MEAN RESULTS OF METEOROLOGICAL OBSERVATIONS. 



[1853 



June, and indicated 28-727 inches; the yearly mean was 29-086 

 inches, the yearly range was equal to 1-602 inches. The 

 atmospheric wave of November was marked by its usual fluctu- 

 ations, the final trough terminated on the 30th day. 



Thermometer. — The mean temperature of the air in January, 

 was 12 =-65, iu February 21 c -90, in March 20 ° -7, in April 

 38 ° -38, in May 52 c -27, in June 66 ° 12, in July 72 ° 33, in 

 August 68 ° .02, in September 59 z -15, in October 45 c -69, in 

 November 33 c -0, in December 24 ° -64 F. 



The highest reading of the maximum thermometer was in 

 Julv, and marked 100 ° -5 ; the lowest reading of the minimum 

 thermometer was in January, and was -28 : "0. The mean tem- 

 perature of the quarterly periods was, winter 16 = 45, spring 

 37 ° -11, summer, 68 ° -82, autumn 45 ° .94. The yearly mean 

 was 42 ° -86, and the yearly range 1 2S ° -5. The greatest inten- 

 sity of the Sun's rays was in July, and indicated 122 z 5, the 

 least intensity was in November, and was 62 ° 4. 



The mean humidity of the atmosphere in winter was -781, in 

 spring -806, in summer -810, and in autumn -S95. The yearly 

 mean of humidity was -S23. 



Rain fell on 88 days, amounting to 47-131 inches and was 

 accompanied by thunder and lightning on 17 days. Snow fell 

 on 48 days amounting to 84-61 inches on the surface. The 

 equivalent of 1 to 10 as used by the Smithsonian Institute at 

 Washington, for the comparison of melted snow to rain does not 

 hold good in this climate ; it varies from 1 to 5 to 1 to 8. I 

 have undertaken a series of experiments on this point, which I 

 have not at present brought to a close. 



The whole amount of snow which fell in the winter 1851-2, 

 amounted to 95-920 inches; the first snow fell on the 25th of 

 October, 1851, and the last on the 16th of April, 1852. 



The amount of evaporation was regularly measured and re- 

 corded during that period of the year, when the thermometer 

 stood above the freezing point, and owing to frosty nights, and 

 frost also during some days, no accurate measure could be taken. 

 The amount of evaporation in May was 3-720 inches, iu June 

 3-450, iu July 4-150, in August 2-620, in September 2-020, and 

 in October 1-220 : this period includes what I consider could be 

 taken with anything approaching to accuracy. 



The most prevalent wind during the year was the west, the 

 next in frequency was the E. N. E., the least prevalent wind was 

 the N. by W. The mean of the maximum velocity (as measured 

 by an anemometer similar in construction to Dr. Robinson's) was 

 17-632 miles per hour ; the mean minimum velocity was equal to 

 0-463 miles per hour. 



Tne Aurora Borealis was visible on thirty-six nights, at the 

 following hours, and its appearance was generally followed by 

 rain in summer and snow in winter. 



January 19th, 10 p.m. Faint-auroral arch — sky clear; 26th, 

 10 p. m. Do., dark clouds in the horizon. 



February loth, 4 a.m. Bright aurora in the north, streamers 

 shooting to the zenith; sky clear. 19^/j, at 6-30 p. m., the hea- 

 vens presented a curtain or canopy of auroral light; streamers of 

 yellow, green and crimson were sent up in rapid succession from 

 the horizon to the zenith, where they formed a cupola or corona 

 near a Auriga; at the horizon, the arch extended from E. to N. 

 W. Stars of the 4th and 5th magnitude were visible through 

 these magnificent curtains of auroral light. These appearances 

 lasted about 30 minutes, and then gradually faded away, as if to 

 seek a rest, and to shine forth with still greater splendour ; for at 

 10 p. m., the northern horizon presented a low auroral arch of a 

 yellow colour, while in the southern horizon, stretching from E. 



to W., a most splendid display of streamers rose to an apex, about 

 60 ° above the horizon ; the streamers were of the same colour 

 as in the former part of the evening; these appearances lasted 20 

 minutes ; the northern arch remained still visible. Volta's No. 1 

 electrometer marked 0-76 positive electricity; there was no 

 change indicated during or after the phenomenon. 20*A, 10 p. 

 m. Low auroral arch in the north very faint ; sky clear. 



