Polytechnic Association Proceedings. 945 



and the thermometer not quite to zero, with snow. I have 

 answered your questions, though not specifically. 

 "Yours, respectfully, 



" B. T, Blackall, Manager A. & P. Tel Coy 



The recent phenomenon was also observed at Cleveland, in the 

 office of the same line of telegraph. Foreign currents made it 

 impossible to work one of their wires. At this point it wa^ first 

 noticed at 9 a. m., when the current grew so strong that the mana- 

 ger of the line "ordered the No. 1 wire opened to Painesville, 

 thirty miles east." This did not help it in the least. " I judged," 

 wi-ites the operator, "that our wires were crossed with Western 

 Union, and that we were getting the full strength of their one 

 hundred cups of battery. One thing very strange was that the 

 current pulsated, and the armature of the magnet, disconnected 

 from the battery, and the wire open east, vibrated like a pendulum." 

 An unusual exhibition of northern lights took place during the 

 electrical display noted in the above letter from Rochester as having 

 occurred several years since. No reports of such an exhibition 

 during the recent phenomena have been received. At Eochester 

 a snowstorm prevented any examination of the slcy; but at Coburg 

 and Toronto, in Canada — the former of these places being nearly 

 on the magnetic meridian of Rochester — no aurora was seen. 



From sketches of a group of sun-spots; observed between the 

 6th and 11th of January, and noticed in The Tnbune, it appears 

 that interesting changes took place in the group on the 9th inst. 

 The observations on that day were made at 9 a. m., New York 

 mean time, and 4 p. m. The change was the subject of remark at 

 the time in an observatory in Brooklyn. One part of the group 

 appeared to have performed a retrograde rotation, toward the cen- 

 tral and largest spot, during the time elapsing between the hours 

 above stated. The motion was very rapid, roughly estimated at 

 about three hundred miles an hour, and this in a direction contrary 

 to the direction of the sun's rotation. The large central spot had 

 rotated in a similar direction, with a velocity much slower than the 

 smaller spots, and yet by a very perceptible amount. The pheno- 

 mena did not seem accounted for by the apparent change of place 

 of the group by the sun's rotation, aud consequent change in per- 

 spective. It does not seem improbable, therefore, that the recent 

 phenomenon may have owed its origin directly to an electrical 

 influence from these spots upon the crust of the earth, or to an 



fiNST.] 60 



