I. On the heating effects of electric currents. No. II

1888 ◽  
Vol 43 (258-265) ◽  
pp. 280-295 ◽  
Keyword(s):  
Royal Society ◽  
Atmospheric Electricity ◽  
Platinum Wire ◽  
Electric Currents ◽  
Heating Effects ◽  
The Wire ◽  
The Law ◽  
Submarine Cables

On March 19th, 1884, I submitted to the Royal Society a paper on the heating effects of electric currents, showing the strength of current necessary to fuse the fine platinum wire employed for protecting submarine cables from the ill effects of atmospheric electricity. The paper proved that the law that regulates the production of heat is one which can be expressed by the formula C = ad 3/2 , “ a ” being a constant dependent on the metal used, and “ d ” the diameter of the wire. The current observed was that which heated the wire up to the point of self-luminosity (525°C.).

scholarly journals IV. On the heating effects of electric currents. No. III

1888 ◽  
Vol 44 (266-272) ◽  
pp. 109-111 ◽  
Keyword(s):  
Electric Currents ◽  
Heating Effects ◽  
The Law

I have taken a great deal of pains to verify the dimensions of the currents, as detailed in my paper read on December 22,1887, required to fuse different wires of such thicknesses that the law C = ad 3/2 is strictly followed; and I submit the following as the final values of the constant “ a ” for the different metals :—

scholarly journals XI. Description of a pendulum-electrograph now in use at the Melbourne Observatory

1868 ◽  
Vol 16 ◽  
pp. 458-464 ◽  
Keyword(s):  
Royal Society ◽  
Atmospheric Electricity ◽  
Zero Point ◽  
Platinum Wire ◽  
Registration Method ◽  
Rapid Changes ◽  
Series Of Experiments

About eighteen months since, being desirous of making some improvements in our mode of observing atmospheric electricity, I tried a series of experiments with Sir William Thomson’s various methods of obtaining observations and measures of the electric state of the atmosphere; the results of these were so very satisfactory that I bad a divided-ring reflecting electrometer made, as nearly similar as possible, judging from the descriptions available, to those used by himself. This was attached to a water dropping collector, and I obtained the deflections of the needle measured by means of a telescope and reflected scale. Prior to this, all observations of atmospheric electricity were made with Quetelet’s modification of the Peltier electrometer, where the needle and its little directing magnet are suspended by a cocoon fibre instead of on a point. The use of this, however, was very troublesome, involving its being carried to the highest part of the building at every observation, brought down, and placed on its stand within doors, the needle brought to rest by a magnet, and, after reading off the force of repulsion, the ascertaining of the character of the electricity by a separate operation. After using the divided-ring electrometer for a few weeks, it became apparent that no method of observing atmospheric electricity that was not continuous could possibly afford results that would embrace the numerous and rapid changes which take place. I found also in observing with the divided-ring electrometer that the torsion of the platinum wire was uncertain, requiring very frequent alteration of the zero-point, especially after great disturbances. I therefore endeavoured to devise an electrograph that should act by gravity instead of torsion; and for this purpose the electrometers of Sir W. Thomson and the photographic registration method adopted in the Kew magnetographs afforded me a sufficient groundwork. In August last I so far succeeded as to obtain regular photographic curves of the electric condition of the air about 18 feet from the earth’s surface; experience of the first temporary apparatus suggested modifications; and in November an improved instrument was erected, of which a brief description was read before the Royal Society of Victoria in December. Some defects in the performance of this, however, led to even a further modification; and since December last the improved electrograph has performed most satisfactorily.

scholarly journals II. On the heating effects of electric currents

1883 ◽  
Vol 36 (228-231) ◽  
pp. 464-471 ◽  
Keyword(s):  
Practical Importance ◽  
Atmospheric Electricity ◽  
High Potential ◽  
Electric Currents ◽  
Great Practical Importance ◽  
Low Resistance ◽  
Thin Wires ◽  
Heating Effects ◽  
Electrical Conductors ◽  
Great Danger

The production of heat in electrical conductors due to the trans­ference of electricity through them has become a matter of very great practical importance. A knowledge of the variation of the law, due to the dimensions and character of the conductor, is essential for lightning protectors and for the leads of electric lights. Atmospheric electricity has proved a great danger to insulated wires, subterranean and submarine, and to telegraphic apparatus generally. Not only do the direct discharges of atmospheric electri­city enter the wires, but very powerful currents are induced in neighbouring wires when ijhese discharges take place, either between cloud and cloud or between cloud and earth. Various plans have been devised to protect apparatus and wires from these currents. Lightning protectors based on the effect of points, on the facility of discharge through vacua, on the low resistance of thin air-spaces to high potential, and on the fusibility of thin wires, have been used.

