army of the United States continues to be higher than that of any foreign armies, except the British and Italian. The principal causes of deaths were pneumonia and shot-wounds.

-Dr. William Osler, professor of clinical medicine in the University of Pennsylvania, has been appointed physician to the Johns Hopkins Hospital, and professor of medicine in the Johns Hopkins University. Dr. Osler took his degree in the McGill University, Montreal. He subsequently studied in London, Berlin, and Vienna, and in 1885 was appointed Gulstonian lecturer in the Royal College of Physicians, London, and in 1886 Cartwright lecturer in the College of Physicians and Surgeons, New York.

- Prof. Simon Newcomb has gained great benefit from his sojourn at Chelsea Hospital, and has now gone to Asheville, N.C., accompanied by his daughter, for the purpose of enjoying the fresh mountain air there.

- Major J. W. Powell, at the meeting of the Philosophical Society of Washington last Saturday, read a paper on 'The Laws of Corrasion,' explaining their methods of operation under various conditions; Prof. E. B. Fernow also read a very important paper on 'The Influence of Forests upon Quantity and Frequency of Rains.' The full text of the former, which is a very important discussion of a law first definitely announced by Major Powell in his letter to the New Orleans Chamber of Commerce, and a full abstract of the latter, will be published in early issues of Science.

-The wisdom of the policy of Surgeon-General Hamilton in establishing a camp of refuge for persons fleeing from points infected with yellow-fever is amply vindicated by the record of Camp Perry. The following despatch from Dr. Hutton, who is in charge of the camp, gives some interesting facts: "Oct. 20: To-day completes two months at Camp Perry; 810 refugees from infected points have been received; 721 have been discharged; 25 cases of fever developed; I death Sept. 9; not a case contracted in camp. Our 60 unacclimated employees, 5 of whom have been two months in fever-camp, not a single case of fever of any kind among them. Not a known case of fever reported from the 721 cases discharged and scattered to all parts of the country. In view of these facts, how any sanitarians can consider Camp Perry as an infected place is incomprehensible. Drs. Faget and Posey of New Orleans, Guitéras, and Geddings give this their emphatic indorsement."

Messrs. James W. Queen & Co., Philadelphia, have just issued a new catalogue of chemical apparatus. In this they have omitted reference to old and obsolete forms, and endeavored to make a catalogue the most complete and useful ever issued in this country. The catalogue will be mailed to any address on the receipt of fifty cents. The firm has added to its manufacturing facilities, and is prepared to make all kinds of scientific apparatus. Their facilities for making platinum ware are especially to be noted.

— The autumn meeting of the American Oriental Society in Philadelphia, Wednesday, Oct. 31, was the first to be held in that city, the society accepting at its May session the invitations extended on behalf of the University of Pennsylvania and the Oriental Club of Philadelphia. On Wednesday, at 3 o'clock P.M., the society met in the chapel of the University of Pennsylvania; and on Thursday morning and afternoon, in the hall of the Historical Society. The following is a list of the papers read: 'Report on the Exhibit of Oriental Antiquities of the Cincinnati Exposition,' by Cyrus Adler; 'On a New Testament Manuscript, Peshito Version, dated A.D. 1206, with a Text of the Traditions of the Apostles,' by Isaac H. Hall; A New Vedic Text on Omens and Portents,' by J. T. Hartfield; 'Qualitative Variations, in the Calcutta and Bombay Texts, of the Mahabharata,' and 'On the Later Puranas (in Sanscrit Literature),' by E. W. Hopkins; A New Reference in the Avesta to "the Life-Book" Hereafter,' by A. V. W. Jackson; 'On Transposed Stems in the Babylonian Talmud,' by Marcus Jastrow; 'On a Fragment of the Grammatical Works of Abu Zakarijjah Hajjug,' and 'On Symbols of the Sun-God and the Word Kuduru,' by Morris Jastrow, jun.; On a Samaritan Hebrew Manuscript in the Library of Andover Seminary,' by George F. Moore; 'On Rome Assyrian and Babylonian Royal Prayers,' and The Pantheon of Assur-banipal,' by D. G. Lyon; Remarks on

the Arabic Dialect of Cairo,' by C. H. Toy; The Babylonian Caduceus,' and 'A Babylonian Cylinder from Urumia,' by William Hayes Ward; 'Note on the Arch of Chosroes,' by Talcott Williams. Reports were read on The Collection of Oriental Antiquities recently deposited in Washington,' by one of the curators of the National Museum; and on 'The Recent Purchase of Cuneiform Tablets for the University of Pennsylvania,' by a member of the Chaldean Exploration Party.

