Meaning of "but" in this context [closed]

I read this sentence in The Life of Samuel Johnson:

"The booksellers who contracted with Johnson, single and unaided, for the execution of a work, which in other countries has not been effected but by the co-operating exertions of many, were Mr. Robert Dodsley, Mr. Charles Hitch, Mr. Andrew Millar, the two Messieurs Longman, and the two Messieurs Knapton."

I am not certain about the meaning of "but" in this context. "But" means "only" OR "however". I can skip it and still understand the whole sentence. However, I want to know exactly about it because I am learning the English language.

Solution 1:

It means, here, “except”. “Effected” means “made to happen” here. The “not . . . but” in combination mean “only.”

Solution 2:

As Xanne's answer says it means "except". This is a valid meaning of "but", however it isn't used much these days: ordinary English has changed quite a lot since 1791.

Gooling "but define" returns, among others, this entry from the Online Oxford Living Dictionary in which:

meaning 2 is

{with negative or in questions} Used to indicate the impossibility of anything other than what is being stated.

and meaning 5 is

archaic {with negative} Without it being the case that.

It's always worth looking words up if the meaning you know doesn't make sense in the text you are reading. Lots of English words have (or have had) multiple meanings.