As a solo-surveyor, it's sometimes difficult to use a spirit level, unfurled tape measure and a camera at the same time to photograph how out of plumb or level walls and floors are. The taper gauge makes this a bit easier and can be used to accurately measure how out walls and floors are. They can then be accurately monitored with the seasons if necessary.  

​

I thought this would be an easy thing to get hold of as it seems quite a simple thing, but I was wrong. Seems they are mainly used in welding and it was over £25 for this small wedge of metal!