{HEAD ~ These three new types} of leveling instruments do not rely on spirit level bubbles in glass vials used in dumpy levels and in tilting levels, nor on {TAIL ~ the so called self leveling pendulums} used in the automatic levels 
not rely on
{ HEAD ~ These three new types } of leveling instruments do not rely on spirit level bubbles in glass vials used in dumpy levels and in tilting levels , nor on { TAIL ~ the so called self leveling pendulums } used in the automatic levels
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH