78 TWENTIETH ANNUAL REPORT ON THE STATE CABINET. 



unprecedented height of 30.504 inches. Thirdly. At night the 

 sky has been generally clear, so as to allow unobstructed radiation 

 by cooling ; and in the daytime the sky has been overcast, so as 

 to obstruct the sun's heat from reaching the earth. As observed 

 elsewhere^ and reported in the newspapers and by personal corre- 

 spondence, I find, firsts that in almost all cases, perhaps all, the 

 wave of cold, so to call it, passes from west to east, and the cold 

 reaches its maximum of intensity in the Mississippi valley some 

 fifty or sixty hours before it reaches this place. In case of the 

 unusual cold term last January (Jan. 8th at Geneva), the cold 

 wave appeared on the Pacific coast seven or eight days before it 

 reached us, and I have heard of it in England some ten or twelve 

 days after it had passed our meridian. There were in this case, 

 however, some unusual breaks in the wave ; as the cold at Buffalo 

 and Rochester, for example, was not unusual, being only 3 deg. 

 or 4 deg. below, while it was 12 deg. below at Geneva, and in- 

 creased as it progressed eastward to 31 deg. below at Utica. In 

 fact it would appear as though one wave, that of which we first 

 hear as on the Pacific coast, had expended itself, reaching Geneva 

 on the night of the 4-5th, the thermometer falling to 1 deg. above 

 on the morning of the 5th, it being on that morning 3 deg. below 

 at Rochester ; and another commenced immediately, forcing the 

 thermometer to 5 deg. below on the morning of the 7th, and to 

 12 deg. below on the morning of the 8th, increasing in intensity 

 eastward. The second phenomenon that I have observed is, that 

 the crest of the wave, or line of maximum cold, always passes in 

 a curvilinear direction from north to the south, inclining ever- 

 more to the west, until it is lost in the tropics. One such line 

 passed through Montreal, Rouse's Point (N.Y.), Utica, Pittsburg 

 (Pa.), Nashville (Tenn.), New-Orleans, Galveston, &c. ; so that the 

 moment of greatest cold was simultaneous in all the places on this 

 line, while both to the west and to the east of them the weather 

 at that moment was warmer, being 32 deg. at Chicago and 25 or 

 26 deg. at Portland (Maine) ; the cold always reaching its maxi- 

 mum at the time when the wind had reached a point of compass 

 somewhat north of east, blowing in fact about in the line that I 

 have indicated as that of the greatest cold. 



Now I think that I can generally predict the approach of such 

 a cold term some days — two at least — before its arrival, by obser- 

 vations that are to be made in my own observatory. And the 

 phenomena just described suggest that the balance of the winds, 



