# Popular Science Monthly/Volume 44/January 1894/Popular Miscellany

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POPULAR MISCELLANY.
Political Science at the Brooklyn Institute.—The School of Political Science of the Brooklyn Institute announces an advance course in American politics, conducted by Dr. Lewis G. Janes. It will be the aim of the instructor to give a concise and correct history of our national politics from the Revolutionary period to the present time, with some account of the great statesmen and political leaders of our country. A clear statement of the facts of each political situation, with a just view of the great legal and constitutional questions involved in our political controversies, without partisan bias, will enable the student to form an intelligent judgment upon the several topics. The lectures of the first term will be devoted to the formative period of our politics, from the Revolution to the Mexican War; those of the second term to the period of reconstruction, from the Mexican War to the present Five discussions are also provided for, concerning the relative influence of the ideas of Jefferson and of Hamilton in molding American institutions; the good or evil of the influence of Andrew Jackson in our politics; the justice of the Mexican War; the impeachment of President Johnson; and the wisdom of President Cleveland's pension vetoes. The courses will be given to two classes, in two sections of Brooklyn, on different evenings of the week.
The Grave of R. A. Proctor.—Prof. Richard A. Proctor, the eminent astronomical writer, died in this city on his way from his home in Florida to fulfill lecture engagements in England, September 12, 1888, of yellow fever. The attack was sudden, and death followed very quickly. None of his family were near him, and he was buried by strangers in the lot in Greenwood Cemetery owned by the undertaker who took charge of his remains. No further care seems to have been taken of his grave until attention was called to its neglected condition through dispatches published in the papers by Mr. Edward J. Bok. A lot was then provided and a suitable monument was ordered by Mr. G. W. Childs, of Philadelphia, and on October 3, 1893, the remains were removed to this lot in the presence of a number of citizens, thus expressing their regard for Prof. Proctor's memory and for his services to science, with religious exercises and a eulogy by the Rev. Dr. T. De Witt Talmage. The lot in which the remains have been permanently interred is near the Fort Hamilton Avenue entrance to Greenwood Cemetery, opposite the village of Flatbush, and is surrounded by a substantial railing. The monument is of polished bluish Quincy granite, and besides the formal record bears the following tribute by Herbert Spencer: "On public as on private grounds Prof. Proctor's premature death was much to be lamented. He united great detailed knowledge with broad general views in an unusual degree, and, while admirably fitted for a popular expositor, was at the same time well equipped for original investigation, which, had he lived, would have added to our astronomical knowledge. Prof. Proctor was also to be admired for his endeavors to keep the pursuit of science free from the corrupting and paralyzing influence of state aid. Herbert Spencer."
Inductoscripts.—At the Nottingham meeting of the British Association for the Advancement of Science an interesting feature was introduced in the display of novel scientific apparatus and exhibits. Among these were the "inductoscripts" of Rev. F. J. Smith, obtained by placing an ordinary photographic plate, film upward, on a metal plate. A coin, or other metallic conductor with a design upon it, is then laid on the film and a discharge of electricity is passed from the coin to the metal plate. On developing the photographic plate in the ordinary way the design of the coin appears upon it. An instrument designed by Prof. Milne, F. R. S., of Japan, for registering the intensity of earth tremors, was also ​exhibited. A pyrometer of platinum, in which was measured the electrical resistance of the metal when exposed to high temperatures, was shown by Mr. Callendar. The display of electrical apparatus also included a very fine high-resistance galvanometer designed by Prof. Oliver Lodge for physiological work; and a magnetic curve-traces contributed by Prof. Ewing. An instrument invented by Mr. John Anderton for projecting solids on a screen attracted much attention. Prof. Boys exhibited photographs of flying bullets, and Dr. Isaac Roberts some admirable photographs, chiefly of nebulæ, showing the probable formation of heavenly bodies. The marked success of the exhibition may lead to like collections being displayed at future meetings of the American Association.
