Evening Republican, Volume 14, Number 107, Rensselaer, Jasper County, 5 May 1910 — CO-OPERATIVE OBSERVERS TO OBSERVE PHENOMENA. [ARTICLE]

CO-OPERATIVE OBSERVERS TO OBSERVE PHENOMENA.

nldlanapolls Office Asks Assistants to Report What Happens When the Earth Passes Through the Comet’s Tall. L. C. Klosterman, of St. Josoph’a College, the local observer for the Indianapolis branch of the weathertureau, has received the appended article from the section director, and Mr. Klosterman believes that the public may take a great interest in watching the expected meterological phenomena and he asks persons to report to him any observations that have unusual interest. The section director’s article reads: If the earth .should pass through the tail of Halley’s comet, as astronomers expect it will on the 18th of May next, an opportunity of a kind that has not previously occurred in the history of the Weather Bureau will be offered for the study of certain meteorological phenomena. It has been decided to take advantage of this opportunity and therefore I shall be pleased to have your assistance in making observations, so far as weather conditions will permit, on the 17th, 18th especially, and 19th of May, 1910. Owing to the position of the moon on the given dates, it hi probable-that the most satisfactory night observations will be obtained during the last two or three hours before daylight. If you are willing to assist us in this work, kindly observe tthe following phenomena so far as you may he able to do so, and render an immediate report in suitable form for transmission to the Central Office as a whole: 1. Auroral Displays—Auroras serve as indicators of the electrical state of the outer atmosphere, and as this state possibly may be affected by the tail of the comet as we pass through it, auroras should be watched for at that time. The location, color, shape, extent, and other features as well as the times of appearance, changes and disappearance should all be carefully noted.

2. Meteoric Trails.—The number, times of appearance, lengths of duration, and directions and lengths of visible paths of meteors should be noted on all three nights, but especially on the night of the 18th. 3. Bishop’s Ring.—This curious dust halo was seen around the sun after the eruptions both of Krakatoa and Mont Pele, and conceivably might follow the passage of the earth through a comet. It therefore should be carefully looked for on the days specified, and occasionally, for some days thereafter. As the light of this ring is rather faint, observations of it are best made when the suit is hidden behind some steeple or other opaque object. 4 Color of the Sun and Sky.—Both the* general color of the sky and the color of the sun depend on the dust and other contents of the atmosphere, and should be carefully noted on the given dates.

5. Twilight Phenomena.—Twilight colors, their distribution and order of changes depend largely on the dust in the atmosphere, and, consequently, these are phenomena that need to be observed on the days indicated. 6. Luminous Clouds. —Neither the material of these clouds nor the cause of their light is definitely known. They seem to belong to the high atmosphere, and therefore should be looked for at night In connection with uro transit across the comet's tail. These clouds are cirrus-like in appearance, but may be distinguished from true cirrus b)%j£e fact,that they are brighter than the background of the clear nocturnal sky. During the forepart of the night they are seen above the northwestern horizon. 7. Zodiacal Light.—From work re-

cently done at the Lick and Mount Wilson observatories it seems probable that the zodiacal light is caused by reflection of solar light from dust in and near the plane of the ecliptic. If so. then a change might be expected in it at the time of the comet’s near ap- , proach to the earth, therefore the extent, the brilliancy, and other features of the zodiacal light as they approach at that time should be carefully noted. 8. Gegenschein (Counter Glow).— But little is known of this faint glow seen in the ecliptic at # a point directly opposite to the sun, or along the shadow of the earth. Presumably It has the same origin as the zodiacle light, and consequently may be modified during the transit of the earth across the tail of a comet. At any rate it should be observed on the .nights mentioned and its brilliancy at these times compared with that on nights when there certainly is no cometary disturbance. '» To locate the Gegenschein at any hour of the night look in the direction the sun was twelve hours previously. 9. General Phenomena.—Solar and lunar halos and coronas, and all appearances that may seem unusual and worth noting.