It is only in the more open spots that a botanist is able to make close acquaintance with the smaller trees and shrubs. Near to the stream I was able to hook down a branch and secure flowering specimens of a Begonia that grew to a height of over twenty feet. In such situations Melastomaceæ were everywhere abundant, but for variety of forms the ferns surpassed any of the families of flowering plants. I was surprised to find that the beautiful tree ferns, that add so much to the charm of the tropical flora, were rarely to be found with fructification, and the huge fronds being of quite unmanageable dimensions, I did not attempt to collect specimens. Of the smaller kinds, when I was able, with the kind assistance of Mr. Baker, of Kew, to name my specimens, I found that I had collected thirty-five species in the neighbourhood of Petropolis.

During my stay here I visited a German gentleman whose singular manner of life excites the interest and curiosity of the European residents. I am ignorant of the motives that have led Mr. Doer, evidently an educated and cultivated man, to lead the life of a hermit far from his native country. He has built for himself a small house in the forest, on one of the hills that enclose the basin of Petropolis, and lives quite alone, except for the daily visit of a boy who carries the provisions that satisfy his very moderate wants. He seems to be entirely occupied in studying the habits of the native animals of the country, and especially those of the Lepidopterous insects—butterflies and moths—that adorn this region. By attention to the habitual food of the various species, he has succeeded in keeping in his house the caterpillars that in due time produce the perfect insect, and has preserved in cabinets large collections of fine specimens.

At the suggestion of the friend who accompanied me, Mr. Doer was good enough to introduce me to the family of small monkeys which he has raised and domesticated. The senior members had been brought from some place in Northern Brazil, but they had multiplied, some of the offspring being born in his house, and now formed a rather numerous party. The creatures habitually passed the day in the forest, never, in Mr. Doer’s belief, wandering to a distance from the house, and at night came in and nestled among the rafters of the roof. The call was by a peculiar note, somewhat resembling a low whistle, repeated two or three times, and before a minute had elapsed the little creatures came swarming about the open window. They were decidedly pretty, their large black eyes giving an impression of intelligence, but I did not detect any indication of attachment to their master. I cannot say to what species they belonged. They had large ears like those of the marmoset, but differed in having a prehensile tail. One of them hung with his head downward, suspended by the tail from some projection above the window. After receiving some fragments of sweetmeat they soon departed, returning to their favourite haunts among the trees of the forest.

Starting early one morning, and reaching the crest of the range that divides Petropolis from the Bay of Rio Janeiro, I enjoyed in great perfection a spectacle that is commonly visible at this season when the weather is clear and settled. Before sunrise a stratum of mist extends over the bay and the low country surrounding it. As I saw it, this may have been about a thousand feet in thickness when the sun first reached it, and the fantastic summits of the mountains rose like islets from a sea of dazzling white. As the sun’s rays began to act, the mist appeared to melt away from above; the lower hills and the rocky islands of the bay emerged in succession, and finally the veil completely disappeared, and the whole wondrous view was completely disclosed.

The beautiful effects displayed in the gradual disappearance of mist as seen from a height in early morning must be familiar to every genuine mountaineer, and may be enjoyed amongst the hills of the British Islands. Among my own recollections, a certain morning, when I stood alone at sunrise on the highest peak of the Pilatus, near Lucerne, showed the phenomenon in a most striking way, accompanied as it was by the coloured halo that surrounds the shadow of the observer thrown on the cloud-stratum below. But in my previous experience the disappearance of the mist was always accompanied by the upward movement of some portions of the mass. The surface appears to heave under the action of force acting from below, and some masses are generally carried up so as temporarily to envelope the observer. In the view over the Bay of Rio I was much farther away from the surface of the mist than in previous experiences of the kind, and I may have been misled by distance from the scene of action, but, though watching attentively, I saw no appearance of heaving of the surface or any break in its regular form. The waste seemed to proceed altogether from the upper surface, and the emergence of the prominent objects in regular succession gave direct evidence to that effect.

