This is, I hope, my last post on this topic (applause from the
rest who hope so too). I can see it turning into something like
the U of Chicago latke vs. hamantash debates. Everyone is free
to do whatever suits them.
I believe that Bill Lull's preference for drum charts over
circular charts is because the "straightline" format makes it
easier to link chart information from each period into an
extended time series, for analysis. That, after all, is what
environmental monitoring is all about, and not pulling a chart,
saying "Um," and filing it away. Incidentally, most data logger
software makes this much easier, building continuous time
series for analysis automatically.
BTW, anyone who runs a recording hygrometer on 115v AC will
get an infallible record of exactly when the power went off,
but nothing for the length of time when it was.

According to Lori van Handel:
>
> Henry, what I think you mean to say (for those not familiar with Bill
> Lull, etc.) is that circular chart-hygrothermographs are known to be
> unreliable and that the pens often get caught up in each otherr, and in
> general, they are not a sound investment.  Is that right?
>
> Lori van Handel
> [log in to unmask]
>
> On Wed, 14 Feb 1996, Henry Grunder wrote:
>
> > You might have wanted to talk to Bill Lull about circular
> > charts before youn committed.
> >