{TAIL ~ 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 {HEAD ~ the so called self leveling pendulums} used in the automatic levels 
{ TAIL ~ 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 { HEAD ~ the so called self leveling pendulums } used in the automatic levels
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