During the first five days of my visit the weather at Petropolis was perfectly enjoyable. The temperature varied from about 60° Fahr. at sunrise to about 70° in the afternoon; but the effect of radiation must have been intense, as in an exposed situation a minimum thermometer descended on one night to 46°, and on the next to 44°, and the dew was heavier than I have ever seen it elsewhere, so that in some places the quantity fallen from the leaves of the trees made the ground perfectly wet in the morning. The barometer varied very little, even after the weather changed, and stood as nearly as possible three inches lower than at Rio, showing a difference of level of about 2900 feet. On the 16th of July the sky became overcast, and some rain fell in the afternoon, the thermometer rising at two p.m. to 73° Fahr., and moderate rain fell on each succeeding day until the evening of the 19th, but scarcely any movement of the air was perceptible. There is a remarkable difference in the distribution of rainfall between the part of Brazil lying within about fifteen degrees of the equator and the region south of that limit. At Pernambuco (south lat. 8° 4′), out of an annual rainfall of about a hundred and ten inches, nearly ninety inches fall during the six months from March to August, and at Bahia, with less total rainfall, the proportion is nearly the same. But at Rio Janeiro the rainy season falls in summer, from November to March, and winter is the dry season. Of an annual rainfall of forty-eight and a half inches, only five and a half inches fall in the winter months, June, July, and August, and less than an inch and a half in July. No doubt the amount of rain is greater at a mountain station such as Petropolis, while the proportion falling in the different seasons must be about the same.

At Petropolis, as well as elsewhere in South America, I was struck by the fact that the children of European parents born in the country speedily acquire the indolent habits of the native population of Spanish or Portuguese origin. The direct influence of climate is doubtless one cause of the change of disposition, but I suspect that the chief share is due to the great difference in the conditions of life which are the indirect results of climate. Where mere existence is so enjoyable, where physical wants are so few and so easily supplied, the chief stimulus to exertion is wanting, and the natural distaste for labour prevails over the hope of gain. A boy will prefer to pick up a few pence by collecting flowers, or roots, or butterflies in the forest near his home, to earning ten times as much by walking to a distance, especially if expected to carry a light weight. On my first visit to Itamariti I took with me a German boy, whom I left in charge of the superfluous horse that I had been advised to take with me. Finding the occupation a bore, and probably fearing that he would have to carry back the portfolio and vasculum that I had taken for plant-collecting, he fastened the bridle to a tree and disappeared, never coming to claim the pay promised for his unaccomplished day’s work.

All delightful times come to an end, and, as I resolved to visit Tijuca before departing from Brazil, I quitted Petropolis on the morning of July 20, and made my return to Rio amid brilliant sunshine, in which the glorious scenery of the bay renewed its indelible impression on my memory. In passing over the tract of low land between Raiz da Serra and the shore, partly overgrown by shrubs or small trees ten or twelve feet in height, I found them covered with masses of large flowers of the most brilliant purple hue, where ten days before not a single flower had been visible. The train halted for half a minute at a solitary half-way house, and I was able to break off a branch from the nearest plant. It belonged, as I suspected, to the family of Melastomaceæ, and is known to botanists as Pleroma granulosum of Don; but one seeing dried specimens in a European herbarium, could form no conception of the gorgeous effect of the masses of rich colour that were here displayed, outshining the splendours of the Indian rhododendrons now familiar to European eyes. I again found the same species at Tijuca; but the soil and situation were, I suppose, less favourable, and the show of bloom was neither so rich nor so abundant.

I was told that the local name of this splendid plant is quaresma, because it flowers in Lent, which in Brazil falls in autumn; but I afterwards ascertained that the same name is given to several other species of Melastomaceæ having brilliant flowers, and it seems improbable that the same species which I found bursting into flower in mid-winter should have also flowered three or four months before. The only remains of fruit that I found were dry, empty capsules that had apparently survived the preceding summer.

