One of the most singular things connected with prospecting in this particular portion of the mountains is the means by which large deposits of silver near a tunnel can be located. If an iridescent, smoke-like appearance spreads over the rocks at any point of a new tunnel or drift at the end of a week or two, the engineers always drift for it and generally strike silver. This stain is called by them "silver smoke," and is said to be unknown in any other mines. I was given a half dozen theories in regard to it, mostly of a chemical character, but the mere fact that such a strange condition exists to help man pry into nature's secrets is more interesting than any explanation. From the garden of the hacienda, surrounded by banana and orange groves and all kinds of tropical plants and flowers, one can look up the steep sides of the mountains, which rise abruptly on both sides, to the oaks and pines beyond, and, while sitting on the veranda sipping ices or drinking cool and refreshing drinks, and vigorously using the fan, realize that only a mile above, on the cumbra or crest of the steep mountain, the ice water flows freely in the little mountain streams and the heaviest flannels only would be comfortable. My stay at Batopilas was somewhat prolonged in waiting for a party that was soon to descend with bullion to Chihuahua. I had originally intended to continue my course toward the Pacific, but the hot weather, more severe in May and June than during July and August, owing to the rainy season tempering the latter, and the fact that I could find a more interesting trip through the Sierra Madres by another trail than that by which I had entered, determined me to turn my face eastward and keep on the high plateau with its grand equable climate. In leaving Batopilas the large pack train carrying the bullion was given two days' start, and we were to ride and join them after they had made the cumbra or crest of the mountains. This trail took me well to the southward of the one traversed on entering the mountains, and gave me a new and interesting country.