Arizona republican., 1910-10-03
FINDING ORE BODIES
 BY MECHANICAL MEANS
A Recent Demonstration in Pima County to Be Tested By Develop
 ment.

The mining world will watch with unusual interest the development of the Kelvin Sultana mine ill Pinal county, not only because the develop ment of any big mine is interesting, but because in this instance it will be a practical test of a mechanical device for locating bodies of copper ore that, if successful, will eventually revolu- tionize and economiZe the methods of ore discovery. The device referred to is known as the electro -terreohmeter, an invention that has been in exist ence for several years but the use of which has been very limited. It IS said there are only four of them in existence. John Longear, well-known mining engineer, has the rights for the use of the instrument in northern Michigan, Wisconsin and Minnesota. It is said that he depends upon it very largely in his operations and that he has in the last seven years placed millions of dollars owrth of mineral ground with the steel trust, an indi- cation that he had demonstrated its worth It is further stated that he paid $60, ,000 for the use of the in- strument in the territory named. An other of the instruments is owned by George F. Baldwin of Chicago, the principal owner of the Kelvin Sultana property and president of the com pany, and it is this one that was used by Neil McMillan, general manager of the property in the explorations of which mention is about to be made. Where the other two electro terreoh- meters are owned or used, the writer is not informed
 The Kelvin Sultana property is just across the Gila river from Kelvin. It was originally known as the Bryan group of mines and has passed through successive ownerships until it came into the hands of the Kelvin Sultana company, this having been previously mentioned in detail in these columns. The Kelvin Sultana company was organized only few months ago and Neil McMillen, a mining man of experience, was made geenral manager. He came to Arizona in July, looked the property over thoroughly and as he believes located its large ore bodies with the electro terreohmeter, leaving here about the middle of August, announcing that de- velopment work would be undertaken as soon as possible and pushed with vigor. At that time mention was made of his presence here and his plans for development, though noth- ing was made public concerning his experiments with the electric device or the manner in which he satisfied himself concerning the mineral re- sources of the property.
 Since returning to Chicago various circulars have been issued by the company descriptive of its plans, stat ing that eompressors and power drills have been ordered and outlining the plan of developing what the manager believes to be the big known" ore body of the property, though admit ting that it has never been exposed to human gaze, notwithstanding it has been scratched a little by the previous development of the preceding com panies. In other words the workings thus far have not been deep enough to penetrate the large bodies, though fine ore has been encountered in many places and taking the average of the selected ore that has been shipped and that ran high in copper, and the average of the ore left on the dumps, MT. McMillan estimates that the aver age of all the copper ore in the prop erty will run six per cent in copper, four ounces in silver and fifteen per cent iron.
 Returning to the interesting feature of the case, the electrical ore finder, MT. McMillan announces that he is positively certain that he has located an ore body at least 600 feet wide and 1000 feet long and that it approaches as near to the surface as 200 feet, per haps a little nearer in places. He be- lieves the ore body is much larger but on account of the surrounding surface conditions, the ground being greatly evaded, the instrument could not be used satisfactorily. Mir. McMillan says that the electro -terrohmeter is not to be classed with the 'willow wand, the "magician's scepters," the clairvo- wants dreams, or any of those some what occult methods of imparting al- legged truths to the gullible seekers after the unknowable. On the other hand it is contended that it is merely an application of the same principle that has been employed for yeacs in locating breaks in telephone and tele- graph wires, broken cables in the ocean and forgotten water mains in the streets Describing the instrument and its use MT. McMillan says:
 Tn the use of this instrument we have a scientific electrical process by which we can definitely determine whether or not there is mineral in any given locality in the earth, the com- parative amount and the appr1XiEiat te depth from the surface to the ore.
 "The instrument and the manner in which it is used is simple; the instru- ment itself consisting of box con- taining a battery and slide wire scale of high resistance and the wires nec- essary to make the various eonnec- tions Connection is then made with the earth by means of brass rods driven into the earth, one close to the instrument which point is designated The Station;' another rod is driven s-t af