The Sandwich Islands lie upwards of 2,000 miles southwest of San Francisco, and consist of fifteen islands, of which only eight appear to be inhabited, viz., Hawaii, Mauai, Lanai, Kahoolawe, Molokai, Oahu, Kaui, and Niihau. The total area is about 7,000 square miles, and the native population is under 50,000. There are besides upwards of 5,000 foreigners, the Chinese being more largely represented than any other nation, Americans and British coming next. There is, however, a large native white population, descendants of American missionaries and others who settled in the islands years ago; most of the Government offices for the Sandwich group has a Constitutional Monarchy-being filled by whites of this class. The islands have for many years been professedly Christian in religion. They extend from 18° 50' to 22° 20' N. lat., and from 154° 53' to 160° 15 W. long. Their official designation is the "Hawaiian Islands." "Their climate for salubrity and general equa bility is reputed the finest on earth. It is almost absolutely equable, and a man may take his choice between broiling all the year round on the sea level on the leeward side of the islands at a temperature of 80°, and enjoying the charms of a fireside at an altitude where there is frost every night of the year. There is no sickly season, and there are no diseases of locality. The trade winds blow for nine months of the year, and on the windward coasts there is an abundance of rain, and a perennial luxuriance of vegetation." So says Miss Bird, whose delightful book we recommend to all who wish for a full and graphic account of the present condition of the Sandwich Islands and islanders. She spent seven months of the year 1873 on the islands for the sake of her health, rode and sailed and climbed about fearlessly everywhere, using her eyes to the very best advantage. The result is, that in less than 500 pages she gives a panoramic picture of the various phases of nature and life in the Sandwich Islands, which leaves little to be desired. The largest of the islands is Hawaii-its area is 4,000 square miles-but the capital, Honolulu, the headquarters of one of our Transit expeditions, is on Oahu. Hawaii Miss Bird calls a huge slag, and the same, we fancy, may be said of most of the other islands; everywhere there are unmistakable signs of the fiercest volcanic outbursts, and every now and again are the inhabitants reminded of the instability of the foundations of their lovely dwelling-place. Nevertheless, nobody in Hawaii troubles himself with the thought of the terrible possibilities that may at any moment happen. Natives and foreign residents appear to resign themselves unreservedly to the perpetual "afternoon" influence of the land, where there seems to be little need of "taking thought for the morrow." Miss Bird gives us many glimpses of the luxuriant vegetation which is to be found almost everywhere on the lower slopes of the islands; a mere list of the various trees to be met with would occupy more space than we can afford. Almost all the roots and fruits of the torrid and temperate zones can be grown on the islands, though the flora is far scantier than that of the South Sea groups. The indigenous fauna is small, consisting only of hogs, dogs, goats, and an anomalous bat that flies by day. There are few insects except such as have been imported, and there is no great variety of bird-life. In Hawaii, as well as in others of the islands, the coast line is everywhere broken by deep "gulches" or ravines, often from 1,000 to 2,000 feet in depth, running for miles into the interior, clothed from top to bottom of their nearly perpendicular sides with almost impenetrable vegetation, and having the narrow valleys below raked by torrent-like rivers, which are often 'swollen to many hundred yards in breadth. No doubt the principal attraction to the scientific reader in Miss Bird's narrative will be her account of the visits which she was brave and determined enough to make to the volcanoes, active and extinct, on Hawaii and Mauai. All the principal islands of the group, being of volcanic origin, are more or less mountainous, ranging in extreme height from 400 ft. in Kahoolawe to close on 14,000 in Hawaii, the loftiest island in Oceania. As our readers, no doubt, know, there are on the island of Hawaii two active and at least two extinct volcanoes; indeed, almost everywhere in the interior evidence of former volcanic action is to be met with. "To the south of the Waimea plains violent volcanic action is everywhere apparent, not only in tufa cones, but in tracts of ashes, scoriæ, and volcanic sand." Mauna Loa, somewhat to the south of the centre of the island of Hawaii, is the highest active volcano in the