hard bottom

hard bottom

[′härd ‚bäd·əm]
(mining engineering)
A condition encountered in some opencut mines wherein the rock occasionally does not break down to grade because of an extra-hard streak of ground or because insufficient powder is used.
References in classic literature ?
With this end in view, every Sunday during my first year of office I drew the whole population of the township, willing or unwilling, up on to the mountain, where I myself had traced out on a hard bottom the road between our village and the highway to Grenoble.
Let us settle ourselves, and work and wedge our feet downward through the mud and slush of opinion, and prejudice, and tradition, and delusion, and appearance, that alluvion which covers the globe, through Paris and London, through New York and Boston and Concord, through Church and State, through poetry and philosophy and religion, till we come to a hard bottom and rocks in place, which we can call reality, and say, This is, and no mistake; and then begin, having a point d'appui, below freshet and frost and fire, a place where you might found a wall or a state, or set a lamp-post safely, or perhaps a gauge, not a Nilometer, but a Realometer, that future ages might know how deep a freshet of shams and appearances had gathered from time to time.
Table 3 Relative abundance (%) of fishes observed during dives of remotely operated vehicles in 2012 and 2013 on 2 habitats types: 1) artificial (shipwreck) substrata and natural hard bottom (AS/NHB) and 2) soft substrata (SS) near Norfolk Canyon, Middle Atlantic Bight.
When the lure finds hard bottom, you should detect a distinct clunk.
Features include low-friction, heavy-duty skate wheel conveyors suitable for either returnable totes or hard bottom containers, easy reconfiguration with simple tools, and multiple pipe colors provides for color coding.
Work carried out in hard bottom (boulder, cobble, pebble) habitat on the continental shelf in the Gulf of Alaska (GOA) (Freese et al., 1999) showed that a single trawl pass can displace boulders and remove or damage large epifaunal invertebrates.
The deeper passes such as Coon Key Pass, Whitney Channel, Dismal Key, Fakahatchee Pass and West Pass are all traditional trout areas in the winter and while each has its subtleties and "spots on spots," each has good current and deeper water with hard bottom. While populations of trout will always inhabit these deeper haunts in the winter, they absolutely shine when cold fronts and heavy winds push the trout off the grassflats.
Look for subtle, naturally occurring sweet spots--small mussel beds within a weedflat, bigger boulders amid a large rock complex, or even a driveway-sized patch of hard bottom surrounded by silt.
But it was a fairly hard bottom up there even though the water was down a bit."
But unless that happens, you'll find gags inside 50 feet with good success on most hard bottom areas.