Herschel, William

W. Herschel, William Herschel Chronicles, vol. 1, William Herschel Museum, Bath, U.K. 

Ronan CA (1992) John Herschel (1792-1871). Endeavour 16 178-181 John Herschel, William Henry Fox Talbot and Johann Heinrich von Madler (1794-1874) seem to have all come up with the term photography within the same month... 

The first example is the 4-m class William Herschel telescope, at la Pakna, whose optical specifications, drafted by D. Brown, were expressed in terms of allowable wavefront error as a function of spatial frequencies matching those of atmospheric turbulence. 

William Herschel, On the Construction of the Heavens , Phil. Trans., LXXV (1785), 213.1... 

William Herschel, Catalogue of500 new Nebulae, nebulous stars, planetary Nebulae, and Clusters of Stars with Remarks on the... 

Fig. 12.5. Parts of the spectra of two QSOs (with emission redshifts 2.9 and 3.3 respectively) taken with the 4-m William Herschel Telescope on La Palma with a resolution of about 50kms 1 showing Lyman-a lines with damping wings (column densities N(H i) 2 x 1021 cm 2 or 6M0pc-2 and 8 x 1020 cm-2 or 2.4 Mq pc-2 respectively). After Pettini et al. (1997).

Hoskin, M. A. 1963, William Herschel and the Construction of the Heavens, London Oldbourne. 

In the course of investigating the production of platinum from its ores, Wollaston and Tennant found four new elements in 1803. Tennant isolated osmium and iridium Wollaston found rhodium and palladium. As was the contemporary habit, Wollaston named the latter after a newly discovered celestial body. Uranium gained its name this way after William Herschel s discovery of the planet Uranus, and palladium honoured the asteroid Pallas, found in 1802. 

A comment by John Frederick William Herschel in A Preliminary Discourse on the Study of Natural Philosophy [1830] (New York London Johnson Reprint Corporation, 1966), 305. 

In 1800 Sir William Herschel found that a thermometer placed in the region beyond the red end of the solar spectrum (obtained by dispersing solar radiation with a prism) was heated even more than when placed in the visible portion Herschel had discovered infrared radiation. Around 1900 infrared (IR) absorption investigations of molecules began. 

Astronomy. The potential of using the infrared portion of the electromagnetic spectrum for investigating celestial bodies and interstellar space has been considered by some astronomers for a number of years. This concept was first proposed by William Herschel. It has only been within the last few decades, however, that serious experiments in infrared astronomy have been made. 

Line spectra were first observed by J. von Fraunhofer, D. Brewster, and J. F. W. Herschel in the 1820s.180 In the ensuing decades a considerable amount of work was done on spectral phenomena prior to the demonstration by Bunsen and Kirchhoff in 1859 that line spectra could be used for qualitative chemical analysis. Accounts have appeared of the development of the spectroscope both prior and post Bunsen and Kirchhoff.181-183 Significant observations were undoubtedly made prior to 1860 by Stokes, Stewart, Fox Talbot, and others. The priority claims of Stokes, who recorded his ideas in some private letters to William Thomson, have been examined.184 The work of Bunsen and Kirchhoff did not owe a great deal to that of their predecessors, with the exception of the demonstration by W. Swan in 1856 that the almost omnipresent yellow line that coincided with Fraunhofer s dark solar D line was due to contamination by minute quantities of sodium salts.185 186 Platinum played an important role in the early development of spectroscopy. The metal was widely used to support the material in the flame, since it did not colour the flame itself. Bunsen ensured the purity of all his samples for spectrum analysis by recrystallization (sometimes up to fourteen times) in platinum vessels, thereby preventing contamination by minute quantities of salts that could be leached from glass vessels.187 Sharply contrasting views have been expressed about the failure of chemists prior to Bunsen to exploit spectroscopy.188-190... 

The number of known metals had been increased by one—from 17 to 18... A few years ago we thrilled to hear of the discovery of the final planet by Sir William Herschel. He called the new member of our solar system Uranus. I propose to borrow from the honor of that great discovery and call this new element Uranium. 

By this time, scientists were studying light from as many sources as they could conjure. In 1822, the Scotsman David Brewster (1781-1868) invented a device that, by means of a flame, vaporized small amounts of material. The light from this vaporized material could then be smdied. He added 1,600 new spectral lines to those discovered by Fraunhofer and other investigators. During the same year, 1822, John Herschel (1792-1871), William Herschel s son, vaporized various metallic salts and established that the light from the flames could be used to detect the presence of these metals in very small samples. A few years later, William Talbot (1800-1877) showed that the spectrum of each of the chemical elements was unique and that it was possible to identify the chemical elements from their spectra. 

The first platinum to be subjected to experimental investigation was brought to England in 1741 by Charles Wood, an assayer from Jamaica. He determined that the metal could not be fused by the force of any fire then available, formed low-melting alloys with several metals, and had a density similar to that of gold. His results were communicated in 1750 to the Royal Society of London by William Watson and later were published in the Philosophical Transactions (6). This publication sparked interest throughout Europe, for the discovery of a new noble metal was as much a surprise to chemists as the discovery of the new planet Uranus by Herschel was to be to astronomers 30 years later. 

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