MEAN TEMPERATURE AT BURLINGTON AND WILLIAMSTOWN.

WINDS.

With the exception of the first three by the changes of temperature which are columns in the first of the two preceding constantly going on at the surface of the tables, the particulars of which are not known, all the means for the months have been deduced from three daily observations, taken at sun-rise, 1 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 situated 22' farthest north, is about 5 warmer than that of Williamstown, that of the former being 44.69 and the latter 39.4°. But the cause of this difference is obvi-vations. ous in the location of the two places, Bur- Winds. For small sections of country lington being situated on the margin of lake Champlain, and the place of observation elevated only 250 feet above it, while Williamstown lies among the Green Mountains near the geographical centre of the state, and, the place of Judge Paine's observation, elevated 1500 feet above the lake.*

earth; the temperature of these may, therefore, be regarded as a pretty fair indication of the mean annual temperature of the climate. The temperature of a well 40 feet deep, belonging to Mr. Samuel Reed, in Burlington, has been observed 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, 18-444°, April 14, 16-44°, June 1, 10— 44°, July 20, 10-464, and Dec. 8, 2045°, giving a mean of 45.1°, or .3° higher than that deduced from the daily obser

The mean annual temperature of Burlington, deduced from all of the 12 years observations in the preceding table, is 44.1°, and from the seven years observations by the author 44.9°, but, as the year 1828 was very remarkably warm, that should, perhaps, be set aside, and the mean of the other six, 44.4°, taken as probably a fair statement of the mean annual temperature of Burlington. The mean annual temperature of Williamstown, deduced from the whole of Judge Paine's observations, is 40.3.

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

the prevailing winds usually take their direction from the position of the mountains and valleys. That is very much the case in Vermont. Through the valley of the Connecticut and of lake Champlain 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 Champlain east winds are exceedingly rare, as will be seen by the following tables.* Along our smaller rivers, particularly the Winooski and the Lamoille, the prevailing winds are from the northwest. The following tables contain the 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 tables on the following page were copied, three observations of wind and weather were entered each day, which synchronize with the observations of temperature for the same years in the preceding table, on the ninth page.

The following table contains the results of five years observation at Burlington, by Dr. Saunders, and one year at Rutland, by Dr. Williams.

No.Obs. N NE E SE S SW W NW fair. Iclody train] snw fog|thunau

1682 739 11 19 1826 25 43 18 1025 676 289 127 19 45 27 1095 153 13 1676 272|182|125|258| 452 643 89 41 37 15,21

The author has in his possession a meteorological journal kept at Hydepark by Dr. Ariel Huntoon, for a period of 9 years, of which he had intended to .insert an abstract; but, finding the three daily observations to have been made too near the warmest part of the day to furnish the true mean temperature of the 24 hours, and consequently unsuitable for comparison with the other tables, he concluded not to insert it. In order to render meteorological observations of service in determining the relative temperature of places, uniformity in the method of making 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 wird from the east sufficiently strong to turn the vanes upon our churches, it is not uncommon, during the latter part of the night and early in the morning, when the weather is fair, to have a light breeze from the east, which is doubtless occasioned by the rolling down of the cold air from the mountains 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,

METEOROLOGICAL TABLE.-WINDS AND WEATHER AT BURLINGTON.

WINDS.

WEATHER.

8 SW WIN Wfair. cldy r'n sno 1838

93 34 18

30208

28 61 0 4 Dec

The depth of water, which falls during | Snow. For more than three months of a rain storm or thunder shower, is much the year the ground is usually covered less than people generally suppose. A with snow, but the depth of the snow, as fall of 4 or 5 inches during a severe thun- well as the time of its lying upon the der shower would not be thought at all ground, vary much in the different parts extravagant by persons who have paid no of the state. Upon the mountains and attention to the accurate measurement of high lands, snows fall earlier and deeper, the quantity which fell. But during the and lie later in the Spring than upon the seven years observations at Burlington low lands and valleys, and it is believed contained in the above table, the depth of that they fell much deeper in all parts of water which fell in one shower has nev-the state, before the country was much er exceeded two inches, and the whole amount in 24 hours has, in only one instance, exceeded three inches, and that was on the 13th of May, 1833, when the fall of water was 3.54 inches.

cleared, than they have for many years past. As little snow falls at Burlington, probably, as at any place in the state. The following table exhibits the amount at this place for the last five winters:

Fall of Snow at Burlington in the winters of

1837-'8. | Inc. | 1838-'9. | Inc . 1839-'40. | Inc. | 1840-'1. | Inc.

1841-2. Inc.

Nov.

6, 2 Oct. 26, 2 Oct.

8,

66 9, 1 Dec. 11,

3

Nov. 22,
"26,27,

7

66 26, 31

3

66

16,

9

Dec.

66 22,

18,

28, 5
29, 4
5, 4

29, 1

66

15, 11

SLEIGHING.

SEASONS.

APPEARANCES OF BIRDS AND BLOSSOMS.

