Popular Science Monthly/Volume 41/May 1892/Popular Miscellany

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POPULAR MISCELLANY.

Origin of Greenland Vegetation.—Some interesting conclusions are drawn by Mr. Clement Reid from a comparison of the views of Prof. Warming and Prof. Nathorst concerning the origin of the flora of Greenland. Prof. Warming fixes the boundary between the European and American provinces of the arctic flora as in Denmark Strait, and not in Davis Strait, as botanists have generally placed it. The flowering plants of Greenland include three hundred and eighty-six species, none of which are confined to that country. Of these, excluding the circumpolar forms, Prof. Warming finds in the list thirty-six characteristic Western against forty-two Eastern species; but suggests that as the flora of arctic America is better known, the balance will probably be in favor of the Western forms. He, however, includes among the Eastern plants only those now living in Europe, while he classes the Asiatic-American species as Western. Prof. Nathorst reviews these conclusions on the basis of a map of the local distribution of Eastern and Western forms in Greenland. He thus finds that the coast nearest to Iceland contains European forms alone, the southern coast contains European forms in a majority, and that part of the west coast nearest to America yields principally Western species; but taking Greenland as a whole the flora is more European than American. He also finds that the American element of the flora of Greenland is not entirely cut off by the Denmark Strait, but extends eastward as far as Iceland. Prof. Warming believes that the nucleus of the present flora of Greenland represents part of the original flora which was able to live through the Glacial epoch on the non-glaciated areas; but Prof. Nathorst shows that the few non-glaciated mountain-tops must have been far too high for any phanerogams to exist on them, and all the lowlands were then covered with ice and snow. Both the Eastern and Western elements of the present flora of Greenland must, therefore, be supposed to have entered the country in post-glacial times. The tables of distribution show at what points a large number of the plants entered; they came from the nearest land, whether European or American. The ice-foot, which collects in winter beneath the sea-cliffs, is placed in the best possible position to receive any seeds or masses of soil which may fall during the winter. This shore-ice is drifted away in the spring, and may easily discharge its burden on some far distant shore uninjured, and with the seeds just ready to germinate. Winds, migrating birds, and migrating mammals, would all help to transport seeds across the straits.

 

Early Title-pages.—In the earliest printed books and in manuscripts any information on the workmanship of the book was written at the end, in what is called the colophon. It was not till 1470, according to Mr. A. W. Follard, in his History of the Title-page, that a title-page was introduced, and in England not till shortly before 1490, when W. de Machline issued one to his little book on the pestilence. Caxton never used them, but Wynkyn de Worde employed them in nearly all his books. At the beginning of the next century are found the most interesting, if not the most artistic, titles. Popular demand then required a large woodcut on the front page, whatever was the subject of the book. Even school-books were adorned with representations of masters and scholars, the most striking object in the cut being a formidably large birch. The nature of most of the religious books required a frontispiece containing devils. The little books of poetry and romance which issued from the press by hundreds contain the best specimens of this kind of art. Looking at these title-pages from the artistic side alone, England makes but a poor show against France and Italy. Nothing could be finer than the title-pages of the Parisian books in the early part of the sixteenth century. After this time the decadence began, and the printers finally became "dreadfully utilitarian and unromantic."

 

The Primary Color of Leaves.—Having concluded, as has already been mentioned in the Monthly, that the primary color of flowers is white, from which the characteristic hue is developed as a secondary color, E. Williams Hervey asks, in Garden and Forest, What is the primary color of the green parts of the plant? Leaves do not generally have a different color at the base from the usual one, as has been shown to be the case with flowers; and they rarely, except in the purplish leaves of vigorous saplings and a few cultivated plants, have any other color than green. But the leaves of some cultivated plants are spotted, striped, or bordered with white; bleached celery stalks are white, and the inner leaves of cabbages are white. From these instances "we get pretty strong hints that green is derived from white. There remains one more clew. Every botanist knows that the seed contains a miniature and rudimentary plant; that generally the most prominent parts of the seed are the cotyledons or seed leaves, and these are, of course, the first leaves of every species of plants. Now, if we ascertain the color of these seed-leaves, we find the original color of all leaves. This color is uniformly white; ... of course, we do not refer to the colored integument of the seed, which, as in the case of garden leaves, may be white, red, yellow, blue, black, or of mixed colors, but to the kernel, or meat. There are a very few instances only where the green color has impressed, somewhat, that characteristic upon the seed, as in peas, nasturtiums, and maples, which present a pale-green color in the pod or shell. In some instances these cotyledons appear above the surface of the ground, changing from white to green; while in others they remain below." We learn from this study of color, therefore, the author adds, "that white is the primary color of root, stem, and flower, and the foundation of all color."

