Got me looking for more info- F. Ross Holland in his Great American Lighthouses book notes that the 3 1/2 order was the size least used by the US. There were 3 installed in Gulf Coast light towers. He also notes that when introduced, 1st & 2nd orders had 5 concentric wicks, 3rd order used 3 wicks, and a 6th order used 1 wick. He also states that the hyper-radiant lens at Makapuu Pt was 16' tall.

Dave