Seasons. During the winter the ground is usually covered with snow, seldom exceeding one or two feet deep on the low lands, but often attaining the depth of three or four feet on the high lands and mountains. The weather is cold, and, in general, pretty uniformly so, with occasional snows and driving winds, till the beginning of March, when with much

In 1838-'9, sleighs run from December | or hail. The crops oftener suffer from an 23, to January 8, but there was no good excess, than from a deficiency,of moisture, sleighing during the winter. In 1839-'40 though seldom from either. sleighing was excellent from December 16, to February 5, fifty one days. In 1840'41, sleighs run from November 22, to November 29, and from December 7, to December 12, but the sleighing was not good. From December 27, the sleighing was good till the 8th of January, after which there was no good sleighing, although sleighs continued to run till the 20th of March. In 1841-2, sleighing tol-boisterous weather there begin to appear erable from December 18, to January 20, after that no good sleighing though sleighs run at several periods for a few days at a

time.

some slight indications of spring. About the 20th of that month the snows begin to disappear, and early in April the ground is usually bare. But the snows fall some weeks earlier and lie much later upon the mountains than upon the low lands. The

The deepest snows, which fall in Vermont, are usually accompanied by a north or northeasterly wind, but there is some-weather and state of the ground is usually times a considerable fall of snow with a northwesterly, or southeasterly wind. A long continuance of south wind usually brings rain, both in winter and summer. Although snows are frequent in winter and rains in summer, storms are not of long continuance, seldom exceeding 24 hours. Storms from the east, which are common on the sea board, do not often reach the eastern part of this state, and on the west side of the Green Mountains they are wholly unknown, or rather, they come to that portion of the country from a northeastern, or southeastern direction. Thunder showers are common in the months of June, July and August, but seldom at other seasons. They usually come from the west, or southwest, but are not often violent or destructive, and very little damage is ever done by hurricanes

Year.

1828

1829

such as to admit of sowing wheat, rye, oats, barley and peas, the latter part of April. Indian corn is commonly planted about the 20th of May, flowers about the 20th of July, and is ripe in October. Potatoes are planted any time between the 1st of May and the 10th of June. Frosts usually cease about the 10th of May and commence again the latter part of Šept., but in some years slight frosts have been observed, at particular places, in all the summer months, while in others, the tenderest vegetation has continued green and flourishing till November. The observations contained in the following table will afford the means of comparing the springs of a few years past. They are gathered from the Meteorological journal kept by the author at Burlington:

1838 tr 23

1839 66 25
1840 66 15
1841) 27

31 May
25 April 26

21 66 4 6. 7 66 30 "" 16 66 19 2

1832 Mar. 25 Mar. 28
1833 66 23 "28

"26 "" 12 66 14 66 20 May 24 June 3

"C 12 66 15 May 18
"28 66

19
66 4 66
66 21 "L 21 "6
3 66 12 66 17 66 20 66 23
27 " 27 23 66 251 66 26 291 64 31

22

30 June 2

Vegetation, upon the low lands and ture, and bring fruits and vegetables to along the margin of the lakes and large maturity which do not succeed well upon streams, is, in the spring, usually, a week the high lands. To the above remark, or ten days in advance of that upon the with regard to early frosts, there are sevhigh lands and mountains; but frosts usu-eral exceptions. On the low islands and ally occur, in the fall, earliest upon the shores of lake Champlain, vegetation is low lands, allowing to each nearly the frequently green and flourishing long after same time of active vegetation. The low the frosts have seared it in other parts of lands, however, enjoy a higher tempera- the state, and, along several of the rivers,

OPENING AND CLOSING OF LAKE CHAMPLAIN.

DISAPPEARANCE OF THE ICE.

vegetation is protected by the morning It frequently happens that the ice confogs for some time after its growth has tinues upon the lake for some time after been stopped upon the uplands. The the snows are gone in its neighborhood early part of the autumn is usually pleas- and the spring considerably advanced. ant and agreeable and the cold advances In such seasons the ice often disappears gradually, but as it proceeds the changes very suddenly, instances having been. become more considerable and frequent, observed of the lake being entirely covand the great contrast between the tem- ered with ice on one day and the next day perature of the day and night at this sea- no ice was to be seen, it all having disson render much precaution necessary in appeared in a single night. People in the order to guard against its injurious effects neighborhood, being unable to account for upon health. The ground does not usu- its vanishing thus suddenly in any other ally become much frozen till some time way, have very generally supposed it to in November, and about the 25th of that sink. This opinion is advanced in the month the ponds and streams begin to be account of this lake contained in Spafcovered with ice, and the narrow parts of ford's Gazetteer of New York, and the lake Champlain become so much frozen anomaly is very gravely attempted to be as to prevent the navigation from White- accounted for on philosophical principles. hall to St. Johns, and the line boats go in- But the true explanation of this phenomto winter quarters, but the broad portions enon does not require the absurdity of the of the lake continue open till near the first sinking of a lighter body in a heavier. It of February, and the ferry boats from Bur- is a simple result of the law by which lington usually cross till the first of Jan-heat is propagated in fluids. That bodies uary. The following table contains the are expanded, or contracted, according to times of the closing and the opening of the broad lake opposite to Burlington, and when the steamboats commenced and stopped their regular trips through the lake from Whitehall to St. Johns, for several years past:

the increase or diminution of the heat they contain, is a very general law of nature. Fresh water observes this law, when its temperature is above 40°, but below 40° the law is reversed, and it expands with the reduction of temperature.

When winter sets in, the waters of the lake are much warmer than the incumbent atmosphere. The surface, therefore, of the water communicates its heat to the atmosphere, and, becoming heavier in consequence, sinks, admitting the warmer water from below to the surface. Now since heat is propagated in fluids almost entirely by the motion of the fluids, this circulation will go on,if the cold continues,till all the water from the surface downward to the bottom is cooled down to the temperature of 40°. It will then cease. The colder water now being lighter than that below, will remain at the surface and soon be brought down to the freezing point and congealed into ice. This accounts for the ice taking soonest where the water is most shallow, and also for the closing of the broad parts of the lake earliest in those winters in which there is most high wind, the process of cooling being facilitated thereby.

After the ice is formed over the lake, and during the coldest weather, the great mass of water, after getting a few inches below the ice, is of a temperature 8° above the freezing point. While the cold is scvere, the ice will continue to increase in thickness, but the mass of water below the ice will be unaffected by the temperature of the atmosphere above. Now the mean annual temperature of the climate in the neighborhood of lake Champlain