L.-E. JEWELL. — The coincidence of solar and metallie lines, a study of the appearance of lines in the spectra of the electric arc and the sun (Coïncidence des raies solaires et métalliques ; étude comparée de l'apparence des raies dans le spectre de l'arc et dans le spectre solaire). The Astrophysical Journal, t. III, p. 90-113 ; 1896

1897 ◽  
Vol 6 (1) ◽  
pp. 84-84
Author(s):  
E. Bouty
Keyword(s):  
Electric Arc ◽  
The Sun ◽  
Astrophysical Journal

scholarly journals On the temperature of the carbons of the electric arc; with a note on the temperature of the Sun. Experiments made at Daramona, Streete, Co. Westmeath

1895 ◽  
Vol 58 (347-352) ◽  
pp. 24-38 ◽  
Keyword(s):  
Specific Heat ◽  
Boiling Point ◽  
Electric Arc ◽  
The Sun

The temperature of the positive pole of the electric arc, which is now generally believed to be the boiling point of carbon, is usually taken, on the authority of Violle, as approximately equal to 3500° C. Violle’s method of determining it was as follows:—The carbons of the arc were placed horizontally, and the positive pole was so arranged that pieces of its substance could be detached while the arc was passing; these white-hot pieces fell into a calorimeter, and from the amount of heat given up, the temperature was calculated, assuming the specific heat of carbon at this point to have its theoretical value. The method does not seem at first sight a very reliable one, and Violle states that the result is only to be regarded as an approximation.

scholarly journals Publication announcement

1895 ◽  
Vol 57 (340-346) ◽  
pp. 32-32
Keyword(s):  
Electric Arc ◽  
The Sun

II. “On the Temperature of the Carbons of the Electric Arc; with a Note on the Temperature of the Sun.” By W. E. Wilson and P. L. Gray. Communicated by Dr. G. J. Stoney, F. R. S. Received November 14, 1894. [Publication deferred.] III. “Observations of Sun-spot Spectra, 1879—1894.” By J. Norman Lockyer, C.B., F. R. S. Received November 15, 1894. [Publication deferred.]

Light Therapy in Mental Hospitals

1929 ◽  
Vol 75 (310) ◽  
pp. 410-419 ◽  
Author(s):  
H. Dove Cormac
Keyword(s):  
Ultra Violet ◽  
Light Therapy ◽  
Electric Arc ◽  
Mercury Vapour ◽  
The Sun ◽  
The Past ◽  
Mental Hospitals ◽  
Quartz Mercury ◽  
Mercury Vapour Lamp ◽  
Carbon Arc

The value of sunlight in the maintenance of health has been recognized from early ages, and history records sun-worship by many nations in the past as well as at the present time. In Europe records exist of the use of the light of the sun for medical and surgical purposes since before the Christian era, but it was only towards the end of the last century that its possibilities began to be studied and the value of the electric arc lamp as a substitute recognized. In 1893 Finsen demonstrated the value of sunlight and electric arc radiation in the treatment of lupus, and at the beginning of the present century Bernhard of Samaden treated wounds and tuberculous lesions with sunlight. In 1903 Rollier opened his first clinic at Leysin, where he obtained excellent results in the treatment of tuberculosis, especially of the surgical type, by insolation in the brilliant Alpine sunshine. In 1908 Gauvain introduced heliotherapy at Hayling Island and at Alton. Nagelschmidt used the air-cooled quartz mercury vapour lamp for general irradiation in the same year, and in 1913 Reyn commenced the use of the carbon arc for the same purpose. The value of ultra-violet rays in the cure of rickets was not recognized till demonstrated by Huldschinsky in 1918, though Palm (1), as early as 1890, urged that deficiency of sunshine was a cause of the condition.

III. On the effect of pressure of the surrounding gas on the temperature of the crater of an electric arc light. Preliminary notes of observations made at Daramona, Street, co. Westmeath

1895 ◽  
Vol 58 (347-352) ◽  
pp. 174-176
Keyword(s):  
Electric Arc ◽  
The Sun ◽  
Solid Carbon ◽  
Effect Of Pressure ◽  
Solid Form

Of late years it has often been assumed that the temperature of the crater forming the positive pole of the electric arc is that of the boiling of carbon. The most modern determinations give this point as about 3300°—3500° C. Solar physicists have thought that the photosphere of the sun consists of a layer of clouds form ed of particles of solid carbon. As the temperature of these clouds is certainly not below 8000° C., it seems very difficult to explain how carbon can be boiling in the arc at 3500° and yet remain in the solid form in the sun at 8000°.

VI. Researches in spectrum analysis in connexion with the spectrum of the Sun. No. VII

1879 ◽  
Vol 28 (190-195) ◽  
pp. 157-180 ◽  
Keyword(s):  
Spectrum Analysis ◽  
Large Scale ◽  
Solar Spectrum ◽  
Electric Arc ◽  
The Sun ◽  
Metallic Elements ◽  
Complete Spectrum

It is known to many Fellows of the Society that I have for the last four years been engaged upon the preparation of a map of the solar spectrum on a large scale, the work including a comparison of the Fraunhofer lines with those visible in the spectrum of the vapour of each of the metallic elements in the electric arc. To give an idea of the thoroughness of the work, at all events in intention, I may state that the complete spectrum of the sun, on the scale of the working map, will be half a furlong long; that to map the metallic lines and purify the spectra in the manner which has already been described to the Society, more than 100,000 observations have been made and about 2,000 photographs taken.

Chromospheric activity as a function of age in main-sequence stars

1966 ◽  
Vol 24 ◽  
pp. 40-43
Author(s):  
O. C. Wilson ◽  
A. Skumanich
Keyword(s):  
Main Sequence ◽  
The Sun ◽  
Main Sequence Stars ◽  
Tentative Conclusion ◽  
Chromospheric Activity ◽  
General Field ◽  
Large Clusters

Evidence previously presented by one of the authors (1) suggests strongly that chromospheric activity decreases with age in main sequence stars. This tentative conclusion rests principally upon a comparison of the members of large clusters (Hyades, Praesepe, Pleiades) with non-cluster objects in the general field, including the Sun. It is at least conceivable, however, that cluster and non-cluster stars might differ in some fundamental fashion which could influence the degree of chromospheric activity, and that the observed differences in chromospheric activity would then be attributable to the circumstances of stellar origin rather than to age.

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