CLlMATOLOaY. 



have 55° in April, and 45° in March. Tho following table gives the mean temperature for 

 Mairli, ami the increase of the moan temperature from month to month, until June. 



Stations. 

 Eastport, Maine .... 

 I'ortliuid, Maine 

 Xew York (Governor's iHlaud) . 

 Moiuli of Js'iagara Kiver 

 I'itt.-lnirg (tliieo miles N. E. of city) 

 Haltiuioro (Fort Xlrllenry) 

 ■NVasliingtou (14 inilo.'* S. of capitol) 

 Augusta (tlirco miles W.) . 

 St. Louis (throe miles lielow) 

 Xo-n-port (opposite Cincinnati) . 



l>etrolt 



San Francisco .... 

 Fort Vancouver (80 miles from the mouth 

 of tho Columbia) 



3.7 



The increase from March to April, and from April to May is nearly alike ; While the 

 increase from May to June is less — showing that the uniformity in the advance of the tem- 

 perature belongs to a less period than three mouths. " The period we designate as Spring, 

 is, oh the whole, too long for identification as a single quantity in the continental temperate 

 regions of this hemisphere. The natural seasons are unequally divided in time ; in truth 

 the winter and summer being longer, and the spring and autumn shorter than ninety days. 

 An admirable analysis of ten years observations at Albion mines. Nova Scotia, has been 

 made by their author, Henry Poole, Esq., by which it appears that the seasons there are 

 naturally resolved into periods of sixty-six and sixty-three days for spring and autumn, 

 and 120 and 116 days for winter and summer. The winter minimum temperature is .Janu- 

 ary 20th, or thirty days after the solstice, and the summer maximum July 22d, or thirty- 

 one days after the solstice. The mean annual temperature is passed on May 1st, and No- 

 vember 1st, forty-one and forty-four days after the equinoxes respectively. 



A taljle is given of the means and of the extreme variations of temperature for the three 

 spring months for thirty-four years from 1820 to 1854, at Fort Columbus, near New York, 

 Fort Gibson on the Arkansas, and Fort Snelling at the mouth of the St. Peters, on the Mis- 

 sissipjn. 



This table shows how irregular is our spring climate — how great are the oscillations of 

 temperature — and that the greatest deviations are below and not above the mean. The 

 extreme cold of March, 1843, was felt over the whole country. The extremes of tempe- 

 rature lessen as the spring advances. It is important to ascertain the districts in which the 

 thermometer falls to the freezing point once or more in the course of a month. 



" On the coast of California an examination of the minima for five years, affords but two 

 instances of the observation of 32= in March ; while, in the interior, and in Oregon, it may 

 be anticipated several times in this month; though the lowest observed point at stations 

 not much elevated, is 19°. In April it is never reached in California at the sea-level, or near 

 it, and rarely in Oregon ; at Puget's Sound, three times in six years. In May, there are no 

 instances of its occurrence on the Pacific, except at stations elevated 2000 feet or more. 