- The Colorado Ornithological Association has been re-organized under the title of Colorado Biological Association.' Its objects are the detailed investigation and recording of the fauna and flora of Colorado, recent and fossil. Annual reports and special bulletins will be issued. The former are to contain a full bibliography of the published records for the State during the year. Mr. T. D. A. Cockerell of West Cliff, Custer County, is secretary of the association.

Benjamin B. Chamberlin, who has recently died, was born at Keeseville, Me., March 13, 1831. He was the son of the Rev. Parmalee Chamberlin, a Methodist clergyman, formerly well known in New York. After leaving school, he was apprenticed to Benjamin J. Lossing, then an engraver in New York, and subsequently went to Cincinnati to embark in business for himself. About 1865 he returned to New York. While in Cincinnati he turned his attention to collecting, his first hobby being medallions; and after his return to New York he took up the study of minerals, making a specialty of collecting those of New York and vicinity. For this work he had exceptional facilities, as the Fourth Avenue improvement was then in progress, and blasting was going on in many parts of the city now built over. He leaves one collection at the Nyack Library. His foreign collection he sold recently to Mr. Edward Pearson for the new school at Cloudland, N.J. He had been ailing for some years, but his death, which occurred at the home of his brother-in-law, Mr. E. H. Cole, at Nyack, on Oct. 13, was very sudden. At noon he had a severe hemorrhage, and at half-past two passed away, almost without a struggle. The cause of his death is believed to have been rheumatism of the heart. He was buried at Nyack Cemetery, Oct. 16.

Mr. John Gilmer Speed has become the editor of The American Magazine. Mr. Speed was for several years managing editor of the New York World, before it was purchased by its present proprietor. Since then he has spent much time in foreign travel, and has also been a frequent contributor to the magazines and newspaper press. He has written a life of John Keats, and edited his letters and poems. In conducting the magazine, it is Mr. Speed's purpose to make it all that its name implies, an illustrated monthly, representative of American thought and life. E. and F. N. Spon announce as in preparation, A Treatise on Masonry Construction,' by Ira O. Baker; 'Metallic Alloys,' by W. T. Brannt; Notes in Thermo-dynamics and Steam-Engine Experiments,' by Prof. C. H. Peabody; and · A Practical Treatise on Modern Printing Machinery,' by F. J. F. Wilson and D. Grey.

-

A.

& C. Black, Edinburgh, will publish this month the twenty-fourth and concluding volume of the Encyclopædia Britannica,' which has been under way nearly ten years. A general index to this encyclopædia is also in press, and may be looked for some time next year. Arrangements are being made, it is reported, with the sanction of the German Emperor, for the publication of an English translation of the Reminiscences of Ludwig Schneider, who was for twenty-six years the reader, secretary, and confidential friend of the Emperor William. Schneider's diaries were regularly revised by the Emperor every year, and his book is a work of great interest and importance. He accompanied the Emperor throughout the campaigns of 1866 and 1870-71, and one of the most interesting passages is his Majesty's own account of the battle of Rézonville. Much of the genuine value of the Atlantic lies in the terse, clean-cut, and vigorous articles on American history by John Fiske, the latest of which is entitled The Eve of Independence.' Mr. Fiske's historical articles are worthy of the highest praise. Lillie B. Chace Wyman continues her Studies of Factory-Life;' Miss Murfree, her serial story entitled The Despot of Broomsedge Cove;' and William Howe Downes, his papers on 'Boston Painters and Paintings.' William Roscoe Thayer con

tributes an article on The Makers of New Italy,' and John Trowbridge writes on Economy in College-Work.' The issue of The Youth's Companion for November contains the article, written expressly for that periodical by Mr. Gladstone, on 'The Future of the English-Speaking Races.' Outing for November contains, besides other notable features, the commencement of a series of articles on the Outdoor Life of the Presidents,' from the pen of John P. Foley; and the Progress of Athletism,' by Charles Turner.

