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phenomena of the higher classes, such as arches, streamers, a corona, and auroral waves, the corona and waves being remarkably developed. The southern arch, however, was perhaps the most remarkable phenomenon of the exhibition.

Second Class Aurora Borealis.

December 23.-In the evening there was an auroral exhibition. A dark arch was formed in the north, having an altitude at its culminating point of 15°, and its centre of curvature lying in the magnetic meridian. Numberless streamers shot upward from the arch to an elevation of 45°. The aurora was visible about one hour. The brilliancy of the streamers would place this exhibition in the second class aurora.

Lunar Halo.

December 27.-In the evening I saw a beautiful halo around the moon. The interior diameter of the ring was about 3°, and its exterior diameter was fully 70. The inner edge of the ring was of a deep crimson color, and its exterior a brilliant blue; while it had an intermediate annulus of yellow, bordering on an orange color. The width of the red ring was 1°, that of the blue 10, and that of the yellow 1°. The phenomenon was seen only about three or four minutes.

Auroras of the Third and Fourth Classes.

1852-January 23.- In the evening saw a fourth class aurora borealis.

January 24.-In the evening I observed the aurora borealis, but the exhibition was of little importance, being of the lowest class.

February 7.-- In the evening saw aurora borealis.

February 18.-In the evening there occurred quite a brilliant exhibition of the aurora borealis, with finely developed streamers. I saw a very curious auroral meteor in the constellation Virgo. Its shape was that of the head of a huge spear. Its foremost point was in the vicinity of Spica, and the two anterior points were situated, the one near y, and the other near 7 of that constellation. It remained visible only a few minutes.

February 19.—In the evening observed a slight auroral corruscation.


February 26.-In the morning I observed two brilliant parhelia, one on each side of the sun. The sun's altitude at the time was nearly 15°, and the mock suns were distant about 30° on each side of the real

On their inner, or sides nest the sun, their light was of dazzling brightness, and their outer sides were tinged with the prismatic hues.


Minor auroras.

March 9.-In the evening the sky was clear and serene. auroral arch in the north, having its centre coinciding with the mag. netic meridian.

March 12.-In the evening, saw the aurora borealis.
March 17.-In the evening, saw a fourth class aurora borealis.


March 17.-Soon after sunrise I observed two parhelia, one on each side of the sun, which remained visible at least two hours.

March 19.-After sunrise I saw a parhelion.


Aurora borealis,

November 10.-In the evening I saw an auroral display, consisting of a number of short streamers beset around the magnetic north. While gazing on there I beheld a meteor resembling an electric spark, which suddenly emerged from a brilliant streamer that lay in the magnetic meridian, and vanished in a moment. It appeared to have a lateral and downward movement of about 20. Color of streamers yellowish white.

November 11.--In the evening I observed an auroral exhibition, which was much more brilliant than that of the 10th instant. The streamers reached a height of 45°, being intensely bright, and of a yellowish white color.

Solar halo.

1853— May 27.- When the sun had descended about a semi-diameter of its lower limb, below the horizon in the west, I saw the following semi-circle of a solar halo. The interior diameter of the circular halo was about 8°, and its exterior diameter 18°. Its interior was crimson colored, and the several prismatic hues were depicted outward in succession. It was very brilliant, and a beautiful object for contemplation.

Aurora borealis.

June 2.- In the evening, saw an auroral exhibition. The streamers were quite brilliant, long, and slender.

June 27.–At a little past Sh. in the evening I saw a fine aurora. It was in the form of a great arch, about 140° in length, and from 20 to 3° in breadth. The arch on the east approached within 3° of Altair; on or near the meridian it passed through Corona Borealis; and its western extremity was near ( Leonis. It was very brilliant; and I

observed a number of oscillations or waves pass along its meridian portion longitudinally. These waves were slow in progress, and somewhat gyratory in appearance. Only a faint illumination was observed in the north.


July 12.-When the sun had been hidden nearly fifteen minutes by the western hills, and was just on the point of passing below the plane of the horizon, I saw a beautiful rainbow. The bow was entire, and of splendid prismatic hues. Fragments of a secondary bow were seen. The bow in a few minutes showed a great preponderance of red rays, and did not disappear until the moment of sunset.

Aurora borealis.

, September 2.- In the evening, observed an auroral exhibition. At first, a dark segment of a circle appeared in the magnetic north, about 10° in altitude at its culminating point. This was soon beset around its exterior with brilliant rays of a yellowish white. These rays extending out laterally shortly formed a serpentine arch, still with the black beneath. Then a few streamers shot upwards towards the zenith. Shortly afterwards these phenomena died away, and the northern sky remained quite luminous, with here and there patches of cirrus in filmentous wisps. I saw several small stars through the dark auroral vapor first observed.

