990828-033a
The elastic earth. The item is a granite core
bit sample, sawed perhaps a foot in length down
the middle. It was actually quite easy to squeeze
the left end and close the gap with little effort.
Actually quite a nice item for display, and hands
on overall appreciation of the earths movements.
990828-034a
John Lahr's exhibits. To the left is a sliding
rock for creating the make a quake, with the sensor computer, monitor and
Dataq converter on the table, in view.
990828-035a
A closeup of the vertical sensor and Dataq module.
990828-037a
Another John Lahr exhibit table. The young man
on the left is using the phone to generate
vibrations, which were displayed on the oscilloscope.
Jan Lahr assisted the setup of various
sensors used on the table. Geophones (acouple),
ordinary speakers, were among the sensors used.
990828-038a
Another John Lahr exhibit. Actually a nicely
made demonstration unit. The rubber band serves
as the spring, with the mass being a cyclinder magnet,
which inducts a voltage, current into the coil.
990828-039a
Also on the table....a L-4 seismometer by Mark Products
Inc. A strip chart recorder was also there, with the paper output
visible behind the seismometer.