world, rising to a height of 13,760 feet. The whole of the south side of Hawaii, down to and below the water's edge, is composed of its slopes, its base being 180 miles in circumference. "Its whole bulk above a height of 8,000 feet is one frightful desert," though vegetation, in the form of grey lichens, a little withered grass, and a hardy asplenium, extends 2,000 feet further up. During Miss Bird's visit to the summit, the thermometer regis tered 11° of frost. The crater Mokuaweo weo, is six miles in circumference, 11,000 feet long, 8,000 feet wide, with precipitous sides 800 feet deep. The crater appears to be in a state of constant activity, and at times overflows, carrying destruction to the lowest levels of the island. Miss Bird tells us that since white men inhabited the islands there have been ten eruptions from Mauna Loa. Of the condition of the crater, the following description, by Miss Bird, of what she saw on her visit, accomplished amid hardships that few men would care to undergo, will give the reader a vivid idea: "When the sun had set, and the brief red glow of the tropics had vanished, a new world came into being, and wonder after wonder flashed forth from the previously lifeless crater. Everywhere through its vast expanse appeared glints of fire-fires bright and steady, burning in rows like blast furnaces; fires lone and isolated, un winking like planets, or twinkling like stars; rows of little fires marking the margin of the lowest level of the crater; fire molten in deep crevasses; fire in wavy lines; fire, calm, stationary, and restful: an incandescent lake two miles in length beneath a deceptive crust of darkness, and whose depth one dare not fathom even in thought. Broad in the glare, giving light enough to read by at a distance of three-quarters of a mile, making the moon look as blue as an ordinary English sky, its golden gleam changed to a vivid rose-colour, lighting up the whole of the vast precipices of that part of the crater with a rosy red, bringing out every detail here, throwing cliffs and heights into huge black masses there, rising, falling, never intermitting, leaping in lofty jets with glorious shapes like wheatsheafs, corruscating, reddening, the most glorious thing beneath the moon was the firefountain of Mokuaweoweo." On the east flank of Mauna Loa, about 4,000 feet in height, is the crater of Kilauea, which, Miss Bird says, has the appearance of a great pit on a rolling plain. "But such a pit! It is nine miles in circumference, and its lowest area, which not long ago fell about 300 feet, just as ice on a pond falls when the water below it is withdrawn, covers six square miles. The depth of the crater varies from 800 to 1,100 feet in different years, according as the molten sea below is at flood or ebb." We wish we had space to quote Miss Bird's fearfully vivid description of what she saw during the two visits she made to Kilauea, descriptions which, were they not evidently written on the spot with a truthful pen, would almost deserve to be called sensational. She also made the ascent of Mauna Kea, to the north of Mauna Loa, the highest peak in Oceania, perpetually covered with snow, a dead volcano, whose top consists of deep soft ashes and sand. On the west side of Hawaii is another extinct volcano, Hualulai, 10,000 feet high, which has only slept since 1801, when there was a tremendous eruption from it, which flooded several villages, destroyed many plantations and fish-ponds, filled up a deep bay twenty miles in extent, and formed the present coast. The largest extinct volcano in the world, Haleakala, is in the centre of the island of Mauai, lying to the northwest of Hawaii. It is 10,200 feet in height; its terminal crater is nineteen miles in circumference, 2,000 feet deep, and contains numerous subsidiary cones, some of which are 800 feet high. Miss Bird of course visited it, and, as usual, her description is exceedingly graphic and full, and is considerably helped out by an excellent map of the crater. It seems that very few of the usual volcanic products are present in this extinct crater.