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as those from very distant objects) images free from aberration. It is used in reflecting telescopes. -- Parabolic spindle, the solid generated by revolving the portion of a parabola cut off by a line drawn at right angles to the axis of the curve, about that line as an axis. -- Parabolic spiral, a spiral curve conce…

they may be interchanged without varying the focus of the instrument (as a microscope or telescope) with which they are used.

representing objects in the direction of the diagonal of a cube. -- Perspective glass, a telescope which shows objects in the right position.

An optical glass; a telescope. [Obs.] Crashaw.

A modified kind of telescope adapted to taking photographs of the sun.

under Range. -- Position micrometer, a micrometer applied to the tube of an astronomical telescope for measuring angles of position in the field of view. -- Single position (Arith.), the method of solving problems, in which the result obtained by operating with an assumed number is to the true result as the number as…

The degree to which a lens, mirror, or any optical instrument, magnifies; in the telescope, and usually in the microscope, the number of times it multiplies, or augments, the apparent diameter of an object; sometimes, in microscopes, the number of times it multiplies the apparent surface.

ne of the prime vertical. -- Prime-vertical transit instrument, a transit instrument the telescope of which revolves in the plane of the prime vertical, -- used for observing the transit of stars over this circle.

also mirror galvanometer. -- Reflecting goniometer. See under Goniometer. -- Reflecting telescope. See under Telescope.

A reflecting telescope.

des through which the refracted beam passes in the decomposition of light. -- Refracting telescope. (Opt.) See under Telescope.

A refracting telescope, in which the image to be viewed is formed by the refraction of light in passing through a convex lens.

on of a force. -- Resolution of a nebula (Astron.), the exhibition of it to the eye by a telescope of such power as to show it to be composed of small stars.

A system of wires or lines in the focus of a telescope or other instrument; a reticle.

One of certain narrow, crooked valleys seen, by aid of the telescope, on the surface of the moon.

and ending in desquamation about the sixth or seventh day. -- Scarlet fish (Zoöl.), the telescope fish; -- so called from its red color. See under Telescope. -- Scarlet ibis (Zoöl.) See under Ibis. -- Scarlet maple (Bot.), the red maple. See Maple. -- Scarlet mite (Zoöl.), any one of numerous species of bright red…

Of or pertaining to a sundial. Sciotheric telescope (Dialing), an instrument consisting of a horizontal dial, with a telescope attached to it, used for determining the time, whether of day or night.

ing an instrument for viewing (with the eye) or observing (in any way); as in microscope, telescope, altoscope, anemoscope.

making spectroheliograms, consisting of a spectroscopic camera used in combination with a telescope, and provided with clockwork for moving the sun's image across the slit. -- Spec`tro*he`li*o*graph"ic (#), a.

A reflector of polished metal, especially one used in reflecting telescopes. See Speculum metal, below.