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