 

A New Electric Light.—A vast improvement in artificial illumination is promised in the light which Mr. Tesla, "the able lieutenant of Mr. Edison," has been exhibiting in London. An experiment performed by him before the Royal Institution consists, according to the Spectator's account, in joining two sheets of tin-foil, one over the lecturer's head, the other on the table, to the poles of the generator. The space between these two sheets immediately became electrified, and a long vacuum-tube waved about in it, without attachment to any conductor, glowed in the darkness like a flaming sword. The experiment was intended to illustrate the possibility of rendering an entire room so electric, by plates in the ceiling or under the floor, that vacuum-bulbs placed anywhere within it would yield a light. Thus we shall be able to fill our rooms with the potentiality of light, and then, by the simple introduction of vacuum-tubes, to obtain any quantity of it. Those who want a daylight without heat will be able to run a vacuum-tube round the whole length of the cornice, and so obtain a diffused illumination of almost any brilliancy. The fact is noticed, in connection with the experiments, that the lecturer stood in an "electrostatic field" capable of illuminating a lamp without wires, and felt nothing. More, he held a vacuum-tube in one hand and touched a "terminal" with the other, a process which made him "the channel for a current of something like fifty thousand volts," and yet did not receive any injury.

 

Venerable Trees.—A very interesting work is in course of publication by M. Gadeau de Kerville, on the ancient trees of Normandy. The most remarkable trees so far described are the two yews of La Haye de Koutot, in the department of the Eure. They are respectively 91/2 and 81/4 metres in circumference at the base of the trunk, and 171/2 and 141/2 metres high. Their ages are estimated by the author to be not less than fifteen hundred years. A chapel has been constructed in the hollow trunk of one of these yews, three metres high and two metres deep. Before it was transformed into a chapel the hollow would hold forty persons, and eight musicians have played in it in concert. The beech of Montigny, estimated by the author to be between six hundred and nine hundred years old, is 18 metres high and 8·20 metres in circumference at the base. There are oaks from two hundred to nine hundred years old, one of which is nearly forty metres high.

 

Curious Effects of an Earthquake.—Some striking features are described by Prof. John Milne as marking the recent destructive earthquake in Japan, by which nearly 8,000 persons were killed and at least 41,000 houses were leveled. The movements of the wave were horizontal, and a defect of the seismograph was noticed in its failure to record anything of them except the "dip." In many places so-called "foreign" buildings of brick and stone fell in heaps of ruin between Japanese buildings yet standing. "Cotton-mills have fallen in, while their tall brick chimneys have been whipped off at about half their height. Huge cast-iron columns, which, unlike chimneys, are uniform in section, acting as piers for railway bridges, have been cut in two near their base. In some instances these have been snapped into pieces much as we might snap a carrot, and the fragments thrown down upon the shingle beaches of the rivers. The greatest efforts appear to have been exerted where masonry piers carrying two-hundred-foot girders over lengths of eighteen hundred feet have been cut in two, and then danced and twisted over their solid foundations to a considerable distance from their true positions. These piers have a sectional area of twenty-six by ten feet, and are from thirty to fifty feet in height. Embankments have been spread outward or shot away, brick arches have fallen between their abutments, while the railway line itself has been bent into a series of snakelike folds and hummocked into waves. . . . Here and there a temple has escaped destruction, partly perhaps on account of the quality of materials employed in its construction, but also in consequence of the multiplicity of joints which come between the roof and the supporting columns. At these joints there has been a basket-like yielding, and the interstice of the roof has not, therefore, acted with its whole force in tending to rupture its supports."

