scholarly journals XXV. On a new series of periodical colours produced by the grooved surfaces of metallic and transparent bodies

1829 ◽  
Vol 119 ◽  
pp. 301-316 ◽  
Keyword(s):  
Royal Society ◽  
The Other ◽  
Metallic Surface ◽  
Intermediate Space ◽  
Original Surface ◽  
Series Of Experiments ◽  
The Subject ◽  
The Common ◽  
Academy Of Sciences ◽  
Distinguished Member

In the year 1822, when I received from Mr. Barton some very fine specimens of his Iris ornaments, I availed myself of the opportunity of performing a series of experiments on the action of grooved surfaces upon light. As the subject was to a certain extent new, many of the results which I obtained seemed to possess considerable interest, and I accordingly communicated to the Royal Society of Edinburgh a general account of them, which was read on the 3rd of February 1823. The interruptions, however, of professional pursuits prevented me, but at distant intervals, from pursuing the inquiry; and having found that M. Fraunhofer was actively engaged in the very same research, with all the advantages of the finest apparatus and materials, I abandoned the subject, though with some reluctance, to his superior powers and means of investigation. During a visit paid to Edinburgh by the Chevalier Yelin, a friend of Fraunhofer’s and a distinguished member of the Academy of Sciences of Munich, I showed him the general results which I had obtained; and as he assured me that the phenomena which had principally occupied my attention had entirely escaped the notice of his friend, I was thus induced to resume my labours, the results of which, in relation to one branch of the subject, I shall now submit to the consideration of the Society. When a flat and polished metallic surface is covered with equal and equidistant grooves, we may characterize it by the relation of two quantities, one of which m represents the breadth of each groove, or of the surface that is removed, while the other n represents the breadth of the intermediate space, or of the original surface that is left. If the image of a candle is seen by reflexion from such a surface, the trace of the plane of reflexion being parallel to the grooves, we observe the colourless image of a candle in the middle of a row of prismatic images arranged in a line perpendicular to the grooves. The colourless image of the candle is formed by the original portions n of the metallic surface, while the prismatic images are formed by the sides of the grooves m . This may be demonstrated ocularly by increasing m , and consequently diminishing n till the latter nearly disappears. In this case the intensity of the prismatic images rises to a maximum, while the ordinary colourless image becomes extremely faint, and vice versâ. The general phenomena of the prismatic images, such as their distance from the common image, and the dispersion of their colours, depend entirely on the magnitude of m + n , or the number of grooves and intervals that occupy any given space; and the laws of these phenomena have been accurately determined by M. Fraunhofer.

XXIII. On the water-barometer erected in the hall of the Royal Society

1832 ◽  
Vol 122 ◽  
pp. 539-574 ◽  
Keyword(s):  
Royal Society ◽  
Physical Science ◽  
The Other ◽  
Metallic Tube ◽  
French Academy ◽  
History Of ◽  
The Subject ◽  
The Common ◽  
Academy Of Sciences ◽  
Made In

I have for some time entertained an opinion, in common with some others who have turned their attention tot he subject, that a good series of observations with a Water-Barometer, accurately constructed, might throw some light upon several important points of physical science: amongst others, upon the tides of the atmosphere; the horary oscillations of the counterpoising column; the ascending and descending rate of its greater oscillations; and the tension of vapour at different atmospheric temperatures. I have sought in vain in various scientific works, and in the Transactions of Philosophical Societies, for the record of any such observations, or for a description of an instrument calculated to afford the required information with anything approaching to precision. In the first volume of the History of the French Academy of Sciences, a cursory reference is made, in the following words, to some experiments of M. Mariotte upon the subject, of which no particulars appear to have been preserved. “Le même M. Mariotte fit aussi à l’observatoire des experiences sur le baromètre ordinaire à mercure comparé au baromètre à eau. Dans l’un le mercure s’eléva à 28 polices, et dans Fautre l’eau fut a 31 pieds Cequi donne le rapport du mercure à l’eau de 13½ à 1.” Histoire de I'Acadérmie, tom. i. p. 234. It also appears that Otto Guricke constructed a philosophical toy for the amusement of himself and friends, upon the principle of the water-barometer; but the column of water probably in this, as in all the other instances which I have met with, was raised by the imperfect rarefaction of the air in the tube above it, or by filling with water a metallic tube, of sufficient length, cemented to a glass one at its upper extremity, and fitted with a stop-cock at each end; so that when full the upper one might be closed and the lower opened, when the water would fall till it afforded an equipoise to the pressure of the atmo­sphere. The imperfections of such an instrument, it is quite clear, would render it totally unfit for the delicate investigations required in the present state of science; as, to render the observations of any value, it is absolutely necessary that the water should be thoroughly purged of air, by boiling, and its insinuation or reabsorption effectually guarded against. I was convinced that the only chance of securing these two necessary ends, was to form the whole length of tube of one piece of glass, and to boil the water in it, as is done with mercury in the common barometer. The practical difficulties which opposed themselves to such a construction long appeared to me insurmount­able; but I at length contrived a plan for the purpose, which, having been honoured with the approval of the late Meteorological Committee of this Society, was ordered to be carried into execution by the President and Council.