Diversity of Forms and Conditions of Animal Life.—In a paper presented to the Convention of the College Association of the Middle States and Maryland, Dr. Spencer Trotter, speaking of the diversity of life on the earth's surface, remarks upon its correspondence, in a broad way, with the diversity of surroundings. Aquatic animals, like fishes, crayfish, and many insects, inhabit the waters of ponds, lakes, and streams. Frogs and other amphibious creatures are denizens of bays and streams. Some snakes and turtles are aquatic, while others are wholly lovers of the dry land. Birds are found in every situation: ducks and divers on the lakes and rivers; herons and bitterns in marshy fens; gulls and petrels on the open sea; sandpipers along the shores; eagles on lofty mountain peaks; while a host of species enliven the woods and fields. The haunts of mammals are no less diversified. The tree-loving squirrels, the burrowing ground hog, the mole digging out its long subterranean galleries, the water-loving beaver and otter, are each and all associated in the mind with their favorite surroundings. The idea of the animal and its particular home is not new. The story is told in peculiar language in Psalm civ: "The cedars of Lebanon, which he hath planted; where the birds make their nests: as for the stork, the fir trees are her house. The high hills are a refuge for the wild goats; and the rocks for the conies." If this diversity of life is so apparent in a limited area, it is far more so when we come to journey over an extended portion of the earth's surface. As the horizon widens newer and more significant features rise into view. Lofty mountain ranges, broad seas, trackless deserts, treeless plains, and vast forests successively present themselves. Climate and vegetation change from one region to another, and it is not a matter of surprise to find corresponding changes in animal life. Many kinds of animals are limited to particular regions, while others range through wide areas of country under a variety of physical changes. A traveler starting on the Atlantic seaboard of the United States and journeying westward along the fortieth parallel will pass successively through a number of distinct regions, each characterized by certain conditions of climate, vegetation, and peculiar animals. A number of familiar forms will, however, be found throughout the entire extent of the journey across the continent. If the traveler cross the Pacific to Japan, he will find forms of familiar types, though the species are all different from those he knew in America. Should he sail westward by the shortest route to England, he would pass the shores of countries wholly different from those he had left and from each other, each tenanted by strange forms of life—beasts, birds, reptiles, insects, and vegetation—distinct from any he had previously seen. In England, he would be struck by the likeness of the birds to those of Japan, while he would see none of the familiar species of North American birds. We learn from a survey of these conditions how intimately related an animal is to the earth, and how each species is fitted to the special conditions of the region it inhabits.
Crocodiles, Alligators, and the Heloderm.—Crocodiles from the Nile, India, and Ceylon share the tanks at the London Zoölogical Gardens with the alligators from America. The crocodile, says an English writer who has observed them, evidently bears the same analogy to the alligator as the frog to the toad. It is lighter in color and in build, and a more active as well as a more malicious creature. It is not so entirely hideous, though the lower jaw shows projecting tusks like those of a wild boar. The creature's eyes, celebrated in connection with the "crocodile tears" ​with which legend declared that it attracted its sympathizing victims to the bank of the stream, are highly decorative, if not beautiful. The head, narrow and flat, resembles the head of a snake; the nose is sharp, and the fixed and motionless eyes are of the palest dusty gold, set in a short, horny pillar of a deeper golden brown. The crocodile's coat of armor is less complete than that of the alligator, and its quick, vivacious movements make it far more troublesome to the keepers when the tank has to be refilled and cleaned than the big alligators, which will allow themselves to be used as stepping-stones as the water ebbs away. "The heloderm, a fat and torpid lizard from Arizona, is supposed to be the sole existing member of its tribe, which possesses not only the poison glands that exist in most of the toads, but also the true poison teeth, with a channel for the emission of the venom. The lizard is about a foot and a half long, with a fat, fleshy body, a round tail ending in a blunt point, and a flat head with squared sides, resembling a small padlock. The whole body is covered with a curious coat of scales, like black and pink beads, arranged in an arabesque pattern. In its daily life it is a dull and stupid creature, feeding mainly on eggs, which it breaks and laps with its tongue. Its first and only victim was a guinea-pig that was put into its cage with a view to testing the reports as to its poisonous nature, which were by no means universally credited. The lizard bit the guinea-pig in the leg, and the animal died in a minute and a half, almost as soon as after the bite of a cobra."
Fresh Air for Legislators.—The Speaker of the British House of Commons recently pointed out a great need of the house over which he presides, and of other legislative bodies as well. Having arrived at Leamington for a little rest, he expressed his pleasure at finding himself there, "under the open air of heaven," after scenes of great anxiety and responsibility. There are very few men, as the Lancet remarks, commenting on this observation, having business of their own to attend to who can stand the work of Parliament from three in the afternoon till twelve at night without breaking down. The air of the house—whatever the "scientific ventilation"—is not the "open air of heaven." In addition to the want of air and want of space, are the temperature of discussion and the tension of highly strung men greatly differing in opinion. The Speaker is quoted as saying that the deterioration of members in health is evident from day to day, and that he sees men gradually becoming degenerate. He has been told by a cabinet minister, who is a peer, that he can recognize members of the House of Commons "by their pallid countenances," and can distinguish between them and members of the House of Lords. "It is the height of unreason to expect good legislation under such absurd conditions."
