HYGROTHERMOGRAPH model MM-01 This is an instrument that measures, and records, both humidity and temperature over a 7 day period on a graph paper. The drum is a wind up clockwork type and slowly rotates to record the data. Graph paper is available on the web but you can make your own on the computer included is one used piece for reference. Made by Arthur Bailey Pty Ltd Japan PRICE $100.00 plus postage.
