The adjustable arm 2 further comprising {HEAD ~ means} for controllably applying {TAIL ~ an axial force} to the contacting regions of the first and second parts of either or both of said base and central housings to supply friction to assist in the maintaining of the positioning of the lamp 
for controllably applying
The adjustable arm 2 further comprising { HEAD ~ means } for controllably applying { TAIL ~ an axial force } to the contacting regions of the first and second parts of either or both of said base and central housings to supply friction to assist in the maintaining of the positioning of the lamp
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH