scholarly journals IV. On a method of meteorological registration of the chemical action of total daylight

1864 ◽  
Vol 13 ◽  
pp. 555-559
Keyword(s):  
Short Length ◽  
Present Communication ◽  
Small Space ◽  
Arbitrary Degree ◽  
Chemical Action ◽  
Simple Mode ◽  
Accurate Comparison ◽  
Considerable Length ◽  
The Times ◽  
Sodium Solution

The aim of the present communication is to describe a simple mode of measuring the chemical action of total daylight, adapted to the purpose of regular meteorological registration. This method is founded upon that described by Prof. Bunsen and the author in their last Memoir on Photochemical Measurements, depending upon the law that equal products of the intensity of the acting light into the times of insolation correspond within very wide limits to equal shades of tints produced upon chloride-of-silver paper of uniform sensitiveness—light of the intensity 50, acting for the time 1, thus producing the same blackening effect as light of the intensity 1 acting for the time 50. For the purpose of exposing this paper to light for a known but very short length of time, a pendulum photometer was constructed; and by means of this instrument a strip of paper is so exposed that the different times of insolation for all points along the length of the strip can be calculated to within small fractions of a second, when the duration and amplitude of vibration of the pendulum are known. The strip of sensitive paper insolated daring the oscillation of the pendulum exhibits throughout its length a regularly diminishing shade from dark to white; and by reference to a Table, the time needed to produce any one of these shades can be ascertained. The unit of photo-chemical action is assumed to be that intensity of light which produces in the unit of time (one second) a given but arbitrary degree of shade termed the standard tint. The reciprocals of the times during which the points on the strip have to be exposed in order to attain the standard tint, give the intensities of the acting light expressed in terms of the above unit. By means of this method a regular series of daily observations can be kept up without difficulty; the whole apparatus needed can be packed up into small space; the observations can be carried on without regard to wind or weather; and no less than forty-five separate determinations can be made upon 36 square centimetres of sensitive paper. Strips of the standard chloride-of-silver paper tinted in the pendulum photometer remain as the basis of the new mode of measurement. Two strips of this paper are exposed as usual in the pendulum photometer: one of these strips is fixed in hyposulphite-of-sodium solution, washed, dried, and pasted upon a board, furnished with a millimetre-scale. This fixed strip is now graduated in terms of the unfixed pendulum strip by reading off, by the light of a soda-flame, the position of those points on each strip which possess equal degrees of tint, the position of the standard tint upon the unfixed strip being ascertained for the purpose of the graduation. Upon this comparison with the unfixed pendulum strip depends the subsequent use of the fixed strip. A detailed description of the methods of preparing and graduating the strips, and of the apparatus for exposure and reading, is next given. The following conditions must be fulfilled in order that the method may be adopted as a trustworthy mode of measuring the chemical action of light:— 1st. The tint of the standard strips fixed in hyposulphite must remain perfectly unalterable during a considerable length of time. 2nd. The tints upon these fixed strips must shade regularly into each other, so as to render possible an accurate comparison with, and graduation in terms of, the unfixed pendulum strips. 3rd. Simultaneous measurements made with different strips thus graduated must show close agreement amongst themselves, and they must give the same results as determinations made by means of the pendulum photometer, according to the method described in the last memoir.

XII. The Bakerian Lecture.—On a method of meteorological registration of the chemical action of total daylight

1865 ◽  
Vol 155 ◽  
pp. 605-631 ◽  
Keyword(s):  
Royal Society ◽  
Short Length ◽  
Direct Sunlight ◽  
Arbitrary Degree ◽  
Chemical Action ◽  
Reflected Light ◽  
Standard Paper ◽  
Calm Weather ◽  
The Times ◽  
Made In

In the last memoir on Photochemical Measurements, presented to the Royal Society, Professor Bunsen and I described a method for determining, by simple observations, the varying amount of chemical action effected by the direct and diffuse sunlight on photographic paper, founded upon a law discovered by us, viz. that equal products of the intensity of the light into the times of insolation correspond within very wide limits to equal shades of tints produced on chloride-of-silver paper of uniform sensitiveness—so that light of the intensity 50, acting for the time 1, produces the same blackening effect as light of the intensity 1 acting for the time 50. For the purpose of exposing this paper to light for a known but very short length of time, a pendulum photometer was constructed; and by means of this instrument a strip of paper is so exposed that the different times of insolation for all points along the length of the strip can be calculated to within small fractions of a second, when the duration and amplitude of vibration of the pendulum are known. The strip of sensitive paper insolated during the oscillation of the pendulum exhibits throughout its length a regularly diminishing shade from dark to white; and by reference to a Table, the time needed to produce any one of these shades can be ascertained. The unit of photo-chemical intensity is assumed to be that of the light which produces upon the standard paper in the unit of time (one second) a given but arbitrary degree of shade termed the normal tint. The reciprocals of the times during which the points on the strip have to be exposed in order to attain the normal tint, give the intensities of the acting light expressed in terms of the above unit. According to this method the chemical action of the total daylight ( i. e . the direct sunlight and the reflected light from the whole heavens) has been determined, by means of observations made at frequent intervals throughout the day, and curves representing the variation of daily chemical intensity at Manchester have been drawn. The labour of obtaining a regular series of such daily measurements of the chemical action of daylight according to this method is, however, very considerable; the apparatus required is bulky, the observations can only be made in calm weather, and the quantity of sensitive paper needed for a day’s observations is large.

