Sieve Grip Tractor
Although tractors first appeared in New Zealand in 1909 farmers were unable to take up the new technology. Most tractors were American made and sent to Britain for the war effort.
In 1919 there were only 136 tractors in the country. The first tractors had steel wheels like the Sieve Grip. It's three wheels were designed to grip the ground no matter how wet or rough and were considered cultivators in themselves. There are around 82 sieve grips left in the world.