Toronto Astronomical Society
Meeting Minutes - 1869 May 4
Regular Meeting May 4th 1869
at Mr. Elvins'
Present:- Mr. Winder, President, in the chair, Messrs Turnbull, Brunt, Ridgway, Potter, Elvins & Clare.
Visitor, Mr. Davidson.
The minutes of previous meeting were read and confirmed.
Mr. Brunt proposed, seconded by Mr. Elvins that M. Wm. Thompson be a member of the Astronomical Club.
Mr. Ridgway intimated that he would have presented his paper on the figure of the earth, but was anxious first, as a necessary preliminary to the full consideration of the subject, to investigate the phenomenon called mirage.
Mr. Brunt called attention to the principal astronomical phenomenon of interest for the month. Winicke's Comet although vainly sought during the preceding month, we might possibly hear of, if not see, during this month. It would probably be found in the neighbourhood of Leo. The Sun, too, as having arrived nearly at its maximum period of solar spots was worthy of attention. These periods occurring at intervals of about eleven years, the solar spots will arrive at heir maximum in 71, consequently there would be few days now when we might not expect to
find see spots. He also made allusion to the successful completion of Mr. Turnbull's large reflector, the companion to the pole-star appearing through it as large as a star of the 4th magnitude to the naked eye. Also, to the safe arrival of the great telescope sent-out to Melbourne.
Mr. Winder, the president, read a paper relating to the late brilliant displays of Aurora especially as they appeared on the evenings of April 15th and May 3. On the former occasion almost the entire sky was covered with brilliant corruscation, light sometimes arising in columns, and passing the zenith, and sometimes waving like canvas thrown to the breeze. An unusual
appearance feature was the appearance of an arch of light toward both the north and the south, the latter being the more distant.
On the evening of May 3, the light arose about 11 o'Clock, and was seen as an exceedingly beautiful luminous cloud along the horizon in the North, extending from NW to NE by E. From this high, bright cloud, at times majestic columns of a remarkably beautiful purple colour ascended towards the zenith, the display continuing until obscured by clouds after one o'Clock, and differing from that of April 15th in being quiet and grand, while the former might be compared to a kaleidoscope, fromt he rapidity of its changes. Reference was made to the fact that during htese displays the magnetic needle becomes restless, and varies several degrees, that lines of telegraph may be worked without the aid of the batteries, and that the centre of the arch of light in the north is found to be exactly in the direction of the magnetic needle at the place of observation. He also alluded to the proximate coincidence between solar phenomena and the display of Aurora Borealis and Aurora Australis as pointing to a cosmical origin like that of meteoric showers. He believed the aurora to be
connected with of electric origin, and probably connected with excessive humidity in the upper strata of the earth's atmosphere. During the display of May 3, he tested the Aurora with the Spectroscope, and also with the Polariscope and inferred from his observations that the light is exceedingly diffused, the brightest column being giving a spectrum of less brilliancy than that of a 5th magnitude star. He did not think it was reflected light as he failed to detect the slightest trace of polarization.
Mr. Elvins read a paper on the Lunar Craters, Messier and Messier A. He stated that he had observed these spots with care under different illuminations in reference to the change which they have been thought to have undergone, and had come to the conclusion that in all probability they are the same now as they were seen long ago. He stated that the two craters are not alike when the sun is just rising on them, or two or three days after, when the true craters are seen filled with shadow, but they soon become two white spots like Linie, and are seen thus through the greater part of the lunation. During the whole of this time they are precisely alike, and he thought it likely that it is the white spots to which the early observers refer and not to the black shadows int he craters proper.
Mr. Elvins also presented a paper on the "Zodiacal Light during the spring of 1869" and another on the "Aurora of April 15th 1869"
Mr. Winder showed a drawing of the appearance of the sun on that day (
April (May 4), showing the spots on the sun. He spoke of the probable connection of these spots with the Aurora.
Observations were made by several members in reference to their recollection of more than usually brilliant auroras, and it was suggested that each member should collect what information he could on this subject with the view of arriving at some definite conclusion as to their periodicity.
Moved by Mr. Ridgway, seconded by Mr. Turnbull that the name of the Association be changed from "Astronomical Club" to "Astronomical Society." Passed.
Moved by Mr. Elvins, seconded by Mr. Ridgway that Mr. Turnbull be Vice President for the remaining portion of the present year of the Society. Mr. Turnbull declining.
Mr. Elvins moved, seconded by Mr. Turnbull that Mr. Ridgway be appointed Vice President for the remaining portion of the present year of the Society.
Next meeting at Mr. Turnbull's, 25 Nassau St.