Why did Mr. Rochester propose outdoors in Jane Eyre? Is Mr. Rochester's proposal related to the folk ballad of midsummer-eve, June 23?
Rochester proposes outdoors in keeping with the pathetic fallacy used throughout the novel. The pathetic fallacy is a device in which the weather/setting reflects the emotions of the characters. Because Jane is so intimately tied with her surroundings (the cold, wet weather in Gateshead reflects her isolation and depression, the various storms symbolize her own passion, etc.), it is only fitting that this culmination of their courtship should take place outside. The gentle summer eve in the garden mirrors their love. Or, at least, it should. Yet a storm comes that night, symbolizing that this relationship will not be free and easy. Both Jane and Rochester have overly passionate natures, & the hidden obstacle to their love still remains. It will be a difficult life. Also, the chestnut tree, which represents Jane & Rochester's love, under which Rochester proposes, is split during the storm. This connects back to the storm itself and suggests that their love too will be split.
While I cannot find a direct connection between the two, I assume that the motifs of the folk ballad would reflect the ideas found in Jane Eyre. Because I do not know when the ballad was written, I can't say that Bronte was influenced by it. However, having grown up on the moors, I would argue that Bronte was very open to the power of natural settings, & in tune to the changes of the seasons.