Navigation Rhumbs Spirals Tables of meridional parts Stereographic projection Return to TOPICS Return to previous level Fundamental tables Nautical triangles Direct calculations 'It should be mentioned that nowhere in the nearly 675 sheets relevant to these mer-parts does Harriot explain any step he takes.' (Pepper, 1968, 838) For a detailed analysis of Harriot's tables of meridional parts and the supporting calculations, see the article quoted above: Jon Pepper, 'Harriot's calculations of the meridional parts as logarithimic tangents', Archive for History of Exact Sciences, 4 (1968), 359–413. The mapping presented here is based on Pepper's analysis but goes into greater detail, particularly under 'Spirals' and 'Direct calculations' .