6. Note on the Wire Microphone

1880 ◽  
Vol 10 ◽  
pp. 700-706
Author(s):  
R. M. Ferguson
Keyword(s):  
Royal Society ◽  
Platinum Wire ◽  
The Subject ◽  
The Wire ◽  
Royal Society Of London

At our last meeting Professor Chrystal showed us that a fine platinum wire attached to a stretched disc of skin could act as an electric telephone receiver for the sounds of a violin. The wire was included in a galvanic circuit, and the variations of current were made by a microphone attached to the violin. The account he gave of this interesting experiment was that the receiving wire became extended by the heat of the current either as it was established or suddenly increased by the microphone, and correspondingly shortened on the current ceasing. These extensions and contractions were rendered audible by the disc. A similar demonstration with a like commentary was made by Mr Preece to the Royal Society of London, an account of which was published in “Nature” (June 10). Mr Preece got his wires to speak. At the first May meeting of this Society in 1878 I discussed the subject of the sounds emitted by fine wires, giving passage to intermittent currents. I found that the ordinary thread telephone gave us an easy means of hearing these sounds in non-magnetic metals. De la Rive had heard them in 1845, but since his time no one had been able to hear them, and they were almost looked on as apocryphal. I attached the thread of the skin or paper telephone transversely to the sounding wire, and not directly, as Professor Chrystal has done, for the simple reason that I found that the transverse method gave equally good results with very much less trouble. The cause in both cases seemed to me the same, viz., an internal molecular click which marked the setting in and stoppage of the current.

XXIV. On the nature of the function expressive of the law of human mortality, and on a new mode of determining the value of life contingencies. In a letter to Francis Baily, Esq. F. R. S. &c

1825 ◽  
Vol 115 ◽  
pp. 513-583 ◽  
Keyword(s):  
Royal Society ◽  
Value Of Life ◽  
Human Mortality ◽  
The Law

Dear Sir, The frequent opportunities I have had of receiving pleasure from your writings and conversation, have induced me to prefer offering to the Royal Society through your medium, this Paper on Life Contingencies, which forms part of a continuation of my original paper on the same subject, published among the valuable papers of the Society, as by passing through your hands it may receive the advantage of your judgment.

scholarly journals Mathematical contributions to the theory of evolution.—On the law of reversion

1900 ◽  
Vol 66 (424-433) ◽  
pp. 140-164 ◽  
Keyword(s):  
Royal Society ◽  
Theory Of Evolution ◽  
The Law

(1) Introductory .—In a memoir recently presented to the Royal Society, I have endeavoured to emphasise the importance of distinguishing between three diverse types of heredity, namely (i), Blended Inheritance, (ii) Exclusive Inheritance, and (iii) Particulate Inheritance.

scholarly journals II. On some phenomena exhibited by gun-cotton and gunpowder under special conditions of exposure to heat

1864 ◽  
Vol 13 ◽  
pp. 204-217
Keyword(s):  
Rapid Method ◽  
High Temperatures ◽  
Royal Society ◽  
Sufficient Accuracy ◽  
Hot Wire ◽  
Full Extent ◽  
Mechanical Condition ◽  
Series Of Experiments ◽  
The Wire ◽  
Made In

