Using the Scale of Chords–a Twenty Page Pamphlet (PDF Download)


Download file for a twenty-page pamphlet on using and making a Scale of Chords.




In traditional layout work, the joiner rarely needed to know the numerical value (i.e. degree) of an angle. Line intersections were usually generated to a certain “run-to-rise pitch” or through standard geometric constructions.  When a number of degrees was needed–an increasing occurrence when machines with numerically indexed fences came into the trade–a joiner would make and use this scale to lift that number directly from the line drawing. Conversely, they could draw a line to a specified degree or pitch using the scale as a layout tool. With careful alignment (and good eyesight!) the scale can be read to an accuracy of plus or minus two-tenths of a degree. Large versions for larger scale drawings (loftings in boatbuilding parlance) were even more accurate. This twenty-page downloadable pamphlet shows you how to use and make this ancient layout tool. Please note that you are purchasing a downloadable file that you can view or print out, not a hard copy of the pamphlet.