Requisites of a Flying Machine.—The principle seems to be accepted now by most of the students of aërial navigation that the successful air vessel, instead of a balloon, must be a body heavier than the air, and must be sustained as well as propelled in some way similar to that by which a bird flies. This principle was fully set forth in The Popular Science Monthly for January, 1892, by M. G. Trouvé, whose aviator, therein described, had wings acting almost precisely like those of a bird. M. Trouvé proposed for his machine an ingenious motor, which was to be actuated by the alternate compression and expansion of a gas in a Bourdon tube. Previous to M. Trouvé's paper, articles setting forth the principle of "heavier than the air" had been published by Mr. O. Chanute, Prof. S. P. Langley, and Mr. H. S. Maxim, and several have been published since in American magazines and journals. A writer who discusses the subject of aërial navigation in the Boston Herald raises the objection to a wing-motion, such as M. Trouvé's aviator contemplates, that the power needed to secure the velocity which an oscillating machine would require would probably cause the machine to destroy itself by the violence of its own vibrations. He proposes instead to depend on an aëroplane to hold the machine in the air, and to use a screw propeller as a source of motive power. He would pattern and proportion the aëroplane after the position of the motionless wings of a loon in scaling descent, as after they have been paralyzed by a shot hitting the brain; place the screw in front, on the principle that an arrow can not fly except with its heavier end foremost, and ​guide the machine by horizontal and vertical rudders. The machine may be started by causing it to descend an inclined plane, and then to move horizontally, when its course is that of a scaling bird, and the power is applied, with the rudders, to keep up and direct the motion. Few persons who have seriously considered the subject now doubt the possibility of aërial navigation on the principle of "heavier than the air." But the construction of a practicable machine demands a variety of gifts and resources not to be found in one man: there must be an inventor, a mechanical engineer, a mathematician, a practical mechanic, and a syndicate of capitalists.
The Earliest Historical Art.—The earliest condition of art in Egypt, says Prof. W. M. Flinders Petrie, stands in a far different light from that of the history of art in other countries. In the first place, it is as early as, or earlier than, any other source of art that we know. Other countries have largely borrowed from Egypt or from Mesopotamia, but these two great deltas have not had any external influence acting on them; they stood far in advance of the civilization of the rest of the world in the early ages, and their art appears to be the outcome of the first stable and well-organized governments that were known. Tranquillity and the command of large resources were needful before any great progress could be made in architecture or the imitative arts; and no land appears to have enjoyed such conditions before the dawn of the historical period in Egypt. We have, then, to deal with a state of things in which art was, in the course of actual growth, free from the influence of any external guidance, and with only its own antecedents to build upon. This art also stands apart in the fact that all traces of its origin and rise are absent. We are still as much ignorant as ever of the course of its development. Where the tentative stages are to be found which led up to the triumphs of the fourth dynasty is as yet a mystery. Certain sculptures, which are undoubtedly very early, have been assigned to the second and third dynasties solely on account of the style. But there is no absolute evidence of the date of a single sculpture or a single block before the first king of the fourth dynasty, Snefru (the predecessor of Khufu, or Cheops), under whom we find some of the most perfect works that ever were executed. In one line, however, there are remains of an earlier style. The rock carvings of Upper Egypt certainly date back to a long prehistoric age—an age when the ostrich and the elephant were familiar in Egypt. But these rude figures have no relation to the art of historical times; and we should as soon learn the history of the Parthenon from the weapons of the stone age in Greece as trace the Egyptian schools in the rude carvings of the primitive man.
