at least two generally orthogonally aligned directions within a horizontal plane to permit adjustment and calibration of the preselected position relative to the objects of interest a plunger member activates the nib and selectively reference marks the slide finally the device includes a mechanism for selectively varying the size of the mark and for automatically maintaining the size once selected application_number US 82195386 A description referring initially to fig1 a microscope 10 includes a lens turret system 12 which is adapted for carrying a plurality of magnifying lens systems known as lens objectives thereon each of these lens objectives of which only one is illustrated in fig1 is designed to provide differing powers of magnification in the illustrated embodiment the objective 14 is known as a scanning objective having a power of magnification sufficient to permit some detailed observation of a microscope slide 16 so as to identify various details and objects of interest thereon yet not so powerful as to provide detailed study of such objects in this manner a microscope slide 16 may be scanned back and forth to determine and locate various objects of interest which can then be relocated for detailed study under greater magnification after complete scanning of the slide 16 by turning of the lens turret 12 to a different more powerful objective typically the microscope slide 16.