1874.] lOD [Blodget. 



We shall undoubtedly be compelled to revise our views as to the pri- 

 mary or leading condition of general storms. The barometer is by no 

 means a certain guide, and instances of severe storms with continuing 

 high pressure throughout are frequently recurring. The recent severe 

 storm of Saturday and Sunday, April 25th and 26th. This storm began 

 with the barometer .15 above the mean, and scarcely fell below the mean 

 (of 30. inches) after ten or twelve hours of continued severity, and when 

 at its height here, on Saturday evening. At Pittsburgh, Cincinnati, 

 Louisville, &c., there was also no perceptible depression below the mean, 

 the barometer being generally at almost exactly 30 inches. No storm 

 was anticipated by the signal office, nor were there any evidences such 

 as usually appear, justifying anticipations of a severe storm. Yet few 

 storms have been as severe, the N. E. wind of Saturday night being ex- 

 tremely heavy here, while northeastward, to Nova Scotia, the slow but 

 certain progress continued throughout the day and night of Sunday. On 

 Monday morning, it is true, a considerable barometric depression appears 

 in Maine and Nova Scotia, of half an inch, or more, in places, but this 

 appears to have set in eastward of New York, almost exclusively. The 

 storm was violent and long continued at New York and southward, with 

 very little barometric depression, not enough to warrant expectations of 

 a storm, or any severity of winds. There have been several conspicuous 

 instances of a similar character since the Signal Service observations gave 

 us such excellent opportunities for observation. 



I repeat, that the evidence is cumulative in support of the position that 

 the atmospheric movement in the colder seasons in these latitudes is one 

 of constant descent of volumes ; that the cold gales of the spring months, 

 strike in at areas east of the Alleghanies from the northwest, when they 

 are unknown west of that line ; and occur in repeated instances not only 

 when by no possibility they could be continuous, or connected with like 

 movements propagated from the northwest, but also when the winds, 

 even so near as Pittsburgh, blew all the time in an opposite direction. 



The almost inexplicable phenomena presented by the severity, the per- 

 sistence and force of these winds, with the low temperature they bring, 

 become easy of solution, under the view that their volume is perpetually 

 renewed at all points where they prevail, by constant pouring from above, 

 as if a current of cold water was renewed and enforced in its movement 

 by so pouring a stream downward, as well as along the sm-face. On each 

 of the last three days the facts of such forcible descending winds were 

 experienced here, and during the full period of ten days preceding there 

 -was, as the Signal Office charts will show, a marked absence of west or 

 northwest winds at all points of the western or northwestern interior, 

 from which it is usually supposed these high cold winds are derived, and 

 propagated eastward along the sui'face to the Atlantic Coast. In fact, 

 for a week from April 25th to May 1st, the weather was warmer at Pem- 

 bina, lat. 490 N., than at Philadelphia, in 42° N., being 44° for the 1 a. 

 M. observation at Pembina, to 42° for the same at Philadelphia. 



A. p. S. — VOL. XIV. T 



