Liability of Agent to third parties

Name of principal disclosed Agent is not liable except: Where the agent contracts outside the scope of his actual or apparent authority; Agent agrees to be liable; Usage or custom makes the agent liable; Agent contracts by deed in his own name; and Where the principal is in fact non-existent. Kelner v Baxter (1866): where promoters of a company signed "on behalf of the proposed company" for goods. Black v Smallwood (1966): where the directors signed as directors on behalf of the company. Among them, I hope to explain the meaning of "Usage or custom makes the agent liable;" and give examples.

Question from James Cook University, Singapore BU 1112BU1112 T8 ENG.docx https://www.coursehero.com/u/file/106488208/BU1112-T8-ENGdocx/?justUnlocked=1#/doc/qa