* Volcanic action in the Sandwich Islands would seem to have died out from west to east; this is inferred from the state of the lava and the great depth of soil in some of the western islands, as in Oahu and Kauai, the latter the most westerly of the inhabited islands. Some very remarkable instances of the powerful effects of weathering in causing degradation are to be seen in this island. The Punchbowl, a crater behind Honolulu, was in 1786 observed to be composed of high peaks; but atmospheric influences have reduced it to the appearance of a single wasting tufa cone; and the cone of Diamond Hill, to the According to Mr. Brigham, the products of the Hawaiian volcanoes are native sulphur, pyrites, salt, sal ammoniac, hydrochloric acid, hematite, sulphurous acid, sulphuric acid, quartz, crystals, palagonite, feldspar, chrysolite, Thompsonite, gypsum, solfatarite, copperas, nitre, arragonite, Labradorite, limonite. south of the town, is also, from the same causes, rapidly diminishing. The native population of the Sandwich Islands, which belongs to the Malay or Malyo-Polynesian division of Oceania, is fast dying out, at the fearful rate of something like 1,000 per year; so that unless some counteracting circumstances intervene, it must in a very few years become entirely extinct. Cook calculated the population of the islands in 1778 to be about 400,000; now the native population is under 50,000. That the decay is to a considerable extent owing to contact with whites there is no doubt. But when every allowance is made for the effects of such contact upon the native population, it is questionable whether this will account completely for its rapid decrease. A similar decrease seems to be going on all over the Pacific islands, even in places where the whites have always been extremely few. From this point of view M. Leborgne has recently turned his attention to the small Gambier group, which consists of four islands. Magaréva, the most important island, had in 1840 a population of 1,130; it is now only 650. Dr. Hamy, in an article in La Nature, ascribes the prevalent diseases mainly to consanguineous marriages, a cause which is likely to obtain in many of the other isolated Pacific groups. This may have something to do with the diminution of the Hawaiian. population, as also the fact that the careless, happy, and extremely sociable people seem to be almost devoid of anything like parental affection, taking little care of their to take them; the consequence is that a large proportion children, and readily parting with them to anyone willing die in infancy. Another point to be noted is that in 1872 the males exceeded the females by 6,400 souls. At all events there is no doubt that the populations of most of the Pacific islands are rapidly disappearing, and that ere very long the only tenant of their lovely homes will be the omnipresent white man, who has foisted on them an exotic civilisation which seems to have unmanned them, to have completely checked their natural development, and whose invariable concomitants have been disease and widespread destruction. We again recommend Miss Bird's most attractive book to the favourable notice of our readers. A small map of the islands is prefixed, and the few illustrations are beautifully executed. OUR BOOK SHELF Sun and Earth as Great Forces in Chemistry. By Thos. W. Hall, M.D. (London: Trübner and Co.) THE author of this work, professing himself the preacher of a new doctrine, theorises, to use his own words, "on the phenomena of chemistry... considering the whole of chemistry as but heat acting on matter." The sun is considered to exert some subtle chemical influence on matter, but, unfortunately for science, these effects, we are told, cannot be studied experimentally, "yet we can do so theoretically to a very useful extent." After carefully perusing the twelve chapters in which this eminently ourselves whether Dr. Hall's views are not more of the theoretical treatment is carried out, we are driven to ask nature of complication than of explanation. It may be safely affirmed that the phenomena of chemistry are far more easily explained by existing theories-imperfect though they be-than by the obscure reasoning based on perfectly gratuitous assumptions in which the present ble," these investigations should always be borne in mind, that the pitch of the reed is dependent not on vibrating length, but on vibrating divergence on the amplitude of the reed's motion. The pitch of the air-column is not necessarily the same as the pitch of the air-reed; they may be and often are at variance: and this pipe will afford a happy means of demonstration of the statement made in a previous letter, that the tone of every organpipe is dual. As regards the reed, whatever the modifications of length by height of mouth, of thickness by varied wind-way, or of strength by amount of wind-pressure, the final result is bound by this law of divergence. In the typical air-reed, any deviation from the direct line of force taken by the stream of air is the beginning of vibration; its highest possible rate of vibration begins existence on its least divergence from the direct line; consequently, its highest pitch is its inceptive tone at this stage or condition of untamed energy. "most rudimentary and The bass has always been considered the basis and commencement