The adjustable arm 2 further comprising means for controllably applying 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 {HEAD ~ friction} to assist in {TAIL ~ the maintaining} of the positioning of the lamp 
The adjustable arm 2 further comprising means for controllably applying 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 { HEAD ~ friction } to assist in { TAIL ~ the maintaining } of the positioning of the lamp
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 OTH HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH