A hole made in ice to observe the height of the tide.

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1. A small depression of the sea floor. 2. An opening through a piece of sea ice, or an open space between ice cakes. 3. A small bay, particularly in New England


A rounded wooden block with hole used to set up ship's stays


A hole for ship's cable


The shaft or hole in the side of a vessel's bow through which the anchor chain passes.


An irresponsible and reckless individual whose behavior (either intended or unintended) endangers the group he or she belongs to. A loose cannon, weighing thousands of pounds, would crush anything and anyone in its path, and possibly even break a hole in the hull, thus endangering the seaworthiness of the whole ship.


A small drain hole or slot in a frame or plate for the purpose of preventing water or oil from collecting


Part of the oil gun which discharges the atomized fuel oil mixture into the furnace through multiple openings. The hole pattern in the tip has a great effect on flame size and shape.


A hole of at least 3/8 in diameter required through the body below the valve-seat level in safety valves larger than 2-in diameter; used to prevent condensate from collecting at this point.


1. The bending of the rays of radiant energy around the edges of an obstacle or when passing near the edges of an opening, or through a small hole or slit, resulting in the formation of a spectrum. See also REFLECTION REFRACTION. 2. The bending of a wave as it passes an obstruction.


An optical instrument used as an aid in viewing or photo- graphing distant objects, particularly celestial objects. A reflecting telescope collects light by means of a concave mirror; a refracting telescope by means of a lens or system of lenses. A Cassegrainian telescope is a reflecting telescope in which the immergent light is reflected from the main mirror onto a secondary mirror, where it is reflected through a hole in the main mirror to an eyepiece; a Newtonian telescope is a reflecting telescope in which the immergent beam is reflected from the main mirror onto a small plane mirror, and from there to an eyepiece at the side of the telescope.

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