In operation, when viewing {HEAD ~ the exterior surface} of {TAIL ~ the lamp}, a viewer sees only a portion of the complete image when the light source is extinguished  
of
In operation , when viewing { HEAD ~ the exterior surface } of { TAIL ~ the lamp } , a viewer sees only a portion of the complete image when the light source is extinguished
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH