Barigo Barograph's Felt Tip Pen Long Duration

Mechanical barographs have a solid rotating brass drum that is driven by a quartz battery movement to rotate the drum once a week. A felt tip pen at the end of the writing arm shows changes in the air pressure on a paper diagram that is wrapped around the drum. The base plate is of brushed and nickel-plated brass, and the metal parts are chromed. This barograph comes with a supply of chart and felt tip pen for one year.