New York, Hoboken N. J. , Chicago, Detroit, St. Louis, San Francisco, Los Angeles, Montreal: Keuffel & Esser Co. 1948. First Edition. 40 pages. Printed card covers with comb binding. Imprint and title from front cover. A beat up example, with drink "ring" stain to front cover, scratches, drink spill to rear cover. Occasional spotting internally. A well used reference copy. Good. Comb. 
A brief manual showing the basic principles of these instruments and how they are used.