of musical tone; every relation of tones has been examined on that ground, and it has undoubtedly been the source of many errors, one might almost say in the nature of superstitions, so tenacious has been its hold, so blinding its influence on the perceptions. Tone has its beginnings in the highest activity, and descends to the lowest and slowest; the development of its mechanical relations proceeds by definite degrees, and the issue depends on the affinity existing between the pipe and the reed, both possessing definite form, power, and character, and blending these by law. The vibration of the aeroplastic reed is thus shown to be isotonic, not isochronous; the laws of its vibrations are identical with those of the things most like itself, of sound-waves, of light-waves. It was my good fortune some time ago to have placed in my hands a specimen of a variety of "Gamba" devised by the famous organ-builder, Schulze, of Paulenzelle. The "Gambas" form a class of pipes variously constructed in scale, and they are so called from the quality of their tone imitating the old "Viol da Gamba" and its modern representative the "violoncello." The general characteristics of the class are-cylindrical pipe of comparatively slender scale, low-cut mouth, full-winded at foot, and slow in speaking; the slow speech is a necessity, and is caused by the wind being, as it is technically termed, "much thrown out;" that is, the line of force of the current of wind is set more outward than ordinarily, for without such arrangement the fundamental or ground tone of the pipe would not secure its hold; some harmonic would usurp possession; for the air-reed, being short in consequence of low mouth, and strong from excess of wind, would keep to harmonics as the "flute harmonique " does; the latter has a low languid (or interior level within the mouth), the "Gamba" has a higher languid in relation to the under lip, thus directing the stream at a more oblique angle to that level. The tone has decided introductory and transitive harmonics. Of their sequence, although but momentary, the ear conveys a clear impression to our consciousness. We call it a "stringy quality," and it is a very interesting inquiry how this peculiar pipe-tone is built up. The characteristic quality pertaining to all stringed instruments whose tone is elicited by the bow, does, we may well suppose, arise through a process bearing a close analogy to this. ""dis volume abounds. Neither is the work free from the LETTERS TO THE EDITOR On [The Editor does not hold himself responsible for opinions expressed On the Building up of the Tone in the "Gamba" Organ- IN considering the nature of this pipe, and in determining the It is a disadvantage, this slow speech of the "Gamba," often felt to be excessively slow. Most skilful voicing is needful to give sufficient time for the appearance of the introductory harmonics without too greatly delaying the fundamental, for it is a nice point to strike the mean between having the wind so much thrown out that the pipe will not speak any tone, and risking, by giving quicker speech, the sudden "flying off to the octave, with obstinate persistence not to descend. Take note of this. If you hold your hand or your finger near the mouth of any speaking organ-pipe, there is forthwith a sensible flattening of its pitch, deepening with the nearer approach of the hand; in tuning organs it is the ordinary custom to test pitch by this simple method, determining thereby whether the pipe will best bear flattening for its nearer approximation to a desired pitch or concord with others. Suppose yourself to be tuning a set of "Gamba" pipes: you would notice perchance that a restive pipe continually darting off to harmonics would be corrected and steadily held in check so long as your hand or finger was near or across its mouth. We can thus well under. stand how it might occur to Schulze that the temporary expedient could be made permanent. This is what Schulze did: he fixed a small bar across the mouth. The device proved successful. In pipes thus treated the tendency of the reed to settle at the octave is suppressed, speech is quickened, more wind may be given without danger, and the quality becomes in con sequence more characteristic, more "stringy." Schulze has extended his method to large pedal pipes, producing a stop of remarkable beauty, called the "Violone." Applying the air-reed theory to this Schulze's "Gamba," we shall see how fruitful it is in illustration of the actual process of tone-making. Without diagrams and with but few technical terms it may be made clear and comprehensible. Let us take a specimen-pipe. It is of slender, graceful proportions, what is called "narrow scale," length