scholarly journals XIV. On the absorption of gases by solids

1881 ◽  
Vol 32 (212-215) ◽  
pp. 407-408
Keyword(s):  
Royal Society ◽  
Hydraulic Press ◽  
Careful Examination ◽  
Solid Matter ◽  
Chemical Action ◽  
High Pressure And Temperature ◽  
Solid Iron ◽  
Series Of Experiments ◽  
The Subject ◽  
Very High

During the progress of the investigations which I have from time to time had the honour of bringing under the notice of the Royal Society, I have again and again noticed the apparent disappearance of gases inclosed in vessels of various materials when the disappearance could not be accounted for upon the assumption of ordinary leakage. After a careful examination of the subject I found that the solids absorbed or dissolved the gases, giving rise to a striking example of the fixation of a gas in a solid without chemical action. In carrying out that most troublesome investigation, the crystalline separation of carbon from its compounds, the tubes used for experiment have been in nine cases out of ten found to be empty on opening them, and in most cases a careful testing by hydraulic press showed no leakage. The gases seemed to go through the solid iron, although it was 2 inches thick. A series of experiments with various linings were tried. The tube was electro-plated with copper, silver, and gold, but with no greater success. Siliceous linings were tried fusible enamels and glass—but still the' tubes refused to hold the contents. Out of thirty-four experiments made since my last results were published, only four contained any liquid or condensed gaseous matter after the furnacing. I became convinced that the solid matter at the very high pressure and temperature used must be pervious to gases.

Who Got There First

2000 ◽  
Author(s):  
John H. Lienhard
Keyword(s):  
Acid Solution ◽  
Electrical Current ◽  
Smithsonian Institution ◽  
Liquid Pool ◽  
The Other ◽  
Electric Contact ◽  
Variable Resistance ◽  
Scientists And Engineers ◽  
The Subject ◽  
The Common

Years ago, a curator at the Smithsonian Institution said to me, “Scientists and engineers are nutty on the subject of priority.” That was before I realized just how far-reaching that nuttiness was or how misguided the very concept of priority is. As an example, try searching out the inventor of the telephone. Instead of Alexander Graham Bell, you may get the name of a German, Johann Philipp Reis. The common wisdom is that Reis invented a primitive telephone that was only marginally functional, while Bell’s phone really worked. Reis was a twenty-six-year-old science teacher when he began work on the telephone in 1860. His essential idea came from a paper by a French investigator named Bourseul. In 1854 Bourseul had explained how to transmit speech electrically. He wrote: . . . Speak against one diaphragm and let each vibration “make or break” the electric contact. The electric pulsations thereby produced will set the other diaphragm working, and [it then reproduces] the transmitted sound. . . . Only one part of Bourseul’s idea was shaky. To send sound, the first diaphragm should not make and break contact; instead it should vary the flow of electricity to the second diaphragm continuously. While Reis had used Bourseul’s term “make or break,” his diaphragm actually drove a thin rod to varying depth in an electric coil. Instead of making and breaking the current, he really did vary it continuously. Bell faced the same problem when he began work on his telephone a decade later. First, he used a diaphragm-driven needle that entered a water-acid solution to create a continuously variable resistance and a smoothly varying electrical current. Bell got the idea from another American, inventor Elisha Gray. Of course, a liquid pool comes with two problems. One is evaporation; the other is immobility. Bell soon gave it up in favor of a system closer to Reis’ electromagnet. Still, it is clear that Gray’s variable-resistance pool had pointed the way for Bell. Next we must ask whether Bell was influenced by Reis’ invention. Reis died two years before Bell received his patent. (He was only forty, and he never got around to seeking a patent of his own.)

scholarly journals VIII. On the structure and development of the skull of the common frog ( Rana temporaria , L.)

