Fred T. Hodgson · Frederick J. Drake and Co. · leaf 476
e arches that couldbe economically and safely constructed were limited tospans of a few feet. The general rule that the line ofresistance fell within the middle third had to be ob-served for simple concrete arches, as for those in brick-work and masonry; and the thickness of the archesat the crown… … HOW TO USE THEM carrying capacity, but by suitably providing for %2ietensile stresses to enable arches of much greater spanand smaller rise to be built. Some general types ofarches in reinforced concrete are shown in Figs. 13, 14,15 and 16. Fig. 13 shows an ordinary arch with topand bottom…
