Referring to FIG 2, {HEAD ~ the linear motion} of a microscope slide 2 and the limited rotary motion of {TAIL ~ an oscillating arm} 19 carrying lens 18 are depicted 
Referring to FIG 2 , { HEAD ~ the linear motion } of a microscope slide 2 and the limited rotary motion of { TAIL ~ an oscillating arm } 19 carrying lens 18 are depicted
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH