A needle rubbed with lodestone and suspended (floated on water, balanced on a fingernail or cup rim, or hung by a single silk thread with wax) consistently orients north-south, though it often points slightly east of true south rather than due south. The silk-thread suspension is noted as the steadiest method.
Marine shells and ovoid stones embedded in strata exposed in a cliff hundreds of miles inland indicate that the location was once a seashore. Land and sea positions therefore change over long spans, and present geography does not reflect the permanent past.
Individual characters each carved on separate pieces of fired clay can be set in an iron frame, printed, then disassembled and reused in new combinations, making large print runs cheap while single copies are not worth the setup. The gain comes from treating text as recombinable discrete parts rather than as whole fixed blocks.
The notebook records who actually solved a problem (an artisan, an obscure official, an unnamed craftsman) and the concrete method used, rather than attributing credit to famous or high-status figures. Knowledge is documented by procedure and verifiable result, not by the reputation of its source.
A planet or object that seems to grow and shrink, or move irregularly, can be explained by its changing distance from the observer rather than by actual change in the thing itself. Treating observed variation as an artifact of viewpoint, not of the object, resolves puzzles that a literal reading leaves mysterious.