The experiments upon which I have been engaged for some time past, in connexion with the manufacture and properties of gun-cotton, have brought under my notice some interesting points in the behaviour of both gun. cotton and gunpowder, when exposed to high temperatures, under parti­cular conditions. I believe that these phenomena have not been previously observed, at any rate to their full extent, and I therefore venture to lay before the Royal Society a brief account of them. Being anxious to possess some rapid method of testing the uniformity of products obtained by carrying out General von Lenk’s system of manu­facture of gun-cotton, I instituted experiments for the purpose of ascer­taining whether, by igniting equal weights of gun-cotton of the same com­position, by voltaic agency, within a partially exhausted vessel connected with a barometric tube, I could rely upon obtaining a uniform depression of the mercurial column, in different experiments made in atmospheres of uniform rarefaction, and whether slight differences in the composition of the gun-cotton would be indicated, with sufficient accuracy, by a corre­sponding difference in the volume of gas disengaged, or in the depression of the mercury. I found that, provided the mechanical condition of the gun-cotton, and its position with reference to the source of heat, were in all instances the same, the indications furnished by these experiments were sufficiently accurate for practical purposes. Each experiment was made with fifteen grains of gun-cotton, which were wrapped compactly round the platinum wire; the apparatus was exhausted until the column of mercury was raised to a height varying from 29 inches to 29·5 inches. The flash which accompanied the deflagration of the gun-cotton was apparently similar to that observed upon its ignition in open air ; but it was noticed that an interval of time always occurred between the first application of heat (or incandescence of the wire) and the flashing of the gun-cotton, and that during this interval there was a very perceptible fall of the column of mercury. On several occasions, when the gun-cotton, in the form of “roving,” or loosely twisted strand, was only laid over the wire, so that it hung down on either side, the red-hot wire simply cut it into two pieces, which fell to the bottom of the exhausted vessel, without continuing to burn. As these results appeared to indicate that the effects of heat upon gun-cotton, in a highly rarefied atmosphere, differed importantly from those observed under ordinary circumstances, or in a very imperfect va­cuum, a series of experiments, under variously modified conditions, was instituted, of which the following are the most important.

scholarly journals VI. Electrification of air, of vapour of water, and of other gases

1898 ◽  
Vol 191 ◽  
pp. 187-228 ◽  
Keyword(s):  
Royal Society ◽  
Atmospheric Electricity ◽  
British Association ◽  
Present Communication ◽  
The Subject

1. In this paper we describe a long series or experiments on the electrification of air and other gases, with which we have been occupied from May, 1894, up to the present time (June, 1897). Some results of our earlier experiments, and of preliminary efforts to find convenient methods of investigation, have from time to time been communicated to the Royal Society, the British Association, and the Glasgow Philosophical Society. 2. The method for testing the electrification of air, which we used in our earliest experiments, was an application of the water-dropper (long well-known in the ordinary observation of atmospheric electricity). Its use by Maclean and Goto, in 1890, led to an interesting discovery that air in an enclosed vessel, previously non-electrified, becomes electrified by a jet of water falling through it. An investigation of properties of matter concerned in this effect, related as it is to the “development of electricity in the breaking up of a liquid into drops,” which had been discovered by Holmgren as early as 1873, and to the later investigations and discoveries described by Lenard, in his paper on the “Electricity of Waterfalls,” forms the subject of 25-37 of the present communication.

Joule's 1840 manuscript on the production of heat by voltaic electricity

2020 ◽  
Author(s):  
Roberto de Andrade Martins
Keyword(s):  
Detailed Analysis ◽  
Experimental Research ◽  
Royal Society ◽  
Detailed Comparison ◽  
Electric Currents ◽  
Full Paper ◽  
Unpublished Manuscript ◽  
Philosophical Magazine ◽  
First Time

In 1840, James Prescott Joule submitted to the Royal Society a paper describing experimental research on the heat produced by electric currents in metallic conductors, and inferring that the effect was proportional to the resistance of the conductors and to the square of the intensity of the current. Only an abstract of this paper was published in the Proceedings of the Royal Society , although a full paper with a similar title was printed in the Philosophical Magazine in 1841. Several authors have assumed that the content of the 1841 publication was the same as the rejected 1840 paper; however, the unpublished manuscript has been found within the archives of the Royal Society and is published here for the first time, along with a detailed analysis and comparison with the 1841 paper. The unpublished version is much shorter, and is different in certain respects from the published article. A detailed comparison throws light on several shortcomings of the unpublished version. The present work also studies the assessment of Joule's paper by the Royal Society, and elucidates the roles of Peter Roget and Samuel Christie in this connection.

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