WATCH CAP

A ported or closed cover for the end of a filter element.

An instrument for measuring azimuths, particularly a device which fits over a central pivot in the glass cover of a magnetic compass.

An instrument for measuring bearings, particularly a device consisting of a slender bar with a vane at each end, and designed to fit over a central pivot in the glass cover of a magnetic compass. See also AZIMUTH BAR.

Ice without snow cover

An instrument for measuring azimuths, particularly a device consisting of a slender bar with a vane at each end, and designed to fit over a central pivot in the glass cover of a magnetic compass.

The designation for the sky cover when the sky is completely hidden by obscuring phenomena in contact with, or extending to the surface.

That portion of the sky cover which is attributed to clouds, usually measured in tenths of sky covered.

A principal cloud type (cloud genus), appearing as a whitish veil, usually fibrous but sometimes smooth, which may totally cover the sky, and which often produces halo phenomena, either partial or complete. Sometimes a banded aspect may appear, but the intervals between the bands are filled with thinner cloud veil. The edge of a veil of cirrostratus may be straight and clear-cut, but more often it is irregular and fringed with cirrus. Some of the ice crystals which comprise the cloud are large enough to fall, and thereby produce a fibrous aspect. Cirrostratus occasionally may be so thin and transparent as to render it nearly indiscernible, especially through haze or at night. At such times, the existence of a halo may be the only revealing feature. The angle of incidence of illumination upon a cirrostratus layer is an important consideration in evaluating the identifyin

A portable cover secured over the deck opening of the hawsepipes and the chain pipes to restrict the flow of water through the openings

Small, single-cell, jellylike marine animals with hard shells of many chambers. In some areas the shells of dead for- aminifera are so numerous they cover the ocean bottom.