# Popular Science Monthly/Volume 20/November 1881/Correspondence

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THE COPPER-MINES OF ISLE ROYALE.
Messrs. Editors.
I HAVE read with much pleasure Professor Winchell's paper on the "Ancient Copper-Mines of Isle Royale," in "The Popular Science Monthly" for September. As the Professor's very laudable object is undoubtedly "to make a little history" respecting the wonderful copper-mines of Lake Superior, and as no narrative (with the exception of some occasional geological reports) respecting the late working of them has to my knowledge been published, and as he has inadvertently made some quite important omissions, with your leave I will endeavor to supply the deficiency. On page 602 he says: "The finding of these thin chips of copper is the first indication of the proximity of a large mass. In the summer of 1874 the first of these large masses was discovered."
In the summer of 1822, fifty-two years before "the summer of 1874," General Cass, at that time the United States Territorial Governor of what now constitutes the States of Michigan, Wisconsin, and Minnesota, and ex-officio Superintendent of Indian Affairs for the Northwest, made his celebrated trip from Detroit to the head of Lake Superior, with his party, "in birchen canoes," and thence overland to the Mississippi River. He stopped at the mouth of the Ontonagon River, on the south shore of Lake Superior, two or three days to recruit his voyageurs after a "canoe-paddle" of nearly one thousand miles from Detroit. Knowing what the "early Jesuits" had said about copper in that country, in the published memoirs of their operations in the "Great Lake country," nearly two hundred years before, he naturally sought information of the Indians he found there respecting it. They took him to a mass of copper which was lying on the bank of the Ontonagon River, some eight miles from its mouth. It was found to be, apparently, pure native copper. In 1845, I think it was, Julius Eldred, of Detroit, by permission of the Government, took it to Washington, for the purpose of its being eventually put into the Washington Monument, as a contribution showing the mineral resources of Michigan. It weighed something like six thousand pounds. In 1848 the Minnesota Mining Company commenced work on their mine, in the range of hills some twenty-one miles (by the course of the stream) up the Ontonagon River. They began work in what are called the "ancient diggings." This "digging" was simply an open trench, some ten to twelve feet wide, running on the course of a mineral vein that had been excavated by the "ancients" in the "country rock" to uncover the vein. I do not now recollect the length of that particular trench. The country is full of them.
I give you what Mr. William Hickok, one of the owners and originators of the Minnesota mine—which mine, by-the-way, has produced several million dollars' worth of copper—and who now resides at Tarrytown in this State, says of their work and what they found. In reply to a note I addressed him respecting it on the 25th ultimo, he writes: "The mass of copper discovered by Mr. Knapp in the Minnesota mine in 1848, of which you inquire, was found in the vein, resting upon skids about twenty-five feet from the surface. It weighed 12,480 pounds. All the rock had been cleaned from its surface, giving it the appearance of being as pure as refined copper. There were found in the excavation a large number of 'stone hammers,' weighing from one to forty pounds each, and encircled by a 'groove' cut undoubtedly for the purpose of receiving a hickory 'withe,' to be used as a handle. There were also several copper implements, such as chisels, etc., found, that showed, from the manner they had been used—the battered heads of the chisels, for instance—that the 'art' of hardening and welding that metal (an art now lost) was known by those who had made them. There was at that time growing in that excavation (which was filled with alluvial soil) over the vein and the mass of copper a hemlock-tree, of about three hundred and seventy-five years' growth, judging from the number of its concentric rings. We must, I think, go back to the 'stone age' to find the workers of these copper-mines. The discovery of the mass of copper in the vein of the Minnesota mine entirely free from rock, ready to be moved, unlocks the mystery of those 'floating masses'—that seen by General Cass was one of them—found in various places on the surface, showing that they had all been mined and taken from the veins, and had been abandoned while being transported to the lake, for some cause to us unknown."
It occurs to me that, if the foregoing is added to Professor Winchell's very valuable paper, the account of those remarkable ​mineral deposits will be somewhat more complete.Yours very truly,
* C. A. Trowbridge.
* New York, September 6, 1881.
NUMBER-FORMS AND COLORS.
Messrs. Editors.
In "The Visions of Sane Persons," in the "Monthly" for August, the author, Francis Gallon, speaks of a certain proportion of people (five per cent.) to whom the thought of a series of consecutive numbers invariably brings the vision of them arranged in a perfectly defined and constant position.
From my earliest recollection, numbers have always appeared to me arranged in a straight line of regularly increasing height, extending from north to south: 1 is flat on the ground; 2 close to it, but a little higher and a little farther to the south, and so on. The row of figures extends upward at an angle of about forty degrees. I said that 1 was flat on the ground. I do not mean the literal ground, for the whole vision appears surrounded by and outlined against that brownish-red light which falls through our closed lids upon our eyes, when we shut them in the full glare of sunlight. I meant that 1 is at the feet of the imaginary person who, wishing to read these numbers, stands with his back to the north, looking southward and upward at this regularly ascending row.
Not only do they have position; they also have color—that is, nearly all of them. The conception of color or non-color is associated with them all: 1 is transparent, like glass or water; 2 has a reddish tinge; 3 is a bluish-green (I have in mature years seen the exact shade that my childish imagination invested this number with—in shallow bays, and waters of the tropical Pacific); 4 is also red, but a different shade from 2—more of a crimson; 5 is a very pretty, delicate gray, always spotless—a Quaker woman's dress reminds me of 5; 6 is a deeper shade of 3, a deeper blue-green; 7 I always disliked. It is a yellowish brown, the hue of withered fields and bare earth in winter, when there is no snow on the ground; 8 is black; 9 is a decided green, a darker shade of 3 and 0. Whether this is because it combines them I can not say; 10 is colorless, being composed of two numerals that are colorless, though, as previously indicated, the conception of non-color is associated with it.
The ’teens likewise have colors, but not individual ones. The numeral in the units' column gives color to the whole, though it is somewhat diluted by the colorless quality of the 1 by which it stands. It is as if an equal quantity of clear water had been poured into a colored liquid. In the numbers above twenty, sometimes one numeral, sometimes another, gives color to the number, but this is done in an arbitrary manner, and I can perceive no rule. These higher numbers, too, are somewhat confused, not so clear as those of lower denomination. The only ones that are distinct are 22, 33, 44, 55, etc. I will add, in conclusion, that there is connected with them no conception beyond form, position, and color.
Will some chemist, or some one well read in history, please explain the allusions and references in this passage from Victor Hugo's "Les Miserables"? It will be found in Chapter CCXLIX, of Lascelles Wraxall's translation: "It was from the drain of Munster that John of Leyden produced his false moon; and it was from the cesspool-well of Kekhscheb that his Oriental Menæchmus, Mokannah, the veiled prophet of Khorassan, brought his false sun."
* Louise Coffin Jones.
* Oskaloosa, Iowa, August 5, 1881.