Extending upwardly of {TAIL ~ the base plate} 51 is {HEAD ~ a pair} of telescope supporting members 54 between which a telescope 55 is pivotally mounted by a pivot shaft 56 
Extending upwardly of is
Extending upwardly of { TAIL ~ the base plate } 51 is { HEAD ~ a pair } of telescope supporting members 54 between which a telescope 55 is pivotally mounted by a pivot shaft 56
REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH REL HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH