How am I to know the true bottom when I see it? asks the inexperienced digger. Well, nothing but long experience and intelligent observation will prevent mistakes at times, particularly in deep ground; but as a general rule, though it may sound paradoxical, you may know the bottom by the top. That is, we will assume you are sinking in, say, 10 to 12 feet ground in a gully on the bank of which the country rock is exposed, and is, say, for instance, a clay slate or sandy slate set at a certain angle; then, in all probability, unless there be a distinct fault or change in the country rock between the slate outcrop and your shaft, the bottom will be a similar slate, standing at the same angle; and this will very probably be overlaid by a deposit of pipeclay, formed by the decomposition of the slates. From the crevices of these slates, sometimes penetrating to a considerable distance, you may get gold, but it is useless attempting to sink through them. If the outcropping strata be a soft calcareous (limy) sandstone or soft felspathic rock, and that be also the true bottom, great care should be exercised or one is apt to sink through the bottom, which may be very loose and decomposed. I have known mistakes made in this way when many feet have been sunk, and driven through what was actually bed rock, though so soft as to deceive even men of experience. The formation, however, must be the guide, and except in some specially difficult cases, a man can soon tell when he is really on bed rock or "bottom." On an alluvial lead the object of every one is to "get on the gutter," that is, to reach the lowest part of the old underground watercourse, through which for centuries the gold may have been accretionising from the percolation of the mineral-impregnated water; or, when derived from reefs or broken down leaders, the flow of water has acted as a natural sluice wherein the gold is therefore most thickly collected. Sometimes the lead runs for miles and is of considerable width, at others it is irregular, and the gold-bearing "gutter" small and hard to find. In many instances, for reasons not readily apparent, the best gold is not found exactly at the lowest portion of these narrow gutters, but a little way up the sides. This fact should be taken into consideration in prospecting new ground, for many times a claim has been deserted after cleaning up the "bottom," and another man has got far better gold considerably higher up on the sides of the gutter. For shallow alluvial deposits, where a man quickly works out his 30 by 30 feet claim, it may be cheaper at times to "paddock" the whole ground--that is, take all away from surface to bottom, but if he is in wet ground and he has to drive, great care should be taken to properly secure the roof by means of timber. How this may best be done the local circumstances only can decide. CHAPTER III LODE OR REEF PROSPECTING