1871 ◽  
Vol 161 ◽  
pp. 137-211 ◽  
Keyword(s):  
Rana Temporaria ◽  
The Other ◽  
Common Frog ◽  
Frog Rana Temporaria ◽  
The Subject ◽  
The Common ◽  
Working Out

Since the sending in of my last communication, that on the Skull of the Fowl, our knowledge of the morphology of the facial arches has been very greatly extended by Professor Huxley’s invaluable paper “On the Representatives of the Malleus and the Incus of the Mammalia in the other Vertebrata” (see Proc. Zool. Soc. May 1869, pp. 391-407). After comparing the components of the mandibular and hyoid arches in an extended series of vertebrate types, the author concludes his paper by saying (p. 406), “in the higher Amphibia changes of a most remarkable kind take place, of which I do not now propose to speak, as my friend Mr. Parker is engaged in working out that part of the subject.”

scholarly journals VII.—On the Motion of a Heavy Body along the Circumference of a Circle

1865 ◽  
Vol 24 (1) ◽  
pp. 59-71
Author(s):  
Edward Sang
Keyword(s):  
Royal Society ◽  
Elliptic Functions ◽  
The Other ◽  
Philosophical Magazine ◽  
Circular Arc ◽  
Heavy Body ◽  
Great Ease ◽  
Fourth Volume ◽  
The Common ◽  
The One

In the year 1861 I laid before the Royal Society of Edinburgh a theorem concerning the time of descent in a circular arc, by help of which that time can be computed with great ease and rapidity. A concise statement of it is printed in the fourth volume of the Society's Proceedings at page 419.The theorem in question was arrived at by the comparison of two formulæ, the one being the common series and the other an expression given in the “Edinburgh Philosophical Magazine” for November 1828, by a writer under the signature J. W. L. Each of these series is reached by a long train of transformations, developments, and integrations, which require great familiarity with the most advanced branches of the infinitesimal calculus; yet the theorem which results from their comparison has an aspect of extreme simplicity, and seems as if surely it might be attained to by a much shorter and less rugged road. For that reason I did not, at the time, give an account of the manner in which it was arrived at, intending to seek out a better proof. On comparing it with what is known in the theory of elliptic functions, its resemblance to the beautiful theorem of Halle became obvious; but then the coefficients in Halle's formulæ are necessarily less than unit, whereas for this theorem they are required to be greater than unit.

scholarly journals I. On the evidence of the existence of the decennial inequality in the solar-diurnal magnetic variations, and its non-existence in the lunar-diurnal variation, of the declination at Hobarton

1857 ◽  
Vol 147 ◽  
pp. 1-8 ◽  
Keyword(s):  
Diurnal Variation ◽  
Royal Society ◽  
Magnetic Elements ◽  
Imperial Academy ◽  
The Subject ◽  
British Colonial ◽  
The Mean ◽  
Hourly Observation ◽  
Academy Of Sciences ◽  
Magnetic Observatories

In a report presented to the British Association at Liverpool in September 1854, entitled "On some of the results obtained at the British Colonial Magnetic Observatories," I stated that, as far as my examination of the observations had then gone, I had found in the Lunar-diurnal magnetic variation no trace of the decennial period which is so distinctly marked in all the variations connected with the Sun. And in a subsequent communication to the Royal Society in June 1856, “On the Lunar-diurnal Variation at Toronto,” in which the moon’s influence on each of the three magnetic elements was examined, the conclusion arrived at was to the same effect, viz. that the observations at Toronto “showed no appearance of the decennial period which constitutes so marked a feature in the solar-diurnal variations.” Since these statements were made, I have read M. Kreil’s memoir “On the Influence of the Moon on the horizontal component of the Magnetic Force,” presented to the Imperial Academy of Sciences at Vienna in 1852 and printed in 1853, from which I learn (pp. 45, 46) that M. Kreil is of opinion that the observations of different years at Milan and Prague, when combined, would rather favour the supposition that the same decennial period which exists in the solar variation affects also the lunar magnetic influence. The question is one of such manifest importance in its theoretical bearing, that I considered it desirable to lose no time in re-examining it by the aid of the Hobarton observations, which, as it appeared to me, were particularly suitable for the purpose, inasmuch as they consist of eight consecutive years of hourly observation (from January 1841 to December 1848 inclusive), made with one and the same set of instruments, and by a uniform system of observation. The results of this examination have been, as it appears to me, so decidedly confirmatory of the conclusions drawn from the Toronto observations, both as regards the existence of the decennial period in the two classes of solar-diurnal variation (viz. in the mean diurnal variation occasioned by the disturbances of large amount, and in what may be termed the more regular solar-diurnal variation), and the non-existence of a similar decennial period in the case of the lunar-diurnal variation, that I have been induced to make these results the subject of a communication to the Royal Society.

