Schematic of the different kinds of ritual tripods different ranks of nobility were allowed to have during the early (or Western) Zhou dynasty. I get the feeling that the kings were running out of ideas when it came around to what they were going to sacrifice in their last few, since the 8th and 9th tripods are just for 'fresh' versions of the same things that were sacrificed in their 4th and 5th. But hey, if you've got all those tripods it's a shame to let them go to waste.