The limit of pressure to which an underground dam may with safety be subjected, is a question that—as far as the writer knows—has not received the same attention from authorities on engineering construction, or practical mining, that has been accorded to questions on which the design and strength of other structures or machines in connection … Read more
It has been more especially in these large low grade ore bodies, that modern methods have been beneficial; for small lodes must be rich to pay at all, as they cannot be worked on the same gigantic scale, but even in these a percentage of metal is saved which formerly was absolutely lost. To make … Read more
In the Engineering and Mining Journal there appeared an article by Fred T. Greene, describing a method of measuring stopes by the use of strings, a clinometer and a tape. I had occasion to use a somewhat similar method, for the purpose of accurately ascertaining the volume of a very irregular drift connecting two mines. This … Read more
I have chosen this subject in view of the fact that, while there are many and ample opportunities of getting reliable assays made, there are but few who are in a position to obtain reliable data on the sampling of minerals and metals; my long experience, where, for five years, I had charge of the Refining … Read more
In presenting the subject of “ Armored Turrets for Coast Defense ” to this Institute, I am indebted to the Gruson Iron-works, a company incorporated under the laws of the State of New York, for valuable information, model and plans, by which I hope to make clear the construction and peculiar merits of this class … Read more
It has already been shown by Maclaurin, that the dissolving power of a cyanide solution saturated with oxygen increases with its strength until a strength of 5 or 10 per cent, is reached, and diminishes again as the strength in cyanide increases beyond that point. But, so far as I am aware, no one has … Read more
The practice of the cyanide-process of gold-extraction has brought to light many important contradictions of familiar chemical analogies, which still obscure both the theory and the practice of the art with distinctions subtler and more difficult to make or follow than those which delighted the heart of the old-time metaphysician. Yet Nature herself has drawn … Read more
The extreme difficulty of obtaining a short and, at the same time, exact method for the determination of gold and silver in copper materials has been well illustrated in “Assays of Copper and Copper-Matte,” and its discussion, by Dr. A. R. Ledoux and other leading authorities on this subject. Two general methods were used by the … Read more
As it is my opinion that deep alluvial mining methods in Victoria and in the Murray Flats in New South Wales are practically in their infancy, and considering that we, the old school, of alluvial miners, who have thirty or forty years’ experience to guide us, must in the natural order of things hand over the management … Read more
The following paper deals with a method for the “Approximate Analysis ” of Chloridized Ores, which are free from arsenic, antimony and lime. When these are present the analysis is rendered far more complicated, and many of the methods which I am about to describe could not be applied. Sufficient scope is therefore offered for … Read more