Alongside the vast fuel tank which powers the Space Shuttle into orbit are two spindly tubes known as Solid Rocket Boosters (or SRBs). Their shape is not ideal: their manufacturer, a firm called Thiokol, had intended them to be fatter, but was constrained by the width of a horse’s rear end.
It appears that Roman chariots arrived at a standard axle width of 4’ 81/2” for the simple reason that this width could accommodate two horses’ bums between the shafts. Standardisation of axle length was vital, as on muddy roads your wheels formed ruts that set solid in dry weather. A vehicle with a non-standard axle can become fatally cross-rutted, a danger for off-road drivers even today. So the 4’ 81/2” standard became literally entrenched.
Axle-makers maintained this length for the next couple of millennia, even into the railway age (helped by the fact that many early rail carriages were adapted road vehicles).
Get Britain's best politics newsletters
Register to get The Spectator's insight and opinion straight to your inbox. You can then read two free articles each week.
Already a subscriber? Log in
Comments
Join the debate for just £1 a month
Be part of the conversation with other Spectator readers by getting your first three months for £3.
UNLOCK ACCESS Just £1 a monthAlready a subscriber? Log in