x.

It appears that a "doorknob" was ground onto the end of a sapphire shaft. Then it was set into a hole drilled in the stylus bar. I marvel that Edison was able to grind thousands of styluses of such tiny precision.

[billybob62]

Thanks for posting that.