The November Century begins the thirty-seventh volume and nineteenth year of the magazine; and the number is made notable by the beginning of several new series, or magazine 'features.' The most important of these is the first instalment of The Century 'Gallery of Old Masters,' engraved by T. Cole, and described by W. J. Stillman and by Mr. Cole himself. The engravings in this series were made in the presence of the original pictures themselves. They are actual copies, and unique in the history of art; for such careful copies have never before been made on wood. Another series begun in November is Mr. Cable's Strange True Stories of Louisiana.' After a preface by Mr. Cable himself, comes the extraordinary story of The Young Aunt with White Hair,' from an old French manuscript. Among the leading contributions to this number are instalments of the Life of Lincoln' and of George Kennan's papers on the Siberian exile system. The guilds of the city of London are described by Norman Moore. Other contributions include Bird Music: The Loon,' by Simeon Pease Cheney; 'Mammy's Li'l' Boy,' a negro dialect crooning song, by H. S. Edwards, illustrated by E. W. Kemble; Memoranda on the Civil War;' Open Letters by George Kennan, Rev. T. T. Munger, Richard Hoffman, and others; etc.

- Dr. John C. Branner, in the first volume of the Proceedings of the Lackawanna Institute of History and Science, gives an interesting sketch of the effects of glaciation in the Lackawanna-Wyoming region, his principal object being to attract special attention to a detailed study of these phenomena. He also publishes a list of localities at which glacial striæ have been observed in that region, for the guidance of those who may take up the work where he was obliged to leave it on being appointed director of the Geological Survey of Arkansas.

- The Boylston medical prize of four hundred and fifty dollars has been awarded by Harvard University to Dr. George H. F. Nuttall of San Francisco, for a dissertation entitled A Contribution to the Study of Immunity."

The Journal of Economics for October opens with a paper by James Bonar on the Austrian economists. Their principal work has been on the theory of value, which they profess to present in an entirely new light; but Mr. Bonar shows that their view, though expressed in new terms, is not so different from that of the English writers as they seem to suppose. Their discussion of subjective value' is in his opinion their principal contribution to economics. Another theoretical article is that by Stuart Wood on A New View of the Theory of Wages.' The author starts with the fact that in some employments a certain work can be done either by. labor or by capital; and from this he deduces the law that in such cases the price paid for a given amount of labor will be equal to the interest on the capital that can be substituted for it. Then the rates of interest and wages thus established will also prevail in all other employments. According to this theory, wages depend on interest; but what interest itself depends on, the author neglects to say. Professor Dunbar's paper on Alexander Hamilton shows that in his sinking-fund scheme, and in establishing the Bank of the United States, Hamilton followed English precedents, though with some variations; but that his plan for establishing the national credit on a firm basis was so comprehensive and so successful as to entitle him to rank as a great financial statesman. The article on The Australian Tariff Experiment' is a comparative exhibit of the effects of free trade in New South Wales and of protection in Victoria. The general outcome is to show that manufactures have prospered as well in the free trade colony as in the protected one, while in commerce and in growth of population the former has taken the lead. Wages are essentially the same in both; so that in this case, at least, protection has not raised wages. The acts given in this paper have been published in different forms

elsewhere; but, in the present state of our own tariff question, this new presentation of them will attract attention, and doubtless be useful.

LETTERS TO THE EDITOR.

**Correspondents are requested to be as brief as possible. The writer's name is in all cases required as proof of good faith.

Twenty copies of the number containing his communication will be furnished free to any correspondent on request. The editor will be glad to publish any queries consonant with the character of the journal. Dream Excitation.

