Mean results of Metereological Observations taken at Quebec during winter of 1853-1854

 

By W. Noble

 

[Originally published by the Literary and Historical Society of Quebec in Transactions, Original Series, Vol. 4, No. 3 (1855)]

 

 

Read before the Society, the 18th October, 1854.

 

The means of the accompanying observations are derived from observations taken at 6 A. M., 2 P. M., and 10 P. M.

 

BAROMETKR.—The mean height of the Barometer, corrected and reduced to 32 F., was in October 29,638, December 29.662, January 20.776, February 29.797, March 29.618, and April 29.797

 

The highest recorded Barometric pressure was 30.496 ins. on the 25th February, and the lowest 28,781 ins. on the 18th March, giving a range during the period of observations, of 1.715 ins., and a mean monthly range of 1.321 ins.

 

It is, of course, impossible, in observations so partial, to deduce with' much probability of accuracy, any general results, yet I cannot pass over without notice the usual great height of the Barometer before an easterly wind, and its rapid fall after that wind has commenced.

 

The following table shews the mean height of the Barometer for twenty-four hours before every easterly wind, and also its mean height for the next two days:

 

It appears, therefore, from this table that while the mean height of the Barometer for the five winter months was 29.741 ins., the mean height during the 24 hours previous to the commencement of an easterly wind was 29.990 ins. during the first twenty-four hours after its commencement 29.775, and during the next twenty-four hours 29.358 ins.

 

The maximum height observed, 30.496 ins., occured the day before the commencement of an easterly wind.

 

The only case of any importance where the Barometer appears to have remained at a considerable height during the prevalence of an easterly wind is in the period from the 28th to the 30th April inclusive, and for these three days the mean height is 30.032 ins. During this considerable height there fell 2 ins. of rain.

 

Although I have not examined the results of the Montreal and Toronto Observations so closely as those taken at Quebec, yet the same general remarks appear to apply to both of these places.

 

TEMPERATURE.—The mean temperature of the air during the month of December was 17° 6, during January 7° 5, February 8° 1, March 24° 3, and April 34° 23.

 

The mean temperature of the three winter months was 11° 0, the coldest day was the 29th of January, when the mean temperature was as low as —16° 1, the minimum thermometer was also on the same day, and was —29°

 

The following are the mean maxima, mean minima, and mean daily ranges for.

 

December, January, February, March, April,

22°.4           15".         17°         31B.9   41°.0

10.1    12°.b            —2.7     17°.8.     —5.4    22°.4       14.4    17".5            23.3    17°.7

 

The greatest daily range was on the 30th of January, and amounted to 46°.5, and the least was on the 14th April, 2°.8.

 

There were 2 days in November in which the thermometer sank below zero, 7 in December, 20 in January, 17 in February, and 4 in March, making a total of 50 days during the winter upon which the thermometer was registered below zero. There was 1 day in September in which the thermometer was below 32°, there were 14 in October, 23 in November, it was below 32° every day during the whole of December, January, February, March, and every day in April except 4 the 5th, 26th, 29th and 30th. It was also registered 4 times below 32° in May. It therefore appears. that during the last winter the thermometer sank below freezing 189 nights, or rather more than half the year.

 

The river St. Lawrence was frozen across, opposite Quebec, on the 6th February, and broke up on the 24th April.

 

The river St. Charles ice broke up on the 5th of May.

 

If my observations had been continued during the whole of this year, I believe we should have obtained a very close approximation to the mean temperature of Quebec, as in my opinion the great cold of last winter would be compensated for by the heat of the summer, and thus Col. Sabine's remark with regard to the temperature of Toronto may perhaps be extended to Montreal and Quebec, viz: that with great fluctuations of the monthly there is very little fluctuation in the annual temperature.

 

In the absence of all Authentic Thermometric Registers at Quebec, it is difficult to arrive at a true mean annual temperature. Kaemtz, in his treatise on meteorology, gives as the result of 13 years observation 43°.7 as the mean temperature of Montreal. Dr. Smallwood makes the mean temperature of Montreal, for the year 1853, 42°.9, and I would assign 38.5 or 38 as the probable mean temperature of Quebec.

 

It may shew in some degree the difference between our climate and that of Europe, if I remark that the mean temperature of Paris and London, both of which places are north of Quebec, are respectively 51.4 and 50.7, and (although last winter is not to be taken as an average,) while our coldest month was 7°.5, the mean coldest month at Paris is 35°.2 and that at London 37.4.

 

ELASTICITY.—The mean elasticity for the month of December is .096, for January .064, for February .065, March .116, and for April .150, giving a mean elasticity, for the winter quarter, of .073. inches of Mercury.

 

HUMIDITY.—The mean humidity for December was, (saturation being represented by 1.00,) .84, for January .79, for February .74, March .82, and April .81, and the mean for the three winter months was .79.

 

RAIN.—No appreciable amount of rain fell in December, January, or February; there being only one shower in January.

 

.13 inches fell in March on two days, and 2.85 inches in April on five days, the rain on the 16th March being accompanied by thunder and lightning.