thirty-seven inches and a quarter, diameter one inch and five-eighths, mouth or embouchure in breadth one inch and a quarter, and three-eighths of an inch high, and its pitch answers to the note E in the tenor octave. It has a very fine wind-way, large foothole, and is considerably overblown, for it will bear it. There is a bar in front of the mouth, fixed upon the little upright strips projecting at the sides about a quarter of an inch, which are termed ears; they are common to pipes until the size is too small to require it. Builders say the ears are added to pipes to steady the tone. On the theory advanced in these papers, we find their purpose is to prevent any flank movement of the atmosphere during the vibration of our air-reed, for the angle formed by the vertical line of the mouth and the line of force of the outwardly inclined stream of air presents an opening of weakness, and these ears are as ridges or outworks thrown up to guard against any premature invasion by the external air which, as intimated in an earlier letter, pierces through at the proper time only, just under the edge of the upper lip. We readily perceive that the 'Gamba pipe has three specialties: overblown wind, to give a stiffer reed; a low-cut mouth, as a provision for shortness of reed; and wind much thrown out as a means compulsory for ensuring a greater amplitude in the reed's motion,-the result of the combination being that the tone is rich in harmonics; harmonics precede the groundtone, and follow it, and coalesce into it, and linger behind as though the last to quit the pipe. There is nothing more beautiful in all the varied wealth of an organ than a well-voiced "Gamba." Every tone suggests a symphony, many-tinted, autumnal. There is another remarkable feature peculiar to these-the artist can shade them with less depth of ground-tone and more varied and delicate hues in the harmonics, which nevertheless come out more brightly in the contrast, and compensate the ear with a new variety, toned with less body yet with equal fulness, through the heightening of the harmonic colour, and the more gradual blending of the whole. : In the pipe we are examining we shall find that the wind is not so much thrown out as in the older class of the species, and herein lies the real meaning of the difference, for by the agency of the bar an equal amplitude is enforced in the air-reed, but one of new form and see how gracefully it is drawn,—yes, happily we can see, for the new form bears an impress highly significant. A little bit of paper deftly applied will enable us to watch the process of nature. Take away the bar, and the pipe will not sound its ground-tone-it is only able to produce its string of brilliant harmonics. Look at the air-reed: how minute a space it traverses whilst these high notes are thrilling in your ears. In substitute for the removed bar, now lay a small pencil across the mouth, and see how in coy consent the air-reed yields, comes out to you with a fine curve, and all the power of the pipe is affirmed coincidently with this visibly extended amplitude of the reed's motion. You can change it from one state to the other by this movable bar, and you have to notice that the reed is almost upright in stem, but bends over, arching at the tip,notice also that the inward curve of the reed is less than the outward curve. The explanation of this influence will be quickly divined if you fully comprehend the way in which the reed builds itself up in a curve, leaning outward upon the external air : the air composing the reed issues from the wind-way in a dense stream; the particles are most compressed at the root, and gradually expand and become less energetic as they reach higher freedom -the velocity of the upward stream motion attracts the external air with force, strongly, to the root, bearing with lessened force on the less compressed portions higher up, and the gradation of force so manifested gives rise to the curve-the curve delineates the force, we may say the curve expresses the constant flow of the surrounding air to this diversified region of "least pressure,' ," its impulses being in graduated power from root to tip. By the bar we interfere with the direction of this flow, concentrate it more on the lower portion of the stem, and shield the tip of the reed from its influence; the upper portion, having thus lost so much of its natural support, is bent by the outflowing nodal wave of the pipe in a more supple curve, and to an extent now. equal to the required amplitude for its pitch. The form differs The curve of the "Gamba" is not the same as the curve of the "diapason." The distinct agency of the air-reed and the nature of the aircolumn in relation therewith being