AURORAL OBSERVATIONS 



Remarks Regarding Sketches 



On a previous Polar expedition I had made many attempts to photograph the aurora, but 

 without material success. By long exposure some small effects of the light with that^of the 

 stars on the sensitive plates could be obtained. These, however, were without value as a 

 matter of record, as this phenomenon is so rapid in its variations that to depict the same 

 correctly instantaneous photographs are necessary. This is not possible, owing to the insuffi- 

 cient light. Accordingly recourse had to be taken to sketching. 



In connection with the work at the magnetic observatory a number of sketches of the 

 aurora were made, using for the purpose a board with compass attached for orientation. Tlie 

 cardinal points indicated on the plates are accordingly magnetic. The drawings were made 

 upon black sheets of paper, upon each of which a circle representing the horizon was previously 

 drawn in chalk. The sheets were so placed together and pinned at the corners that they could 

 be torn oEE as the sketches were completed. A pin at the center represented the zenith point. 

 Having had some experience in rapid sketching, it did not take long to place on the paper 

 rough chalk sketches of the beautiful auroral light, using the board as a plane table, and drawing 

 in the circle of the chalk horizon the display that was taking place in the heavens overhead. 



Owing to numerous other duties and on account of the generally prevalent bad weather 

 opportunities for sketching were few. The attendant physical difficulties for work of this kind 

 in the open air, under the flickering light of a small lantern, without shelter of any kind, and 

 with a temperature of from 30 "" to 50° Fahrenheit below zero, may be readily imagined. In 

 spite of these difficulties some very interesting and, it is believed, representative sketches were 

 secured. The results of this work are shown by plates numbers i to 19, the titles of which 

 give the dates and times of the phenomena so recorded. 



In order to make as complete a record as possible of this phenomenon during the time the 

 Expedition was at work, the various auroral notes have been gathered together from the 

 meteorologic records for both the Teplitz Bay and Cape Flora stations. The notes at Camp 

 Abruzzi between October, 1903, and March, 1904, as also for those at Cape Flora, were collected 

 by Sergeant Francis I/Oug, Weather Observer. Those between October, 1904, and February, 

 1905, were made by different members of the party, chiefly by Messrs. Peters, Porter, ,and 

 Dr. Seitz. The times given are local mean, civil reckoning through twenty-four hours for the 

 respective stations. The first figure entered indicates the day of the mouth, those fqllowiug 

 the hour and minute, thus: 21: 18: 10 means the 21st day of the month at local mean time 

 18* 10^ or 6" lo"" P. M. Directions given in these notes are all true, and not magnetic as in the 

 cases of the sketches. The references are to the beginning and ending. of the display, the 

 extent of the same and the altitude, thus : 21: 18: 10 to 20: 20, K to W.about 60°, means that 

 an aurora was observed on the 21st day of the particular month under which the note comes 

 between 18- lo" and 2& 20™, add that, it extended from east to west at an altitude of about 60°. 

 In connection with these notes reference should .also be made, to siich references of aurorse as 

 are contained dn the notes accompanying the declination results at T«plitz Bay on pages ,32^0 

 40, as these are not included in the following. 



365 



