while the range above the mean in England is very small. It is the tropical element of our summers, then, that causes the grape, the corn, etc., to ripen, while England, with a higher mean temperature, is unable to mature them successfully. Ireland, where southern plants may remain out-doors, unfrosted, the whole winter, can not mature those fruits and grasses which ripen in Wisconsin. In England a depression of 2° below the mean of 60° will greatly reduce the quantity, or prevent the ripening of wheat altogether, 60° being essential to a good crop. Wheat, requiring a lower temperature than corn, is better adapted to the climate of Wisconsin. This grain may be grown as far north as Hudson bay.

Autumn, including September, October and November, is of short duration in Wisconsin. North of the 42d parallel, or the southern boundary line of the state, November belongs properly to the winter months, its mean temperature being about 32°. The decrease of heat from August to September is generally from 8° to 9°; 11° from September to October, and 14° from October to November. The average temperature for these three months is about 45°. A beautiful season, commonly known as Indian summer, frequently occurs in the latter part of October and in November. This period is characterized by a mild temperature and a hazy, calm atmosphere.. According to Loomis, this appears to be due to "an uncommonly tranquil condition of the atmosphere, during which the air becomes filled with dust and smoke arising from numerous fires, by which its transparency is greatly impaired." This phenomenon extends as far north as Lake Superior, but it is more conspicuous and protracted in Kansas and Missouri, and is not observed in the southern states.

Destructive frosts generally occur in September, and sometimes in August. "A. temperature of 36° to 40° at sunrise is usually attended with frosts destructive to vegetation, the position of the thermometer being usually such as to represent less than the actual refrigeration at the open surface." In 1875, during October, at Milwaukee, the mercury fell seven times below the freezing point, and twice below zero in November, the lowest being 14°.

The winters are generally long and severe, but occasionally mild and almost without snow. The mean winter temperature varies between 23° in the southeastern part of the state, and 16° at Ashland, in the northern. For this season the extremes are great. The line of 20° is of importance, as it marks the average temperature which is fatal to the growth of all the tender trees, such as the pear and the peach. In the winter of 1875 and 1876, the mean temperature for December, January and February, in the upper lake region, was about 4° above the average mean for many years, while during the previous winter the average temperature for January and February was about 12° below the mean for many years, showing a great difference between cold and mild winters. In the same winter, 1875-'76, at Milwaukee, the thermometer fell only six times below zero, the lowest being 12°, while during the preceding winter the mercury sank thirty-six times below zero, the lowest being 23°. In the northern and northwestern part of the state the temperature sometimes falls to the freezing point of mercury. During the exceptionally cold Winter of 1872-3, at La Crosse, the thermometer sank nearly fifty times below zero; on December 24, it indicated 37° below, and on January 18, 43° below zero, averaging about 12° below the usual mean for those months. The moderating effect of Lake Michigan can be seen by observing how the lines indicating the mean winter temperature curve northward as they approach the lake. Milwaukee, Sheboygan, Manitowoc, Two Rivers, and the Grand Traverse region of Michigan, have the same average winter temperature. The same is true regarding Galena, Ill., Beloit, and Kewaunee. A similar influence is noticed in all parts of the state. Lapham concludes that this is not wholly due to the presence of Lake Michigan, but that the mountain range which extends from a little west of Lake Superior to the coast of Labrador (from 1,100 to 2,240 feet high) protects the lake region in no inconsiderable degree from the excessive cold of winter.

Dr.

According to the same authority, the time at which the Milwaukee river was closed wi h ice, for a period of nine years, varied between November 15 and December 1; the time at which it became free from ice, between March 3 and April 13. In the lake district, snow and rain are interspersed through all the winter months, rain being sometimes as profuse as at any other season. In the northwestern part the winter is more rigid and dry. Northern New York and the New England states usually have snow lying on the ground the whole winter, but in the southern lake district it rarely remains so long. In 1842-43, however, sleighing commenced about the middle of November, and lasted till about the same time in April-five months.

