The wheel is frequently described as the great invention. The wheel-and-axle pair is the invention; a disc that rolls is obvious, and attaching it usefully is not. Here are twelve…
The thing worth understanding first is that a rope is not a long thing. It is an enormous number of short things arranged so that pulling on the assembly squeezes…
There is a category of object that has to be got right first time, and a large bell is among the more demanding examples.
It is cast in one piece…
The distinction worth holding is between measuring and comparing. A ruler asserts a length and can be wrong about it. The instruments below compare one thing against another, or against…
Sand seems like the least plausible thing to run short of. It is the archetype of abundance — the thing in the metaphor about counting grains, covering deserts and beaches…
For most of the history of ocean navigation, a ship's crew could tell you how far north or south they were with reasonable confidence and had very little idea how…