Large image is Marvin barograph. Lower left image is Marvin nephoscope.
In: The Aims and Methods of Meteorological Work by Cleveland Abbe. In: Maryland
Weather Service, Johns Hopkins Press, Baltimore, 1899. Volume I. Page 324.
Image ID: wea00924, NOAA's National Weather Service (NWS) Collection Photographer: Archival Photograph by Mr. Sean Linehan, NOS, NGS