10 



NATURAL HISTORY OF VERMONT. 



Part L 



MEAN TEMPERiTURK AT BURLINGTON AND AVILLIAMSTOWN. 



With the exneption of the first three 

 columns in the Jirst of the two preceding 

 tables, the particulars of which are not 

 known, all the means for the months 

 have been deduced I'rom three daily obser- 

 vations, taken at sun-rise, I o'clock, P. 

 M. and 9 in the evening. Now, as the 

 three daily observations at Burlington 

 synchronize for several years with those 

 at Williamstown, the two tables enable 

 us to make a very accurate comparison of 

 the mean temperature of the two places ; 

 and the comparison shows that the mean 

 temperature of Burlington, although sit- 

 uated 22' farthest north, is about 5^ warm- 

 er than that of Williamstown, that of the 

 former being 44.6? and the latter 39.4°. 

 But the cause of this difference is obvi- 

 ous in the location of the two places, Bur- 

 lington being situated on the margin of 

 lake Champlain, and the place of obser- 

 vation elevated only 2.j() feet above it, 

 while Williamstown lies among the Green 

 Mountains near the geograpliical centre 

 of the state, and, the place of Judge 

 Paine's observation, elevated 1500 feet 

 above the lake.* 



The mean annual temperature of Bur- 

 lington, deduced from all of tlie 12 years 

 observations in the preceding table, is 

 44.1", and from the seven years observa- 

 tions by the author 44.9'', but, as the year 

 1828 was very remarkaljly warm, that 

 should, periiaps, be set aside, and the 

 mean of the other six, 44 .4°, taken as prob- 

 ably a fair statement of tiie mean annual 

 temperature of Burlington. The mean 

 annual temperature of Williamstown, de- 

 duced from the wliole of Judge Paine's 

 observations, is 40. Ij?. 



Many perennial springs, and deep 

 wells are found to continue nearly of the 

 same temperature, both in summer and 

 winter, and to be but very little affected 



by the changes of temperature which are 

 constantly going on at the surface of the 

 eartli ; the temperature of these may, 

 therefore, be regarded as a pretty fair in- 

 dication of the mean annual temperature 

 of the climate. The temperature of a 

 well 40 feet deep, belonging to Mr. Sam- 

 uel Reed, in Burlington, has been ob- 

 served and noted during the year 1841 as 

 follows, the first number after the day of 

 the month being the depth in feet to the 

 surface of the water at the time of the 

 observation: Jan, 1, 14 — 46°, Feb. 12, 

 18— 44.1", April 14, 16—44", Junel, 10— 

 44", July 20, 10— 46A'^, and Dec. 8, 20— 

 45.^", giving a mean of 45.1°, or .3" higher 

 than that deduced from the daily obser- 

 vations. 



Winds. — For small sections of country 

 the prevailing winds usually take their 

 direction from the position of tiie moun- 

 tains and valleys. That is very much the 

 case in Vermont. Throuoh the valley of 

 the Connecticut and of lake Cliamplain 

 the winds usually blow" in a northerly or 

 southerly direction, while easterly and 

 westerly winds are comparatively of rare 

 occurrence. In the valley of lake Cham- 

 plain east winds are exceedingly rare, as 

 W'ill be seen by the following tables.* 

 Along our smaller rivers, particnlarl}^ the 

 VVinooski and the Lamoille, the prevail- 

 ing winds are from the northwest. The 

 following tables contain tlie result of 

 observations made at Burlington, for 

 eleven years, and at Rutland for one 

 year. In the journal kept by the author 

 at Burlington, and from which the ta- 

 bles on the following page were copied, 

 three observations of wind and weather 

 were enti^red each day, which synchro- 

 nize with the observations of tempera- 

 ture for the same years in the preceding 

 table, on the ninth page. 



The folV'''^ '*-\K table contains the results of five years observation at Burlington, 

 by Dr. Saunders, and one year at Rutland, by Dr. Williams. 



Place. 



Time. INo.Obs.l n IneI e IseI e ) aw I w ! nw ] fair. Iclodylrain 



Burlino-tonl]803— 81 1682l739lnlinl l!826l 25l 431 181 10251 676 289 

 Rutland |]789 | 1095ll53ll3|j6l76|272|l82il25|25S!l 452] 6431 89 



snwifofiltliun 



127; 19 45 

 41137 15 



* The author has in his possession a meteorologi- 

 cal journal kept at Hydepark by Dr. Ariel Huntoon, 

 for a period of 9 years, of wliii-li lie hml inteniled to 

 insert an al)stract ; but, fnidins; the three daily ob- 

 servations to have been made too near the warmest 

 part of the day to furnish the true mean tempera- 

 ture of the 24 hours, and consequently unsuitable 

 for comparison with the other tables, he concluded 

 not to insert it. In order to render meteorolog'ical 

 observations of service in determining the relative 

 temperature of places, imiformity in the method of 

 waking them seems to be indispensable, and a want 

 of this renders a great part of the journals which 

 have been kept nearly useless. 



* Although, at Burlington, we seldom have a 

 wind from ihe east sufficiently strong to turn the 

 vane? upon our cliurclies, it is not uncommon, dur- 

 ing the latter part of the night and early in the 

 morning, when the weather is fair, lo have a light 

 breeze from the east, which is doubtless occasioned 

 hy the rolling down of the cold air from the moun- 

 tains to supply the rarefaction over the lake. In 

 other words, it is strictly a land breeze-, similar to 

 what occurs between the tropics. That these breezes 

 are local and limited is evident from the fact, that, 

 at the same time, the general motion of the air is in^ 

 a different direction, as indicated by the motion of 

 clouds in higher regions of the atmosphere. 