Although I reached Rio some time before midday, so many matters required my attention that I found it impossible to return for a fuller visit to the Botanic Garden. Mr. Corbett had kindly offered to present me to the emperor, and, if time had permitted, I should have gladly taken the opportunity of making the personal acquaintance of a sovereign who stands alone among living rulers for the extent and variety of his scientific attainments, and for the active interest he has shown in the progress of natural knowledge. Irrespective of the qualities that appeal to the sympathies of men of science, Dom Pedro is evidently one of the remarkable men of our time. His exceptional energies, physical and mental, are incessantly devoted to every branch of public affairs, and it is said that he has even succeeded in inspiring some of his subjects with a share of his own zeal. But, so far as I could learn, he cannot be said to have achieved popularity. Among indolent and listless people, indefatigable industry produces an unpleasant effect. Improvements may or may not be desirable, but they are certain to give some trouble: it would be far pleasanter to let things remain as they are. Perhaps, whenever the time comes for Brazil to be deprived of the guidance of the present emperor, its people will become sensible of the loss they have sustained.

The steamer of the Royal Mail Company was to depart on July 24, so that no time was to be lost in making my visit to Tijuca. That place lies among the hills north-west of the city, about nine hundred feet above the sea, and the distance is quite inconsiderable; but the arrangements for visitors are inconvenient. A tramway runs over the flat country to the foot of the hill, and from the terminus the remainder of the way is accomplished by carriage or omnibus. But no luggage is taken by the tramway, and this has to be forwarded on the previous day. When I reached the station, about eleven a.m. on the 21st, I had an unpleasant quarter of an hour, during which it appeared that the case containing most of my Petropolis collections was lost or mislaid. At length it was found lying in an outhouse; no omnibus was available, but I soon succeeded in hiring a carriage to convey me to Tijuca.

The country between the city and the lower slopes of the hills is covered with the villas of wealthy natives, many of them large and handsome houses, each surrounded by a garden or pleasure-ground. In these grounds the mango, bread-fruit tree, and others, with large thick leaves giving dense shade, were invariably planted; and here and there palms, of which I thought I could distinguish four or five species, gave to the whole the aspect of completely tropical vegetation. Amidst the mass of trees, it was rarely possible to get a glimpse of the exquisite scenery surrounding Rio on every side, and it was only towards the top of the hill that I gained a view of the bay. Tijuca lies on the farther, or westward, slope, nearly surrounded by forest, and consists of only a few houses, of which the chief is White’s Hotel. As I afterwards learned, Mr. White, who is engaged in business in the city, was in the habit of hospitably entertaining his friends at a spot which naturally attracted frequent visits, and at length judiciously turned his house into an hotel, where a moderate number of guests find charming scenery, comparative coolness in the hot season, and far more of creature-comforts than are to be had in the hotels of Rio.

Time allowed me no more than a short stroll in the immediate neighbourhood before the hour of dinner, at which I met several intelligent and well-informed gentlemen, and amongst them three English engineers, from whom I received much information as to the country which they have made their home.

Amongst other questions discussed was that, so important to Europeans, regarding the annual visitation of yellow fever and the best method of treatment. I was especially struck by the experiences of the youngest of the party, who had come out from England a few years before to superintend some considerable new works for the drainage of Rio. For two years he lived altogether in the city, constantly requiring to go below, and sometimes remaining for hours in the main sewers. During that time he was never attacked by the fever, and no fatal cases arose among the workmen engaged in the same work. Since its completion this gentleman had been engaged on other works of a more ordinary character, and had habitually slept in the country during the hot season; but, under conditions apparently more favourable, he had been twice stricken by the fever. The first attack, which was probably slight, was at once cut short by a large dose of castor oil and aconite administered by a friend. In the following year he experienced a more serious attack, and had been treated by a doctor of good repute, mainly with tartar emetic. It appears that professors of the healing art in Brazil regulate their charges, not by the amount of time or labour which they give, but by the estimated value of the patient’s life. If he survives, it is considered that the remuneration should be in the nature of salvage—a considerable percentage on the amount of his income. In the present case the young engineer had been required to pay a fee of £180. In some cases, where the doctor’s demand appeared utterly unreasonable, foreigners have attempted to appeal to the tribunals, but it appears that the results of litigation have not encouraged others to resort to the protection of the law.

