Russell and Barbour separated in 1879 and in just one short year Barbour came to reject the idea that Christ had returned invisibly in 1874. I only have one page of a July 1880 issue of The Herald of the Morning (page 2), but he clearly states:
And he [Jesus] will come back to the church, in like manner as they saw him go; and not in an invisible manner.
He goes on to explain the details of "Our Mistake."
A PDF of that page from the July 1880 Herald can be downloaded here:
http://www.filesend.net/download.php?f=8e42a2e44a12bcc7eb2d2375fad255a2
This was the subject of several articles in the 1880 Watch Towers. According to the July 1880 WT, Barbour was now teaching that Christ would return in the flesh in 1881:
But there is to be more than one of these deceiving teachers; While one says He is coming in the desert, another says: "Behold he is in the secret chambers." Do we find teaching of this kind now, in the days of the Son of man? Yes, it seems to us that this is being fulfilled; a brother whom we knew well and loved much, thinks that God has given him what he terms "New Oil" (perhaps he does not notice that the virgins of Matt. 25, do not get any new oil; it is the same oil they had at first). But this brother is we think fulfilling this scripture. He is teaching that after 1881, Christ will appear in the flesh secretly, to be seen only by himself and those who believe exactly as he believes. This teaching not only leads to unscriptural expectations, but seems to open the minds of those who receive it to a perilous snare of the devil, which snare is referred to in the "Three Worlds," a book written by this very brother, in 1876, now out of print but possessed by many of our readers, extracts from which will follow this article. The wide diversity of views as stated in that article, and his present view as stated above seems to make good his claim that he has new oil; but it does not commend itself to us as being as good as the old "The old is better." Nor does it answer the conditions of the parable for no new oil was given.
In the August 1880 WT, Russell editorialized that Barbour and his group had lost the light:
Should we wonder if these brethren who have thus laid aside the imputed righteousness of Christ should be deprived of the light which was intended only for "the path of the just,"--those justified by faith in the ransom, and not by their own works.
Such has been the result; these who once rejoiced in the light of "The sure word of Prophecy" which shows us the presence of our Lord as the "Bridegroom," "Reaper" and "King," that proves to us that the "times of restitution of all things began in 1874," and that consequently "the heavens" which were to receive Him until that time, now no longer receive him, but that He is present, and that soon when the separation of wheat and tares is complete, "we shall be changed to His glorious likeness and see Him as He is. All, all this light they have lost, and have now reached the condition of outer-darkness, the condition of darkness on the subject of the Lord's presence that the world and a worldly church have always occupied. The parable says "there shall be wailing and gnashing of teeth," meaning, we suppose, that such shall go through the time of trouble upon the world. With pain and sorrow we part company, but rejoice to know that many who followed them in a measure and were sorely tried are now able to discern between light and "outer darkness." "They went out from us, but they were not of us; for if they had been of us they no doubt would have continued with us; but they went out from us that they might be made manifest, that they were not all of us." But "you have an anointing from the Holy one. You all know it." (1 John 2:19-20.) The Holy Spirit has revealed to us through the word the presence of the Bridegroom and we heard his voice and opened the door of faith and He came in to us and supped with us, and caused us to sit down to meat (truth), and himself has been our teacher and served us, (Rev. 3:20, Luke 12:37). And our faith does not stand in the wisdom of men but in the power and word of God. (1 Cor. 2:5.) And still beloved, there may be other trials for you.