Public Parks in Massachusetts.—The Trustees of Public Reservations of Massachusetts is a chartered body established for the purpose of providing a ready instrument by means of which any person or body of persons may insure the preservation of any beautiful or historical place in the State. This may be accomplished by putting the tract in its hands. It also receives money for the maintenance and adornment of such places. As the years pass, a variety of motives are found to inspire the giving of lands into the hands of the trustees. The largest recent instance of this confidence is the gift of twenty acres of fine woodland in Stoneham by Mrs. Fanny Foster Tudor, now deceased, named by her desire, in memory of her daughter, Virginia Wood, for which a maintenance fund—the Virginia Wood Fund has been collected and invested by other friends. It appears, from facts collected by Mr. J. B. Harrison respecting the present provision of open spaces in Massachusetts, that the large areas of undivided common lands which were once to be found in most of the townships of the Commonwealth have all been allotted or sold to individuals, except in Nantucket, where there still remain at least one thousand acres open to the public. The Park Board and Water Board of Lynn have lately restored to public ownership about two thousand acres of woodland which was once a common of this large kind. The smaller commons which the first proprietors of townships almost invariably laid out for "training fields" and sites for "meeting houses" appear to be still the only public open places in most of the townships of the State. Some of them have been ​encroached upon, some have passed into the exclusive possession of the "first churches," some into the exclusive possession of the townships, and some are said to be still owned jointly by township and church. Where the towns have come into possession they have frequently given the charge of the commons to village or township improvement associations. Only a few of the rural townships have acquired new public open spaces in recent years. In Manchester public rights in certain sea beaches have been established and a long strip of roadside woodland has been deeded to the town in trust. In Sheffield a beautiful pine grove is held in trust for the public by five trustees. Georgetown has laid out nine small spaces 'within forty years. In the cities of the State the General Park Act, passed in 1882, has borne excellent fruit.
Sanitary and Climatic Influence of Forests.—Concerning the sanitary and climatic relations of forests, Mr. B. E. Fernow concludes, after a discussion of the subject, that the influence claimed for them in promoting greater purity of the air through the greater production of oxygen and ozone does not seem to be sufficient; that the protection they afford against sun and wind and consequent absence of extreme conditions may be considered a favorable factor; and that the soil conditions of the forest, which are unfavorable to the production and existence of pathogenic microbes, especially those of the cholera and yellow fever, and the comparative absence of wind and dust, in which such microbes are carried into the air, may be considered as constituting the principal claim for the hygienic significance of the forest. We may summarize, he says, by saying that the position of the forest as a climatic factor is still uncertain, at least as to its practical and quantitative importance, but that its relation to water and soil conditions is well established. As a climatic factor the forest of the plain appears to be of more importance than that of the mountains, where the more potent influence of elevation obscures and reduces to insignificance the influence of their cover. As a regulator of water conditions the forest of the mountains is the important factor; and since this influence makes itself felt far distant from, the location of the forest, the claim for the attention of government and for statesmanlike policy with reference to this factor of national welfare may be considered as well founded. Every civilized government must in time own or control the forest cover of the mountains, in order to secure desirable forest conditions.
The Scrub Lands of Australia.—The London Times's correspondent, in his little book on Queensland, mentions the "lawyer vine" as the worst obstacle which the clearer of land in that country has to encounter. It is a kind of palm that grows in feathery tufts along a pliant stalk, and festoons itself as a creeper upon other trees. From beneath the tufts of leaves the vine throws down trailing suckers as thick as stout cords, armed with sets of sharp red barbs. These suckers sometimes throw themselves from tree to tree across a road that has not been lately used, and make it as impassable to horses as so many strands of barbed wire. When the vines escape from the undergrowth of wild ginger and tree-fern and stinging bush that fringes the scrub and coil themselves in loose loops upon the ground, they become dangerous traps for man and horse. In the jungle, where they weave themselves in and out of the upright growths, they form a net that at times defies every means of destruction but fire. The work of clearing ground thus encumbered is not light. In some districts it is done by Chinamen. They are not allowed to own freehold land in the colony, but scrub land is often leased to them to clear and use for a certain number of years. The ground, when it is cleared, is extraordinarily rich, and they appear to recoup themselves for their labor with the first crops they grow upon their leaseholds. The owner afterward has it in his power to resume his land, and the Chinaman passes on to clear and use the scrub. In this way the Chinese are employed as a sort of self-acting machine for the opening of the country. They devote themselves principally to the cultivation of fruit. A walk round a Chinese garden is an instructive botanical excursion, so many and strange are the edible varieties of fruit to which one is introduced. Spices, too, and flowers flourish under the care of the Chinamen, and the ​fields of bananas and pineapples dotted with orange and mango orchards, which stretch for miles beside the sugar plantations, are nearly all Chinese. They ship fruit to the southern colonies, but their profits must be very small, for one of the principal complaints made against them is that they can make a living where a white man would starve. Nevertheless, it is found that when they hire themselves out to work they are not a very great deal cheaper than white men.