THE direct influence of slight sense-stimuli upon the flow and make-up of our dream consciousness is a well-known fact, which can be proved by artificial experiment (see MAURY, Le Sommeil et les Rêves, p. 132, etc.), but which it is difficult to confirm under ordinary circumstances, since we seldom waken after a well-marked dream experience in time to catch the stimulus, or without altering the stimulus by movement, etc. On the night of Oct. 22 I had a dream which perfectly fulfilled the conditions of this experiment. I fell asleep about eleven o'clock, and found myself with a companion in a wood, watching a number of wood-cutters at work. After looking at them for some time, one of the workmen drew my attention quite suddenly by giving forth a strange sound, half musical and half speech, by which he seemed to be trying to express something to his neighbor; and the sound came with every blow of his axe in regular rhythm. The sound seemed to me distinctly familiar and yet very strange, and I turned to my friend and said, "What an apology for conversation!" Just as I spoke, I awoke, and the sound of the peculiar tone of a clock down stairs striking twelve broke in upon my consciousness. The four remaining strokes of the clock preserved exactly the rhythm of the woodchopper's axe; and not only so, but the sense of familiarity which had puzzled me in the dream was relieved with a glow of pleasure as I recognized the sound of the clock.

This experience illustrates also the remarkable swiftness with which new sensations are assimilated to the character of a previous dream consciousness. Before the clock began, the men were simply cutting, without order or distinction. But when the sound broke in, it was at once accommodated to the scene by important modifications. One workman is singled out: he begins to ply his axe in the regular time of the clock-beats, and to give forth a sound which preserves in its general character the peculiarities of the real sound. Now, since I experienced in the dream no less than four beats, as the rhythm was perfectly established and clear in my consciousness, and there remained four beats after I awoke, this whole accommodation must have taken place in the interval between the first and the fifth beat (for it was then twelve o'clock). I have since measured the interval between the strokes of the clock, and find it to be two seconds. The whole time from the first to the fifth beat was therefore eight seconds. From this should be taken the time occupied by the dozed state between dreaming and waking, — say, at least one interval of from two to four seconds. There remains a period of four to six seconds as the time of accommodation. This may be called, in a very rough way, the reaction time for a complex case of constructive imagination; for the constructive imagination is nothing more than the free play of images in forms of ideal composition, due to the influx of additions from the sensorium. There is no direct way of measuring this time in the waking state, since the attention interferes with the proMARK BALDWIN. Lake Forest, Ill., Oct. 23.

cess.

Chemical Action between Solids. APROPOS of Messrs. Spring and Hallock's controversy (Science, xii. p. 184), I think that the re-actions between silica and the metallic oxides at temperatures far below the melting-point, not only of both components but even of the silicate itself, have generally been regarded as occurring directly between solids. When certain mixtures of lime and silica are strongly heated, though there be not the slightest indication of fusion, yet some chemical action seems to occur, for the silica now separates in the gelatinous state when acted on by hydrochloric acid (PERCY, Fuel, p. 46, 1875). HENRY M. HOWE.

Boston, Oct, 28.