The average temperature for the three months of spring, March, April and May, from Walworth county to St. Paul, is about 45°. In central Wisconsin the mean for March is about 27°, which is an increase of nearly 7° from February. The lowest temperature of this month in

In 1876

1876 was 40° above zero. April shows an average increase of about 9o over March. the line of 45° for this month passed from LaCrosse to Evanston, Ill., touching Lake Erie at Toledo, showing that the interior west of Lake Michigan is warmer than the lake region. The change from winter to spring is more sudden in the interior than in the vicinity of the lakes. "In the town of Lisbon, fifteen miles from Lake Michigan," says Dr. Lapham, "early spring flowers show themselves about ten days earlier than on the lake. In spring vegetation, in places remote from the lakes, shoots up in a very short time, and flowers show their petals, while on the lake shore the cool air retards them and brings them more gradually into existence." The increase from April to May is about 15°. In May, 1876, Pembina and Milwaukee had nearly the same mean temperature, about 55°.

The extremes of our climate and the sudden changes of temperature no doubt have a marked influence, both physically and mentally, on the American people. And though a more equable climate may be more conducive to perfect health, the great range of our climate from arctic to tropical, and the consequent variety and abundance of vegetable products, combine to make the Mississippi valley perhaps one of the most favorable areas in the world for the development of a strong and wealthy nation.

During the months of summer, in the interior of the eastern United States, at least threefourths of the rain-fall is in showers usually accompanied by electrical discharges and limited to small areas. But in autumn, winter, and spring nearly the whole precipitation takes place in general storms extending over areas of 300, 500 and sometimes over 1,000 miles in diameter, and generally lasting two or three days. An area of low atmospheric pressure causes the wind to blow toward that area from all sides, and when the depression is sudden and great, it is accompanied by much rain or snow. On account of the earth's rotation, the wind blowing toward this region. of low pressure is deflected to the right, causing the air to circulate around the center with a motion spirally inward. In our latitude the storm commences with east winds. When the storm center, or area of lowest barometer, is to the south of us, the wind gradually veers, as the storm passes from west to east with the upper current, round to the northwest by the north point. On the south side of the storm center, the wind veers from southeast to southwest, by the south point. The phenomena attending such a storm when we are in or near the part of its center are usually as follows: After the sky has become overcast with clouds, the wind from the northeast generally begins to rise and blows in the opposing direction to the march of the storm. The clouds which are now moving over us, discharge rain or snow according to circumstances. The barometer continues to fall, and the rain or snow is brought obliquely down from the northern quarter by the prevailing wind. After a while the wind changes slightly in direction and then ceases. The thermometer rises and the barometer has reached its lowest point. This is the center of the storm. After the calm the wind has changed its direction to northwest or west. The

wind blows again, usually more violently than before, accompanied by rain or snow, which is now generally of short duration. The sky clears, and the storm is suddenly succeeded by a temperature 10 or 20 degrees below the mean. Most of the rain and snow falls with the east winds, or before the center passes a given point. The path of these storms is from west to east, or nearly so, and only seldom in other directions. These autumn, winter, and spring rains are generally first noticed on the western plains, but may originate at any point along their path, and move eastward with an average velocity of about 20 miles an hour in summer and 30 miles in winter, but sometimes attaining a velocity of over 50 miles, doing great damage on the lakes. In predicting these storms, the signal service of the army is of incalculable practical benefit, as well as in collecting data for scientific conclusions.

A subject of the greatest importance to every inhabitant of Wisconsin is the influence of forests on climate and the effects of disrobing a county of its trees. The general influence of forests in modifying the extremes of temperature, retarding evaporation and the increased humidity of the air, has already been mentioned. That clearing the land of trees increases the temperature of the ground in summer, is so readily noticed that it is scarcely necessary to mention it; while in winter the sensible cold is never so extreme in woods as on an open surface exposed to the full force of the winds. "The lumbermen in Canada and the northern United States labor in the woods without inconvenience, when the mercury stands many degrees below zero, while in the open grounds, with only a moderate breeze, the same temperature is almost insupportable." "In the state of Michigan it has been found that the winters have greatly increased in severity within the last forty years, and that this increased severity seems to move along even-paced with the destruction of the forests. Thirty years ago the peach was one of the most abundant fruits of that State; at that time frost, injurious to corn at any time from May to October, was a thing unknown. Now the peach is an uncertain crop, and frost often injures the corn." The precise influence of forests on temperature may not at present admit of definite solution, yet the mechanical screen which they furnish to the soil often far to the leeward of them, is sufficiently established, and this alone is enough to encourage extensive planting wherever this protection is wanting.

