A rotary drill with two hardened knurled cones which cut the rock as they roll. Also known as roller bit.
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GULLY
1. A small ravine, especially one cut by running water, but through which water flows only after a rain. 2. On the sea floor, a small valley-like feature
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INTERSECT
To cut or cross. For example, two non parallel lines in a plane intersect in a point, and a plane intersects a sphere in a circle
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RABBET
A groove cut in wood to form part of a joint.
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JOGGLE
A slender triangular recess cut into the faying surface of a frame or steamed timber to fit over the land of clinker planking, or cut into the faying edge of a plank or rebate to avoid feather ends on a strake of planking. The feather end is cut off to produce a nib. The joggle and nib in this case is made wide enough to allow a caulking iron to enter the seam.
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MUSTER STATION
The location on a vessel a person goes either during an emergency or a drill to prepare for one. i.e. a Muster Drill. If a person is believed missing, all hands would report to their muster station for a head count.
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ROACH
The curved cut in edge of sail for preventing chafing.
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STATION BILL
A list which shows the vessel's complement and details their various duties in connection with fire and boat drills.
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CUT
1. A notch or depression produced by excavation or erosion. 2. The intersection of lines of position, constituting a fix, with particular reference to the angle of intersection
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DELTA
1. The low alluvial land, deposited in a more or less triangular form, as the Greek letter delta, at the mouth of a river, which is often cut by several distributaries of the main stream. 2. A change in a variable quantity, such as a change in the value of the declination of a celestial body.
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ERROR ELLIPSE
The contour of equal probability density centered on the intersection of two straight lines of position which results from the one-dimensional normal error distribution associated with each line. For the 50 percent error ellipse, there is a 50 percent probability that a fix will lie within such ellipse. If the angle of cut i
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