The

THE PAST SEASON has been one of unusually successful activity with the United States Fish Commission, a review of whose work is published elsewhere in this issue of Science. Probably the most important accomplishment during the year has been the establishment, at Gloucester and Wood's Holl, of stations capable of hatching four hundred million codfish-eggs, and which, with favorable weather, may be expected to put at least one-fourth of that number of cod-fry into the Atlantic Ocean during the present season. problem of restocking the coast of New England with inshore cod, which has become so scarce except in Ipswich Bay, has been definitely solved. It is only a question of time, and a very short time at that, before codfish can be made to be more plentiful on the coast of New England than they were years ago, and a lost industry restored that will be worth millions of dollars to that section of the country. The only probable causes of delay are bad weather during the hatching-season, and anchor-ice, which kills the small fishes. It is known that only an infinitesimally small proportion of the fry hatched out at the fish-commission stations, and put into the rivers and lakes and the ocean, ever survive to reach maturity. It is only by planting an enormous quantity of the fry that the supply of fish is increased. It is claimed, that, of those artificially propagated, a much larger proportion survive than when the eggs are deposited naturally in the stream. In order to ascertain whether the number of small fishes to survive might not be enormously increased, Commissioner McDonald placed in a pond in Washington, in June, two million shad-fry. Eight hundred thousand of these are still alive, — breathing fishes from three to four inches long each. These will be kept until spring, and then placed in the Potomac. As a rule, they will by that time be able to take care of themselves. The remarkable success of this experiment may cause an entire change in the methods of artificially propagating shad. A new scheme of gathering up the small indigenous fishes hatched in ponds and lakes on the borders of Western and Southern rivers after their annual overflow, and planting them in the rivers, which, in many cases, have been depleted by over-fishing and the destructiveness of the floods, was put into successful operation this year. A hundred thousand fishes were thus rescued from sure death, when, later in the season, these lakes and ponds dry up. On the Pacific coast the steamer Albatross' has done the preliminary work of developing the extremely valuable halibut-fishing grounds that lie off the coast of Washington Territory and Vancouver's Island, convenient to the ports of Puget Sound, defined the boundaries of several deep-sea codfishing banks off the coast of Alaska, and will devote the winter to similar work in lower latitudes. The results of her first season's work are expected to be of very great economic value to the Pacific coast. These are but a few of the branches of work accomplished by the United States Fish Commission during the past season, though probably the most important. This commission is the most profitable of all the bureaus of the government, and ought never to lack for money.

ON NOV. 2 the following telegram was sent from Zanzibar: 'Couriers from Tabora bring direct news from the Stanley expedition, a portion of which was met at the end of November, 1887, by Arabs trading between Lakes Victoria Nyanza, Mvutan Nzige, and Tabora. These Arabs met Stanley's rear guard at a point west of Mvutan Nzige, south-east of Sanga, just as the expedition was preparing to cross extensive swamps. The Arabs did not see Stanley.

The detachment seen consisted of thirty men. They stated that Stanley was two days ahead. The expedition had suffered greatly on the march through a thick forest, where it was impossible to advance more than a mile and a quarter daily. They had also suffered in the marshes, where many had disappeared or died. Forty were drowned in crossing a great river flowing from east to west. One white man had died. Stanley was obliged to fight some tribes that refused to supply him with provisions. The expedition had often halted in the expectation of receiving re-enforcements from the Kongo. The rear guard, at the time met, had only been on the march five days after a halt of three weeks, due to the illness of Stanley and a great part of the escort, who had been attacked with fever. The Arabs estimate the total strength of the expedition, after all losses, at two hundred and fifty men. The health of Stanley was then good. The rear guard, which consisted of natives of Zanzibar, stated that Stanley had decided that he would no longer advance in a north easterly direction, but would strike toward the north, hoping to avoid the swamps. After getting a certain distance north, he intended to take an oblique line to the eastward, and go straight to Wadelai, where it was thought he would arrive fifty days later, about the middle of January, 1888. The Arabs were of the opinion that the expedition was still strong enough to reach Wadelai." We hesitate to accept this news as authentic, as it corresponds too closely to the views recently expressed in numerous newspapers, particularly regarding Stanley's intention to turn northward. Sanga, which is mentioned in this despatch, was visited by Junker in 1882, and marks the south-eastern limit of our knowledge of this region. The Arabs, who claim to have met part of the expedition, must have penetrated beyond the limits of Unyoro. It will be remembered that on Lake Mvutan Nzige and Muta Nzige no information was obtained by explorers regarding. the regions farther west, and that there seems to be little communication in this direction. Therefore the report would imply that the Arabs had recently succeeded in opening this country to their trade. Besides this, their route must have led along Lake Mvutan Nzige, where Emin had re-established, a year since, his influence. Therefore it seems somewhat remarkable that no mention is made of Emin Pacha. Another despatch which was received on Aug. 1 in Zanzibar is undoubtedly an invention. It was stated that two messengers had arrived there who had left the interior about the beginning of April, and who reported that Stanley had not arrived at Wadelai up to that time. The messengers stated that in the month of March Emin Pacha did receive some vague and indecisive news of the explorer, which had filtered through from tribe to tribe, but that the reports were very conflicting. Some declared that Stanley, after losing a number of men and a large portion of his supplies, was hemmed in by hostile tribes between the Mabode country and the Mvutan Nzige, while other rumors were to the effect that he had been attacked by the tribes in the Matongora-Mino district, and after several conflicts had diverted his course in an unknown direction. The wording of this despatch is almost exactly the same as that of another received about fifteen months ago, and therefore it cannot be accepted as genuine.

