Survex 1.0 within sight

[Olly Betts]

In message <399BF6E2.1B71985D@zoo.ox.ac.uk>, John Pybus writes:
>I can think of occations when one might be tempted to use a zero
>variance leg (e.g. a rigid measuring stick used for a plumbed leg) but a
>small positive variance could easily be used, and would probably better
>represent the situation anyway.

Indeed.  Your rigid stick is going to expand and contract with temperature
and is also likely to wear down at the ends, the more you take it caving.

Cheers,
Olly