Worlds and Molecules.—In his lectures at Geneva and Lausanne, M. Raoul Pictet presented mechanics as an exact science, comprising chemistry and physics in its domain. The principal phenomenon of physics is astronomy. The laws of sidereal gravitation apply likewise to the smallest bodies on the earth, to infinitely small ones like the molecules, and also to the atoms. Thus we have a unity of matter in which atoms, uniting from molecules, these group themselves into bodies, and these form worlds. The attraction which controls infinitely large bodies may therefore be regarded as similar to that which unites infinitely little ones. If the atoms touched in a molecule, there would be no force capable of separating them. We are, however, acquainted with dilatation and various ways of separating the atoms and augmenting the distance between them. The hypothesis that they touch is, therefore, not admissible. To explain the theory of chemical phenomena, let us suppose a molecule, A, placed somewhere in sidereal space, having a rectilineal motion toward another molecule, B, immovable, and very remote. In its approach to B there will come a moment when A's motion will slacken. Then astronomical phenomena will end and the phenomena special to physics will begin. At last the molecule A will stop; it has become inert, and can not advance further toward B. It is bound by cohesion. If, now, we suppose a pressure to be imposed on A, to bring it down to B, physical phenomena will cease, the resistance of A will diminish with the distance, and finally the molecule will ally itself with B without touching it; then we have chemical phenomena. The force that unites A and B is affinity. M. Pictet supposes that the absolute zero of temperature, when bodies can no longer react upon one another, is found between these last two phases, and his idea is confirmed by experiment. When sulphuric acid with potash is cooled down to $-$150º C. ($-$236º Fahr.), no reaction is apparent. The bodies are no longer able to combine at that temperature, when occurs a complete death of such action. At $-$80º C. ($-$112º Fahr.), potassium remains unattacked in alcohol and water for whole days. A slight warming produces a small reaction; and if the temperature is raised a little more, combination takes place with energy and an explosion is produced.
Heating and Ventilation of Electric-lighted Buildings.—In his paper on the Heating of Large Buildings, A. R. Wolff, consulting engineer, shows that the introduction of electric lighting with isolated generating plants in large buildings has had a sensible effect on the solution of the heating and ventilating problem by practically conditioning the use of exhaust steam for heating. The quantity of steam required for heating such buildings is nearly equal to the amount used independently for their electric lighting. Since electric-light engines convert only about ten or fifteen per cent of the heat of the steam with which they are supplied into mechanical energy, from eighty-five to ninety per cent of it is retained in the exhaust steam, available and just sufficient, as a rule, to meet the heating and ventilating needs of the building. This means practically that a boiler capacity ample for the heating and ventilating will take care, in addition, of the electric lighting of a large building, or vice versa; and that in the winter months the electric lighting is secured at only a slightly increased fuel expense. It is this fact that makes it difficult for either city or district heating or electric-lighting companies to supply steam or electricity respectively to large buildings. They can not compete with the cheapness of generation of the isolated plant within the building. The facts that electric lights give out less heat and vitiate the atmosphere less than gas, and that they do not flicker, have also an important bearing on the problem of heating and ventilation. The fresh-air supply can be brought in at the top of the room, where there are no lights for it to blow out, and ​exhausted at the bottom, in reversal of the ordinary process, and under this condition it does not produce the draft or cause the sudden cooling that are so objectionable under the usual method of ventilation.