THE ERUPTION OF KRAKATOA. THE Krakatoa committee of the Royal Society has made its final report,' which forms a large quarto volume, and contains a mass of material of the greatest interest. After the remarkable phenom

1 The Eruption of Krakatoa, and Subsequent Phenomena. Ed. by G. J. SYMONS. London, Trübner.

ena following the eruption of Krakatoa on Aug. 27, 1883, became first known, and when the optical phenomena attracted increasing attention of the whole civilized world, the Royal Society of England, on Jan. 17, 1884, passed the following resolution: "Resolved, That a committee, to consist of Sir F. Evans, Professor Judd, Mr. Norman Lockyer, Mr. R. H. Scott, General Strachey, and Mr. G. J. Symons, with power to add to their number, be appointed, to collect the various accounts of the volcanic eruption at Krakatoa, and attendant phenomena, in such form as shall best provide for their preservation, and promote their usefulness." A history of the work of the committee is detailed in the preface, its expansion by fusion with a committee of the Royal Meteorological Society and by election of new members, and its method of proceedings. At the end of November, 1884, the discussion of the data collected was commenced, which were divided into five portions, each going to a separate sub-committee, and each giving a separate report, which forms the present volume. Thus the work is divided into five parts: 1. On the Volcanic Phenomena of the Eruption, and on the Nature and Distribution of the Ejected Materials,' by Prof. J. W. Judd; 2. On the Air-Waves and Sounds caused by the Eruption,' prepared in the Meteorological Office, and presented by Lieut.-Gen. R. Strachey; 3. On the Seismic Sea-Waves caused by the Eruption,' by Capt. W. J. L. Wharton; 4. On the Unusual Optical Phenomena of the Atmosphere, 1883-86, including Twilight Effects, Coronal Appearances, Sky Haze, Colored Suns, Moons, etc.,' by the Hon. F. A. Rollo Russell and Mr. E. Douglas Archibald; 5. Report on the Magnetical and Electrical Phenomena accompanying the Eruption,' by G. M. Whipple.

While the Dutch report by Verbeek deals with the local phenomena, the English committee paid specal attention to the meteorological and other occurrences which took place all over the earth.

The most interesting part of Professor Judd's account is his theory as to the part played by water in causing or aiding eruptions. He believes that the disengagement by heat of volatile substances actually contained in the lava is the primary cause of volcanic activity. He proves that the melting-point of all lavas of Krakatoa of different ages, although of the same chemical composition, vary to a great extent according to the amount of water contained in them, their fusibility being greater when water is present. In this case, on melting, they develop a great amount of gases. "In this way the actual nature of the volcanic manifestations at any ⚫ particular vent are seen to be determined, not so much by the mineralogical constitution of the lava, as by the circumstance of the quantity of water contained in the magma. Where this is great, the lava will be perfectly liquid, and will be almost wholly thrown out in the form of pumice and dust. On the other hand, lavas containing little water will require a very high temperature for their fusion, and they will be characterized by great viscosity rather than perfect liquidity. It is through the introduction of the sea and other surface waters into rock masses by slow percolation from above, and the consequent formation of new compounds, more readily acted upon by subterranean heat, that I am disposed to regard volcanic phenomena as being brought about. In this we find an explanation of the proximity of volcanoes to great bodies of water, which, it seems to me, is far more in accord with the actual phenomena than the supposition that water finds access to volcanic foci by means of actual open fissures."