 

Meteorology Five Centuries ago.—What is probably the oldest journal of the weather in existence has recently been recovered, printed in photographic transcript, and translated. It was kept by the Rev. William Merle, rector of Driby, Lincolnshire, England, from 1337 to 1344, or during seven years of the earlier part of the reign of Edward III. The author was evidently a keen observer, and recorded his facts succinctly and intelligently, so as to give a graphic, even picturesque description of the weather by the week or month; and a reference in one of his notes to a feature of the season of 1331 shows that he had been watching the changes of the seasons for a longer time than was covered by his journal. Some of the entries are suggestive of the conditions and ways of thinking of the times. The frequent mention of weather conditions and phenomena in other parts of the kingdom indicates that there were other observers in England who corresponded with Merle. A comet was seen in the second week of September, 1343, appearing about sunset. Our author called it "ardens draco," or burning dragon, but did not seem terrified by it. He merely remarked that it was a sign of dry weather. In the same year, on the 28th of March, is entered a notice of an earthquake so violent that the stones of the chimneys in certain parts of Lindsey were thrown down. The motion lasted while one might say the angelic salutation, which was about half as long then as it is now. The mention of stones falling in the stone chimneys "lapides in caminis lapideis" is interesting, as it proves the fallacy of the belief that chimneys are a late invention, and that the English of those times were so barbarous that the smoke was got rid of by means of a hole in the roof. The recovery of the journal is due to a mention of it by Dr. Plot, of the Royal Society, in 1685, as being in the Bodleian Library. It was looked for and found.

 

Drops of Fog.—Advantage was taken by Mr. John Aitken, during a visit to the Righi, of the opportunities that were afforded there for investigating the water particles in clouds. With an instrument the author has invented those particles were distinctly seen showering down, and the number falling on the micrometer was easily counted. The number was observed to vary greatly from time to time. The greatest rate actually counted was sixty drops per square millimetre in thirty seconds, but for a few seconds the rate was much quicker. The maximum rate named gives twelve thousand drops per square centimetre per minute, or seventy-seven thousand four hundred drops per square inch per minute. The drops are so extremely small that they rapidly evaporate, more than two or three being seldom visible at the same time on one square of the micrometer. The denser the cloud the quicker was the rate of fall, and as the cloud thinned away the drops fell at longer intervals, and they diminished in size at the same time. It was frequently observed when the mountain-top was in clouds, particularly if they were not very dense overhead, that the surfaces of all exposed objects were dry—not only the stones on the ground, which might have received heat from the earth, but also wooden seats, posts, etc.—and if wetted they soon dried. And while everything was dry, the fog-counter showed that fine rain-drops were falling in immense numbers, and the air, on testing, was found to be saturated. A few observations were therefore made to explain the apparent contradiction of surfaces remaining dry while exposed to a continued shower of fine rain and surrounded by saturated air. The explanation was found to be, simply, radiant heat. A considerable amount of heat, as also of light, was found to penetrate the clouds, notwithstanding their density. This radiant heat is absorbed by all exposed surfaces and heats them, while they in turn heat the air in contact with them, and the fine drops of water are either evaporated in this hot layer of air or after they come in contact with the heated surfaces. Other observations made on Mount Pilatus pointed to the same conclusion. All large objects, such as seats, posts, etc., were dry in cloud when there was any radiation; while small objects, such as pins, fine threads, etc., were covered with beads of water. The large surfaces being more heated by radiation than small ones, when surrounded by air, these surfaces evaporate the drops falling on them, while the small ones, being kept cool by the passing air, are unable to keep themselves free. The observations made with the fog-counter point to the conclusion that the density or thickness of a cloud depends more on the number of water particles than on the number of dust particles in it.

 

Mortality and Morbidity by Professions.—M. Jacques Bertillon recently communicated to the French Society of Public Medicine a table of mortality by professions, compiled from official documents of the city of Paris from 1885 to 1889. This is the first table of the kind that has been made in France. Other tables have been made in England by Mr. William Farr and by Mr. Ogle, compiled from the returns of census years, and in Switzerland by M. Kummer for the years 1879 to 1882. On a comparison of the results of these four tables, made with special reference to the relative number for each profession, and taking the general average of each country observed, the author has found that the same professions give nearly the same results in the three countries. When, however, we compare these results with the tables of morbidity or liability to disease by professions, drawn up by M. Bodio, from the observations of the Italian societies of mutual aid, we find them at times apparently contradictory. This confirms the principle that in the existing condition of things a table of morbidity is not of as much value as a table of mortality as a means of determining the sanitary condition of a population. This arises from the fact that it is a very delicate matter to distinguish a disease from a simple indisposition, as well as to distinguish an acute from a chronic disease, and the latter, again, from an infirmity.

