The evolution of useful things

is an excellent book by Henry Petroski (isbn 0-679-74039-2). As usual I'm going to quote from a few pages:
Can any single theory explain the shape of a Western saw, which cuts on the push stroke, as readily as an Eastern one, which cuts on the pull?
A French book of advice to students recognised the implicit threat involved in using a weapon at the table, and instructed its readers to place the sharp edge of their knife facing towards themselves… Such actions, coupled with the growing widespread use of forks, gave the table knife its now familiar blunt-tipped blade.
Round chopsticks would tend to twist in the fingers and roll off the table, and so squaring one end eliminated two annoyances in what is certainly a brilliant design.
The stories associated with knives, forks, and spoons also illustrate well how interrelated are technology and culture generally.
Luxury, rather than necessity, is the mother of invention.
The very properties of the material that make it possible to be shaped into a useful object also limit its use.
Engineering is invention institutionalised, and engineers engaged in design are inventors who are daily looking for ways to overcome the limitations of what already works.
It is not the form follows function but, rather, that the form of one thing follows from the failure of another thing to function as we would like.
When sewn into a garment, a piece of thread can be thought of as a continuous and flexible ghost of a needle.
It is 3M's policy (and that of other enlightened companies) to allow its engineers to spend a certain percentage of their work time on projects of their own choosing, a practice known as "bootlegging".