An appendix to Mr. Ware’s paper on vision

1832 ◽  
Vol 1 ◽  
pp. 454-455
Keyword(s):  
The Other ◽  
Watch Glass ◽  
Early Age ◽  
Learning To Read ◽  
The Subject ◽  
The Common ◽  
The Right ◽  
The Mind ◽  
Different Parts ◽  
Marble Surface

The author remarks, that Mr. Ware’s observations with regard to short-sightedness, being in general merely the consequence of habit acquired at an early age, is conformable with his own experience in general, and that he himself is a particular instance of natural long-sightedness gradually converted into confirmed short sight. He very well remembers first learning to read, at the common age of four or five years, and that at that time he could see the usual inscriptions across a wide church; but that at the age of nine or ten years he could no longer distinguish the same letters at the same distance, without the assistance of a watch-glass, which has the effect of one slightly concave. In a few years more the same glass was not sufficiently powerful; but yet his degree of short-sightedness was so inconsiderable, that he yielded to the dissuasion of his friends from using the common concave glasses till he was upwards of thirty years of age, when No. 2 was barely sufficient; and he very shortly had recourse to No. 3. In the course of a few years an increase of the defect rendered it necessary for him to employ glasses still deeper, and his sight soon required No. 5, where it has remained stationary to the present time. From the progress which Sir Charles Blagden has observed in his own short-sightedness, he is of opinion that it would have been accelerated by an earlier use of concave glasses, and might have been retarded, or perhaps prevented altogether, by attention to read and write with his book or paper as far distant as might be from his eyes. In this communication he takes the same opportunity of adding an experiment made many years since on the subject of vision, with a view to decide how far the similarity of the images received by the two eyes contribute to the impression made on the mind, that they arise from only one object. In the house where he then resided, was a marble surface ornamented with fluting, in alternate ridges and concavities. When his eyes were directed to these, at the distance of nine inches, they could be seen with perfect distinctness. When the optic axes were directed to a point at some distance behind, the ridges seen by one eye became confounded with the impression of concavities made upon the other, and occasioned the uneasy sensation usual in squinting. But when the eyes were directed to a point still more distant, the impression of one ridge on the right eye corresponded with that made with an adjacent ridge upon the left eye, so that the fluting then appeared distinct and single as at first, but the object appeared at double its real distance, and apparently magnified in that proportion. Though the different parts of the fluting were of the same form, their colours were not exactly alike, and this occasioned some degree of confusion when attention was paid to this degree of dissimilarity.

scholarly journals IV. On repulsion resulting from radiation.—Part VI

1879 ◽  
Vol 170 ◽  
pp. 87-134 ◽  
Keyword(s):  
The Other ◽  
General Character ◽  
Experimental Examination ◽  
Present Part ◽  
Series Of Experiments ◽  
The Subject ◽  
Residual Gas ◽  
At Will ◽  
Thin Mica

387. Although the general character of the reactions which cause repulsion under the influence of radiation is now understood, much light may he thrown on the subject by an experimental examination of the direction and strength of the lines of pressure inside the case of a radiometer on which light is allowed to fall. Radiation will pass almost unimpeded through a very thin, colourless and transparent substance such as mica, but molecular pressure or stress is arrested by such a body (232). By introducing fixed or movable screens in various parts of the case of a radiometer, the direction of pressure can be determined at will, and its force can be modified in many ways, whilst all the other conditions of the experiment remain unchanged. In the present Part I propose to give the results of a long series of experiments on the action of thin mica screens in modifying the movements of the fly of a radiometer; I shall examine the action of the residual gas, the action of the sides of the glass case, and the applicability of the information so afforded to the construction of instruments of greatly increased sensitiveness for the purposes of research and illustration; and I shall also describe other experiments which have been tried from time to time during the last few years—experiments which at the time were isolated in their bearings, but which now fit into their places.

