Questions tagged [us223898]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1 vote
1 answer
89 views

Is there a more basic patent on a parabolic reflector with prismatic fluting?

US563836 A was granted in 1896. Edison's light bulb dates from 1879, US223898 A. There is a key idea, namely a parabolic reflector made of glass. Rather than being silvered to reflect light, the ...
user7178's user avatar