div class=ts-pagebuttonPage 1button div class=ts-image amp-img class=ts-thumb alt=Page 1: stereo photography was employed the profile was marked by targets on or in the plane of desired cross section The tunnel lining was illuminated and the profile plotted using src=https:reader034vdocumentsusreader034viewer20220421055e8331fa0a9dd143a4216066html5thumbnails1jpg width=142 height=106 layout=responsive amp-img divdivdiv class=ts-pagebuttonPage 2button div class=ts-image amp-img class=ts-thumb alt=Page 2: stereo photography was employed the profile was marked by targets on or in the plane of desired cross section The tunnel lining was illuminated and the profile plotted using src=https:reader034vdocumentsusreader034viewer20220421055e8331fa0a9dd143a4216066html5thumbnails2jpg width=142 height=106 layout=responsive amp-img divdivdiv class=ts-pagebuttonPage 3button div class=ts-image amp-img class=ts-thumb alt=Page 3: stereo photography was employed the profile was marked by targets on or in the plane of desired cross section The tunnel lining was illuminated and the profile plotted using src=https:reader034vdocumentsusreader034viewer20220421055e8331fa0a9dd143a4216066html5thumbnails3jpg width=142 height=106 layout=responsive amp-img divdiv