IT IS generally admitted that European trees have rarely exceeded the very respectable age of 800 years. Thus, recent information gathered by the German Forestry Commission assigns to the pine 500 and 700 years as a maximum, 425 years to the silver fir, 275 years to the larch, 245 years to the red beech, 210 years to the aspen, 200 years to the birch, 170 years to the ash, 145 years to the alder, and 130 years to the elm. The heart of the oak begins to rot at about the age of 300 years. The holly oak alone escapes this law, and there is a specimen of this aged 410 years in existence near Afschafenburg in Germany.

At the Edinburgh Forestry Exhibition, four years ago, there were exhibited two transverse sections of a couple of Scotch firs One of these, which was 74 feet in diameter, was 217 years of age; the other, which was but 534 feet in diameter, was older, and exhibited 270 annual rings. A Sequoia gigantea felled in Calaveras County, California, measured 387 feet in height, 3 25 feet in diameter at the base, 15 feet at 125 feet above the earth, and had attained the age of 3,000 years. At Caphyoe (Arcadia) may be seen a plane tree which for a long time was regarded as the one that the historian Pausanias spoke of in the second century.

There is a cypress in the vicinity of Padua which is regarded as having been a contemporary of Julius Cæsar, and according to another and more plausible legend, it was against the trunk. of this tree that Francis I., seeing "all lost save honor," endeavored to break his sword. The oak of Swilcar Lawn in the forest of Needwood was still robust in 1822 at

the age of 600 years, and, at the same epoch, there might have been seen at Chupstead Place, County of Kent, a large elm, around which a fair was annually held during the reign of Henry V., in the fifteenth century.

The age of the Braburn yew, in this same county of Kent, was estimated by De Candolle to be 3,000 years, and he attributed the same age to another yew, that of Fortingal, in Scotland. The English historian Evelyn, in the seventeenth century, cited a linden of the environs of Neustadt (Wurtemberg) then aged more than 1,000 years.

At Hildesheim, in Hanover, there is a celebrated rose bush, the oldest in the world. Charlemagne himself planted it more than a thousand years ago in commemoration of the embassy received from the caliph of the Thousand and One Nights, Haroun, al Raschid. In 818 Louis le Debonnaire, son of Charlemagne, had a chapel constructed, the altar of which was placed over the roots of the rose bush. The stem of this dean of rose bushes is about 24 inches in diameter and 28 feet in height. The branches trained up against the apsis of the chapel cover a surface of 118 square feet. The plant annually bears a large number of flowers.

In addition to the celebrated linden of Morat in Switzerland, several specimens of this tree are cited as having reached a more advanced age. One may be seen not far from the church of Cadier in Keer, in the province of Limburg, whose trunk measures about 20 feet in circumference. It is said to have been planted by the Roman soldiers who were besieging the neighboring city of Attnatica, now Horstens. A violent storm broke off a portion of

its branches in 1868, and the debris amounted to six wagon loads. Some years later its top suffered greatly from a fire that consumed the houses in the vicinity; but, despite these two acci-. dents, the tree is still vigorous, and it shades a vast surface. There is to be seen also at Schwarzenberg, in Saxony, a linden whose trunk is 25 feet in circumference, and two others at Schneeberg, one 16 and the other 14 feet in circumference..

The oldest known 'conifer of Germany, a fir, has recently been felled at Grunnthal, Saxony. It measured 7 feet in diameter at 5 feet above the ground. The ancient acts and charters often mention tree's selected as boundaries of property. Thus, a chest nut tree of Fortworth, England, whose trunk is formed by the adhesion of two trees, figures upon a charter dated 1135. An oak still living at Tilford, near Farnham, is mentioned in a charter of Henry of Blois under the date of 1250. A hawthorn in the vicinity of Norfolk, long known as the Hethel thorn, is the old thorn spoken of in an act of 1200.

