few years ago, proposed the following definition. It must be conceded that this definition, while embodying many splendid features, is not altogether exempt from criticism; but in the absence of anything better, we shall not be very far in error if we use it:

Ore is a natural aggregation of one or more minerals from which useful metal may be profitably extracted.

There is, then, no such thing as "pay ore" or "non-pay ore," expressions still quite common among miners and prospectors of the uneducated types. Prof. James F. Kemp, probably America's best-posted writer upon the subject, in an attempt to formulate one acceptable and unchangeable meaning for the word ore, says, "In its technical sense, an ore is a metalliferous mineral or an aggregate of such minerals, more or less mixed with gangue, and capable of being won and treated at a profit. The test of yielding the metal or metals at a profit seems to me, in the last analysis, the only feasible one to employ." This definition eliminates one of the weak points in the first definition, namely, that an ore must be an association of minerals: there are some common ores (as for example, magnetite) which are not associations, but single minerals.

We now reach certain fundamental concepts which must be accepted by the mining man who desires to be recognized as abreast of modern ideas. Following the publication of Kemp's definition of ore, there was much comment—as was anticipated—with the result that there has been noted a vacancy in scientific matters and it has been thought proper to permit another definition for purely scientific uses. This other definition of ore will cover the materials or aggregates of minerals from which gem stones and other valuable, but not metallic, substances are recovered.

Let us recapitulate. An ore must be an aggregate or association of natural minerals, or a single mineral, from which metal may be profitably recovered. Mines are excavations in the earth from which ore, coal or gems are taken. Mining is the art or practice of operating mines.

Throughout the subject, we see the inseparable idea of profit. The work of carrying on operations in a railroad tunnel is not mining; the driving of adits through barren rocks to reach ore bodies is not mining; the sinking of shafts through worthless "wash" or rocks with a view of opening avenues for the removal of ore is not mining. Mining is carried on only when ore is being produced. The wildcat practice of erecting small, temporary plants and digging prospect holes can be condemned as not being real mining.

Universal Mine (bituminous), Clinton, Indiana.

There is usually little question about the validity of a coal mining proposition, since "the goods show for themselves." Comparatively few cases of fraudulent ventures in coal properties are of record. The product of a coal mine is ready for market just as soon as it is loaded into railroad cars, the mining company receiving its pay, commonly, upon its own recorded weights. There is no freight to pay, no waiting for assays or analyses, and no settlements with mills or smelteries. There are not the allurements for getting rich quickly in coal mining that are so beguiling to the class of investors generally approached by the promoters of mines(?). This must not be construed as stating that nobody has ever been deceived in a coal mine proposition, for, indeed, there have been many failures; however, they have been due, chiefly, to auto-deception as to area, thickness or quality of the coal measures.

III
THE ANTIQUITY OF MINING.

Mining is believed to have been one of man's earliest occupations. In historical writings, many of which date back into antiquity, there are allusions, as well as direct statements, concerning the art and tasks of obtaining valuable metals from Mother Earth. We are told that the very ancient Egyptians made common use of metals and that they possessed knowledge of certain metallurgical and metal-working processes (as for example, the tempering of copper) which we, of today, cannot claim. Six thousand years ago Egypt became a world power through her mining of copper in the Sinai Peninsula. Iron implements found in the great Gizeh Pyramid are supposed to date back to 4,000 B.C. Copper tools have been found in the ruins of ancient Troy. In Assyria, a very good steel saw, 44 inches long, was taken from the ruins of Nimrod. Iron was utilized by the Chinese some 2,000 years B.C. Near Delhi, India, there exists an iron pillar, 22 feet long and weighing six tons, dating back to 400 B.C. It is chiefly interesting in exhibiting an ancient knowledge of welding which is the envy of our modern iron workers. If we accept the Hebrew Scriptures, we must believe that mining was carried on in the time of Tubalcain, spoken of in Genesis. The Old Testament contains numerous verses referring to the mining of metals, the land of perfect abundance being paraphrased in Deuteronomy thus: "Where the stones are of iron and out of its hills are digged mines of brass." Coal was mined and used in Greece in 1330 B.C.

It is quite probable that gold was the earliest metal to be worked. There are two good reasons for this assumption: First, gold was to be found in the native state or as nuggets, thus requiring no reduction process. Second, the ores of gold are usually less refractory than are the ores of other metals. This is especially true of the oxidized ores such as would naturally be discovered by primitive man. These facts, together with the further properties of gold, viz., that its color is attractive, that it resists corrosion or tarnish, and that it is easily worked into ornaments or coin merely by hammering, make it highly probable that humans early made use of this yellow material.

We read in Job 28:1, that "gold is refined;" and modern investigations tend to prove that the Ophir of Biblical reference is the southern portion of Matabeleland or the Rhodesia of present fame among mining regions. It is possible and quite probable that the great quantities of gold used in the building and furnishing of King Solomon's Temple came from the vicinity of the present city of Johannesburg. The "golden fleece" of literature has been explained as a figure of speech for the skins of sheep which were laid in troughs to catch gold upon the principle of the riffle in a modern sluice-box.

Copper was perhaps the second metal to be worked by man. As a rule, it, also, is easily smelted from its ores; and, as above mentioned, we have relics that give evidence of wonderful skill in working this metal in times of remote antiquity.

However, other metals are believed to have been mined, upon commercial scales, before the Christian era. Silver and lead were handled in large quantities from the mines of Laurium, Greece, in the sixth century B.C., and the same mines are being worked to this day, the principal values now being in the lead rather than, as formerly, in the white metal. The Phœnicians, about 500 B.C., invaded Spain for gold, copper and mercury, and Cornwall for tin and copper. The Almaden quicksilver mines of Spain have been operated, almost incessantly, since 415 B.C., and in the 16th century, A.D., the wealth of Europe's greatest family of financiers, the Fügers, was based upon the operation of this remarkable deposit.

Del Mar, in his