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Graphical methods are often used by engineers to solve frequently used or complex formulas which require trial and error solutions. Perhaps the best known graphical tool used by the engineer is the slide rule, but anyone familiar with its use will recognize its limitations both in time and accuracy. For many problems which involve many repetitive computations high speed digital or analog computers are the most effective tools for solution. There are, however, many problems requiring considerable engineering time for slide rule solutions where solutions are not justifiable on computers. The use of nomograms for such problems is desirable.

A nomogram is a graphical representation of a particular formula in which the combination of scales is so arranged on paper that engineer or technicians can readily obtain the desired answer by following a set of simple instructions. Accuracy of a nomogarm is limited by size of the chart. Usually some compromise must be made between accuracy and size.

This publication presents nomograms and charts which solve the hydraulic equations most frequently used for both open channel and pipe flow problems. This method of solution should be of considerable practical value over "cut and try: approach usually applied to these kinds of problems. The first series of figures in this publication solve open channel flow problems, and the last two figures solve pipe flow problems. The use of the nomograms and charts is described briefly and illustrated by example problems in the sections that follow.

This work was started by the author while on the staff of Humboldt State College, Arcata, California, and completed while employed as Research Engineer at the Utah Water Research Laboratory, Logan, Utah.