The Weekly Press, of Philadelphia,

recently gave some statistics as to the largest trees in the United States. Excluding the sequoias, it cites: An oak in Marion County, Florida, whose trunk measures 31 feet in circumference, with a spread of branches 138 feet in diameter; a sugar maple in Bradford County, Pennsylvania, 16 feet in circumference, with a branching of 85 feet in diameter; a chestnut tree in Lancaster County, Pennsylvania, 25 feet in diameter, and with a spread of branches 88 feet in diameter; a sassafras 46 feet in height and 13 feet in circumference at Johnsville, Pennsylvania; a sycamore 28 feet in diameter in Wabash County, Illinois; and an apple tree 112 years of age, still bearing fruit, at Boothby, Maine. The dean of trees of the Eastern United States, the Woodbridge oak, was felled a few years ago in the vicinity of Boston. Prof. Abbott, of New York, estimated its age as 2,000 years, and Prof. Eaton as from 1,500 to 2,000. During the war of independence, Lafayette's army, marching through Woodbridge, rested beneath the shade of this venerable tree.

ARE you acquainted with the Force family? No? Well, allow us to introduce them. They are older than any of the azure-blooded Bostonese, very much older than any family in New York's "Four Hundred," the two hundred and fifty millionaires who own half of Chicago are mushrooms in comparison, and, in sober truth, the world itself is younger than this ancient family.

Old Matter is their parent, and he rules his children with inflexible laws. They can never escape his control; and although they assume a great many varying forms, his tenacious hold on them is so complete and unyielding that he invariadly compels their most implicit obedience.

With some of the members of this family man has been familiar for all time. Motion, for instance, was man's

Light is, perhaps, the member of the family best beloved by man, and he has always been our friend and benefactor. Without him life would hold but little charm for most of us, and during his temporary absence we strive to drown consciousness in sleep.

Gravity is a member of this wonderful family, and was introduced to us by Newton. No one has seen him, however, and he is but little understood; yet his power is unmistakable and uniis unmistakable and universally recognized by science.

Electricity is as old as his brothers, and for twenty or thirty centuries we have been on speaking terms with him; but only within the past fifty years have we learned to utilize the acquaintance, and although we accept his friendly aid in a variety of ways, we can, even now, scarcely say that we know much about him..

These brothers of the Force family are a race of wounderful giants; whose size is co-extensive with the universe and whose age is coeval with creation's dawn.

There are not wanting philosophers who doubt whether there is more than one member in the Force family. They insinuate (and, so far, no one has been ingenious enough to prove the contrary) that heat, light, and electricity are one and the same thing, and that they are simply motion in various forms: That light is a mode of motion, manifested to us through the eye and that its propagation or propulsion in space is exceedingly rapid, being over eleven millions of miles a minute. When this rapid mo

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tion is partially checked, heat is the result, and thus heat is said to be a slower form of motion than light. Both light and heat can be converted into electric energy, and are constantly undergoing this conversion. Thus, they claim, light, heat, and electricity are the same thing, simply being manifested under different conditions. One philosopher has asserted that electric. force is simply motion rendered capable of doing work. This explains without explaining, it simply reiterates the statement that electricity and motion are the same thing under altered conditions.

When we apply heat to water in a closed receptacle, like a boiler, the water is gradually converted into steam, by the heat forcing apart the aqueous atoms. This expansive force acuates the engine, which in turn runs the dynamo. The dynamo has, therefore, utilized the original heat, and started what we will call a current of electricity upon any suitable conductor. But electricity in this shape will not drive our machines. Therefore we use an inverted dynamo, which we call a motor, to reconvert the electric current into motive force, and at once our machinery begins to move. Or we can interpose a storage battery between the dynamo and the motor, store up a stock of electric force therein, and draw from it as we need for mechanical or other purposes by simply moving a switch.

This storage of force is a phenomenon which has always been practiced by nature. When the intertropical, sun shines upon an expanse of water, myrids of little water bladders or spheres rise continually into the atmosphere, and gradually the air becomes completely saturated with them. The air currents convey this saturated

air toward the poles, until, meeting a cooler stratum, the atmosphere is suddenly compressed by cooling, when the water is squeezed out, is condensed into drops, becomes visible as cloud, and finally falls to the earth as rain. The heat that caused the evaporation is liberated upon condensation, is partly absorbed by the cold air that chilled the warmer stratum, and partly converted into electricity. Hence all the phenomena of a storm. The rain, falling upon elevated land, sinks by gravity to lower levels, and yields up the force that originally lifted it. If all the water that falls as rain at high levels could be there stored, and utilized to actuate sufficient turbines, it would do all the work needed by man; but only a very small portion of its work-power is or ever has been used.

