William Dunbar, ‘To the City of London’.
London, thou art of townes A per se.
Soveraign of cities, seemliest in sight,
Of high renoun, riches and royaltie;
Of lordis, barons, and many a goodly knyght;
Of most delectable lusty ladies bright;
Of famous prelatis, in habitis clericall;
Of merchauntis full of substaunce and of myght:
London, thou art the flour of Cities all …
Answer:
Bellows
Explanation:
A bellow or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtight cavity which can be expanded and contracted by operating the handles, and fitted with a valve allowing air to fill the cavity when expanded, and with a tube through which the air is forced out in a stream when the cavity is compressed
Natural Barriers are correct