JF Ptak Science Books
I have written several times on this blog about hair: human hair maps, psycho-babble-istic brain vibrating finger hair restorations, and that sort. (Just check out "hair" in the Google search box and you'll find a number of posts.) The fact is that the patent/quack medicines/cures/fix-alls for hair are still entertaining--mainly because though the methods have changed the need still seems to be there and be a constant sorrow.
There is not much to say about this advertisement except that it was a full page in the Illustrated London News (April 21, 1906, p. 573) and was therefore expensive. The apparatus was basically supposed to suck the hair up and out of its Very Secret Place on the scalp and grow, so we know that the Evans Vacuum Cap Co didn't spend very much money on research. And the product itself is a chair, the vacuum cap, and a pump, so the engineering part was not very expensive, either. The thing was offered money-back if not delighted after 60 days, so the vacuum must have at least been effective enough to stimulate some sort of sensation on the wearer and maybe even produce a scalp-hickey. Perhaps people were really surprised that after 90 or 900 days that the Hiding Hair was still so.
No mention of price, though--that would've been nice.