Thus in a period of 65 consecutive days, commencing with the first of November, the mean of the warmest time of the day was only 37.33°; and the mean of the two extremes of morning and evening 26° very nearly. During the same period the mercury for several days ranged near, and once fell, at the lowest, 13° below zero.

Taking the whole of the thermometrical tables into view, we find the climate of the United States liable to the extremes of 108° above, and 38° below zero. Commencing with the Atlantic coast, and advancing into the great central plains of the continent, the extremes increase in a greater ratio than would be produced by an increase in height; an effect produced no doubt by an immense open surface, exposed in summer to intense radiation, and in winter to prevalent western winds from the frozen regions along, and on both sides of a continuous chain of mountains. By table 32, we. dis. cover, that near the Atlantic coast, and as low as 39° N. there are, in winter, in ordinary seasons, 90 days on which the thermometer ranges below the freezing of water, and it is a fair inference that few winters occur on which there will not also occur sixty consecutive days during which the mean temperature will not be below the freezing of

water.

The head of Climate has extended beyond the expectations of the writer, and therefore the insertion is precluded of some valuable documents supplied VOL. XVIII.-PART I.

by Dr Wm. Palmer, on the foliage and inflorescence of indigenous forest trees. We may merely state, that from these documents and our own observation, there is frequently not much short of a month between the opening of spring in two succeeding years. The ripening of fruit and the fall of the leaf, though not liable to so great a difference in time, are, however, phenomena, which have really no fixed day.

Every season, indeed every day of the year is liáble to present features very distinct from like seasons, or days, of other years. If any months could be chosen, which differ most from each other, these would be March and December. The following notes made at Sandy Spring will place this in a strong light.

March 1829.-It will be observed that the surface of the earth in this vicinity was not clear of lying snow until the 27th of this month; and at its close indications of vegetation were very slight, and confined to the grasses.

March 1830.-On the 20th, peach bud swelling; 26th, red maple in bloom, and weeping willow in full leaf. At the end of the month black haw, and crab apple leaf unfolding; peach flowers nearly expanded; and vegetation generally so far advanced that pasture was sufficiently abundant in the fields. Red clover had covered the ground; flower of the field, cherry tree opening; ploughing had been commenced.

March 1831.-At the end of this month, red maple in bloom; peach bloom opening; weeping willow in leaf; clover and grasses in a vigorous state of growth, though pasture still scarce; ploughing merely commenced.

December 1829.-This month presents the curious phenomenon of a mean temperature of 424 Fahrenheit three degrees above that of the previous November. In December 1829, also much less

3 C*

snow or rain fell than did on the November. At the beginning of the new year, red clover was in a state of not slight vegetation.

December 1830. The mean temperature of this month was almost seven degrees lower than that of the same month 1829. The month was remarka2le for heavy, cloudy and rainy weather, and on the b2d, for severe cold. But the most peculiar phenomenon of the month was, that the highest range of the thermometer was on the morning of the last day, 58°, and in the midst of a thunder storm.

December 1831.-Commenced with 7 or 8 inches lying snow, and presented throughout, the temperature of severe winter, with an extreme 13° below zero of Fahrenheit, or 45° below the freezing of water. Sleighing was good in this vicinity during the whole month.

Rain.-Great as are the extremes of aerial temperature in the United States, there is also another class of meteorological phenomena, if possible, more irregular. The quantity of water which falls in the form of rain, hail, sleet, and snow, differs greatly in different years, but still more in the months of

the same year. We present the reader with the following as the best data we possess on the rain of the United States, premising that there are more difficulties opposed to a correct result on this part of our subject, than we encounter with observations on temperature. Rain itself is far from being easily measured as it falls, and in the state of

Placing equal confidence in the American and European tables, a result comes out, which will no doubt surprise many readers; that is, that more rain falls annually on the former, than on the latter part of the earth. If we examine the different places named in table 57, we find that along the eastern coasts of Ireland and Britain, not more than two thirds as much moisture falls in the form of rain, as does on the United States, in a given time.

We now reach the far most important difference between the climate of the United States and northwestern Europe, the distribution of moisture. If the reader will refer to the articles England and Scotland, he will discover, that in many places, on both countries, days of rain and snow very nearly equal those of fair weather; and under the article Scotland it is expressly stated, that "among the fair days are included, those that are gloomy and foggy, and among the rainy days, those that were showery."

number of days in a great majority of years in the On every comparison we are able to make, the United States, are completely fair; that is, pass without any falling meteor which can come under any other denomination except those of dew or hoar frost. The following table, formed from the summary tables in Lovell's Register, is inserted as embracing a very wide extent, and consequently, not giving a limited view.

TABLE XLI.

Relative state of the weather in the United States— mean of the months, four years.

WEATHER.

Dublin, Ireland, mean of 13 years,
Londonderry, Ireland, mean of seven years, 31.118
Cork, mean of 11 years,

38.93

Staffordshire, England, the annual rains ex

3.92 5.08 3.08 Fair. 18.41 9.58 1.83 0.59 Fair. 12.33 9.42 5.34 3.34 Fair. 17.50 7.58 2.661.16 Fair.

It may be noted as not a little interesting, how very near the proportion of fair days is to that of prevailing winds in the United States. In table 41, the fair days are within an insignificant fraction of 600 in a thousand, or six-tenths. The writer of this article for a long series of years pursued the profession of surveyor, which enforced observation on the weather, and has, in fact, been exposed to the vicissitude of open air, from Canada to Louisiana and Florida, which means of experience added to recent observation of others and his own, risks the conclusion, that in the year there are from 200 to 230 or 240 days, during which, man is relieved from annoyance by falling meteor.

The direct reverse is the case, and in very nearly the same proportions, on the Atlantic coast of Europe, as far south as Portugal, if not even to the coast of Africa. But the rains on the two sides of the Atlantic Ocean present other remarkable contrasts. By combining the results of tables XXXVII., XXXVIII. and XXXIX., the mean annual rains of the United States come out about 37 inches; whilst in table XL. the mean annual rains on north-western Europe, are only 31 inches. The mean annual rains of England according to Mr. Dalton, are 31 inches. From the whole element it appears, therefore, that on the United States, in from about 140 to 150 days there fall two-tenths more rain than falls on north-western Europe in from at the lowest term 180, and thence to 220 days.

The preceding extremes, great as they are, do not, however, represent the entire inequality in the times of an equal quantity of rain falling on the respective continents. Summer droughts so long, so severe, and so common, from the St. Lawrence to the West Indian seas, and it is true occasional on the coast of Europe, but, seasons without them are perhaps more rare on the western, than with them on the eastern shore of the Atlantic Ocean.

In brief, the climate of north-western Europe and that of the United States is alike, in the general and special course of the winds, but from the relative position of the two continents with the Atlantic Ocean, strongly contrasted in every other pheno

menon.

Deep and permanent snow is a strong feature in the climate of the United States, and uncertain as are the occurrence of meteorological changes, none other differ so much as does snow. Some winters pass with slight snow; indeed there are years in which almost none of that meteor of any consequence falls, whilst perhaps the ensuing year is remarkable for excessive falls of snow. Within the

last three years the snow storms have mostly come from the western points, and attended with high and steady winds which drifted the meteor excessively. This latter circumstance is amongst the revolutions in the meteorology of the United States, which must increase with the destruction of the forests. The deep and drifted snows often render the roads extremely difficult to pass, and contribute most powerfully to fill up and increase the masses of ice in rivers and canals. In fact rivers are frozen sooner and longer about in proportion to the excess of snow.

If the eye could be raised above, and powers of vision enlarged so much as to embrace the entire