104 REV. J. FARQUH ARSON’S EXPERIMENTS ON THE INFLUENCE 
of these another clear lane of sky E. and W. and nebulous Aurora over dense 
clouds at S. horizon. Needle on steel point 36' 20" E. Before the watch was 
prepared for the intensity, needle shifted to only 33' E. Intensity then found 
50 oscillations in 226".25. Needle at conclusion of the observation 14' E. 
— 12 p. m. Another arch getting into plane of the dip, the rest of the Aurora 
presenting nearly the same appearances as before. Needle shifted to 22' E. 
Intensity 50 oscil. 1st in 225".5 ; 2nd in 225". 5. Therm, still 30°. Needle 
after observation still 22' E. Steady slight wind near S. W. 
20th Dec. — From % past 8 p. m. till lip. m., a veiy splendid Aurora con- 
tinued, with periodical obscurations and revivals, over a dense cloud resting 
on, and capping the summits of the North hills. Aurora never getting higher 
than 20°. Rest of the sky entirely clear of clouds, and slight steady wind 
at W. Therm. 25°. Needle not affected. 
21st Dec. — 8 p. m. Intensity 225". Therm. 27°. Ground covered with snow. 
22nd Dec. — I have been informed, this day, by the Rev. James Paull, 
minister of Tullynessle, that on the 20th of Dec. about ^ past 9 p. m. he saw 
the Aurora remarkably bright, near the zenith, at his house, about 2 miles N. 
of this place, and I am permitted to use his name for the fact. — 8 P. M. 
Intensity 224".75 ; 225". Therm. 28°. 
23rd Dec. — 8 p. m. Intensity 225''. Therm. 30°. 
24th Dec. — 8 p. m. Intensity 225". Therm. 30°. 
25th Dec. — 8 p. m. Intensity 224". 5 ; 224".75 ; 224".75. Therm. 29°. 
I hope the Royal Society will find in the above observations, and in those 
I transmitted to you on the 15th, a settlement of the much agitated question 
regarding the disturbance of the magnetic needle by the Aurora borealis. 
Mr. Dalton was the first, as far as I am acquainted, who observed that the 
streamers direct their upper extremities to that point in the heavens to which 
the dipping needle is directed, and that the arches they form are at right an- 
gles to the magnetic meridian ; but the definite order in the southward pro- 
gress of the fringes of streamers not having been then ascertained, those circum- 
stances under which alone it now appears that the magnetic needle is disturbed, 
were for a time overlooked ; and results apparently the most opposite were 
announced by different observers of distinguished skill and reputation. 