 

Meteoric Iron.—Native meteoric nickel iron, according to Prof. Ledebur, of Freiberg, is too costly to be available for practical use. The market prices are about 6c?. per gramme for ordinary qualities, and from 1s. 6d. to 2s. 6d. per gramme for the rarer qualities, and from 17s. to 26s. per gramme for iron the fall of which has been observed. Still it is not extremely rare, at least not in museums. The museum at Vienna has 1,033 kilogrammes of it, of specimens that were found in 145 different places; the collection of the University of Berlin is rich in specimens; the Natural History Museum at Paris has a considerable quantity of it; and the British Museum has 3,600 kilogrammes in a single block. The largest piece in any collection is one weighing 5,000 kilogrammes, from Bemdego, Bahia, in the museum at Rio de Janeiro. It is believed to be a fragment of a meteor of 9,000 kilogrammes which was discovered in 1784. A mass described by Humboldt was estimated to weigh from 15,000 to 20,000 kilogrammes. Evidence is adduced by Herr Otto Vogel, of Dusseldorf, to show that meteoric or nickel iron is found over most of the world, and has been worked to the most recent times; and that it was also worked and used in the middle ages and in a remote antiquity. The negroes on the Senegal River were found working it by Buchner; the Namaquas of South Africa made weapons from it; and the Indians of Islahuaca manufactured agricultural implements and other tools from it as early as 1784. Captain Ross, in 1819, found the Eskimos of Greenland using meteoric iron in making lines and other tools; and there is a knife-blade of this iron in the Natural History Museum at Vienna, where is also preserved an arrow-head of it from Madagascar. The author suggests that it may easily be assumed that the first iron that was ever wrought was cosmic iron—that is to say, an iron derived from another world. "On such foundlings," says Mehrtens, "the uncultured inhabitants of our earth may first have tried their skill out of curiosity, and perhaps by chance have discovered the properties of iron."

 

The Power of Assertion.—A political article in a recent number of The Spectator is prefaced by some general remarks on the power that mere assertion exerts. The majority of persons, whether of high or low degree, have little inclination or opportunity for verifying statements. Hence an assertion that is made strongly and circumstantially enough passes with these persons for solid fact. The task of exposing and rebutting a misstatement is almost a waste of labor. In political affairs, especially, there is very little to lose and a great deal to gain in making reckless statements. Even if clearly disproved, no damaging blame attaches to the politician who makes them. He, if adroit (and the politician who is not has missed his calling), will not be found to have perpetrated an absolute falsehood. There are always plenty of political rumors afloat, and one of these can be easily dressed up and given out as "a matter of common knowledge," or "what everybody is saying, you know." The success of such devices shows that mankind has not yet outgrown its pristine credulity.

 

Instinctive Criminality.—In a paper on instinctive criminality, Dr. S. A. K. Strahan holds that the criminal belongs to a decaying race, and is only found in families whose other members show signs of degradation; in fact, it is only one of the many signs of family decay. Besides being hereditary, criminality is interchangeable with other degenerate conditions, such as idiocy, epilepsy, suicide, insanity, scrofula, etc.; and it is a chance whether the insanity or drunkenness, say, of the parent, will appear as such in the child or be transmuted in transmission to one or other of the alternate degenerate conditions. The present system of treatment has proved a disastrous failure; short periods of punishment can have no effect, either curative or deterrent. Everything points in the direction of prolonged or indefinite confinement in industrial penitentiaries.

 

Oscillations in Latitude.—At the recent anniversary meeting of the Royal Society, the president, Sir William Thomson, spoke of the investigation of oscillations of latitude which has been instituted under the auspices of the International Geodetic Union. Comparative observations have been begun at Berlin, and at Honolulu, which is very near the opposite meridian to Berlin. The first several hundred determinations of latitude made at Honolulu during three months of a proposed year of observations, compared with the corresponding results at Berlin, showed that the latitude during that time had increased in Berlin and decreased at Honolulu by about one third of a second. "Thus we have decisive demonstration that motion, relatively to the earth, of the earth's instantaneous axis of rotation, is the cause of variations of latitude which have been observed at Berlin, Greenwich, and other observatories, and which can not be wholly attributed to errors of observation." This, Prof. Foerster remarks, gives observational proof of a conclusion which the author had expressed in 1876, to the effect that irregular movements of the earth's axis to the extent of half a second may be produced by the temporary changes of sea-level due to meteorological causes. It is proposed that four permanent stations for regular and continued observation of latitude at places of approximately equal latitude and on meridians approximately 90° apart, be established under the auspices of the International Geodetic Union. The reason for this arrangement is, that a change in the instantaneous axis of rotation in the direction perpendicular to the meridainof any one place would not alter its latitude, but would alter the latitude of a place 90° from it in longitude by an amount equal to the angular change of the position of the axis. Thus two stations in meridians differing by 90° would theoretically suffice, by observations of latitude, to determine the changes in the position of the instantaneous axis; but differential results, such as those already obtained between Berlin and Honolulu, differing by approximately 180° in longitude, are necessary for eliminating errors of observation sufficiently to give satisfactory and useful results.

