IN presenting a description of milling and treatment methods at the Waihi mine, it is advisable to first traverse a good deal of the past history of the mine, and show the various steps which have led up to present-day practice. The record of the company is one of steady, solid advancement, both in metallurgical and financial results. This is illustrated by the following figures, dating back from 1897. In every department of milling and treatment no expense has been spared in making experiments which might result in lower working cost, increased output, or improved extraction. Many small improvements have been introduced which, though perhaps of little account to a mine operating only on a small scale, have had an important bearing on the results achieved at Waihi.