New York , Hoboken N. J. , Chicago, St. Louis, San Francisco, Montreal: Keuffel & Esser Co. 1920. First Edition. 37, 8, , [3-ads] pages. 5 3/4 x 8 3/4 inches. Printed buff stapled wrappers, rounded corners as issued. Previous owner name on front cover. Creasing, wear and soiling to covers and spine panel. Clean internally noting a few marginal tears. A working copy, but sound. Good. Staplebound. 
Original price fifty cents. Printed 'B' lower left front corner and title page, perhaps indicating a later edition of this manual. We are aware of an edition from 1917 as well.
What rules this specific guide is useful for isn't completely clear. Page 2 contains a NOTICE that this manual applies "particularly to rules Nos. 4031 to 4041, and does not completely cover our newer rules, Nos. 4041F to 4051, which have a slightly different arrangement of the scales on the slide, necessitating these special directions." The balance of Page 2 includes instructions for some of the later rules. So far so good. Page 3 (the start of the "regular manual") notes "Catalogue of Keuffel & Esser Co., Nos 4031 to 4056". The Polyphase Slide rule appears on page 16 (No. 4053-3).
No doubt the manual is of use to most users of K&E rules, as the basic principles are transferrable without significant loss of understanding.