scholarly journals Procesos de documentación arqueológica y generación de modelos virtuales

2011 ◽  
Vol 2 (3) ◽  
pp. 65 ◽  
Author(s):  
Josep Blasco Senabre ◽  
Sebastián Varea ◽  
Fernando Cotino Vila ◽  
Albert Ribera Lacomba ◽  
Oreto García Puchol
Keyword(s):  
Virtual Reality ◽  
Three Dimensional ◽  
3D Models ◽  
Present Communication ◽  
Archaeological Excavation ◽  
Great Range ◽  
The Times

<p>In the present communication we offer some examples that illustrate the methodological corpus applied by our company (Global S.L) in relation with the photogrametrical documentation and the virtual reality in the field of the archaeology. The use of these technologies of computerized documentation offers a great range of possibilities for the graphic documentation of an archaeological excavation, allowing to generate planimetry and pertinent sections and to improve the times in the process of obtaining of information. The possibility of producing 3D models supposes an essential addition to show in a three –dimensional way the current condition of the monument, as well as for its virtual recreation by means of the technologies of virtual reality and increased reality.</p>

XIV. Researches on the tides. —Twelfth series. On the laws of the rise and fall of the sea's surface during each tide

1840 ◽  
Vol 130 ◽  
pp. 255-272 ◽  
Keyword(s):  
Usual Care ◽  
Tide Gauge ◽  
High Water ◽  
Present Communication ◽  
The Subject ◽  
The Times ◽  
The Moment ◽  
Surface Passing

The subject of the present communication is different in its nature from those of previous memoirs on the tides presented by me, and printed by the Society; since it refers, not to comparison of the times and heights of different tides, but to the rate of the rise and fall of the surface of the water in successive stages of the same tide. This inquiry has often been prosecuted at particular places by naval observers, and is of very material importance to navigation. For even supposing the time and height of high water to be known, it is still often requisite, for nautical purposes, to know the height of the water at a given interval before or after the moment of high water. And this inquiry may be the more useful, inasmuch as the laws of rise and fall of the surface are nearly the same at all places; the differences being, for the most part, of such a kind as can be ascertained and allowed for without much difficulty. Hence these laws, once stated, will be applicable on every coast; and the knowledge of them may supersede those laborious trains of observation which have often been instituted in order to ascertain the laws at particular places. The materials of the present investigation (which is principally founded upon ob­servation) are the following: —Five months’ tide observations made at Plymouth, in which, besides the time and height of high and low water, the time of the surface passing two lines above the level of mean water was carefully observed; these latter observations being made, at my request, by direction of the Lords Commissioners of the Admiralty: —Three months’ observations (taken out of a larger series) made at Liverpool, under the direction of Capt. Denham, R. N., in which the height of the surface was noted every half hour: —and twelve months’ observations made at Bristol by Mr. Bunt, by means of his tide-gauge. The latter observations were reduced by Mr. Bunt himself; the others were discussed under my direction by Mr. Dessiou and Mr. Ross, of the Hydrographer’s Office, with their usual care and skill.

scholarly journals XVIII. On a self-recording method of measuring the intensity of the chemical action of total daylight

1874 ◽  
Vol 164 ◽  
pp. 655-673
Keyword(s):  
Chemical Activity ◽  
Present Communication ◽  
Yearly Variation ◽  
Previous Night ◽  
Chemical Action ◽  
Recording Method ◽  
Laws Of Distribution ◽  
Made In

