We will begin by taking the strike of a bedding plane. For these measurements we will use a Brunton compass like the one you see in the pictures above. In order to measure the strike, place the side or edge of the compass against the plane of the outcrop. Sometimes it is easier to put your field book against the outcrop and then the compass against the book to get a smoother and/or a larger surface. Now, rotate the compass keeping the lower side edge of the compass fixed, until the bulls-eye level bubble is centered (the round tube; not the long narrow one). When the bubble is centered, the compass is horizontal against the plane and parallel to the line of strike. Now, with the bulls-eye bubble centered, record the number that either end of the compass needle is showing.