Tired of changing your barogaph charts every Sunday or Monday? I no longer have a monthly quartz movement, however, I do have  a limited number of mechanical monthly clocks with similar fixing arrangements. Monthly charts are available in either inches or millibars and will be supplied as well as a fresh bottle of recording ink and a reprinted instruction pamphlet by Negretti & Zambra. For more information on Monthly clock, have a look at my blog