Work of the United States Fish Commission.—In the work of the United States Commission of Fish and Fisheries, the summer of 1890 was spent by the steamer Albatross in Bering Sea, where the principal banks frequented by the cod were surveyed. The season was too short to complete the work, and it will have to be resumed at some future time. The position of the western margin of the continental platform was, however, defined for a considerable distance, and a good beginning was made toward a knowledge of those physical and biological features of the sea which relate to the habits and distribution of the fur seal and other aquatic mammals. By the surveys of the coasts of Washington, Oregon, and California, the contour of the continental border has been developed from the shore line into depths of two hundred fathoms as far south as Point Conception, while the region between that place and San Diego had been previously explored. Temperature, density, and biological observations in different parts of San Francisco Bay indicate that the waters of that region are not, as has hitherto been supposed, unsuited to the breeding of Atlantic coast oysters. A scientific investigation was made with the Albatross during the early part of 1891, under the direction of Prof. Alexander Agassiz, of the waters lying off the western coast of America between Cape San Francisco and the Galapagos Islands on the south and the Gulf of California on the north. The most extensive and important operations on the Atlantic coast were conducted in the interest of the oyster industry, in the coast waters of South Carolina and Maryland and Virginia, and in Long Island Sound. Dr. Bashford Dean, of Columbia College, was commissioned to study the methods of oyster culture practiced in European countries and to prepare a series of illustrated reports concerning them. The physical inquiries in the mackerel region off the southern New England coast, under the direction of Prof. William Libby, Jr., were continued in 1889 and 1890; and the investigations respecting the interior waters of the country were conducted in twelve States and Territories on an extensive scale and with important practical results. The work of the Division of Fish Culture was continued at twenty-two stations in fifteen States.
The Theory of Special Assessments.—According to the study of this subject made by Victor Rosewater (Columbia College Series), the underlying principle of special assessment for benefit first appeared in this country in the provisions of a provincial law of New York in the year 1691. The effective clause of this statute was copied from an English act passed in 1667, and re-enacted in 1670, to regulate the rebuilding of London after the great fire. Thus the idea was not, as some have supposed, a native American one, but the substance of the plan had been put into English books twenty years before. The New York law remained unrepealed, but inoperative, till 1787, when it was adapted more closely to existing necessities. This method of raising revenue for local improvements remained for a long time peculiar to New York, It did not begin to extend to the other commonwealths till after the people had begun to recover from the effects of the War of 1812. The first development of the system, therefore, corresponds roughly with the movements for the construction of internal improvements covering the years just before and after 1830, and dying out with the crisis of 1837. The era of premature railway building about 1850 witnessed another movement of the kind in the newer States and Territories. The last movement, begun immediately after the close of the civil war, was more general than the others; has not yet wholly ceased; and has passed over into Toronto, Canada. The justification of the policy of special assessments is to be found in the principle that where an expense is to be incurred by a local authority which results in special, distinct, and measurable advantages to the property of particular persons, it is more equitable that those who benefit thereby should contribute to the expense to the extent of those benefits than that the burden should be placed upon others who have received no such special advantages. Among other methods of recovering the expense of improvements, besides ​general taxation, are the imposition of tolls, which has now been generally abandoned, and recoupment, or buying the property before the improvement is made—as in the opening of new streets and public places—and reselling it afterward, which involves a large outlay of capital, and runs counter to the generally existing constitutional provisions respecting the exercise of eminent domain. For young and growing municipalities the method of special assessment is considered the best. "With few exceptions and abuses, it has been operated in the United States to the general satisfaction of all. It rests upon principles of right and justice. It brings quick results at the very time when needed. It discourages the speculative holding of unimproved urban property."
Characteristics of Lunar Craters.—In the study of lunar physiography or physiognomy, says Prof. G. K. Gilbert, interest naturally centers in the craters, for these are the dominant features. All theories begin with them. Their range in size is great, extending from a maximum of about eight hundred miles in diameter to a minimum of less than one mile. The size of the smallest ones is not known, as they are beyond the present power of the telescope. Within this range are several varieties, more or less correlated in size, but their intergradation is so perfect that they are all regarded as phases of a single type. To describe them one should picture to himself a circular plain, ten, twenty, fifty, or one hundred miles in diameter, surrounded by an acclivity which everywhere rises steeply but irregularly to a rude terrace, above which is a circular cliff likewise facing inward toward the plain. This cliff is the inner face of a rugged, compound, annular ridge, composed of shorter ridges which overlap one another, but all trend concentrically. Seen from above, this ridge calls to mind a wreath, and it has been so named. From the outer edge of the wreath a gentle slope descends in all directions to the general surface of the moon, which it is convenient here to call the outer plain. The outer slope of the crater may be identical in surface character with the outer plain, or it may be radially and somewhat delicately ridged as though by streams of lava. The inner slope from the base of the cliff to the margin of the inner plain is broken by uneven and discontinuous terraces. From the center of the inner plain rises a hill or mountain, sometimes symmetric but usually irregular and crowned by several peaks. From the outer plain to the base of the wreath the ascent is one thousand to two thousand feet, and the ascent thence to the top of the wreath may be as much more. The descent from the wreath to the inner plain is ordinarily from five thousand to ten thousand feet, and the height of the central hill is from one thousand to five thousand feet. With rare exceptions the inner plain is several thousand feet lower than the outer plain. The central hill is not universally present, but appears in rather more than half the craters of medium size, and tends to disappear as the craters become larger. Mr. Gilbert attempts to account for the origin of these craters by collisions of meteoric bodies with the moon, or of the moonlets by the aggregation of which under the meteoric theory the moon has been formed, and is supported by the fact that the splash produced by dropping a pebble into pasty mud, etc., has the form of a crater.
