48 having dug non-stop for sixteen days through sixteen layers of concrete , clay times eleven , gravel , sawdust , and now a stone floor that was possibly a road ( roman ) , the unearther at last scraped his spade , which shone like the milky way and had cut more worms than any rotavator , he at last scraped his spade , the handle of which was worn to match thickness and the rivets of which had been replaced several times over by nails scavenged from the loam , mostly rusty , he at last scraped his spade , its shaft buckled and twisted like a witch 's limb , at last scraped his spade , this extraordinary implement - for no ordinary tool could have taken such punishment - at last scraped his spade over the still solid lid of a - wait for it , focus and concentrate , do all those breathing exercises - lid of a lid of a coffin .