In answer to my inquiries, most of my informants made light of the difficulties of exploring the interior of Brazil, but they agreed in the opinion that much time must be given by any traveller wishing to break new ground. Even in the more or less fully settled provinces, the spaces to be traversed are so great, and the means of communication so imperfect, that a large margin must be left for unexpected delays. One gentleman, who had travelled far in Goyaz and Matto Grosso, assured me that he had never encountered any difficulty as to provisions. Three articles of European origin are to be found, so he assured me, at every inhabited place in the interior—Huntley and Palmer’s biscuits, French sardines, and Bass’s pale ale.

July 22 was a day of great enjoyment, devoted to the immediate neighbourhood of Tijuca, where objects of interest were so abundant as to furnish ample occupation for many days. I have said that the place is almost surrounded by the forest which spreads over the adjoining hills. I now learned that less than fifty years before, at a time when coffee-planting in Brazil became a mania, and was counted on as everywhere a certain source of wealth, the aboriginal forest which covered the country was completely cleared, and coffee-planting commenced on the largest scale. Experience soon proved that the conditions either of soil or climate were unfavourable, and after a few years the land was again abandoned to the native vegetation. About thirty-five years had sufficed to produce a new forest, which in other lands might be supposed to be the growth of centuries. The trees averaged from two to three feet in diameter, and many were at least seventy feet in height. One of the largest is locally called ipa; it belongs to the leguminous family, has a trunk nearly quite bare, and the upper branches bore masses of cream-coloured flowers; but, finding it impossible to obtain flower or fruit, I have been unable to identify it. The vegetation here appeared to be even more luxuriant than that of Petropolis, and to indicate a somewhat higher mean temperature. The proportion of tree ferns was decidedly greater, and a good many conspicuous plants not seen there were here abundant. Some of these, such as Bignonia venusta, Allamanda, etc., may have strayed from the gardens; but many more appeared to be certainly indigenous. Of flowering plants the family of Melastomaceæ was decidedly predominant, and within a small area I collected fifteen species, eight of which belonged to the beautiful genus Pleroma. One of these (P. arboreum of Gardner) is a tree growing to a height of forty feet; but the species of this family are more commonly shrubs not exceeding ten or twelve feet in height.

I was unfortunately not acquainted at that time with the observations made near Tijuca by Professor Alexander Agassiz, which appear to him to give evidence of glacial action in this part of Brazil. It would be rash, especially for one who has not been able to examine the deposits referred to, to controvert conclusions resting on such high authority; but I may remark that the evidence is confessedly very imperfect, and that the characteristic striations, either on the live rock or on the transported blocks, which are commonly seen in the theatre of glacial action, have not been observed. I lean to the opinion that the deposits seen near Tijuca are of the same character as those described by M. Liais46 as frequent in Brazil. The crystalline rocks are of very unequal hardness, and while some portions are rapidly disintegrated, the harder parts resist. The disintegrated matter is washed away, and the result is to leave a pile of blocks of unequal dimensions lying in a confused mass.

On the following day, my last in Brazil, one of my new acquaintances was kind enough to guide me on a short excursion in the forest, which enabled me to approach one of the giants of the vegetable kingdom. At the time of the clearing of the aboriginal forest two great trees were spared. One of these had been blown down some years before my visit, and but one now remained. It was easily recognized from a distance, as it presented a great dome of verdure that rose high above the other trees of the forest. The greater part of the way was perfectly easy. A broad track, smooth enough to be passable in a carriage, has been cleared for a distance of many miles over the forest-covered hills.

Following this amid delightful scenery, we reached a point scarcely two hundred yards distant from the great tree. I had already learned that even two hundred yards in a Brazilian forest are not very easily accomplished, but I was assured that a path had been cut a year or two before which allowed easy access to the foot of the tree. We found the path, but it was soon apparent that it had been neglected during the past season, and in this country a few months suffice to produce a tangle of vegetation not easily traversed.

