Review on Bricklaying Guttering Engineering Surveying Equipment by Nigel Cohen

I am building a deck and use a spirit level to determine the height of the concrete. When I noticed that one end of my 32 foot deck was 1/2 inch lower than my siding and the other end was almost 6 inches lower and the level still indicated I needed to lower that end. I flipped the horizontal position and it turned out that the other end was too high.