I’m referring to the old Barnum & Bailey poster on this page. It’s a very long page but the poster is just over a third of the way down under the title The Art of the Big Top #14.
The poster shows a man diving from a great height and heading to what looks like a ski slope. It’s captioned:
This looks like suicide. How is it possible to fall 80 feet, land on one’s chest and survive? But if there’s a trick involved I can’t imagine what it could be. This is in the ring of a circus before a live audience.
Now that I’ve had a chance to examine it some more, it’s clear he’s not landing straight down on his chest, but approaching at an angle which puts him almost parallel to the ramp initially; the ramp then levels off gradually, slowing him via friction. Done right, there should be almost no impact at all.
I’m thinking the “80 feet” might be an exaggeration, and that the actual height was a lot less. Furthermore, the ramp was probably constructed to be somewhat flexible, so that it would “give” after he landed.
The “80 feet” was probably indeed the height from ground level to the platform but the top of the ramp was obviously higher than ground level; likely quite a bit higher. So the actual leap was less than 80 feet.
Presumably the same principle as skiers jumping off very high cliffs and landing on a steep slope - if you don’t hit level ground you don’t slow down as abruptly.
Edit: I just looked at the pic, and I assume the ramp was not really as narrow as it appears in the picture - your aim would have to be VERY good!