Notiser - Notes. A method of counting out petrofabric diagrams.
1, 2

The counting out petrofabric diagrams as described in the literature is carried out by means of a celluloid counter with circular holes representing 1, 1,5 or 2 per cent of the area of the circle of projection. The present writer has found it more convenient to construct a net of circles with the percentage wanted, with the distance between the centres equal to the radius of the circles.