source file: m1544.txt
Date: Sat, 03 Oct 1998 12:17:37 -0500

Subject: Re: TUNING digest 1541

From: Gary Morrison <mr88cet@texas.net>

>    The same thing happens in an airplane when the two engines of a twin get
> out of synch.  I have seen drinks and ashtrays throb with the difference
> pulse.

     That's definitely not a linear system.