Although the method of measuring the varying intensity of the chemically active rays, as affecting chloride-of-silver paper of constant sensitiveness described in the Bakerian Lecture for 1865, has been the means of pointing out many important facts concerning the distribution of the sun’s chemical activity through the atmosphere as well as in different situations on the earth’s surface, it has not as yet been introduced as a regular portion of the work of meteorological observatories. Until this is done, and the measurements are regularly continued and made in many situations, we cannot hope to obtain any thing like a knowledge of the laws of distribution of these rays over the earth’s surface, or any information as to the yearly variation of the solar chemical activity. This non-adoption of the method has to be explained, not in any want of reliance in the process or in the results, but in the fact that, in order to obtain a satisfactory curve of daily chemical intensity, at least hourly observations need to be made; this involves, however, the expenditure of so much time and labour that the permanent observatories, already too heavily weighted, have found it impossible to undertake the necessary work. In the present communication I have to describe a modification of the above-mentioned method, which, whilst preserving untouched the principles upon which it is based and the amount of exactitude of which it is susceptible, reduces the personal attention needed for carrying out the measurements to a minimum, and thus renders its adoption in observatories possible. According to this plan, the constant sensitive paper is exposed to the action of total daylight at given intervals, say at every hour, during the day, by a self-acting arrangement, for accurately known times. The insolation-apparatus, stocked with sensitive paper, is placed in position either early in the morning of the day during which the measurements have to be made, or on the previous night; and by means of electric communication with a properly arranged clock, the sensitive paper is exposed every hour during the day, so that, in the evening, the observer has only to read off in the ordinary manner the hourly intensities which have been recorded on the paper during the day.

scholarly journals Spin coupling in 3 Σ states of PH and PD

1936 ◽  
Vol 156 (887) ◽  
pp. 221-232 ◽  
Keyword(s):  
Discharge Tube ◽  
Spin Coupling ◽  
Complete Analysis ◽  
Present Communication ◽  
Intense Band ◽  
Accurate Comparison ◽  
Large Water ◽  
Concave Grating ◽  
A Current

The authors have already very briefly recorded some observations on the spectrum of PD; in the present communication these results are described in more detail. The spectrum of phosphorus deuteride has been obtained from a large water-cooled discharge tube containing phosphorus in an atmosphere of deuterium. The tube was excited by a D. C. generator and carried a current of about 0.5 amperes at 1500 volts. Details of the experimental arrangements will be given in a later paper containing the complete analysis of the spectrum. The intensity obtained was such that exposures of from 1-2 hours gave satisfactory photographs in the 4th order of the 10-foot concave grating. The spectrum of PD, like that of PH, consists of one intense band near λ 3400, which shades off in both directions and contains five maxima of intensity. The maxima are, however, much more sharply defined for PD. The λ 3400 band of PH, which was described in an earlier communication, was analysed from plates taken in the 2nd order of the grating. It has now been rephotographed in the 4th order for more accurate comparison with PD.

scholarly journals The chromatic behaviour of the eel ( Anguilla vulgaris L.)

1940 ◽  
Vol 128 (852) ◽  
pp. 343-353 ◽  
Keyword(s):  
Blood Supply ◽  
White Background ◽  
Posterior Lobe ◽  
Pituitary Extract ◽  
Present Communication ◽  
Nervous Stimulation ◽  
Black Background ◽  
The Times ◽  
Stimulation Of

Neil (1939) has described the chromatic response of normal and blinded eels to various condition of illumination. From the times taken to equilibrate when passing from white to black “background” and vice versa with overhead illumination, he concluded that co-ordination is humoral. The time taken to equilibrate after transference to darkness from an illuminated white background or vice versa implies that control is bihumoral. Apart form Neill's work and an early comment by Petersen the chromatic behaviour of the eel has engaged little attention. Lode (1890) described contraction of the melanophores after faradic stimulation of the cord. Odiorne (1933) found that injection of posterior lobe pituitary extract caused expansion of the melanophores. The present communication deals with experiments designed to elucidate the mechanism of co-ordination more fully. It includes observations on ( a ) modification of normal chromatic behaviour by total or partial hypophysectomy; ( b ) effect of total and partial hypophysectomy on tolerance to pituitary extracts; ( c ) influence of nervous stimulation in the presence or absence of an intact blood supply. They are based chiefly on the behaviour of the dermal melanophores for recording which the melanophore index ( μ ) of Hogben and Slome (1931) is used throughout.

scholarly journals II. On a self-recording method of measuring the intensity of the chemical action of total daylight

1874 ◽  
Vol 22 (148-155) ◽  
pp. 158-159
Keyword(s):  
Chemical Activity ◽  
Present Communication ◽  
Previous Night ◽  
Chemical Action ◽  
Recording Method ◽  
Regular Work

