Notes on the section in the new Haymarket Tunnel
Henry M. Cadell · Transactions of the Edinburgh Geological Society · 1895
The new Haymarket Tunnel, which runs parallel to and alongside of the original tunnel, has a length of about 1000 yards between the Haymarket Station at its western and St Cuthbert's Churchyard at its eastern end. The excavation was a work of great engineering skill, as the crown of the arch had at places to be constructed in soft, loose soil, a very few feet below the buildings above. At other places the whole of the excavation was in the solid rock, and while the work was in progress I had, through the kindness of Mr W. Laing, one of the engineers in charge, an opportunity of paying several visits and examining the sections as they were opened up during the winter and spring of 1893. The exigencies of the case necessitated the building in of the ring as the cutting advanced, so that the section was closed in a very short time after it was opened up. I was thus only able to catch a series of glimpses of the parts that were open at the time of my visits, and may well have missed interesting parts between. I saw, however, good samples of most of the rock that had been excavated as it was carted away, so that I was enabled to judge pretty accurately of the nature of the rock all the way along the excavation. Since this section is now quite concealed I think that perhaps some useful purpose may be served by placing on record