those Chambers daisy burners
CU tested were the older single row orifice type, the later dual row with flat diverter top "Plane of Flame" burners were far better... we converted our 1955 copper Chambers cooktop at camp in Vermont to the POF type, overall they can't be beat for low heat saucier work and the like and put out 30% more heat than the older type, but when we need to heat up serious quantities of water such boiling Maine lobbies or for canning 18 pints at a time, we do that on the 39 inch '56 Hotpoint with the 2600 watt RF burner for the really big pots.