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Read Ebook: The Practical Astronomer Comprising illustrations of light and colours--practical descriptions of all kinds of telescopes--the use of the equatorial-transit--circular and other astronomical instruments a particular account of the Earl of Rosse's large tel by Dick Thomas
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Ebook has 428 lines and 178170 words, and 9 pages
ON LIGHT.
INTRODUCTION.
Necessity of light to the knowledge and happiness of all sentient beings--Its beautiful and enlivening effects--An emblem of the Deity--Provision made for its universal diffusion
GENERAL PROPERTIES OF LIGHT.
Reflections on the nature of light, and the multifarious effects it produces throughout the universe--A representation of the Divinity--Wisdom and Goodness of God displayed in its formation
ON THE REFRACTION OF LIGHT.
Nature of refraction--Illustrated by experiments--Angle of refraction--Familiar experiments illustrative of refraction--Refraction explains the causes of many curious and interesting phenomena--Its effect on the heavenly bodies--On the twilight--Illustrated by figures
EXTRAORDINARY CASES OF REFRACTION IN RELATION TO TERRESTRIAL OBJECTS.
Extraordinary appearance of the coast of France from Hastings--Appearance of a ship seen by Captain Colby, beyond the coast of Caithness--Scoresby's view of his father's ship when beyond the horizon--Phenomenon near the Himalaya mountains--Bell Rock light-house--Summary statement of the diversified effects of refraction--Reflections on the beneficent and diversified effects produced by the law of refraction--It increases the length of the day, particularly in the polar regions--Is the cause of that splendour which appears in the objects around us--Quantity of refraction in respect to terrestrial objects, and its utility--Its effects may be more diversified in other worlds
ON THE REFRACTION OF LIGHT THROUGH SPHERICAL TRANSPARENT SUBSTANCES, OR LENSES.
REFLECTIONS DEDUCED FROM THE PRECEDING SUBJECT.
ON THE REFLECTION OF LIGHT.
UNCOMMON APPEARANCES OF NATURE PRODUCED BY THE COMBINED INFLUENCE OF REFLECTION AND REFRACTION.
REMARKS AND REFLECTIONS IN REFERENCE TO THE PHENOMENA DESCRIBED ABOVE.
Light, the beauty of the universe, and a symbol of the Divinity--In other worlds it may produce an infinite variety of sublime scenery
SECT. 1.--ON THE COLOURS OF LIGHT.
SECT. 2.--ON THE COLOURS OF NATURAL OBJECTS.
SECT. 3.--PHENOMENA OF THE RAINBOW.
SECT. 4.--REFLECTIONS ON THE BEAUTY AND UTILITY OF COLOURS.
Beauty and variety derived from colours in the scenery of nature--Colours produced by the atmosphere in different countries--What would be the aspect of nature, in heaven and on earth, were there only one colour--How it would affect the common intercourse and employments of society--Wisdom and Beneficence of the Creator displayed in the diversity of colours--Throughout all the systems of the universe, a diversity of colours prevails--This subject has a tendency to inspire us with gratitude
ON TELESCOPES.
HISTORY OF THE INVENTION OF TELESCOPES.
The telescope a noble instrument--Effects it produces--Whether known to the ancients--Friar Bacon's ideas respecting telescopes--First constructed in Holland--The invention claimed by different persons--Galileo's account of the construction of his telescope--Discoveries which he made with this instrument--How his discoveries were received by the learned--Specimens of learned nonsense brought forward by pretended philosophers--Supposed length of Galileo's telescope--Various claimants to the invention of this instrument
OF THE CAMERA OBSCURA.
THE DAGUERREOTYPE.
An important discovery for fixing the images produced by the camera--Description of the Daguerreotype process--Preparation of the plate, fixing the impression, &c.--Preparation of photogenic paper--Beneficial effects which this art may produce--Representations of objects in the heavens, &c.
ON THE OPTICAL ANGLE, AND THE APPARENT MAGNITUDE OF OBJECTS.
ON THE DIFFERENT KINDS OF REFRACTING TELESCOPES.
SECT. 1.--THE GALILEAN TELESCOPE.
Construction and peculiar properties of this instrument
SECT. 2.--THE COMMON ASTRONOMICAL REFRACTING TELESCOPE.
Description of its nature and construction--How its magnifying power is determined. Table of the linear aperture, magnifying powers, &c., of astronomical telescopes from 1 to 120 feet in length--Summary view of the properties of this telescope
SECT. 3.--THE AERIAL TELESCOPE.
This telescope is used without a tube--Description of the apparatus connected with it, illustrated with figures--Huygens' Hartsocker's and Cassini's large telescopes
SECT. 4.--THE COMMON REFRACTING TELESCOPE FOR TERRESTRIAL OBJECTS.
Arrangement of its lenses--Magnifying power--Manner in which the rays of light are refracted through the telescopes now described
SECT. 5.--TELESCOPE FORMED BY A SINGLE LENS.
Various experiments in relation to this point--Experiments with a lens 26 focal distance, and 11-1/2 inches diameter
SECT. 6.--THE ACHROMATIC TELESCOPE.
Imperfections of common refracting telescopes--Dollond's discovery--Newton's error--Explanation of the principle of achromatic telescopes--Combination of lenses--Difficulties in the construction of such instruments--Difficulty in procuring large disks of flint glass--Guinaud's experiments
NOTICES OF SOME LARGE ACHROMATIC TELESCOPES ON THE CONTINENT, AND IN GREAT BRITAIN.
The Dorpat telescope--Sir J. South's telescope--Captain Smyth's--Rev. Dr. Pearson's--Mr. Lawson's--Mr. Cooper's--Mr. Bridges', &c.,--Achromatics in Cambridge and Paris observatories
ACHROMATIC TELESCOPES OF A MODERATE SIZE, WITH THEIR PRICES, AS SOLD BY LONDON OPTICIANS.
PROPORTIONS OR CURVATURE OF THE LENSES WHICH FORM AN ACHROMATIC OBJECT-GLASS.
Various tables and explanations
ACHROMATIC TELESCOPES COMPOSED OF FLUID LENSES.
Blair's fluid telescope, with an account of its performance--Barlow's large refracting telescope with a fluid concave lens--Its construction, and the effect it produces on double stars, &c.--Rogers' achromatic telescope on a new plan--Wilson's telescope, &c.
ON REFLECTING TELESCOPES.
SECT. 1.--HISTORY OF THE INVENTION, AND A GENERAL DESCRIPTION OF THE CONSTRUCTION OF THESE INSTRUMENTS.
SECT. 2.--THE HERSCHELIAN TELESCOPE.
SECT. 3.--RAMAGE'S LARGE REFLECTING TELESCOPE.
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