With regard to the quantity of rain-fall, "we can not positively affirm that the total annual quantity of rain is even locally diminished or increased by the destruction of the woods, though both theoretical considerations and the balance of testimony strongly favor the opinion that more rain falls in wooded than in open countries. One important conclusion, at least, upon the meteorological influence of forests is certain and undisputed: the proposition, namely, that, within their own limits, and near their own borders, they maintain a more uniform degree of humidity in the atmosphere than is observed in cleared grounds. Scarcely less can it be questioned that they tend to promote the frequency of showers, and, if they do not augment the amount of precipitation, they probably equalize its distribution through the different seasons."

There is abundant and undoubted evidence that the amount of water existing on the surface in lakes and rivers, in many parts of the world, is constantly diminishing. In Germany, observations of the Rhine, Oder, Danube, and the Elbe, in the latter case going back for a period of 142 years, demonstrate beyond doubt, that each of these rivers has much decreased in volume, and there is reason to fear that they will eventually disappear from the list of navigable rivers.

"The 'Blue-Grass region of Kentucky, once the pride of the West, has now districts of such barren and arid nature that their stock farmers are moving toward the Cumberland mountains, because the creeks and old springs dried up, and their wells became too low to furnish water for their cattle." In our own state "such has been the change in the flow of the Milwau

kee river, even while the area from which it receives its supply is but partially cleared, that the proprietors of most of the mills and factories have found it necessary to resort to the use of steam, at a largely increased yearly cost, to supply the deficiency of water-power in dry seasons of the year." "What has happened to the Milwaukee river, has happened to all the other water courses in the state from whose banks the forest has been removed; and many farmers who selected land uqon which there was a living brook of clear, pure water, now find these brooks dried up during a considerable portion of the year."

Districts stripped of their forest are said to be more exposed than before to loss of harvests, to droughts and frost. "Hurricanes, before unknown, sweep unopposed over the regions thus denuded, carrying terror and devastation in their track." Parts of Asia Minor, North Africa, and other countries bordering on the Mediterranean, now almost deserts, were once densely populated and the granaries of the world. And there is good reason to believe "that it is the destruction of the forests which has produced this devastation." From such facts Wisconsin, already largely robbed of its forests, should take warning before it is too late.

TREES, SHRUBS AND

By P. R. HOY, M.D.

VINES.

It is not the purpose of this article to give a botanical description, but merely brief notes on the economical value of the woods, and the fitness of the various indigenous trees, shrubs and vines for the purpose of ornament, to be found in Wisconsin.

WHITE OAK-Quercus Alba.-This noble tree is the largest and most important of the American oaks. The excellent properties of the wood render it eminently valuable for a great variety of uses. Wherever strength and durability are required, the white oak stands in the first rank. It is employed in making wagons, coaches and sleds; staves and hoops of the best quality for barrels and casks are obtained from this tree; it is extensively used in architecture, shipbuilding, etc.; vast quantities are used for fencing; the bark is employed in tanning. The domestic consumption of this tree is so great that it is of the first importance to preserve the young trees wherever it is practicable, and to make young plantations where the tree is not found. The white oak is a graceful, ornamental tree, and worthy of particular attention as such; found abundantly in most of the timbered districts.

BURR OAK-Q. Macrocarpa.-This is perhaps the most ornamental of our oaks. Nothing can exceed the graceful beauty of these trees, when not crowded or cramped in their growth, but left free to follow the laws of their development. Who has not admired these trees in our extensive burr oak openings? The large leaves are a dark green above and a bright silvery white beneath, which gives the tree a singularly fine appearance when agitated by the wind. The wood is tough, close-grained, and more durable than the white oak, especially when exposed to frequent changes of moisture and drying; did the tree grow to the same size, it would be preferred for most uses. Abundant, and richly worthy of cultivation, both for utility and ornament.

