RIVEROLOGY by Dr. Klarenc Wade Mak.  Published by Dr. Mak & Himself, Kansas City, Missouri, 1923.  Small softcover (miniature booklet), 84 pages.  Roughly 6 x 4 inches in size.  There are only two black-and-white illustrations.  Good condition.  Soiling, scuffing, creases and edge-wear (creases, tears, chips, etc.) to the covers and some of the pages.  The stapled binding is still firm.  This humorous little mini-booklet gives an informational "tour" of various rivers throughout the world (beginning in Minnesota).