When at length we effected our object, we found ourselves at the base of a cylindrical column or tower, with very smooth and uniform surface, tapering very slightly up to the lowest branch, which was about eighty feet over our heads. We measured the girth, and found it just twenty-nine feet at five feet from the ground. It is needless to say that I could form no conjecture as to the species, or even the family, to which this giant belongs, as I was quite unable to make out the character of the foliage. While near to it we could form no guess as to the height; but my companion, whose profession made him used to accurate estimates, and who had observed it from many points of view, reckoned the height at between 180 and 200 feet. I had not then seen the giant conifers of western North America, but, excluding the two Sequoias, I have not found any single tree to equal this. In the valleys of the Alleghany Mountains in Tennessee, I have indeed beheld not unworthy rivals. The Liriodendron there sends up a stem more than seven feet in diameter, and frequently exceeds 150 feet in height.

To diminish my regret at quitting this beautiful region, the morning of July 24 broke amid dark clouds and heavy rain, which continued till the afternoon. I had counted on enjoying a few hours in Rio before my departure, but, that being impossible, I went directly from Tijuca to the landing-place, and thence on board the steamer of the Royal Mail Company, which was to take me back to England. This was the Tagus, and I had much pleasure in finding her under the command of Captain Gillies, with whom I had made the voyage from Southampton to Colon. In the afternoon we slowly steamed out of the bay. Its glories were veiled, heavy clouds rested on the Organ Mountains; but the Corcovado and the other nearer summits appeared from time to time, and the last impression was that of fleeting images of beauty the like of which I cannot hope again to behold.

The course for steamers from Rio Janeiro to England is as nearly as possible direct. The coast of Brazil from Rio to Pernambuco runs from south-south-west to north-north-east, in the same direction that leads to Europe; and from the headland of Cabo Frio to the entrance of the English Channel at Ushant, a distance of about 72° of latitude and 38° of longitude, the helm is scarcely varied from the same course. It is somewhat remarkable that in so long a voyage, in which one passes from the Tropic of Capricorn to the region of the variable anti-trade-winds of the northern hemisphere, it not very rarely happens, as I was assured by our experienced captain, that north-north-east winds are encountered throughout the entire distance. This was nearly verified in the present case. For comparatively short periods the wind shifted occasionally to the north and north-west; more rarely, and at brief intervals, light breezes from the south and south-east were experienced; but the north-east and north-north-east winds predominated, even on the Brazilian coast, until we reached the latitude of Lisbon.

It is an admitted fact in meteorology, that the trade-winds of the northern are—at least in the Atlantic—stronger than those of the southern hemisphere; but at the winter season of the south, the south-east trade-winds prevail in the equatorial zone, and are not rarely felt as far as eight or even ten degrees north of the equator. But in investigating the extremely complex causes that determine the direction of air currents, and especially those slight movements that make what is called a breeze, it is difficult to trace the separate effect of each agent. The neighbourhood of a coast constantly brings local causes into play, and it may well be that the rapid condensation of large masses of vapour, such as occurs at each heavy fall of rain, may determine temporary currents in the air in directions opposed to the general and ordinary march of the winds. Irrespective, however, of any such local causes, we must bear in mind the general tendency of air currents towards motion of a circular or spiral character. When we meet a breeze blowing in a direction contrary to that which ordinary experience leads us to expect, we must not forget the possibility that it may be a portion of the ordinary current which has formed an eddy. The main facts of meteorology are now well established, but the local deviations may give room for prolonged study.

Although I knew that the delay at both places would be short, I looked forward with much interest to the prospect of landing at Bahia and Pernambuco. The latter place especially is known to be the chief mart for the natural productions of Equatorial America. Skins of animals, birds living and dead, gorgeous butterflies and shells, are easily procurable; and a mere visit to the fish and vegetable markets is sure to make a visitor acquainted with objects of interest. But my expectations were doomed to disappointment.

We reached Bahia on the morning of July 27. The city stands on a point of land north of the entrance to an extensive bay, called by the Portuguese Bahia de Todos Santos, and the proper name of the city is São Salvador; but the concurrent practice of foreigners has established the name now in general use. The steamer lay in the roadstead nearly a mile from the shore, and the heavy boats, carrying some passengers for Europe, moved slowly as they pitched to and fro in the swell of the sea. Just as they came alongside, rain suddenly burst in a torrent from the clouds, which had formed in the course of a few minutes. For the first time in my journey, I regretted the omission to have supplied myself with a waterproof cloak. A thorough wetting in tropical countries usually entails an attack of fever, and for that I was not prepared; so, along with two or three other passengers who wished to go ashore, I remained in the main deck. The rain ceased, and there was an interval of sunshine; but the torrential showers were renewed two or three times before we resumed our voyage in the afternoon.

