c.1300, impose a tax on, from Old French taxer impose a tax (13c.), from Latin taxare evaluate, estimate, assess, handle, also censure, charge, probably a frequentative form of tangere to touch (see tangent). Sense of burden, put a strain on first recorded 1670s; that of censure, reprove is from 1560s.
The average depth of frost penetration ranges from 25 inches (64 cm) in southwestern South Dakota to 50 inches (127 cm) in. the northeast. Depth of frost depends on the amount of residue cover, soil moisture content, and the amount and timing of. snowfalls in relation to temperature extremes.
Most frost tubes have a depth of 60 inches. A plastic PVC pipe is inserted in the ground and a clear tube is placed inside the plastic pipe. A liquid is then placed inside the tube that will change color and freeze when the temperature drops to 32 degrees.