GENTLEMEN:--I notice that at a meeting of your honorable Club, Mr. Latimer read an essay upon the subject of the "Divining Rod," and seemed to be at a loss to know how to tell whether the rod's movements pointed to or indicated any particular substance under the earth. I am now seventy-three years of age, and have been studying and experimenting with it since twenty years of age. I am not satisfied what causes the motion of it in my hands, but by experimenting, I can tell to a certainty whether I am over any substance, either water or mineral, or whether it is sulphur, salt or any other kind of water. I am glad that investigation in this is being made by scientific men, and hope some day it may profit man. For any information you may want, address me at Brownsville, Tennessee. Very respectfully, HARRY SANGSTER. Upon receipt of this letter from Mr. Sangster, I wrote to him asking him to explain to me upon what principle he could discover the difference between metals and water, and between one kind of water and another. To this I have received the following answer, just in time to add it to this publication: BROWNSVILLE, May 10, 1876. C. LATIMER, ESQ., _Cleveland, Ohio_: DEAR SIR:--Your favor of the 5th inst. is before me; also that of the 15th ult. You must excuse me for not answering the latter sooner, owing to ill health and other causes. I am glad to furnish you all the information in my power relative to the matter in question, because I would like to see it developed--as I believe it will be eventually--into a tangible, practical and useful science. The prejudice now prevailing against it will, in my opinion, ere long be dispelled. It is impossible for me, in the space of a letter, to give a full statement of my views, theory and experience on the subject of finding the locality of metals, minerals and water under the surface of the ground; but will endeavor to answer the inquiry of your first letter as concisely and explicitly as possible.