The hoop has wooden spools (clackers) that slide up and down the hoop's spokes as the wheel turns, making the kind of noise that kids love, and would drive adults up the wall. To add to the din there are metal jingles (aka, clangers) in between the sliding wood clackers. These look a lot like the same jingles ("zills") used in Noble & Cooley tambourines.
|Rolling hoop with clackers and jingles (Photo courtesy of Bill Jones)|
|Close-up of clackers and jingles (Photo courtesy of Bill Jones)|
|1901 Noble & Cooley "Giant Rolling Hoop" using additional clackers due to the larger hoop size. This hoop has a smaller diameter hub, perhaps to achieve a longer "throw" for the clackers to travel between the hub and hoop rim, |
thus creating more momentum and of course, MORE NOISE!
(Image from the NCCHP collection in the Internet Archives)