Science calls this power that is latent in a store of high-level water, "energy of position," and the same term is applicable in any case where anything is elevated so that its fall could be made to do work. A man rides in an elevator to the upper story of a building, and, when there, goes to a window and deposits a stone upon the window-sill. Now this stone may not weigh a pound, and baby hands could push it from its resting place. But it possesses "energy of position," and should it be so pushed from the sill, it would kill a man on the street below if it fell upon his head, or it might split the stone side walk, or, falling upon a dynamite bomb, liberate another form of statical energy that might destroy the entire block of buildings.

Thus we see that energy of position can be converted into energy of motion, the power of which is governed by the velocity of the moving body. Electricity stored is like a weight elevated,

or a spring coiled, or a chemical composition capable of explosion, or confined steam, or a lump of coal. Each represents so much power, so much force, or the possibility of so much work. But to utilize that latent power, the force must be allowed to assume motion. Hence, every manifestation of force is but a mode of motion.

That motion is readily convertible into heat is a proposition that has been demonstrated in the experience of everyone. Who has not, when a boy,

rubbed a metal button on his coat sleeve until it became hot, and then applied it to some other boy's skin? Sir Humphrey Davy proved, by experiment, that two pieces of ice rubbed together would melt. Cannon balls, moving at high velocities, have been made red hot by striking an iron target.

Percussion and friction both convert motion into heat and electricity, which is absorbed and stored in the earth or air or surrounding objects, where they assume various conditions of force, such as molecular energy of position, magnetism, and statical electricity.

A curious hypothesis has been advanced with regard to the statical electricity of bodies, which is as yet awaiting confirmation or rejection. According to this hypothesis, neutral bodies are supposed to be more or less charged with positive and negative electricity in combination, and, when excited mechanically or chemically, this union is broken, and electrical separation is the result. The tendency to reunite which is inherent in these two currents is the cause of the energy of motion and other electrical pheno

mena.

Some idea, although in a very crude form, was entertained by the ancient philosophers as to the correlation of

force. That wise old man, Heraclitus, who taught at Ephesus 2,400 years ago, believed fire to be the "great cause," and that everything was in constant motion. Practically, this is a statement in full accord with the most advanced dynamic theory of our modern science.

Democritus, some half a century later, originated the atomic theory, which has since been so conclusively elaborated.

Aristotle asserted that light could not be a substance, but thought it an energy or action.

In recent days, the correlation of energy, the similarity of all force, the unity of all visible power in the one idea of motion, have been demonstrated almost beyond dispute. That all these forces of nature are interchangeable, that heat and light and electric phenomena are but the varying forms. in which the one great power manifests itself under different conditions, would seem to be an inevitable conclusion. That always motion, and never absolute rest, seems to be an eternal law that impels the whole of creation. That between the minute specks of organic life that defies any but the most powerful microscope to define it, and the majestic mountain. that towers above the Sierra, there is no physical difference save size, for each contains matter and is endowed with motion, and each obediently submits to the same immutable laws. Motion is a manifestation of force, and force is an attribute of matter, and

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both are eternal and indestructible— their form alone varying.

But while matter and force are indestructible, they are never at rest, and this incessant activity is preparing disaster for our solar system. For while our sun is constantly emitting light and heat, only a small portion of the force expanded can be intercepted by the planets. Hence there must be a constant drain upon the reserve force of the sun; and as we are unacquainted with any means by which the radiated energy can be restored to us, the conclusion is inevitable that a time must come when the manifestation of every form of force must cease, save, perhaps, attraction, cohesion, gravity, and the motion of its mass it its path through space.

Some scientists have pictured the condition of the world in that awful time, when, without light, there will be one unending night, subject to a cold so intense as to solidify not only the moisture but even the very air we breathe. With neither light nor heat, without air or water, the earth will roll on, a desolate waste, with no living thing upon its cheerless surface. Fortunately for humanity, however, millions of years must pass before that condition of things can overtake us; and as neither we nor any person in whom we have the remotest interest can possibly be affected by it, there is no necessity for us to feel any concern about the matter. "Sufficient unto the day is the evil thereof."