Build a better mouse trap, and the world will beat a path to your door.

Ralph Waldo Emerson is often quoted as follows:

"Build a better mouse trap, and the world will beat a path to your door." (All over the net.)

However, the closest quote of him that has ever been published in print goes:

"If a man has good corn, or wood, or boards, or pigs, to sell, or can make better chairs or knives, crucibles or church organs, than anybody else, you will find a broad hard-beaten road to his house, though it be in the woods." (Journals of Ralph Waldo Emerson, vol 8, pp. 528-529. Constable & Co., London, 1909, available at archive.org.)

Where, then, does the saying come from? Burton Stevenson (1934. The mouse trap. The Colophon, Item 7, pt 19, vol 5, December 1934) has tracked it down to a compendium of aphorisms compiled by two ladies of the First Unitarian Church of Oakland, Sarah S. Beach Yule and Mary S. Keene. The compendium is called Borrowings: A compilation of helpful thoughts from great authors (1889, available at archive.org). It gives the following aphorism on page 38:

 "If a man can write a better book, preach a better sermon, or make a better mouse trap, than his neighbor, though he builds his house in the woods, the world will make a beaten path to his door.     --Emerson"

The ladies did not list references, they just listed a number of poems at the end, but no reference to Emerson. Being asked about the origin of the aphorism in 1912, Mrs. Yule remembered (my emphases):

"To the best of my knowledge and belief, I copied it in my handbook from an address delivered long ago, it being my custom to write everything there that I thought particularly good, if expressed in a concise form; and when we were compiling Borrowings, I drew on this old book freely." (Quoted in Raymond Adams 1947. Emerson's brother and the mousetrap. Modern Language Notes 63(7): 483-486.)

Both Stevenson and Adams trusted that the aphorism in Borrowings was a verbatim quote of what Sarah Yule had heard Emerson say in one of his lectures, but I wonder about the meaning of the passages emphasised  above:

"To the best of my knowledge and belief, ..."

"... that I thought particularly good, if expressed in a concise form, ..."

"... I drew on this old book feely."

There seems to be some scope for the possibility that Mrs. Yule had improved a little what she had heard. Or, as typical for history, we will never know what happened exactly.