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156 [234] FLAMSTEED FLAMSTEED
When only fifteen, Flamsteed, the son of a prosperous dealer in malt, was forced by bad health out of school and into the hobby of reading astronomy. He was the gainer thereby, for he grew in terested enough to begin to construct in struments and by 1670 had published some astronomical work that attracted attention. In that year he became ac quainted with Newton [231] and entered Cambridge. England more than any other nation was interested in improving navigational procedures, since her merchant fleet was becoming the largest in the world. Any scheme for accurate determination of longitude at sea was of interest to the government. Flamsteed was one of those called upon to pass on a method for determin ing longitude that had been suggested, but he shook his head. No method would work, he decided, until such time as a map of the stars more accurate than any existing was prepared. He was among those who petitioned King Charles II for the establishment of a na tional observatory to take care of that job.
Charles II reacted favorably and had one established at Greenwich, a London suburb, putting Flamsteed in charge. Flamsteed thus became the first astrono mer royal, beginning work in 1675. The job was no sinecure. The king had provided the building but had supplied only a tiny salary, with no provision for assistants or instruments. Flamsteed had to build his own instruments or beg the funds with which to have them built. He had to tutor on the side to support him self. Fortunately he was a bear for work, making innumerable observations and then performing all the calculations nec essary to reduce them to useful values, work that would ordinarily be the rou tine functions of assistants. He used a clock systematically in his observations, the first astronomer to do so. On top of low pay (two pounds a week), no help, and poor health Flam steed’s perfectionism brought him into conflict with the great astronomers of the time. Men like Newton felt it was Flam steed’s function to serve as general astro nomical flunky, making and handing over any observations that were called for and doing it at once. Flamsteed had with justification a more exalted notion of his position and grew rebellious at Newton’s unending demands. Newton was quite incapable of seeing another man’s point of view and the two became enemies. Newton took a rather mean re venge by omitting certain credits to Flamsteed in the second edition of the Principia. Flamsteed was pressed to publish his work as quickly as possible, but he re fused to do so until he was all finished, and considering the perfectionism with which he worked, the date at which he would be all finished kept receding into the future in exasperating fashion. Fi nally, in 1708, Newton’s friend Halley [238] managed to get his hands on a number of Flamsteed’s observations and published them at once with the Prince Consort, George of Denmark, under taking the cost of printing. Flamsteed was furious. He called Halley violent names, accused him of irreligion and im morality—yet the two had originally been friends and Halley had helped in the design and construction of the obser vatory. Flamsteed burned every copy of the work he could find (at least three hundred). This incident spurred him on to com pletion, however, and eventually his star catalogue came out in full (though part of it appeared only after his death). It was three times as large as Tycho Brahe’s [156] and the individual stars were located (thanks to the telescope) with six times the precision. It was the first great star map of the telescopic age. When two centuries after his time the nations of the world agreed on an inter national system of marking off meridians of longitude (an offshoot of the problem that got Flamsteed his post in the first place), it was agreed that the meridian of the observatory at Greenwich be the starting place. It is at Longitude 0°0'0" (the Prime Meridian), and that is a kind of monument to the first astronomer royal.
157 [235] PAPIN
HAVERS [237] [235] PAPIN, Denis (pa-pan') French physicist
Loire-et-Cher, August 22, 1647 Died: London, England, early 1712
Papin studied medicine in his youth and obtained his medical degree in 1669 at Angers, but that is not the field in which he gained his fame. He served as assistant to Huygens [215] in 1671 and in 1674 helped introduce improvements in Boyle’s [212] air pump. Papin corre sponded with Leibniz [233] who intro duced Papin’s work to Boyle. In conse quence Papin went to England as Boyle’s assistant in 1675. In 1679 he developed a steam digester, in which water was boiled in a vessel with a tightly fitted lid. The accumu lating steam created a pressure that raised the boiling point of water and at this higher temperature, bones softened and meat cooked in quick time. A safety valve was included in case steam pres sure got too high. This digester was the forerunner of the modem pressure cooker, and it earned Papin membership in the Royal Society in 1680. He cooked a meal for the Royal Society in his digester and prepared a particularly im pressive one for King Charles II. The steam pressure within the digester must have given Papin the notion of making steam do work. He placed a lit tle water at the bottom of a tube and, by heating it, converted it to steam. This ex panded forcibly, pushing a piston ahead of it. Fifteen centuries after Hero [60], men were once again toying with steam, but this time the matter was to be fol lowed up and a century later reach a cli max with Watt [316], Papin never returned to France where, as a Protestant, he would have found the atmosphere unpleasant, thanks to the growing intolerance of Louis XIV. Papin spent some years in Italy, then in Ger many. where he built a steam engine in 1698. In his last years, he returned to England, where he died in obscurity and poverty.
