194 Scientific Intelligence.— Meteorology. 
TABLE shewing the mean monthly and annual temperature, from 1827 till 1838 
-inclusive, mith the mean temperature of all these twelve years, which may be 
considered the mean temperature of our climate. 
Jan. | Feb. | Mar. | April.| May. | June. | July. | Aug. | Sept. | Oct. | Nov. | Dee. 
35.09 | 35.09} 38.59] 43.83) 49.16) 53.40) 55.61 55.04 | 54.33} 50.95] 43.11] 43.24 
a2 8: : 56.04] 58.25 | 57.26 55.41} 54.19] 45.63 | 43.24 
36.14] 39.46| 40.69] 41.51| 49.99 | 53.43) 57.12| 54.86 50.21] 45.56] 41.40] 39.51 
37.96 | 36.71) 41.83} 44.80]-50.77 | 51.66] 56.14) 53.14) 53.46] 49.41] 42.76 | 36.33 
36.70 | 37.71} 42.65) 44.88] 48.70) 55.13) 57.86 | 58.90 | 54.73) 51.73) 40.50 | 44.07 
41.49 | 42.22) 42.22} 46.24) 47.31) 54.73) 54.25) 56.07, 52.61] 49.38} 45.43) 41.40 
87.14] 33.37 | 38.68] 43.23) 51.43] 51.60) 54.73) 52.40) 52.34] 49.20] 41.58) 39.28 
38.90| 40.21) 41.11] 43.05} 48.75| 58.02] 58.03) 56.89, 52.90] 48.67 | 44.01} 45.17 
39.75 | 39.48 | 41.20] 42.25] 46.01} 51.76} 53.57| 54.77 | 53.01] 45.70] 45.68} 40.44 
39.14} 37.46, 39.61] 41.39] 47.77 | 52.03} 52.51! 51.83} 48.35] 45.91] 40.93] 38.57 
38.82 | 39.32! 86.54] 39.13] 45.24] 51.06} 50.55) 53.75! 51.68] 49.36] 41.59] 42.44 
33.56 | 31.31) 38.64] 39.23) 44.75) 48.20] 53.86] 52.28| 50.28) 45.77] 99.71) 41.78 
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Of the meteors, the polar lights are the most remarkable here, 
being often extremely brilliant and beautiful. 
The west or south-west wind is understood to be the strongest, and 
the stone and lime on that side of a house most exposed to it, are 
generally the first to give way. A gale from that quarter is fre- 
quently prognosticated by the great swell of the sea, which rages even 
during a perfect calm. On this subject I take the liberty of repeat- 
ing an observation which I have made elsewhere.* “ This great 
swell, or ‘ sea,’ as it is here called, generally indicates a storm in a 
distant part of the ocean, which may reach Orkney a day or two af- 
terwards ; hence, on the west coast, this great swell is considered a 
prognostic of west wind. From this we infer, 1s¢, that the agitation 
caused by the wind on the surface of the ocean travels faster than the 
wind itself; and, 2d, that the breeze begins to windward, and takes 
some time to reach the point towards which it proceeds to leaward, 
which tends to overturn the usually received theory as to the cause 
of winds. Sometimes, however, the distant storm which causes this 
agitation does not reach these islands at all.” In proof of this, I may 
mention, that, in August 1831, from the 9th to the 13th inclusive, 
the great swell of the sca is remarked in my register, every day being 
also marked calm, with the barometer hich and steady. Afterwards, 
however, I learnt that on the 7th and 8th of that month, there was a 
gale, in latitude 57° 21’ north, longitude 13° 15’ west, which damaged 
a vessel that put back to Stromness to repair, and on the 11th it be- 
gan at Barbadoes, and devastated that and other West India islands, 
but the gale never reached Orkney, though its effects on the sea were 
so conspicuous. 
Climate.—Our insular situation prevents the extremes of tempera- 
" %* Quide to the Highlands and Islands of Scotland, p. 629. 
| 37.90} 38.01} 40.25] 42.76] 47.93) 53.17) 55.20 54,72 | 52.43 | 48.76 42.68 | 41,28] 46.25 