The object of the present communication is to describe an instrument by which the varying intensity of the chemically active rays, as affecting chloride of silver paper of constant sensitiveness, can be made self-recording. The method described by the author in the Bakerian Lecture for 1865, although it has been the means of bringing into notice many important facts concerning the distribution of the sun’s chemical activity throughout the atmosphere, as well as in different situations on the earth’s surface, has not as yet been introduced as a portion of the regular work of meteorological observatories, owing to the fact that, in order to obtain a satisfactory curve of daily chemical intensity, at least hourly observations need to be made, and this involves the expenditure of more time and labour than it has been found possible to give. In the present communication a method is described, which, whilst preserving untouched the principles and accuracy of the former method, reduces the personal attention needed for carrying out the measurements to a minimum, and thus renders its adoption in observatories possible. According to this plan, a constant sensitive paper is exposed by a self-acting arrangement for accurately known times, at given intervals throughout the day. The insolation apparatus stocked with sensitive paper is placed in position either early in the morning of the day during which the measurements have to be made, or on the previous night, and by means of an electric communication with a properly arranged clock, the sensitive paper is exposed every hour during the day, so that, in the evening, the observer has only to read off, in the ordinary manner, the hourly intensities which have been recorded on the paper during the day.

I. On the chemical action of the rays of the solar spectrum on preparations of silver and other substances, both metallic and non-metallic, and on some photographic processes

1840 ◽  
Vol 130 ◽  
pp. 1-59 ◽  
Keyword(s):  
Present State ◽  
White Light ◽  
Solar Spectrum ◽  
Present Communication ◽  
Chemical Action ◽  
Chemical Agents ◽  
Other Substances

1. Lest the title of this communication should induce an expectation of its containing any regular and systematic series of researches developing definite laws, or pointing to any distinct theory of photographic action, it may be as well to commence it by stating its pretensions to be of a much lower kind, its object being simply to place on record a number of insulated facts and observations respecting the relations both of white light and of the differently refrangible rays to various chemical agents, which have offered themselves to my notice in the course of photographic experiments originating in the announcement of M. Daguerre’s discovery. The facts themselves, in the present state of our knowledge, will, I believe, be found by no means devoid of interest, and may lead, in the hands of others more favourably situated for such researches, and, I may add, in a better climate than ours, to inquiries of the utmost interest. 2. In a communication to this Society, which was read on the 14th of March, 1839, and of which an abstract will be found in the notices of its proceedings for that sitting, I have stated the circumstances which first directed my attention to this subject, and the progress I had then made, both in the scientific part of the inquiry and in its application to the photographic art. As that paper was (at my own request) withdrawn from the further immediate notice of the Society, and as the abstract alluded to may not fall into the hands of those who may read the present communication, a brief recapitulation of its contents will be necessary to preserve the connexion by which my inquiries have been linked together.

The Eclipsing Binary WX Eridani

1979 ◽  
Vol 46 ◽  
pp. 385
Author(s):  
M.B.K. Sarma ◽  
K.D. Abhankar
Keyword(s):  
Light Curve ◽  
Spectral Type ◽  
Orbital Period ◽  
Primary Component ◽  
Light Curves ◽  
Absorption Feature ◽  
Primary Star ◽  
Eclipsing Binary ◽  
The Times ◽  
Phase Angles

AbstractThe Algol-type eclipsing binary WX Eridani was observed on 21 nights on the 48-inch telescope of the Japal-Rangapur Observatory during 1973-75 in B and V colours. An improved period of P = 0.82327038 days was obtained from the analysis of the times of five primary minima. An absorption feature between phase angles 50-80, 100-130, 230-260 and 280-310 was present in the light curves. The analysis of the light curves indicated the eclipses to be grazing with primary to be transit and secondary, an occultation. Elements derived from the solution of the light curve using Russel-Merrill method are given. From comparison of the fractional radii with Roche lobes, it is concluded that none of the components have filled their respective lobes but the primary star seems to be evolving. The spectral type of the primary component was estimated to be F3 and is found to be pulsating with two periods equal to one-fifth and one-sixth of the orbital period.

Anchoring Fibrils in Arterial Endothelium

1969 ◽  
Vol 27 ◽  
pp. 274-275
Author(s):  
A. Trillo
Keyword(s):  
Carotid Arteries ◽  
Animal Species ◽  
Cell Layer ◽  
Present Communication ◽  
Internal Elastic Lamina ◽  
Endothelial Cell Layer ◽  
Structural Details ◽  
Rats And Mice ◽  
Arterial Endothelium ◽  
Elastic Lamina

There are conflicting reports regarding some fine structural details of arteries from several animal species. Buck denied the existence of a sub-endothelial space, while Karrer and Keech described a space of variable width which separates the endothelium from the underlying internal elastic lamina in aortas of aging rats and mice respectively.The present communication deals with the ultrastrueture of the interface between the endothelial cell layer and the internal elastic lamina as observed in carotid arteries from rabbits of varying ages.

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