evident, the inference follows that the note produced is dual, consists of two unisonous notes blended into one sound. Quite unexpectedly the chosen pipe furnished me with the talisman to prove its truth. When the reed and the pipe are suitably mated, the union is one of perfect harmony; but the reed rules always: it may be sharp to the pipe, but the pipe can never be sharp to the reed, for on the first intimation of such the reed is roused, and starts forth to a tone of higher velocity. How slight a matter may derange the union of the reed and pipe. If we tease the pipe with this pencil, peace is disturbed. Our beautiful little "Gamba" is very sensitive and high-spirited, and cannot help letting us hear a little of the inner life of the home when things go a trifle wrong. There is one particular place across the mouth for the fixture of the bar: if, resting the pencil at the upper points of the projecting ears, you leisurely bring it down, you will hear the changing harmonics; then, halting just a hair's breadth or so before the true position is arrived at, all tone will be lost, and there will suddenly break forth a wailing "who-hoo, who-hoo;" that torture will continue until you relieve the suspense by moving the pencil another shade in descent, when the discord will resolve into the perfect tone, instantaneously, as two dew-drops when they touch melt into one. Precisely the same "who-hoo" as we hear when tuning two separate diapason pipes so nearly in tune that they are only a shade out of unison and just on the point of accord. The "Gamba" pipe and the reed were similarly at variance; the air-reed, not having quite yielded to the outward influence of the bar, was a trifle sharp to the pipe; the supernodal wave was too short and unable to effect a synchronisation with precision, and therefore the phenomenon of beats was manifested. We could have lengthened the supernodal wave and flattened the note by adding a portion to the top of the pipe, when concord would have followed, as it did by lowering the bar, for in tuning it matters not which note of two is altered to bring about unison; we might alter either pitch of pipe or pitch of reed; but by the lowering of the bar we flatten the reed, and cause thereby the descent of the node (then an uneasy fulcrum) and the lengthening relatively of the supernodal column. As a listener remarked "there was surely a fight going on inside," we settled it by favouritism, taking sides with the little "Gamba," and gaining the reed over in concession of its strength for the sake of concord. That is the explanation as it suggests itself to me, practically, exhibiting how a strong reed drives the node higher up in the pipe, and a weak reed favours the opposite; thus determining the variations in the lengths of pipes of unisonous pitch, so long an unsolved problem. Another point of some importance is also illustrated—that the earliest harmonics in the theoretical series may be out of tune with the fundamental. Here the introductory or transitive harmonics are, it is evident, all sharp to the ground tone, since the influence of the bar does not come into effect until its flattening power ushers in the fundamental; phenomena of this kind occur in other instruments mostly unacknowledged—it is admitted to be the case in the trumpet, which has No. 5 in the series flat, 7 still flatter, and 9 sharp. A diapason pipe will, however, exhibit the same in the small pipes of the higher octave; they may be blown to imitate exactly the clash of the trumpet. As showing the essential nature of the curve of the reed under the influence of the bar, it is worth notice that in the earlier "Violone" stops thus treated a square-faced bar was fitted, but with not so good effect as when the rounded bar was adopted; and in the light of our explanation we see why it should be so, for the curve could not form itself truly. The best form of bar is that given by a split pencil, the half-round, with the flat surface outward. Many other points of interest will be dealt with in another letter, on the interior movements of vibrating aircolumns. The study of the organ-pipe in every mood of its behaviour will make untenable the elegant fancy of a promiscuous assemblage of pulses fluttering and clamouring at the lip of the pipe, one of which out of a thousand it selects. It is a fair-seeming explanation, and under the commanding name of Prof. Tyndall generally accepted, for nothing better had been devised in philosophy. Not too strictly interpreting an ideality of expression, there yet remains an implied theory which is not in any sense borne out by the teachings of experience. The artist has some prescience of the powers that are to work his will; in practice |