March 1th, 7 p.m. Faint aurora, occasional streamers; sky 

 clear. 19th, 10 p.m. Low auroral arch, bright; sky clear. 20th, 

 9 p. m. Faint auroral arch ; sky clear. 



April. No aurora observed this month. 



May 5th, 10 p. m. Faiut auroral patches ; sky clear. 6//;, 10 

 p.m. Faint auroral arch ; sky clear. 18th, 10 p.m. Faint auroral 

 arch ; horizon clouded. 



June 11th 8-45 p. m., the heavens presented an auroral arch 

 3 = broad, of great magnificence ; the arch commenced in the E. 

 at the horizon, stretching to the zenith, and descending nearly due 

 west to the horizon ; the colour was crimson, at other times pale 

 green ; the borders or edges were well defined. Stars of- the 

 4th and 5th magnitudes were distinctly visible through it; a few 

 light cirri were discernible in the eastern horizon, but otherwise 

 the sky was clear; a faint auroral light was visible in the north. 

 1 he arch vanished at 9-20 p. m. -The electrometer marked 0; wind 

 west, velocity 1-10 miles per hour. 15th. Low auroral arch from 

 E. to W.N.W., bright yellow colour; occasional streamers to the 

 zenith, from 9.40 to 11-10 p.m. 2Zrd, 11-40 p.m.. faint auroral 

 light; sky clear. 



July hth, 10 p.m. Auroral bow stretching from E to W.N,W., 

 2 : wide and bright; sky clear. Wind south, velocity 0-12 

 miles. 6th, 10 p. m. Auroral light in the north, moderate bright- 

 ness; streamers; sky clear. 1th, 10 p.m. Patches of auroral 

 light, or clouds from E. N. E. to W. S. W., which vanished, lea- 

 ving abroad auroral arch; sky clear. 10th, 10 p.m. Auroral 

 streamers, bright. Cumul. Strat. 4. 20tk, 9 p. m. An arch of 

 light auroral clouds, 1° in width, passing thrrough the constella- 

 tions Cygnus, Lyra and Hercules to the horizon, lasted 20 

 minutes, sky clear, wind S.W., velocity 6-26 miles. 29th, 8 p.m. 

 Auroral arch bright. Cumul. Strat. 4. Heat lightning very 

 vivid. 



August 5th, 10 p. m. Very faint auroral light. Cirr. Cumul. 

 4. 6th, 10 p.m., do. Cumul. Strat. 4. 10th, p.m. Bright auro- 

 ral arch broad ; dark segment underneath ; sky clear. 11th, 10 

 p. m. Faint auroral clouds in the north ; sky clear. 



September 3rd, 10 p.m. Faint auroral light; sky clear. 4th, 

 1 p. m. Bright auroral arch, extended and sending up occa- 

 sional streamers; sky clear, llth, 10 p.m. Faint auroral areh, 

 low, sky clear; 18th, 10 p.m.,, do. 29lh, 10 p.m. Floating au- 

 roral clouds, varying in brightness; sky clear. 



October 6th, 10 p. m. Masses of auroral clouds in the north of 

 moderate brightness. Cirr. Cumul. 4. 19th, 10 p. m. Auroral 

 arch faint and low. Stratus 2. 20th, 9 p. m. Faint auroral 

 arch, with dark segment underneath, at 9-20, a fine display of 

 streamers ; sky clear. 



November llth, 10 p. m. Bright auroral streamers, not very 

 extended ; sky clear. 



December 1st, 3 a. m. Auroral light in the north, bright and 

 extended ; sky clear. 29th, 10 p. m. Low auroral arch ; sky 

 clear. 



Lunar halos visible on six nights. A lunar rainbow was also 

 visible on the 29th February. "Fogs were observed on six morn- 

 ings. Shooting stars were seen on the 18th of July, and 9th 

 and 10th of August. A slight shock of an earthquake was felt 



