(UN-1 12, 5 b; cf. next.)

1

1835.  Edin. Rev., LX. 460. We must leave the demonstration of its unnavigability to repose with the … demonstrations of the permeability of the Polar Sea.

2

1884.  Ld. Harris, in Nat. Rev., March, 125. Frustrated by the unnavigability of its upper waters.

3