analyses of the structure of the solar surface, as was explained in the Annual for 1874, he has now called to his aid photometry and the thermo-electric pile. He finds that the nuclei of the solar spots are cooler than the neighboring bright portions of the sun's surface, but in general warmer than the limb of the sun as seen through the solar atmosphere. He has, moreover, shown that the light and heat which we receive from the sun emanates from the superficies of the nucleus, which is covered by a thin layer of gaseous material, which latter absorbs both heat and light; but in so doing exercises a distinct selective power in that the absorption of the lower or heat rays of the spectrum is to the absorption of the visual rays as one to six. He finds, moreover, that a sensible amount of heat is received from those portions of the lower envelope that are distant thirty seconds of arc from the visible limb of the sun.

Pickering and Strange have investigated, photometrically, the amount of light absorbed by the solar atmosphere. The probable error of the result is exceedingly small, and shows that the light at the edge is about four tenths of that at the It appears to them that there is a slightly different distribution of the light across the polar and the equatorial diameters.

Professor Mayer has continued to develop his method of obtaining the isothermals of the solar disk, and is now having a telescope arranged for the purpose of making continuous observations in this novel and interesting field. He sug gests that the discordance in results obtained by Secchi and Langley may possibly be due to the fact that these observers have thrown the image of the sun upon inclined instead of horizontal disks of paper, thereby introducing superficial currents of air, whose presence he found extremely deleterious to his own results, and which were almost entirely obviated by employing a perfectly horizontal plane of projection.

Although our review strictly begins with November, 1874, yet we will not omit to notice the work of Violle, published a little earlier than that date, on the effective temperature of the sun. Assuming that the mean emissive power of the sun is sensibly equal to that of steel in fusion, Violle concludes that the true temperature of the sun is about two thousand degrees.

As the first-fruits of the labors of the spectroscopic examination of the spectra of transparent substances, Lockyer announces the probable existence in the solar reversing layer of strontium, cadmium, lead, copper, cerium, and potassium.

The eclipse of the sun of the 6th of April was successfully observed, the photographic observations in Siam being especially successful. It is considered that evidence of high importance was obtained bearing upon the general nature of the spectrum of the coronal atmosphere; the tendency being to conclude that the higher regions of the solar envelope differ chemically from the lower regions; the lower portions, in fact, being composed of less complex chemicals at a high temperature, while the lower temperature of the upper portions allows of the formation of more complex bodies.

Fuhg has published a discussion of numerous observations of the diameter of the sun, and finds no difference between the polar and equatorial diameters. The views of Father Rosa as to the variable diameter of the sun have been already noticed by us. These views have been lately defended by Secchi, as the editor of the posthumous papers of Father Rosa.

The Planets.-Le Verrier has presented to the Paris Academy of Sciences his numerical tables of the movements of Saturn. They are based principally upon the observations at Greenwich and Paris. This completes his work for all the bodies of the solar system,

The measurements obtained by Colonel Tennant by means of Airy's double-image micrometer during the transit of Venus have been subjected by him to some discussion, and he thinks he has a decided indication of the elliptic form of the disk of the planet Venus.

Dr. Galle has published the results of his discussion of the observations of the asteroid Flora, which were made in concert by various observatories for the determination of the solar parallax. His definitive result is 8.87", which agrees very closely with the preliminary results derived by M. Puiseux from French observations of contact. From the concourse of various methods to its determination, we may be sure that this important element will soon be accurately known. No results for the value of the solar parallax, based on measurements of photographs, have yet been published.

1

analyses of the structure of the solar surface, as was explained in the Annual for 1874, he has now called to his aid photometry and the thermo-electric pile. He finds that the nuclei of the solar spots are cooler than the neighboring bright portions of the sun's surface, but in general warmer than the limb of the sun as seen through the solar atmosphere. He has, moreover, shown that the light and heat which we receive from the sun emanates from the superficies of the nucleus, which is covered by a thin layer of gaseous material, which latter absorbs both heat and light; but in so doing exercises a distinct selective power in that the absorption of the lower or heat rays of the spectrum is to the absorption. of the visual rays as one to six. He finds, moreover, that a sensible amount of heat is received from those portions of the lower envelope that are distant thirty seconds of arc from the visible limb of the sun.

Pickering and Strange have investigated, photometrically, the amount of light absorbed by the solar atmosphere. The probable error of the result is exceedingly small, and shows that the light at the edge is about four tenths of that at the It appears to them that there is a slightly different distribution of the light across the polar and the equatorial diameters.