1854- March 26.- In the evening observed brilliant aurora borealis. Saw a fine auroral arch, having an altitude from the northern horizon of above 45°, and reaching from the eastern to the western horizon. Width of arch about 10°. I saw many minor exhibitions of the aurora borealis during the winter of 1853–54.

March 29.- In the evening I observed a beautiful auroral meteor. It resembled the tail of a huge comet, proceeding from a nucleus about 10° north of Spica Virginis. It lay along below Leo Major, branching out into two bright streams, with a fainter dawn between, the northern branch reaching a Canis Minoris, and the southern terminating a few degrees north of Canis Major. The above was its appearance at 8h. 15m. It was very brilliant, and remained visible for sometime.

May 16.-In the evening saw a fine auroral arch, having an altitude of 70° in the north. It was composed of a great number of short transverse streamers 2° or 3° apart.

Rapid oscillations in refraction. September 4.-In the evening I observed rapid vertical oscillations in the lunar orb, when crossed horizontally by thin cirrus bands ; the latter projected in perspective on the lunar disk, reminding one of the belts of Jupiter. She appeared to rise and fall rapidly in the vertical through about 1° arc: corresponding fluctuations being observed in the shadows of objects in her light. A number of other persons observed the phenomenon, which lasted about ten minutes.

The altitude of the moon was about 15°; and the cirrus bands crossing her disk remained apparently unchangeable and motionless. A storm of rain followed before the next morning.




1853–January 31.—On this, as well as several preceding evenings, I have observed a pyramidal column of whitish light, after the ceasing of twilight, extending along the ecliptic from the western horizon to an altitude of 40° or more, which must be the conical body of the zodiacal light.

1854-February 21.-Between 8h, and 9h. in the evening I observed the zodiacal light. Its base at the horizon was above 18° in width, and the altitude of its vertex about 35°.

1855-January 14.--After the ceasing of twilight I saw the cone of zodiacal light. It was very brilliant, as much so as that part of the milky way visible at that season. Its vertex was above 900 from the sun; in fact, a faint illumination seemed to extend almost to the eastern horizon. Its width at its base was more than 200. It was observed on several other evenings of the winter.

1856–February 2.-In the evening observed the zodiacal light; it having been seen on several evenings during the preceding month. It uniformly reaches about 900 from the sun, having an apparent width at the horizon of 40°. Sometimes a faint reflection is observed in the east.

1856– February 8 - After the ceasing of twilight in the evening observed the zodiacal light. Apparent width at the horizon 40°, length 10° from the sun.

1856— Alarch.-I saw the pyramidal column of zodiacal light on every evening, in absence of the moon, during this month. It appears at the horizon of a width varying froin 10° to 40°, and an apparent length of from 30° to 90°, and even upwards.

1857-January. During this month I have frequently observed the zodiacal light. Its vertex is generally not less than 90° from the sun. On some very clear evenings a faint illumination may be traced to the distance of 170° or 180° from the sun, being visible a greater part of the night. Its width at the horizon sometimes reaches 40°. Its axis appears to lie a little above the ecliptis, or to have a small north latitude; the amount of which is difficult of determination.





[Translated from the German for the Smithsonian Institution.]

In revising this translation, originally made by different persons, it has been the constant aim to give as nearly and as literally as possible the exact language of the author. But one exception has been made to this rule. In the case of the citation of English philosophers reference has been made to the original memoirs, and their own language adopted, instead of that of the report, wherever it was evident that the intention had been to give the equivalent German to their English. It is due to the author, however, to state that this change has been at most but a verbal one, not material to the sense. The notice is, however, deemed necessary, because this is the only departure, save in one or two unimportant cases, from the strict rendering of the language of the text.




[Continued from page 456, of the Report of 1856.]


$ 56. Nature of the secondary current.— When a battery is disa charged by a long metallic wire the current in the conducting circuit wire induces a current in an adjoining closed wire conductor.

The wire which forms the conducting circuit of the battery is known as the main wire.

The wire in which a current is induced by the action of the current in the main wire is termed the secondary wire.

[The existence of the secondary current was demonstrated in a series of experiments by Professor Joseph Henry in 1838, published in the

,Transactions of the American Philosophical Society” vol. 6, p. 40, in 1839, a publication apparently unknown to our author.

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