I have already noticed the contrast that exists between the winter and summer climate of this part of Brazil and that of Rio and the southern provinces. In the latter the rainy season is in summer, while nearer the equator, although no season can be called dry, the chief rainfall occurs in winter—that is to say, in the season when the sun is farthest from the zenith. While passing through the equatorial zone, when intervals of bright weather alternated with extremely heavy rain, I frequently consulted the barometer, but was unable to trace the slightest connection between atmospheric pressure and rainfall, the slight oscillations observed being due to the diurnal variation everywhere sensible in the tropics.

The temperature on this part of the coast was only moderately warm, varying from 76° to 78° Fahr. on this and the following day, when we called at Maceio, a place of increasing commercial importance. Our stay was so short that no one attempted to go ashore, although the weather was favourable. Several whales were seen both on the 27th and 28th, but I failed to ascertain to what species they belonged.

On the evening of the 28th we experienced a decided rise of temperature; three hours after sunset the thermometer still stood at 81° Fahr., and, with two remarkable intervals, it did not fall below 80° during the following eight days. During that time my attention was often directed to the physiological effects of heat on the human economy, and both my own experience and the conflicting testimony of travellers lead me to conclude that there are many facts not yet satisfactorily explained.

On the enfeebling effect of moist tropical climates there is a general agreement, both as to the fact and the chief cause; but, as I have remarked in a preceding page, the circumstance that this is little or not at all experienced at sea is apparently anomalous. With regard to the direct effect of the sun’s rays on the surface of the body, and especially in the production of sun-stroke, the evidence of scientific travellers is conflicting, and the explanations offered are by no means satisfactory. On the one hand, it is asserted on good authority that in the equatorial zone the direct effect of the sun is far greater than it is in Europe at the same elevation above the horizon. The rapid reddening and blistering of the skin where exposed, and sun-stroke from exposure of the head, are said to be the ordinary effects. Being extremely sensitive to solar heat, I have always carefully protected my head, and have avoided rash experiments. Of the reddening and blistering of the skin I have had very frequent experience in Europe, upon the Alps and other mountains; but I observed none but very slight effects of this kind in the tropics, even with a nearly vertical sun, either on land or while at sea. Dr. Hann47 cites many statements on the subject. In the West Indies cases of sun-stroke are rare, and the inhabitants expose themselves without danger. In nearly all parts of British India, as is too well known, the danger of exposing the head to the sun is notorious, and the same is certainly true of most parts of tropical Africa.

The most obvious suggestion is that, inasmuch as dry air absorbs less of the solar heat than air charged with aqueous vapour, the injurious effects should be more felt in dry climates than in damp ones. But, so far as what is called sun-stroke is concerned, the balance of evidence is opposed to this conclusion. Sir Joseph Fayrer, who has had wide experience in India, expressly asserts that the hot dry winds in Upper India induce less cases of sun-stroke than the moist though cooler climate of Bengal and Southern India. Dr. Hann quotes Borius for a statement that in Senegambia the rainy season is that in which sun-stroke commonly occurs, while he further asserts that on the Loango coast, in very similar climatal conditions, the affection is almost unknown, and that Europeans even expose the head to the sun with impunity.

My own conclusion, fortified by that of eminent authorities, is that the phenomena here discussed are of a very complex nature; that different physical agencies are concerned in the various effects produced on the body; and that most probably there are many different pathological affections which have been classed together, but which, when more fully studied, will be recognized as distinct.

In the first place, I apprehend that the action of the sun which causes discolouration and blistering of the skin has no relation to that which causes sun-stroke. It is a local effect confined to the surfaces actually exposed, and, if it could be accurately registered, would serve the purpose of an actinometer, depending as it does on the amount of radiant heat reaching the surface in a unit of time.

