There is a useful test of how hard something is to make: look at what people did before they had it.
Before metal needles, sewing was done with points made…
Source: Wikipedia
There is a building material available almost everywhere, requiring no processing, no fuel and no transport, and a very large proportion of the world's population has lived in houses…
There is a tool so ordinary that almost nobody has considered how it works, and the answer turns out to be more particular than expected.
The obvious model is a…
Source: Wikipedia
There is a small piece of rural engineering that walkers cross constantly and rarely examine.
The problem it solves is truly awkward. A boundary must be continuous to hold…
Every terraced landscape is an enormous piece of engineering built by hand over generations, and every element of it answers a specific problem with a slope. Here are seventeen.
1.…
Prints deteriorate through several separate processes, some driven by light, some by chemistry and some by whatever they were stored in. Here are fifteen.
1. Colour Prints Are Made of…