The warmest month during the year was the month of July, and the coldest February. The mean temperature of the warmest day was 81.70 on the 13th July, and the mean temperature of the coldest day was 13.73 (below zero) on the 5th February.

The following table shows the monthly mean temperature for 1871, with the amount of rain and snow; the snow in this case is not reduced by melting into water, but is the observed depth in inches on the surface:

The following table shows the quarterly mean temperature, also the amount of rain and snow in inches for each quarter :

There were three cold terms during the year, one in January, the second in February, and the third in December.

The first was somewhat remarkable for its duration and severity. The temperature was 101 and 20 below zero, and it attained a minimum of 26°8, and the Barometer attained a maximum of 30.985 inches.

The following table will show the variations in temperature and its duration :

The second cold term occurred on the 4th of February and attained a temperature of -28°. The Thermometer was 52h 45m below zero.

The following table contains a record of the observations:

The third cold term of the 21st December set in with somewhat unusual rapidity. The early part of the evening was bright and moonlight, with but light wind from the N. W. The Thermometer attained its zero point at 8.5 p.m. and at 9 p.m. stood at -196. Wind N. W.; velocity 4 miles per hour. Barometer 29.632. At midnight the wind freshened and veered to the W., velocity 12 miles per hour, the Barometer slowly rising, and at 11.49 p.m. (one of the signal hours of the War Department at Washington) it stood at-5°5; at 2 a.m. it stood at -10°6; and from that time it fell rapidly and attained a minimum of —-22°9. The Thermometer was 34h below zero.

The following table has been compiled to show the number of days in each month on which rain or snow fell, also the number of days without either rain or snow.

Rain fell on 109 days; it amounted to 26.507 inches, was accompanied by thunder and lightning in 18 days, and shows a large decrease in the usual annnal rain fall.

Snow fell on 56 days, amounting to 74.53 inches on the surface, which is equivalent to about 7.450 inches of rain.

The first snow of autumn fell on the 18th October, and the winter fairly set in on the 29th November, with unusual severity, and somewhat earlier than the usual period, causing severe losses to shipping from foreign ports as also to the river navigation.

The Thermometer first attained its zero point on the 29th November.

The ice left the front of the city on the 8th of April, and the first steamer arrived in port on the 10th day. The last frost of spring was on the 26th of April.

Winds. The most prevalent wind West, the next in frequency the N. E.

during the year was the

The most windy month.

in the year was May, and the least windy month July.

Below is a table showing the direction of the wind for each month and its mean velocity in miles, irrespective of its direction:

Mean monthly amount of clouds in decimals, a cloudy sky being represented by a whole number (1.00.)

ing the year.

The aurora borealis was visible at observation hours on 26 nights, and exhibited some grand displays on the 10th and 11th of February, 17th March, 9th of April, 7th of August, 7th of September and the 9th of November.

MONTREAL OBSERVATORY, 30th Jan., 1872.