A side point that was not highlighted in the essay, is that these WT scans clearly show that up to 1923 they thought that Jesus had come back in 1878... contradicting their claims in their books that in 1914 they were proclaiming that Jesus was enthroned....lololol
Strictly speaking, 1874 was believed to be the year of Christ's return. 3 1/2 years later in 1878 was when he was said to have became Earth's king. 3 1/2 years later in 1881 was the close of the heavenly calling (originally...then the door to the heavenly calling was "left ajar"). Each of these had been a failed prediction, except for 1881 which by that time they were being a bit more careful in what they were predicting.
See:
http://en.wikipedia.org/wiki/Eschatology_of_Jehovah%27s_Witnesses#History_of_eschatology
for more info.