[236] SAVERY, Thomas English engineer Born: Shilstone, Devonshire, about 1650 Died: London, May 1715 Savery, a military engineer, was a prolific inventor and he lived at a time when one particular invention was badly needed. England was deforested and what trees remained were needed for the navy and could not be used indis criminately for fuel. Fortunately En gland could use its deposits of coal. However, water seeps into coal mines and pumping this out by hand (or even by animal power) was arduous and slow. Guericke [189] had shown that air pressure could do wonders if a vacuum was produced, but producing one by an air pump worked by hand was also ardu ous and slow. It occurred to Savery that a vacuum could be produced by filling a vessel with steam and then condensing the steam. Burning fuel would then sup ply all the necessary energy and human muscle could be conserved. He con nected such a vessel to a tube running down into the water in the mine. The vacuum produced in the vessel would suck water some way up the tube and then steam pressure, after the principle of Papin [235], could be used to blow the water out altogether. This instrument, which Savin called the Miner’s Friend, was the first practi cal steam engine and about 1700 it was actually in use in a few places. Its great drawback was that it used steam under high pressure and the technology of the time was insufficient for the manufacture of vessels that could really handle it safely.
[237] HAVERS, Clopton (hav'erz) English physician Born: Stambourne, Essex, about 1655
Died: Willingale, Essex, April 1702
Havers, the son of a rector, entered Cambridge in 1668 but did not graduate. 158 [238] HALLEY
HALLEY [238] He did not get a full license to practice medicine until 1687, after having re ceived a medical education at the Uni versity of Utrecht in the Netherlands. The mark he made in medicine lay in the first full and complete study of bone structure. The text he published in 1691 on the subject remained standard for a century and a half. The Haversian canals in the bone are named for him. [238] HALLEY, Edmund English astronomer
November 8, 1656 Died: Greenwich, January 14, 1742
Interested in astronomy from his school days, Halley, the son of a wealthy businessman, published work on Kepler’s laws when he was nineteen; and then, with Flamsteed’s [234] encouragement, set off in 1676 to record the stars of the southern hemisphere. All astronomers until his time had been based in the northern hemisphere and except for the reports of mariners and travelers the southern heavens were virgin territory. Halley established the first observatory of the southern hemisphere at the island of St. Helena in the South Atlantic (to become famous a century and a half later as the last home of Napoleon Bona parte). He discovered an object in Cen taurus that was eventually found to be a huge globular cluster of stars, Omega Centauri, closest of all such clusters to ourselves. As it turned out, though, St. Helena had a poor climate for astronomical ob servations and when Halley returned in 1678 he was only able to publish a cata logue of 341 southern stars. This was nevertheless a new and worthy addition to star lore and made his reputation. He was called the southern Tycho [156], was awarded a master’s degree from Ox ford despite his not having fulfilled all the requirements, and was elected to the Royal Society. In England he became a fast and en during friend of Newton [231] in 1684 and it was through Halley’s encour agement and financial help that the Prin-
been found murdered in 1684 and Hal ley inherited a tidy sum and was well-to- do thereafter.) Halley’s fame grew and he dined with Peter the Great of Russia during that monarch’s visit to England. Halley, ac cording to all reports, had a joyous and riotous time of it. Newton’s principle of gravitation ap plied easily and well to the various planets and even to the moon, but it was doubtful how well it applied to those outlaws of the skies, the comets, that seemed to come and go as they pleased. Halley (who, in 1703, was appointed professor of geometry at Oxford) addressed himself to this problem and with Newton’s help compiled records of numerous comets, working out their paths across the sky. (In 1679 Halley had visited the aged Hevelius [194], then the recognized authority on comets, and this may have inspired his interest in the problem.) One of the comets Halley dealt with was that of 1682, which he had person ally observed. By 1705, when he had listed the movements of two dozen comets, he was struck by the similarity of the path of the 1682 comet with those that had appeared in 1456, 1531, and 1607. These four had come at intervals of seventy-five or seventy-six years and it occurred to Halley that what he was dealing with was a single comet in a closed but very elongated orbit about the sun that was visible only when it was relatively close to the earth. Between ap pearances it must recede far beyond Sat urn, the most distant planet then known. Halley predicted, in a book written in 1705, that this same comet would return again about 1758, though he was aware that the gravitational interference of the planets might alter the orbit somewhat and change the time of appearance. (Clairaut [283] later showed this to be true.) Although Halley did not live long enough to witness the return of the comet (he would have had to live to the 159 [238] HALLEY
FONTENELLE [239] age of one hundred and two to do so, in stead of dying at eighty-six, in the cen tennial year of Newton’s birth), it re turned as predicted, allowing for Clairaut’s changes. It has been known as Halley’s comet ever since. It has re turned again in 1835 and in 1910 and, it is confidently expected, will return once more in 1986. Through Halley’s work the comets were tamed once and for all and were shown to be as much subjects of the sun as the earth itself. If cometary motions seemed erratic it was only because come tary orbits were so elongated that some might appear only at intervals of many thousands of years and remain visible during only minute portions of their total orbit. Halley repeated the suggestion of Kepler [169] that the transit of Venus be used to determine the scale of the solar system and this suggestion bore success ful fruit after Halley’s death. He also traveled widely about the turn of the century measuring magnetic varia tions. And in a completely