Professor Mayer has continued to develop his method of obtaining the isothermals of the solar disk, and is now having a telescope arranged for the purpose of making continuous observations in this novel and interesting field. He sug gests that the discordance in results obtained by Secchi and Langley may possibly be due to the fact that these observers have thrown the image of the sun upon inclined instead of horizontal disks of paper, thereby introducing superficial currents of air, whose presence he found extremely deleterious to his own results, and which were almost entirely obviated by employing a perfectly horizontal plane of projection.

Although our review strictly begins with November, 1874, yet we will not omit to notice the work of Violle, published a little earlier than that date, on the effective temperature of the sun. Assuming that the mean emissive power of the sun is sensibly equal to that of steel in fusion, Violle concludes that the true temperature of the sun is about two thousand degrees.

As the first-fruits of the labors of the spectroscopic examination of the spectra of transparent substances, Lockyer announces the probable existence in the solar reversing layer of strontium, cadmium, lead, copper, cerium, and potassium.

The eclipse of the sun of the 6th of April was successfully observed, the photographic observations in Siam being especially successful. It is considered that evidence of high importance was obtained bearing upon the general nature of the spectrum of the coronal atmosphere; the tendency being to conclude that the higher regions of the solar envelope differ chemically from the lower regions; the lower portions, in fact, being composed of less complex chemicals at a high temperature, while the lower temperature of the upper portions allows of the formation of more complex bodies.

Fuhg has published a discussion of numerous observations of the diameter of the sun, and finds no difference between the polar and equatorial diameters. The views of Father Rosa as to the variable diameter of the sun have been already noticed by us. These views have been lately defended by Secchi, as the editor of the posthumous papers of Father Rosa.

The Planets. Le Verrier has presented to the Paris Academy of Sciences his numerical tables of the movements of Saturn. They are based principally upon the observations at Greenwich and Paris. This completes his work for all the bodies of the solar system,

The measurements obtained by Colonel Tennant by means of Airy's double-image micrometer during the transit of Venus have been subjected by him to some discussion, and he thinks he has a decided indication of the elliptic form of the disk of the planet Venus.

Dr. Galle has published the results of his discussion of the observations of the asteroid Flora, which were made in concert by various observatories for the determination of the solar parallax. His definitive result is 8.87", which agrees. very closely with the preliminary results derived by M. Puiseux from French observations of contact. From the concourse of various methods to its determination, we may be sure that this important element will soon be accurately known. No results for the value of the solar parallax, based on measurements of photographs, have yet been published.

tor the Rev. C. Pritchard, Savilian professor of astronomy at

the university.

The observatory at Twickenham, belonging to Mr. Bishop, and for a long time occupied by Mr. Hind, as observer, is shortly to be dismantled, and its instruments presented to the Royal Observatory at Naples.

The astronomical school established at Montsouris, under the authority of the French Bureau of Longitudes, was opened on the 3d of October with six pupils. The period of study is six months.

The new meridian room, intended for the use of the French Bureau of Longitudes, was opened on the 2d of October.

A magnificent astronomical establishment is being erected at Potsdam for the express purpose of studying the sun.

The French government has taken steps toward the establishment of a physical observatory in the neighborhood of Paris, under the direction of Janssen. The building will probably be located either at Versailles or Montelhuy.

Le Verrier proposes to furnish ordinary standard time by telegraphic communication to all the public clocks of Paris.

The observatory of the University of Moscow, Russia, has published the second volume of its annals, which contains valuable photographs of a series of sixteen drawings of the belts of Jupiter, and of the physical appearance of Coggia's comet. The Melbourne Observatory has published the first "Melbourne General Catalogue of Stars."

Mr. C. W. Pritchett has received an endowment of $30,000 for the observatory of the Pritchett Academy, at Glasgow, Missouri. The observatory possesses one of Alvan Clark's 12-inch equatorials.

The observatory of the Lehigh University, at Bethlehem, Pa., organized by Professor A. M. Mayer, has secured Mr. Doolittle as astronomer. Mr. Doolittle was formerly on the Northwestern Boundary Survey, and hopes to make good use of his present opportunities.

The observatory at Gettysburg, Pa., has been placed in charge of Professor P. H. Bickee.

Mr. Sayce has given some interesting items with reference. to the early history of astronomy among the Chaldeans. According to him, astronomy was brought to this people by the Acadians, who, when they came westward from the mount