Annie : Barbour already knew of the 1873 date. It was common in the literature, which Barbour well knew.
Annie, I am greatly indebted to you, your mum, and especially to Bruce Schulz for the enormous amount of research provided on Barbour and others who influenced Russell. But Barbour says he reached the 1873 date while at sea, prior to consulting Horae. I previously quoted what he wrote in Evidences for the Coming of the Lord in 1873; or the Midnight Cry, pp.32,33:
The midnight cry, or coming of the Lord in 1873, began on the sea... In our explanation [of the 1,290 days in Daniel 12] in 1843, why did we begin the thousand years thirty years before the abomination was set up? Here is our mistake; and it is one of thirty years. The days end in '73, not '43. All this came in a moment. From that hour, says the brother [i.e. Barbour], the whole truth of our position was made clear.
Now Barbour reached London at the end of this voyage in 1860 and he wrote Evidences for the Coming of the Lord in 1873, Or Midnight Cry in 1870. So he had ten years when he may well have read much or all of the literature to which you refer. But if he reached the 1873 date on board ship, as he says he did, then he did it without the benefit of Elliott, Bowen, et al. The only person he credits by name is Miller. He says in Evidences for the Coming of the Lord in 1873, Or Midnight Cry, pp.33,34
I do not say 1873 had not been mentioned prior to that. Bro. Miller stated soon after 1843 had past, "that he could see no light this side of 1873"; and others may have said as much, or more, at that early day. But as a persistent cry, so far as at present known to the writer [i.e. Barbour], it began as above stated, early in the midnight hour..
What difference does it make? None. But it is not correct to say that Barbour/Russell was not influenced by Miller and the Second Adventists.