 

SNOW.—Snow was observed on the mountains on the 7th October, and the first snow fell in Quebec upon the 24th of the same month.

 

The depth of snow measured during

 

October was3 ins., which fell on 1 day.

November " 15 ins                       7 days.

December " 37.5 ins                   14 "

January, "    41.5 ins                   17 "

February,"    43.9 ins                 11 "

March, " 55.8 ins                       13 "

April, " 3.3 ins………………..   5 "

 

Making a total of 200 ins., or 16 ft. 8 ins., which fell during 68 days.

 

It may be observed that this method of measuring the snow after every fall, in some level place, is liable to a very serious objection, as it is evident that, if 9 ins. fall, the quantity must be considerably greater than 9 times the amount measured, should only one inch fall.

Mr. Campbell and myself, who are carrying on the Meteorological Observations for the ensuing winter, purpose reducing the snow, after each fall, to water, with the view of comparing the actual amount of snow that falls, for different measurements.

 

WIND.—The number of observations recorded is not sufficient to determine accurately either the prevailing wind or the mean velocity.

 

The W. N. W., however, seems to be the most prevalent wind, and the mean recorded velocity is 9.5 miles per hour.

 

CLOUD.—The various descriptions of clouds observed, appear in the Meteorological Register. I will only remark, that before and after great magnetic disturbances, the clouds at considerable elevations have been frequently observed arranged in bands, sometimes parallel to, and sometimes at right angles to, the Magnetic Meridian.

 

AURORA.—The Aurora Borealis has been observed at Quebec upon 117 nights.

 

The accompanying table shews the number of auroras observed in Quebec, Montreal and Toronto during the annexed months. It also shews the number of nights on which is was possible to see aurora at each station.

 

It appears from this table, that while aurora was visible at Quebec 117 out of 138 possible nights, it was only visible at Montreal 40 out of 123 possible nights, and at Toronto 54 out of 126, or 85, 32, and 37 per cent, respectively.

 

I think we may attribute the difference in the percentage between Montreal and Toronto to the fact, that at Montreal there is only one observer, while at Toronto there is watch kept up all night.

 

I regard the difference between Quebec and Montreal as very remarkable; for example: during the latter half of the month of August, aurora was visible at Quebec upon every possible night, while at Montreal and Toronto there was the same number (3) observed out of 22 possible nights in the former, and 23 in the latter place. Now at Quebec all the auroras observed, with the exception of two or three were either low arches of about 5° or 6° above the horison, or faint auroral light. Hence I am led to the conclusion that Quebec is on the verge of that circle round the magnetic pole, within which aurora is observed nearly every clear night.

 

When we reflect that the majority of clear nights upon which aurora is recorded occur near full moon, and also that a single observer can watch only during a very small portion of the night, I think we may assume that aurora is visible here nearly 95 out of 100 possible nights.

Last winter is remarkable for the splendor and frequency of auroras of the first class.

 

I transcribe from the Journal of Auroras the description of the aurora of the 10th April, the most splendid I have ever seen, and remarkable for the accompanying great magnetic disturbance.

 

It is worthy of observation, that at this period of great magnetic disturbance, violent storms and hurricanes occured in different parts of the globe.

 

"10th.—At two, P. M., I noticed the clouds, (chiefly ci. cu.), arranged in, and parallel to, the magnetic meridian—the early part of the night hazy, and a very fine lunar halo, 40 ° in diameter, visible from 8 till 12. I first saw aurora at 11 J, P. M.; the chief characteristics were then a number of streamers changing to brilliant colours very rapidly, and a good deal of motion from W. to E. There was a total absence of the usual dark segment, and very little brilliance near the north horison. There was a narrow band of luminous vapour occasionally, of the most brilliant colours, passing through the zenith at right angles to the magnetic meridian. Corona formed at 11 h. 45 m. At about 12 h. 10 m. the chief display was in the north, spreading E. and W., and there was a great deal of motion from north towards the zenith. I cannot express it better than by saying, that for about 6 minutes it appeared as if a flood of luminous matter was flowing towards the zenith with immense rapidity. At 12 h. 59 m. large patches of streamers in the N. E. At 1 h. 10 m. streamers in the north. At 1 h. 12 m.a great deal of motion from W. to E. At 1 h. 28 m. no violent motion; streamers N. E. At 2 h. 45 m. there was precisely the same appearance in the S. E. as there had formerly been in the N. W. (at 11 1/4.) The corona reformed, and the appearance was magnificent. Brilliant patches appeared in every direction, except due north, where there were long lines of luminous cirrus clouds at right angles to the magnetic meridian. There was also a greal deal of motion from W. to E. After this the aurora appeared in patches near the north horison. At 6 h. 15 m. was the maximum of magnetic disturbance. At 6 h.24 m. I thought I saw aurora; not the slightest appearance of a cloud in the sky.

 

"This aurora was observed at Toronto, but owing probably to its late appearance, it is not noticed in the Montreal observations, although the same characteristics distinguished the sky at 10, P. M.

 

"I lay upon the table a copy of the magnetic disturbance on this day, as registered at Greenwich and Quebec.