Hamster Wheel

Found this old postcard someplace (I mirrored it upside down).  The back simply reads "Circus Vargas, Under the World's Largest Big Top".  I'm not sure what year this is from, but judging by the white high-tops and the quality of the postcard, I would guess somewhere in the late 70's to early 80's.  I like the intense concentration on the guys face, and his mid-air poise.  The image also makes me think of the metaphorical hamster wheel many of us must dutifully operate every day when we go to work.