Volumes 1-8 and New Series 1-13 were issued.
Later just called "The Witness".
[Founded by Ross in 1870 as The Northern Evangelistic Intelligencer, the magazine changed its name to The Northern Intelligencer in 1873, later The Northern Witness in 1875, and after Ross passed the editorship to J. R. Caldwell in 1876, it became The Witness in 1887 (an overdue reflection of its broadening influence), with the editorship passing on to Henry Pickering in 1914 at a monthly circulation of 16,000. It was long regarded as the principal Brethren review worldwide, and saw its monthly circulation climb to 30,000 by 1941 at the end of Pickering’s editorship.] From http://impact59.files.wordpress.com/2010/01/donald-ross-soteriological-retrospective-dec09.pdf
The numbering is curious, as 20 volumes of the original series were issued, before in 1891 commencing the 'New Series'. After 21 volumes of the N.S., in 1912 began the 'Enlarged Series'. This only lasted two years though, before in 1914 switching back to the original numbering and that year thus being volume 44!
The Witness merged with The Harvester in 1980.
There were I think 13 volumes issued. I only have one volume. It continued as Echoes of Service.
See their website for more information.
I have the first volume; I don't know much else about it! Apparently Sims was loose OB and favoured women preaching etc. He has an obituary in Believers Pathway, and he was Canadian.