Fecha de publicación: 06/11/1913 Fuente: WIPO "pollen" 1111. Pollen, A. H., and Isherwood, H. Jan. 15. Protractors.-In an instrument for plotting the courses of a ship and its target, a dial 60 concentric to the target pricker 55 is kept always parallel to itself and is used to ascertain the bearing of the target's course.