Armies tend to get equipped with felt overboots every time their local megalomaniac decides it’s a good idea to pick a fight with Russia (The French army still gets these issued with only a single word of explanation: “Moscow”).
Standing on a Northern railway platform recently, I was reminded of these facts, whilst also thinking that wet leather is a surprisingly good thermal conductor of heat from my feet to the frozen ground.
Rather than go with felt, though, I thought that it would be good to stand on two vacuum flasks.
Today’s invention is a clip-on sole for shoes containing two, flat ‘vacuum’ chambers; one for the forefoot and one for the heel. Each of these chambers would have a thin outer wall made of fibreglass, to sustain the low internal pressure, whilst also minimising the conduction of heat from foot to floor.