 

Swedish Wood and Iron.—According to our minister in Stockholm, the two great products of Sweden after agriculture are wood and iron. The Norland is still covered for the most part with an extensive black forest, consisting largely of pine and spruce. Upon the great water-shed called the fjeld or Kölen (the keel of the country likened to a boat turned bottom upward) stand the chief timber forests; and extensive lumbering operations are carried on along the numerous rivers and their tributaries that flow thence. At the mouths of most of the rivers are towns which take their names as well as their business and prosperity from the streams where are large saw-mills. Lumber operations are also conducted south of Stockholm on both coasts, and there is a considerable export from Gothenburg; but the great bulk of the timber is cut and sawn in Norland, and eighty-five per cent of the lumber exports come from the north of Stockholm. The Swedish lumber trade has assumed its present importance only within the present century, and in fact during the past thirty years. More than one quarter of the wooded area of Sweden, or 14,300,000 acres, belongs to the crown. The forests are supervised with great care, and all Sweden is divided into forest districts, and these, in turn, into revirs. Each district is under the supervision of a chief forest inspector, and each revir is guarded by a forest ranger and a number of under-keepers. Our minister thinks that the vast forests of Sweden will be preserved and maintained substantially as they stand to-day, and that Sweden's lumber export her greatest source of revenue will be maintained and kept good for ages to come. The Swedish iron, celebrated throughout the world, is soft and ductile, and preserves great pliability and strength. It still furnishes the raw material for the best tools and weapons, the finest springs and drawn wire, and the best kind of nails for riveting and clinching. Its excellence depends partly on its being free from phosphorus and sulphur, and partly on the superior manner of the smelting, which is done with charcoal. The supply of ore is practically inexhaustible. It is found all over the country; it occurs in the thick strata of the rock and forms the bulk of great mountains in various parts of the kingdom. The largest of these iron mountains is Gellivare, situated in Swedish Lapland, beyond the Arctic Circle. The ore occurs here chiefly in four gigantic strata, and covers so large an area that it is estimated that, if only one metre in depth is taken out a year, the yield would be 943,600 tons, nearly equal to the amount now produced by all the mines in Sweden. The ore contains seventy per cent of iron. Much of it, however, contains apatite, and in such large quantities that the question of turning to account the phosphoric acid held in that mineral is entertained. Iron is chiefly mined in central Sweden, but the best iron comes from the Dannemora mines, a little east of the chief area. Besides making the rougher forms of iron, the Swedes build iron steamships of fine quality, and are very skillful in the manufacture of cutlery, for which they have a dozen factories.

 

Suspended Matter in Flame.—In a communication to the Royal Society of Edinburgh, Mr. G. C. Stokes announces that he has secured an optical proof of the existence of suspended matter in flames. Passing a beam of sunlight, condensed by a lens, through the flame of a candle, he noticed that where the cone of rays cut the luminous envelope there were two patches of light brighter than the general flame, which were evidently due to sunlight scattered by matter in the envelope which was in a state of suspension. The patches corresponded in area to the intersection of the double cone by the envelope, and their thickness was insensibly small. Within the envelope, as well as outside, there was none of this scattering. When the beam was passed through the blue base of the flame, there was no scattered light. A luminous gasflame showed the patches indicating scattered light like the flame of a candle, but less copiously. They were not seen in a Bunsen flame or in the flame of alcohol, but were well seen in the luminous flame of ether. The phenomenon shows the separation of carbon, associated, it may be, with some hydrogen, in the flame, and the extreme thinness of the layer which this forms. It shows, too, the mode of separation of the carbon namely, that it is due to the action of heat on the volatile hydrocarbon or vapor of ether, as the case may be. At the base, where there is a plentiful supply of oxygen, the molecules are burned at once. Higher up, the heated products of combustion have time to decompose the combustible vapor before it gets oxygen enough to burn it. Since making his communication, Prof. Stokes has found that he was anticipated in part of his observation in a paper published a few years ago by Mr. Busch.

