This advertisement for “Graham’s Glass Vacuum Cap” appeared in the Oct. 7, 1905 [1] issue of “Scientific American [2]“. It proclaims: “See Your Hair Grow”. The instructions say that: “…when you have caused a good, healthy, red glow in the scalp…” it will cause hair to grow. I would think a red, glowing scalp would be a sign of other problems…
[3]