Autumnal catarrh (Hay fever) with three maps.

Wyman conducted experiments that convinced him that ragweed was a cause of hay fever. He then collected data from correspondents and published the first pollen maps of the U.S. so that sufferers could plan vacations in low pollen areas. The pollen maps cover the United States, New England States, and White Mountains and vicinity. Digital facsimile from Google Books at this link.