Gold is found in gravel of every variety, from finest pipe-clay to boulders weighing tons. Sometimes volcanic eruptions have covered these deposits since the ancient rivers laid them down, and in many cases their courses do not in the least agree with the valleys of the shrunken streams that have replaced them. Gold may be distributed through the whole thickness of a bed, but ninety-nine times out of a hundred the richest layer of gravel is just above the bed rock upon which all the gravel rests. Gold may even be found among the grass roots, especially in dry localities where there has been little water to carry it downward. When the bed rock consists of upturned slates the gold frequently penetrates it for some little distance. Sand is nearly always poorer than gravel. The experience of miners in the Victoria gold fields is that gold is always found on the bars or points, and not in the deep pools and bends. The great difficulty with which any but the very finest particles of gold can be moved by water accounts for the value of the deposits depending largely upon the local rocks. It is very fortunate that gold's specific gravity is so great, for were it less its recovery would be much more difficult. The sluices and other apparatus of the miner are really nothing but the operations of nature imitated on a much smaller scale. There is one thing, however, time, that nature can afford to expend in prodigious periods, while man must not waste a single minute. It not being possible to point out where the ancient river beds lie, smothered as they are by hundreds of feet of overlying drift, lava, and other later deposits, the only feasible plan is a series of boring with the diamond drill. When gold has been discovered the finder must act with the greatest prudence, for even gold may be bought too dear. The surest test is a mill run, that is passing 10 to 50 tons through all the operations of crushing, milling, roasting, amalgamating, etc., and so ascertaining what returns are likely to be obtainable when the deposit is worked on a commercial scale. True sampling is necessary. All parts of the vein should be included, and the lode cross-cut by galleries in more than one spot. It is the very great necessity of these expensive preparatory explorations that has given rise to the saying, "Quartz mining is for rich men." Many gold mines have been abandoned as unprofitable that could have been mined at a profit had their owners been wealthy and enterprising enough to do a great deal of expensive prospecting by diamond drill, cross cuts, drifts and rises. In one instance that came to the writer's knowledge a clever mining engineer cleared nearly $200,000 profit by leasing for a term of years a gold mine that was supposed to be exhausted. A drill hole sunk less than 50 feet below the old workings revealed a pocket of ore in the vein, and paying quartz was found for many hundred feet below.