Alidade: alternatives and connections

An instrument for taking altitudes, as a quadrant, sextant, etc.

The diameter of the exposed part of the object glass of a telescope or other optical instrument; as, a telescope of four-inch aperture.

An instrument formerly used for taking the altitude of the heavenly bodies, but now superseded by the quadrant and sextant; -- so call…

The process of estimating the caliber a tube, as of a thermometer tube, in order to graduate it to a scale of degrees; also, more gene…

An instrument for the accurate measurement of small differences of height; esp. of the differences in the height of the upper surfaces…

Consisting of a hundred degrees; graduated into a hundred divisions or equal parts.

The act of collimating; the adjustment of the line of the sights, as the axial line of the telescope of an instrument, into its proper…

An instrument resembling the astrolabe, formerly used for measuring the angles between heavenly bodies; -- called also pantacosm.

One of a series of progressive steps upward or downward, in quality, rank, acquirement, and the like; a stage in progression; grade; g…

An instrument for measuring angles, in surveying, etc. It resembles a protractor, but has an alidade, sights, and a compass.

An instrument, formerly much used for showing the time of day from the shadow of a style or gnomon on a graduated arc or surface; esp.…

A dog which suddenly drops upon the ground when it sights game, -- formerly a common, and still an occasional, habit of the setter.

An instrument consisting of a telescope so mounted as to have two axes of motion at right angles to each other, one of them parallel t…

One who, or that which, finds; specifically (Astron.), a small telescope of low power and large field of view, attached to a larger te…

Of or pertaining to Galileo; as, the Galilean telescope. See Telescope.

A small domesticated cyprinoid fish (Carassius auratus); -- so named from its color. It is native of China, and is said to have been i…

A graduated cup, tube, or flask; a measuring glass used by apothecaries and chemists. See under Graduated.

A thin quadrant, made of brass, wood, etc., showing a stereographic projection on the plane of the equator. By it are found the hour o…