Tartaglia on ballistics, 16th century. Surveyor (lower left) using a geometric quadrant with plumb-bob to measure the angle to a cliff-top castle. This method of surveying establishes the distances involved and allows calculation of the trajectory of missiles used in artillery bombardments. Published in 'La noua scientia' (The New Science, 1550) by Italian mathematician and engineer Niccolo Tartaglia (1499-1557).