The date is 1845, when daguerreotype image processing was dominant, but this looks like a glass plate image to me. I could be very wrong about that.
You are absolutely right John. Now I feel silly.I don't think that's a number ,I think it's the paddle wheel struts. the braces are there but very flimsy
Actually John ,both sides look a bit chewed up. Just in front of him looks like a single cylinder with lots of piping and what may be a piston rod and crank shaft at the leading end. He doesn't look exactly happy does he - I wonder if he hit something, or the wheels started to break up, there's a bit missing from at least two blades.You are absolutely right John. Now I feel silly.
I was looking at the starboard paddles when I mentioned many braces between them missing. Looks to me as if a fair amount of them are missing.
I just noticed something which I find pretty odd about the paddles. Look at the paddles themselves on the far wheel. It looks like they are hinged so that they all hang vertically. Obviously, we'd expect the one in the top position to appear vertical. But look at the ones at 1 o'clock, 2 and 3 o'clock, ten and eleven o'clock. That seems very odd to me and I can't think of a practical reason to configure them that way. Maybe that's the feature this gent is trying to demonstrate. Could it be paddles that don't throw spray (and therefore don't need shielding) or something of that nature? And if they really are hinged, I wonder how they are locked for the actual underwater part of their revolution?
Coming back to acknowledge rebelatsea's observations. Perhaps I am just seeing a broken wheel.
It's called a feathering wheel, and you get the same power out of a wheel half the diameter of an ordinary wheel. It needs extra machinery inside the wheel and I can't see that here, so your guess is as good as mine.I've seen drawings of paddles like that. The idea is to keep the paddle vertical for the whole time it is in the water, so that all the force goes into pushing the ship forward. As you say, there would need to be some sort of block to hold the paddle in place while in the water. So, it's more efficient but also more complex, probably why it does not seem to have been widespread.
Actually if you look closely at the starboard wheel I think you can see the shaft that is moving the blades on the inside of the three forward paddle blades. The top blade is showing just a little of the shaft, but the 2 blades progressively forward each show more of the shaft.It's called a feathering wheel, and you get the same power out of a wheel half the diameter of an ordinary wheel. It needs extra machinery inside the wheel and I can't see that here, so your guess is as good as mine.
I've had a close look at the blades, and they are actually stepped blades. That was another way of making them more efficient.Actually if you look closely at the starboard wheel I think you can see the shaft that is moving the blades on the inside of the three forward paddle blades. The top blade is showing just a little of the shaft, but the 2 blades progressively forward each show more of the shaft.