NAUTICAL SLIDE RULE
Weems & Plath
Gives immediate solution to all time-speed
problems. Equally applicable for nautical or statute miles. Speed in knots or
m.p.h., time in hours, minutes, or seconds, and distance in nautical or statute
miles (or yards if desired, and if speed is in knots). Easy to read and accurate.
Two rotating disks on a 7.5 inch square base. SW 0.2 lb.