Beginning with An Ever-Rotating Wheel of Information:
Mr. King is mentioned in Northanger Abbey:
They made their appearance in the Lower Rooms; and here fortune was more favourable to our heroine. The master of the ceremonies introduced to her a very gentlemanlike young man as a partner; his name was Tilney.
… and later, Mr. Tilney says to Catherine Morland that she should say …
“I danced with a very agreeable young man, introduced by Mr. King; had a great deal of conversation with him—seems a most extraordinary genius—hope I may know more of him. That, madam, is what I wish you to say.”
James King was the master of ceremonies at the Lower Rooms in Bath and later the Upper Rooms. His mention in My Particular Friend as being the emcee first at the Lower Rooms and then later in the Upper Rooms would seem to date the events in this book to 1805. Or it may be that the mention of Lower Rooms in this section is an error.