 

The Vlachs of Turkey.—The Vlachs of Turkey are described by Mrs. L. M. J. Garnett, in her Women of Turkey and their Folk Lore, as a nomadic people, shepherds or traders, who leave a great deal of responsibility to their wives. The women, besides managing their households, have to cultivate the vineyard and garden, herd the sheep, shear the wool, weave the cloth, and generally perform every variety of labor, "not the least arduous part of which is the assiduous attention required by their lords and masters when they return from their wanderings for a spell of domestic repose." The customs of this people are a mixture of Greek and Roman tradition. They belong to the Orthodox Church, and their ceremonies at birth and baptism are essentially similar to those of the Greeks. The marriage forms (save the sacred rite) are more like the Roman. These ceremonies are very minute and protracted; and "it must require a liberal education to master all the details of a Vlach or Greek wedding: to find the five-twigged branch and decorate it with an apple and tufts of red wool and fix it on the top of the bride's house; to prepare the ring-cake and then engage in a hot struggle for it. . . . The unfortunate Vlach must be perpetually trying to remember what function he or she has to perform each week. On New Year's day come the children with olive branches; on the morrow every visitor must throw salt on the fire, and then put an egg in the hen-house in prayerful hope that a considerate fowl may sit on it; in February all the dogs must be thoroughly beaten as a precaution against hydrophobia—indeed, there is always some ceremony to the fore, generally accompanied by songs and ballads." To the Greek, too, every accident has its interpretation. To drop oil is unlucky, but wine may be spilt with advantage; a rainbow over a cemetery means a coming epidemic; and the recipe concerning "the hair of the dog that bit you" is practically enforced by inserting tufts of the dog's hair in the wound made by his teeth.

 

India-rubber Trees.—India-rubber trees, according to W. R. Fisher, in Nature, are extensively cultivated in flourishing plantations in the Charduar forest, at the foot of the Himalaya Mountains, in Assam. The climate of the place is essentially damp. The forest contains a great number of woody species, both evergreen and deciduous, with a few enormous old rubber trees disseminated through it. Trees have been measured here 129 feet high, with a girth around the principal aërial roots of 138 feet, while the girth of the crown was 611 feet. As rubber trees can not stand shade, and the seeds damp off unless fully exposed to light and well drained, the natural reproduction of Ficus elastica generally takes place in the forks of stag-headed or lightly foliaged trees high up in the crown, where the seeds are left by birds; and from such a site the aerial roots in process of time descend to the ground and develop into a vast hollow cylinder around the foster-stem, and it is speedily inclosed and killed by the vigorous crown of the epiphyte, which eventually replaces it in the forest. In its epiphytic growth the aërial roots of Ficus elastica may take several years to reach the ground, but, once well rooted, nothing can probably surpass it in its native habitat for rapidity of growth and vigor. At first attempts were made to propagate by cuttings, which struck easily; but it was soon discovered that rubber seed germinates freely on well-drained beds covered with powdered charcoal or brick-dust, and that the seedlings, though at first as small as cress, grew rapidly, and became about two feet high in twelve months, and were much hardier against drought than plants produced from cuttings. The base of the stem of the seedlings swells out like a carrot, and this probably enables them to tide through the dry season in safety.

 

Tin Production of Cornwall.—A review, by Mr. J. H. Collins, of the tin production of Cornwall during seven centuries shows how rapidly it has grown. An extensive commerce in the metal was already carried on in extremely ancient times. In the thirteenth century of our era, 486 tons of tin were taken annually from the mines; in the fourteenth century, 828 tons; in the fifteenth century, 732 tons; in the sixteenth century, 802 tons; in the seventeenth century, 1,300 tons; in the eighteenth century, 3,938 tons; and in the nineteenth century (ninety years), 8,795 tons. The total quantity raised is not less than 1,938,800 tons. The mean average for the fifty years ending in 1849 was 6,008 tons per year, and for the fifty years ending in 1889, 12,278 tons per year. This remarkable increase during the last forty years has been in the face of extensive production in the Strait of Malacca and Australia. Of sudden advances in production, the most noticeable, in the latter part of the fourteenth century, was probably occasioned by the great demand for bell-metal. The second period of rapid advance was in the latter part of the eighteenth century, when bronze was commonly used for cannon. The third period is that of the general use of tinned metals.