It accordingly comments on the Sphaerica of Theodosius, the Moving Sphere of Autolycus, Theodosius's book on Day and Night, the treatise of Aristarchus On the Size and Distances of the Sun and Moon, and Euclid's Optics and Phaenomena.
The theory of electro-optics received great attention from Kelvin, Maxwell, Rayleigh, G.
But his researches in physical optics constitute his chief title-deed to immortality.
This resolution of the original wave is the well-known "Principle of Huygens," and by its means he was enabled to prove the fundamental laws of optics, and to assign the correct construction for the direction of the extraordinary ray in uniaxial crystals.
On his mother's death in 1759 Marat set out on his travels, and spent two years at Bordeaux in the study of medicine, whence he moved to Paris, where he made use of his knowledge of his two favourite sciences, optics and electricity, to subdue an obstinate disease of the eyes.
Wood, Physical Optics.) According to A.
At a later period he was one of the leading contributors to the Encyclopaedia Britannica (seventh and eighth editions), the articles on Electricity, Hydrodynamics, Magnetism, Microscope, Optics, Stereoscope, Voltaic Electricity, &c., being from his pen.
Various writers on optics in the 17th century discussed the principle of the simple dark chamber alone and with single or compound lenses, among them Jean Tarde (Les Astres de Borbon, 1623); Descartes, the pupil of Kepler (Dioptrique, 1637); Bettinus (Apiaria, 1645); A.
There is a great deal of practical information on lenses in connexion with the camera and other optical instruments, and the book is valuable as a repertory of early practical optics, also for the numerous references to and extracts from previous writers.
Of recent years most treatises on physical optics, e.g.
Schuster, Theory of Optics, p. 115.
Attempts have been made, principally founded on some remarks of Huygens, to show that Descartes had learned the principles of refraction from the manuscript of a treatise by Willebrord Snell, but the facts are uncertain; and, so far as Descartes founds his optics on any one, it is probably on the researches of Kepler.
The chief of his other contributions to optics was the explanation of the rainbow - an explanation far from complete, since the unequal refrangibility of the rays of light was yet undiscovered - but a decided advance upon his predecessors, notably on the De radiis visas et lucis (1611) of Marc-Antonio de Dominis, archbishop of Spalato.
The following branches have especially felt his influence: - chemical physics, capillarity and viscosity, theory of gases, flow of liquids, photography, optics, colour vision, wave theory, electric and magnetic problems, electrical measurements, elasticity, sound and hydrodynamics.
In addition to the various works of Brewster already noticed, the following may be mentioned: - Notes and Introduction to Carlyle's translation of Legendre's Elements of Geometry (1824); Treatise on Optics (1831); Letters on Natural Magic, addressed to Sir Walter Scott (1831); The Martyrs of Science, or the Lives of Galileo, Tycho Brake, and Kepler (1841); More Worlds than One (1854).
Many other points of physiological optics are touched on, in general erroneously.
In optics he was the first, in 1802, to observe the dark lines in the solar spectrum.
Having entered the Society of Jesus in 1586, he was successively professor of philosophy at Douai and rector of the Jesuit College at Antwerp. He wrote a treatise on optics in six books (Antwerp, 1613), notable for containing the principles of stereographic projection.
He died on the 5th of June 1716, leaving unfinished a series of elaborate retearches on optics, and a large amount of unpublished manuscript.
The results of his leisure were in 1787 a new translation of Newton's Optics, and in 1788 his Memoires academiques, ou nouvelles decouvertes sur la lumiere.
For the theory of dispersion see P. Drude, Theory of Optics (Eng.
Wood, Physical Optics; and A.
His work was mainly concerned with electricity and magnetism, though he also made some contributions to optics and physiology.
Devoting himself next to optics, he produced memoirs which entitle him to a high place among the early, searchers after a true dynamical theory of light.
11 Astronomical inquiries in connexion with optics, meteorological phenomena, and, in a word, the whole field of natural laws, excited his desire to explain them.
In optics, it is that portion of the diameter of an object-glass or mirror through which light can pass free from obstruction.
Thanks to Fresnel and his followers, this department of optics is now precisely the one in which the theory has gained its greatest triumphs.
According to common optics, where images are absolute, the diffraction pattern is supposed to be infinitely small, and two radiant points, however near together, form separated images.
Archbishop Peckham, or Pisanus, in his Perspectiva Communis (1279), and Vitello, in his Optics (1270), also attempted the solution of Aristotle's problem, but unsuccessfully.
Arbes have used a method depending on total reflection (Drude's Theory of Optics, p. 394).
For descriptive accounts, see Wood's Physical Optics, T.
Hence there arose a new science of electro-optics, and in all parts of Europe and the United States innumerable investigators took possession of the novel field of research with the greatest delight.
The smaller the hole (so far at least as geometrical optics is concerned) the less confused will the picture be.
A-, privative, xpcopa, colour), in optics,, the property of transmitting white light, without decomposing it into the colours of the spectrum; "achromatic lenses" are lenses which possess this property.
He also wrote at this time a translation of Newton's Optics, for which the author presented him with Soo.
He overhastily concluded from some rough experiments (Optics, bk.
Prop. 3) "that all refracting substances diverged the prismatic colours in a constant proportion to their mean refraction"; and he drew the natural conclusion "that refraction could not be produced without colour," and therefore "that no improvement could be expected from the refracting telescope" (Treatise on Optics, p. 112).
Grammar, music, painting, sculpture, medicine, geometry, mathematics and optics; c. 2 is on the general principles of architectural design; c. 3 on the considerations which determine a design, such as strength, utility, beauty; c. 4 on the nature of different sorts of ground for sites; c. 5 on walls of fortification; c. 6 on aspects towards the north, south and other points; c. 7 on the proper situations of temples dedicated to the various deities.
Optics and spectroscopy.
Accordingly, for the next three or four years, he remained steadily at work, and nothing appeared from him in public except a short treatise on optics (Tractatus opticus, L.W.
The Vindex episode, referred to in the Six Lessons, becomes intelligible only by going beyond Molesworth to the original Latin edition of 1655 They were composed originally, in a somewhat different and rather more extended form, as the second part of an English treatise on Optics, completed by the year 1646.
Sir Isaac Newton appears to have been the first to use a glass globe instead of sulphur (Optics, 8th Query).