What historical item is commonly cited as a potential inspiration for the reflective nature of the Cats Eye?

Answer

Diamond studs on horse harnesses or carriages

One of the common anecdotes surrounding the inspiration for the Cat's Eye suggests that Percy Shaw observed diamond studs on horse harnesses or carriages, which would capture and reflect the light from street lamps. This observation, combined with the dangerous reality of driving on dark roads, helped crystallize his idea for a device embedded in the road that could perform a similar reflective function for motor vehicles.

What historical item is commonly cited as a potential inspiration for the reflective nature of the Cats Eye?
personinventorengineeringreflectorroad safety