Twentieth century hand-book for steam engineers and electricians with questions and answers; a practical non-technical treatise .. (1913)
Swingle, Calvin Franklin, 1846- [from old catalog] · Chicago, F. J. Drake & company · leaf 1402
of liquid through a pipe, we estimate the-size of the pipe and the comparison of sizes in the pipes bySquaring the diameter, in inches, and multiplying the re-;ult by the standard fraction .7854. By way of explanation^ve will dwell upon the above method for a short time. In<Fig. 658 we have a… … Fig. 658 have .7854 of a square inch. If the diameter of this circleis 2 inches instead of 1, you can readily see by Fig. 659that its area is four times as great or 2X^=4. We thenmultiply by the standard number .7854 in order to find thearea contained in the two-inch circle; and if the diameterwere…
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