Cylinder blocks
Free blocks . Take only whole ones if wanted
According to Ralph, these cylinder blocks may be for building circular pyramids. However, according to the photo, these are not cylinders at all. They are square or rectangles or hexagons or decahedrons or maybe shape shifters. At least Sparky isn’t insisting we take blocks we don’t want. Everyone knows that leads to blocks being abandoned in the desert and reproducing with geods and running in packs. Not a good way to live for blocks.
Thanks, Ralph, lovely find.
Welcome To Fabulous Sparkyville 
Have to guess that sparkii speel mangled “cinder blicks”–a common name for Concrete Masonry Units.
Said term of art dating back to a product of limited utility using smelter waste (“cinders”) bonded with lime or portland cement.
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Aa a matter of fact, one can construct a cylinder of CMU. It fust needs to be a shade over 12 feet in diameter.
Which will require rather more blocks than Spark has in this ad.
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Hmm, looks like Spark took a dare about knocking his blocks off a shade too literally . . .
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Blocks, some are broken
As much as Sparky’s spelling
Masonry as sieve.
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To the Back Wall, the Back Wall
To wall up the breach
With cylinder blocks.
In peace nothing so becomes
A geometry as a tea cup
But in War to take up
The Moebius instead.
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