Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
An arrangement for ensuring the fixity of the eye piece and the stability of the line of sight with regard to the vertical in sighting apparatus on board vessels
Improvements relating to means or apparatus to be employed in testing or investigating and in maintaining or correcting or remedying and/or developing the power of humanvision
Improvements in and relating to an arrangement for projecting in superposition the images of a work piece and of a reference drawing through an outline projector