The Royal Cinnamon of Tonkin.—The cinnamon of Thanh-Hoa, Tonkin, called royal cinnamon, is highly esteemed by the Annamites, and great value is attached to pieces of its bark as presents. It is not cultivated, but grows in thick, hardly accessible forests on the Muong Mountains, where some cantons are tributary to Annam. Each canton must furnish the king a tribute of three stools of cinnamon a year. When an inhabitant learns of a stool, he immediately informs the mayor of his village; the mayor informs the sub-prefect, and he advises the governor of the province of the fact, who makes report of the matter to the court. The Quang phu, or sub-prefect, sends a squad of men to guard the tree, who are not relieved till the crop is gathered, in the presence of the Quang phu or of some mandarin deputized by him. The whole crop is supposed to go to the king, but the officers know how to retain a little of it. So precious a spice as is this particular kind has not entered into commerce, and so jealously is it guarded that it is extremely difficult to ​obtain a specimen except through some fraud; and persons detected in defrauding the government of its cinnamon usually have to atone for the offense with their lives.
A Himalayan Landscape.—Mr. W. M. Conway, the Himalayan explorer, describes the view as an astonishing one which surrounds the traveler from Srinagar to Gilgit when he has emerged from the defiles which sunder the valley of Hunza Nagyr from Gilgit, and has climbed the vast ancient moraines near Tashot that form the final rampart of the fertile basin. "The bottom of the valley is, as usual, deeply furrowed by débris, the surface of which is covered by terraced fields, faced with Cyclopean masonry, and rich with growing crops and countless fruit trees. The mountains fling themselves aloft on either hand with astounding precipitousness, as it were, into the uppermost heights of heaven—so steeply, in fact, that a spring avalanche falling from the summit of Rakipershi on the south must almost reach the bottom of the valley. Rakipershi is 25,500 feet high; the Hunza peak is about 24,000 feet high. Their summits are separated by a distance of nineteen miles. Both mountains are visible from base to summit at one and the same time from the level floor of the valley between them, which is not more than 7,000 feet above the sea. No mountain view I saw in the Karakorums surpasses this for grim wonder of colossal scale, combined with savage grandeur of form and contrast of smiling foreground."
Composition of Clays.—The word clay, says Mr. Robert T. Hill, in his paper (United States Geological Survey) on the Clay Materials of the United States, has a diverse and elastic meaning. To the popular mind it is the familiar, gritless, plastic earth which is readily molded when wet. To the manufacturer it is the material he molds and bakes, which may be the natural plastic material of the popular mind, or a mixture of many ingredients either natural or artificial, according to the refinement of the ultimate product; this product varies as to simplicity of processes from the ordinary brick clays, which are natural mixtures of the essential sand and clay with iron and other accessories, to the washed, ground, screened, and compressed mixture of kaolin, feldspar, flint, and plastic clay from which the potter shapes china and porcelain into works of art. Clay material in nature is not always plastic, and many of the most valuable products are made from consolidated rock, as the Cornwall stone or rock kaolin, which is a crumbling granite. Many common brick clays are more like impure sand than clay, and some of these, from the earliest times, have been molded with straw to give them sufficient tenacity for the handling necessary before burning. Much of the aboriginal pottery of America is composed of various earths, with just enough clay to hold the particles together. The chief function of clay in the fictile arts is its partial fusion upon firing, and upon this and the skill of the artisan who fires the kiln depends the product, which is wonderfully varied by the mixtures of fluxes and tempering material. Plasticity is desirable for the handling of the unfired material. Nearly all unconsolidated or powdered material may be made to adhere by water and other ingredients than clay, so that it can be shaped for burning, but plastic clay is the cheapest natural material used for this purpose in all clay burning. The material for the coarse products occurs naturally, and is mixed with the non-plastic kaolins by the porcelain-maker to give the "clay" the necessary tenacity for handling and shaping.