Making a seismograph

I'm not totally sure I'm clear about the difference between a seismograph and a seismometer---I think seismograph is the older term, referring to a machine that actually outputs the data on paper (a seismogram). Now, they're usually called seismometers because they record the data digitally. If I've got that right, that would make our machine a seismograph. This was a fun project suggested in one of the books we read. It's easy to make---you just poke a hole in a paper cup so that a marker tip will fit through, like this:

You suspend the cup and marker from a string inside a box. Thread a long strip of paper through slits on either side of the box, and then gently shake the box as another person pulls the paper through.

Here is the seismogram our seismograph made! I think we recorded some large earthquakes. :)