The diamond fields of South Africa, covering an area of perhaps one thousand square miles, are between longitude 24° and 28° east, and latitude 27° and 30° south. It is estimated that, down to the end of 1876, eighty-five million dollars worth of diamonds had been taken out, and this estimate does not include thousands of stones that were carried directly to England by their owners, and did not pass through the market at Cape Town. Diamond owners would have been ruined completely by the African discoveries, had it not been for the fact that the great majority of the diamonds found there are of poor quality. Professor Lenant, who has given considerable attention to the matter, says that of the Cape diamonds, about ten per cent. may be classified as first quality, fifteen per cent. of the second, and twenty-five per cent. of the third. The remainder, under the name of “bort,” is employed in cutting diamonds and for various other purposes, by the lapidary, by the engineer in rock drills, for cutting glass, and similar purposes. [Sidenote: DIFFICULTIES OF MINING.] Unfortunately for the miners at the Cape, there is a very short supply of water. If they could have adopted the system of hydraulic mining to their work, they would have saved enormous labor and expense. At many of the fields which are distant from the rivers, the gravel is removed by means of buckets, drawn up by long ropes, and it very often happens that a single heavy rain of a few hours, will destroy the entire labor of months, the pit becomes filled with water, and there will be no way of extracting it except by evaporation, or by the laborious process of hoisting or pumping. One of the fields, known as Colesberg Kopje, fell off, in one year, more than fifty per cent. from the yield of previous years, in consequence of the heavy caving and floodings caused by the rains. The value of claims in that region has gradually fallen, and so desperate is the condition that, at last accounts, money was loaned upon mining licenses at the rate of ten per cent. a month, with a foreclosure at the end of the first month if the interest was not paid. At the diamond camp, the small stones form the basis of value. They might be used for currency except for one fact. Gold dust, in California, was used for currency, for a long time. Its value, of course, is directly proportioned to its weight, a pound nugget being worth exactly twelve times as much as an ounce nugget of the same fineness, but the value of diamonds increases with enormous rapidity as they grow heavier, so they cannot be put in bunch or weighed out the same as gold. Transactions frequently take place in diamonds, and the amount of exchange is often very difficult to compute.