position micrometer
now rare
noun
An apparatus for measuring the position angle of one celestial object relative to another, containing a thread or wire mounted at the common focus of the objective lens and eyepiece of a telescope, which can be rotated in a plane perpendicular to the axis of the telescope; an apparatus similarly used with a microscope.
Origin
Mid 19th century; earliest use found in The Penny Cyclopaedia.
- centre line
- centremost
- centre of attention
- centre of attraction
- centre of buoyancy
- centre of curvature
- centre of excellence
- centre of flotation
- centre of gravity
- centre of mass
- centre of pressure
- centrepiece
- centrepin
- centre punch
- centre spread
- centre stage
- centrex
- centric
- -centric
- centrical
- centricity
- -centricity
- centrifugal
- centrifugal force
- centrifugally