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distance is FG. HKD is the angle of thrust due totiie height of the pier — HFG the angle due to thecousinet HEF into which the angles of any weights

WHG, \¥HF, WEF, WGF, whose bases do not ex-ceed HF, nor make a greater angle with a vertical linethan the angle HFG, resolve. Such weights increasingin length as the secant of the angle PEN, they makewith a vertical line to EP radius = the modulus offracture of the material, while they diminish in widthEF as the secant of the angle GFE to GF radius =the modulus of horizontal thrust.

Draw KM parallel to HF and TM parallel to ADintersecting in M.

FEHF is the section of the cousinet or base of theweight.

HKMTFIi the section of the abutment wall.

If the abutment wall be required to be equallystrong in every part.

Let the vertical line KT be the axis of a logarith- p; g- 8>mic curve IHA, whose subtangent equals the mo-dulus of fracture of the material.

Draw HK making an angle KHG with the axisequal to the angle HFG of thrust before obtained,and touching the logarithmic curve. From K takeKG in the axis equal to the subtangent, and drawGH horizontal, cutting the curve in H, the point ofcontact. From G set off GD on the axis equal theheight of the pier, and DT equal to GF the modulusof horizontal thrust and draw DA cutting the curvein A. Draw the tangent AL to the point A, andAB at right angles to AL, cutting TB drawn parallelto AD in B. Draw HF at right angles to HK

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