SWAMP WHITE OAK-Q. Bicolor.-Is a valuable and ornamental tree, not quite so large or as common as the burr oak. The wood is close-grained, durable, splits freely, and is well worthy of cultivation in wet, swampy grounds, where it will thrive.

POST OAK-Q. Obtusiloba.—Is a scraggy, small tree, found sparingly in this state. The timber is durable, and makes good fuel. Not worthy of cultivation.

SWAMP CHESTNUT OAK-Q. Prinus.—This species of chestnut oak is a large, gracefuι tree, wood rather open-grained, yet valuable for most purposes to which the oaks are applied; makes the best fuel of any of this family. A rare tree, found at Janesville and Brown's lake, near Burlington. Worthy of cultivation.

RED OAK-Q. Rubra.-The red oak is a well-known, common, large tree. The wood is coarse-grained, and the least durable of the oaks, nearly worthless for fuel, and scarcely worthy of cultivation, even for ornament.

PIN OAK-Q. Palustris.-This is one of the most common trees in many sections of the state. The wood is of little value except for fuel. The tree is quite ornamental, and should be sparingly cultivated for this purpose.

SHINGLE OAK-Q. Imbricaria.—Is a tree of medium size, found sparingly as far north as Wisconsin. It is ornamental, and the wood is used for shingles and staves.

SCARLET OAK-Q. Coccinea.-This is an ornamental tree, especially in autumn, when its leaves turn scarlet, hence the name. Wood of little value; common.

SUGAR MAPLE—Acer Saccharium.—This well-known and noble tree is found growing abundantly in many sections of the state. The wood is close-grained and susceptible of a beautiful polish, which renders it valuable for many kinds of furniture, more especially the varieties known as bird's-eye and curled maples. The wood lacks the durability of the oak; consequently is not valuable for purposes where it will be exposed to the weather. For fuel it ranks next to hickory, The sugar manufactured from this tree affords no inconsiderable resource for the comfort and even wealth of many sections of the northern states, especially those newly settled, where it would be difficult and expensive to procure their supply from a distance. As an ornamental tree it stands almost at the head of the catalogue. The foliage is beautiful, compact, and free from the attacks of insects. It puts forth its yellow blossoms early, and in the autumn the leaves change in color and show the most beautiful tints of red and yellow long before they fall. Worthy of especial attention for fuel and ornament, and well adapted to street-planting.

RED MAPLE—A. Rubrum.—Is another fine maple of more rapid growth than the foregoing species. With wood rather lighter, but quite as valuable for cabinet-work for fuel not quite so good. The young trees bear transplanting even better than other maples. Though highly ornamental, this tree hardly equals the first-named species. It puts forth, in early spring, its scarlet blossoms before a leaf has yet appeared. Well adapted to street-planting.

MOUNTAIN MAPLE-A. Spicatum.-Is a small branching tree, or rather shrub, found growing in clumps. Not worthy of much attention.

SILVER MAPLE-A. Dasycarpum.—-This is a common tree growing on the banks of streams, especially in the western part of the state, grown largely for ornament, yet for the purpose it is the least valuable of the maples. The branches are long and straggling, and so brittle that they are liable to be injured by winds.

Box MAPLE-Negundo Aceroides.—This tree is frequently called box elder. It is of a rapid growth and quite ornamental. The wood is not much used in the arts, but is good fuel. Should be cultivated. It grows on Sugar and Rock rivers.

WHITE ELM-Ulmus Americana.-This large and graceful tree stands confessedly at the head of the list of ornamental deciduous trees. Its wide-spreading branches and long, pendulous branchlets form a beautiful and conspicuous head. It grows rapidly, is free from disease

and the destructive attacks of insects, will thrive on most soils, and for planting along streets, in public grounds or lawns, is unsurpassed by any American tree. The wood is but little used in the arts; makes good firewood; should be planted along all the roads and streets, near every dwelling, and on all public grounds.