Professor Judd shows very clearly that the effect of the inrush of water upon lava is quite different, and, especially in the case of Krakatoa, resulted in the formidable violence of the eruption. When the volcano became so far eviscerated as to give access to the water of the sea, the latter cooled the surface of the magma, and as a result the activity of the volcano diminished. As, however, the disengagement of volatile substances actually contained in this material continued, the formation of this crust would have the same effect as fastening down the safety-valve of a steamboiler, while the fires below were maintained in full activity. This constant augmentation of tension beneath Krakatoa, in the end gave rise to the tremendous explosions which made the eruption of the volcano so remarkable.

In the second part, General Strachey discusses the remarkable atmospheric oscillations, which, starting from Krakatoa, moved as many as seven times over the earth. Their propagation from the

volcano to its antipodes and back is shown on a number of interesting maps. The principal results of the inquiry into the movements of this disturbance are, that it had very nearly the characteristic velocity of sound, ranging from 648 to 726 English miles an hour, and that its mode of propagation by an aerial oscillation of comparatively short duration was also closely analogous to that of sound. Waves travelling with and against the direction of the earth's rotation show differences of velocity of about twenty-eight English miles an hour. This may probably be accounted for by the circumstance that the winds along the paths of this portion of the wave would, on the whole, have been westerly, which would have caused an increase of velocity in the wave moving in the opposite direction; so that the observed difference of twenty-eight miles could be produced by an average westerly current of fourteen miles per hour, which is not unlikely.

The author continues, "There is some appearance of a greater retardation of the wave in passing in a direction opposed to the earth's rotation over the northern European stations as compared with those in the south of Europe, which may possibly be due to the lower temperature of the more northern part of the zone traversed. This difference is not to be traced in the wave moving in the opposite direction, which may be accounted for by the path of the wave, when approaching Europe from the west, having lain for a long distance over the Atlantic, where the differences of temperature between the northern and the southern borders of the zone traversed would have been relatively small.

"The path of the wave that passed over the Canadian and United States stations, and Havana, lies nearly on the meridian drawn through Krakatoa, and must have crossed both the polar circles near the poles. The velocities obtained from these stations are peculiar. The direct wave from Krakatoa, which travelled nearly due north and close to the north pole, and its repetitions after passing round the earth in the same direction, had nearly the same velocities as those observed at the European stations, with an apparent decided retardation in the intervals between the first and third passages, and (but to a less extent) between the third and fifth. The wave that passed through the antipodes before reaching the North American stations went nearly due south close to the south pole; and its velocity on this its first partial passage round the earth was very decidedly reduced; but in its next complete circuit the velocity appears to have been much increased, almost reaching the full rate of the true sound-wave. It is difficult to account for this, but the fact seems to be indisputable. Probably an explanation of this peculiar feature of the phenomena may be found in the conditions of the wind and weather in the southern ocean during the days on which the wave passed over it, which are not known to us."

In the second part of General Strachey's report a list of places is given at which the sounds of the explosions at Krakatoa were heard on the 26th and 27th of August. In all directions the sound was heard at a distance of two thousand miles from the volcano, while south-westward it was even noticed at Rodriguez, very nearly three thousand miles from Krakatoa.

Captain Wharton, in his discussion of the seismic sea-waves caused by the eruption, distinguishes two descriptions of waves, long ones, with periods of over an hour; and shorter but higher waves, with irregular and much briefer intervals. The greatest disturbance which followed the great explosion of the volcano resulted in waves about fifty feet high in the Strait of Sunda, and caused the vastest destruction. The speed of both classes of waves was about the same, and it is remarkable that it was in all cases less than the depth of water would demand according to theory. To the north and east in the Java Sea the long wave can be traced for 450 miles, but it was at this distance reduced to a very small undulation. To the west, on the other hand, the long wave travelled over great distances, and reached Cape Horn and the shores of Europe. The shorter waves did not extend beyond Ceylon and Mauritius. South-eastward the disturbance did not continue beyond the west coast of Australia; the disturbances noted in New Zealand and in the Pacific evidently being caused by other seismic action, and having no connection whatever with the eruption of Krakatoa.

By far the greater portion of the report is taken up by the dis