This may be of interest to researchers. Below is information on how to download a text file (about 70 MB) of the Watch Tower magazine from 1879-1916 in searchable PDF. Info on the file follows.
This PDF is a text edition of all Watch Tower issues from 1879 to 1916. It is the most complete collection to date, including the supplement on the Tabernacle published with the February 1882 issue; the extra edition published April 25, 1894 entitled "A Conspiracy Exposed" (both of which are not in Watch Tower Reprints); the full text and music of the "Musical Tower" (February 1, 1896); and the January 1, 1912 issue publicizing Pastor Russell's "Round the World Tour." The vast majority of these text file issues were produced by Bible Students Library and are used by permission.
To download the file. Go to:
http://www.filesend.net/download.php?f=8a1d312ac9af051d6547f387fcc80469
At the bottom of the page will appear a yellow "download" button. (Initially, there may be a countdown before the yellow "download" button appears.) Once the download button appears, click on it and you can begin your download.
A note to some researchers: There was an initial test version of this file that had a limited distribution. This version includes more text and has permission for distribution.