This card may have suggested a riding hat or helmet, or a jockey cap but note the horses are not being ridden. And it may also have been a top hat, the usual choice of a ringmaster, but ours is bareheaded - as well as the fact that he is probably a horse trainer, rather than the ringmaster, who would not be holding those poles.
In fact we were after a "plug" hat. This is another name for a bowler, and it is described officially as a hard felt hat with a rounded top and a narrow brim. I am not sure why it came to have this name, but perhaps it was because it was rather tight fitting and it so it was like inserting a plug (your head) into a socket (the hat). It does seem to be an American term for it, especially used in what we call the Wild West, where such hats were very popular. However there is also a thought that in America a plug hat was actually another name for a top hat.
This set has three official Lorillard versions, plus an anonymous one. The trio are described together in our original World Tobacco Issues Index as :
CIRCUS SCENES (A). Lg. 101 x 57. Without captions. Unnd. (25). See ABC/268 and X2/268.A. Ref USA/268
(a) "Red Cross" wording front and back.
(b) "Red Cross" wording on front, plain back. Brand issue
(c) "Sensation" wording front and back.
For anonymous issue without wording front or back, see ZH1-4
The updated version is exactly the same apart from the references to ABC/268 and X2/268.A. The ABC code is the American Book of Checklists, which by then was a collectors item and long out of print, so not as easily accessible as it would have been in the 1950s. The X2 code refers to the original handbook to the original World Tobacco Issues Index, which was first issued as a separate booklet and then combined in a single cover later. Whilst it has the same text as above, there is a photo of all the cards, which I will do my best to scan by the weekend.