Further to pdubs point, which is quite correct and had the side effect of putting the distributor in the way of a lot of cold water. In spite of this icing was still a problem in Minis as late as the 70's . The solution was to adjust the air intake by loosening the filter case mounting nut and rotating it until the air intake tube was over the exhaust manifold.
Other cars of similar age, my personal memory is of a Peugeot 104ZS, (where are you now ANB 736T)had manual sliders to alter the mix of ambient and warmed by the exhaust air to the intake. In later versions automatic devices controlled by a wax capsule carried out the function.
Presumably fuel injection and electronic engine management put this in the same category as the starting handle.
Now drive a diesel
[This message has been edited by Airbanda (edited 16 March 2001).]