. Transactions. f begin-ning, is such a curve; which may be called a secondary logarith-mic plot. The area enclosed by the curve and the base line, be-tween any two vertical lines, represents the percentage of mate-rial in the sample, between the two sizes corresponding to thevertical lines taken. The scale is so chosen for Figs. 12 to 14 ill i: i INC i sizing i ! 1>83 and lii to L8, thai -•> Bqoarea represent 10 per cent.; and thepercentage between any two adjoining Rittinger sizes is Bhownby the average height of the curve between them, measuredl.\ the vertical scale of percentage
. Transactions. f begin-ning, is such a curve; which may be called a secondary logarith-mic plot. The area enclosed by the curve and the base line, be-tween any two vertical lines, represents the percentage of mate-rial in the sample, between the two sizes corresponding to thevertical lines taken. The scale is so chosen for Figs. 12 to 14 ill i: i INC i sizing i ! 1>83 and lii to L8, thai -•> Bqoarea represent 10 per cent.; and thepercentage between any two adjoining Rittinger sizes is Bhownby the average height of the curve between them, measuredl.\ the vertical scale of percentages n the K-it of the plot. This curve Bhows pictoriallv the relative quantities betw<any Bet of sizes, but the actual quantity ie not easy of determi-nation except by measurement with a planimeter. It camtherefore, till the plain- of the cumulative logarithmic plot aBimple method of graphic representation. The pictorial qualityof this diagram is its chief merit, as it shows the predominating Fig. 32 16 Diameters in millimeters 0. b -2 -3 -4 -5 -6 —7 10 98 765432 3F LOGARITHMS OF DIAMETERS MULTIPLIED BY Each fifth vertical section line corresponds to a size of the Eittinger Scale, Cumulative and Secondary Logarithmic Plots for Sample No. 1 Mill No. 28. (See Table V. and Fig. 5.) - by a glance at the vertical scale. Referring to Fig. 12, it3een that no grains will be found in the sample coarser thanthe size represented by the point c. This point is at onthe scale of logarithms; divide this by and we have ,which is the common logarithm of the size; and a reference toI table of logarithms shows it to correspond to mm. Just as should be expected in a sized product, a consider-able proportion of the coarsest grains is shown by the verticalheight of the curve at this point. The predominating size isfound, however, at the point p. The reading of the scale of 284 THE PLOTTING OP BIZING-TBSTS. Logarithms a
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