scholarly journals On a new register-pyrometer, for measuring the expansions of solids, and determining the higher degrees of temperature upon the common thermometric scale

1833 ◽  
Vol 2 ◽  
pp. 404-406
Keyword(s):  
Melting Point ◽  
High Temperatures ◽  
The Other ◽  
Royal Institution ◽  
Guyton De Morveau ◽  
Higher Temperature ◽  
The Subject ◽  
The Common ◽  
The One ◽  
Universal Application

In the year 1821, the author published in the Journal of the Royal Institution an account of a new pyrometer, and of some determinations of high temperatures, in connexion with the scale of the mercurial thermometer, obtained by its means. The use of the instrument then described was, however, limited; and the author was subsequently led to the invention of a pyrometer of a more universal application, both to scientific researches and to various purposes of art. Fie introduces the subject by an account of the late attempt of M. Guyton de Morveau, to employ the expansions of platina for the admeasurement of high temperatures, and for connecting the indications of Wedgwood’s pyrometer with the mercurial scale, and verifying its regularity. The experiments of that philosopher were by the contraction of porcelain, and by actual comparison with those of the platina pyrometer, at no higher temperature than the melting point of antimony; but they are sufficient to establish the existence of a great error in Wedgwood’s original estimation of his degrees up to that point. This he carries on by calculation, on the hypothesis of uniform progression of expansion, up to the melting point of iron; the construction of his instrument not admitting of its application to higher temperatures than a red heat, in which platina becomes soft and ductile. Mr. Daniell shows, by an examination of M. Guyton’s results, that he has failed in establishing the point he laboured to prove; namely, the regularity of the contraction of the clay pieces. The pyrometer of the author consists of two distinct parts; the one designated the register , the other the scale .

Brighter than how many suns? Sir Isaac Newton’s burning mirror

1989 ◽  
Vol 43 (1) ◽  
pp. 31-51 ◽  
Keyword(s):  
Royal Society ◽  
Scientific Literature ◽  
Radiant Heat ◽  
The Other ◽  
Sir Isaac Newton ◽  
Isaac Newton ◽  
Other Hand ◽  
The Press ◽  
The Subject ◽  
Hearsay Evidence

There are a number of references in the scientific literature to a burning mirror designed by Sir Isaac Newton (1). Together, they record that it was made from seven separate concave glasses, each about a foot in diameter, that Newton demonstrated its effects at several meetings of the Royal Society and that he presented it to the Society. Nonetheless, neither the earliest published list of instruments possessed by the Royal Society nor the most recent one mentions the burning mirror; the latest compiler does not even include it amongst those items, once owned, now lost. No reference to the instrument apparently survives in the Society’s main records. It is not listed by the author of the recent compendium on Newton’s life and work (2). There is, however, some contemporary information still extant (Appendix 1). Notes of the principles of its design and some of its effects are to be found in the Society’s Journal Book for 1704; some of the dimensions and the arrangement of the mirrors are given in a Lexicon published by John Harris which he donated to the Royal Society at the same meeting, 12 July 1704, at which Newton gave the Society the speculum. The last reference in the Journal Book is dated 15 November that year, when Mr Halley, the then secretary to the Society, was desired to draw up an account of the speculum and its effects (3). No such account appears to have been presented to the Royal Society. There is no reference in Newton’s published papers and letters of his chasing Halley to complete the task, nor is there any mention of it in the general references to Halley. The latter was, of course, quite accustomed to performing odd jobs for Newton; that same year he was to help the Opticks through the press. The only other contemporary reference to the burning mirror, though only hearsay evidence since Flamsteed was not present at the meeting, is in a letter the latter wrote to James Pound; this confirms that there were seven mirrors and that the aperture of each was near a foot in diameter (4). Because John Harris gave his Dictionary to the Royal Society in Newton’s presence, it is reasonable to assume that his description is accurate. As Newton would hardly have left an inaccurate one unchallenged, then, belatedly, the account desired of Mr Halley can be presented. In some respects, the delay is advantageous, since the subject of radiant heat and its effects, although already by Newton’s period an ancient one, is today rather better understood. On the other hand, some data has to be inferred, that could have been measured, and some assumptions made about Newton’s procedures and understanding that could have been checked (5).

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