A brick-solid image to convey a sense of Anglo-Saxon verse, implying it is precisely constructed and built for the ages.  But then this is a poet writing about poetry.  

… the pointed masonry of Anglo-Saxon verse. 

For a rich selection of other Heaney similes and metaphors, see our celebration of Beowulf, both his version and that of Kevin Crossley-Holland.

Source: Seamus Heaney, Finders Keepers: Selected prose 1971-2001 (London: Faber and Faber, 2003), p. 18

Photo credit: bluebudgie at pixabay