different field, he was the first (in 1693) to prepare de tailed mortality tables. This made it pos sible to study life and death statistically and led to modem insurance practices. In 1718 he pointed out that at least three stars, Sirius, Procyon, and Arc- turus, had changed their positions mark edly since Greek times and had even changed position perceptibly since the time of Tycho Brahe a century and a half earlier. From this he concluded that stars had proper motions of their own which were perceptible only over ex tended periods of time because of their vast distances from us. The stars, after all, were not fixed. In 1720 Halley’s enemy Flamsteed was dead and the post of astronomer royal was vacant. Halley was appointed. He inherited a virtually instrumentless obser vatory, since the instruments that had existed had been Flamsteed’s personal property and were removed either by heirs or by creditors. Halley reequipped the observatory and devoted his twenty-
year tenure largely to careful observa tions of the moon. [239] FONTENELLE, Bernard le Bovier de (fohnt-nelO French science writer Born: Rouen, February 11, 1657 Died: Paris, January 9, 1757 Fontenelle, the son of a well-thought- of but not very well-off lawyer, was educated under the Jesuits in Rouen. He originally planned to be a lawyer, but that didn’t Work out, and he turned to literature. At first he tried poetry, operas, dra matic stuff of all kinds, and then found himself with a book entitled Conver sations on the Plurality of Worlds pub lished in 1686. This was an introduction to the interested and intelligent layman of the new astronomy of the telescope; a careful consideration of each of the planets from Mercury to Saturn, with speculations as to the kind of life that might be found upon them. He wasn’t a scientist, and he was, in any case, a follower of Descartes [183], who never quite caught up with Newton [231], Still, his book went through nu merous editions and he was careful to correct the errors when he could and to bring it up to date. He was elected to the French Acad emy in 1691 and became perpetual sec retary of the French Academy of Sci ences in 1697. He wrote annual sum maries of its activities and obituaries for famous scientists as they died. He was perhaps the first person to make a repu tation in science on the basis of his pop ular science writing alone. He was that rarity; a happy man— calm, equable, doing what he most loved to do and successful at it, loving society and finding himself welcome everywhere, in constant good health and keeping all his faculties into advanced old age. In the end, he died one month before his hundredth birthday. To have lived that final month could surely have been all that remained for him to ask for. [240] GREGORY
STAHL [241] [240] GREGORY, David Scottish mathematician and as tronomer
Born: Aberdeen, June 3, 1659 Died: Maidenhead, Berkshire, England, October 10, 1708 David Gregory was a nephew of James Gregory [226]. He had just be come professor of mathematics at the University of Edinburgh in 1683 at the recommendation of Newton [231] and Flamsteed [234], when Newton’s Prin- cipia Mathematica was published. He claimed afterward to have been the first to give public lectures on Newtonian theory. In 1702, by which time he was a professor of astronomy at Oxford and a personal friend of Newton, he published a book in defense of the theory. He did not agree with Newton on the subject of chromatic aberration, how ever. He noted something that had es caped Newton, that different kinds of glass spread out the colors of the spec trum to different extents. He suggested then that a proper combination of two kinds of glass might produce no spec trum at all. This was realized by Dollond [273] a half century later. [241] STAHL, Georg Ernst (shtahl) German chemist
21, 1660 Died: Berlin, May 14, 1734 Stahl, the son of a minister, was a physician by profession (having obtained his degree at Jena in 1684) and a suc cessful one. He was for a time court physician at Weimar, even before he was thirty. He also managed to marry four times, and his lectures on medicine at the University of Halle were both fa mous and well attended. By 1716 he be came physician to King Frederick Wil liam I of Prussia. His greatest fame, however, lies in a chemical theory he adapted from the views his teacher Becher [222] published a half century earlier. The matter of combustion had always interested practi cal chemists if for no other reason than that metals could not be formed from their ores without the action of burning wood or coal. In the seventeenth cen tury, scientists were beginning to play with the power of steam, and it led to the invention of the Savery [236] steam engine. This made the subject of com bustion (the energy of which produced the steam in the first place) even more interesting. Alchemists such as Geber [76] had tried to establish sulfur as the principle of combustion and Becher had spoken of
of phlogiston (from a Greek word meaning “to set on fire”). Combustible objects, Stahl held, were rich in phlogiston and the process of combustion involved a loss of phlogiston. What was left behind after combustion was without phlogiston and therefore could no longer bum. Thus wood pos sessed phlogiston, but ash did not. Stahl recognized that the rusting of metals was analogous to the burning of wood (a great and by no means obvious discovery) and considered that a metal possessed phlogiston but that a rust (or “calx”) did not. Air was considered only indirectly use ful to combustion, for it served only as a carrier, holding the phlogiston as it left the wood or metal and passing it on sometimes to something else. Thus, phlogiston could be transferred from charcoal (considered rich in it) to a metal ore, which was poor in it. In this way the charcoal burned and the ore was converted to metal. Actually this viewpoint had much to recommend it about the year 1700, which was when it was proposed. It did explain a great deal about combustion, certainly more than any previous theory had. It also helped transfer chemical in terest from medicine, where it had rested from the time of Paracelsus [131], to the preparation of minerals and gases— which in turn led inevitably to the devel opment of modern chemistry. The chief difficulty involved in the Download 17.33 Mb. Do'stlaringiz bilan baham: 
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