Familiar unit seen in many museums. Records temperature (from 10-110F) and relative humidity (from 0-100%) on a drum mounted chart. Both scales can be fully calibrated by adjusting the mechanical linkages. This unit runs a bit slow, about 1/2 day on the week, so the clock mechanism may need lubrication.
We have ink, but no original charts. There are photocopies of the lightly used original 7 day chart that was found with the unit.
Unit is 12 wide, 9 high, 6 deep.