Sun-stroke proper is, I believe, an affection of the cerebro-spinal system arising from the overheating of those parts of the body. It is by no means confined to the tropics, or to very hot countries, as many cases occur annually in Europe, and still more frequently in the eastern states of North America.

Nearly allied to sun-stroke, but perhaps sufficiently different to deserve separate classification, are those attacks which some writers style cases of thermic fever, which arise mainly in places where the body is for a continuance exposed to temperatures exceeding the normal amount of the human body. In producing thermic fever, it would appear that the depressing effect of a hot moist climate acts powerfully as a predisposing cause, and such cases not uncommonly arise where there has been no exposure whatever to the direct rays of the sun.

It is easy to understand that, as a general rule, seamen are less exposed than other classes to any of the injurious effects of heat, but it is remarkable that they should enjoy complete exemption. Cases are not very uncommon among seamen going ashore in hot countries, but I have not found a well-authenticated case of sun-stroke arising on board ship; and cases of thermic fever in the Red Sea usually arise in the engine-room of a steamer rather than among the men on deck.

On the morning of July 29 we reached Pernambuco, to which I had looked forward as the last Brazilian city that I was likely to see. It had been described to me as the Venice of South America, and the comparison is to a slight extent justified by its position on a lagoon of smooth water, separated from the open roadstead by a coral reef several miles in length. It enjoys the further distinction, unusual in a place within eight degrees of the equator, of being remarkably healthy. But on this occasion fortune was against me.

No doubt for some sufficient reason, we did not enter the rather intricate passage leading inside the reef, but lay to in rough water outside. For a short time the scene was brilliant. The hot sun beat down on the deep blue water, and lit up the foam on the crests of the dancing waves, and the sky overhead showed such a pure azure that one could not suppose the air to be saturated with vapour. Before long boats were seen approaching, tossed to and fro in the broken water; but before they drew near, heavy clouds had gathered in the course of a few minutes, and a torrent of water was discharged such as I had never experienced except in passing under a waterfall. As each boat came alongside, a seat was let down from the upper deck, and the passengers were hoisted up in turn, those who had not efficient waterproofs being as thoroughly drenched as if they had been dipped in the sea. Four or five times during the day the sky cleared, the blazing sun returned, and the decks were nearly dry, when another downpour of torrential rain drove us all to seek shelter, each shower lasting only from ten to fifteen minutes.

During the hotter hours of the day a rather strong breeze set in towards the shore, and I have no doubt that it is to its full exposure to this ordinary sea-breeze that the city owes its comparative healthiness. It was interesting to watch the manœuvres of the catamarans, in which the native fishermen were pursuing their avocations. This most primitive of sea-craft is formed of two or three logs well spliced together, with some weight to serve as ballast fastened underneath. In the forepart a stout stick some ten feet long stands up as a mast and supports a small sail, and amid-ships a short rail, supported on two uprights, enabled the two men who form the crew to hold on when much knocked about by the waves. A single paddle seems to serve as a rudder, but it is not easy to understand how such a rude substitute for a boat is able to work out to sea against the breeze which commonly sets towards the shore.

A large proportion of the steerage passengers who came on board at Bahia and Pernambuco were Portuguese returning to their native country after a residence, either as artisans or as agricultural settlers, in Brazil. My command of the language is unfortunately so limited that I failed to extract from these fellow-passengers any interesting information. With scarcely an exception, each carried at least one parrot, usually intended for sale at Lisbon, where it appears that they are in some request. Comparatively high prices are given for birds that freely simulate human speech.

We were under steam in the afternoon of the 29th, and soon lost to view the South American continent. On the following day the barometer for the first time showed the diminution of pressure which is normally found in the equatorial zone. Between nine a.m. and four p.m. the ship’s mercurial barometer fell about a quarter of an inch from 30·30 to 30·06 inches, and my aneroid showed nearly the same amount of difference. It must be remembered, however, that nearly one-half of the effect (at least one-tenth of an inch) must be set down to the daily oscillation of the height of the barometer, which so constantly occurs within the tropics, the highest pressures recurring at ten a.m. and ten p.m., and the lowest about four p.m. and four a.m.

I carried with me on this journey only a single aneroid barometer, an excellent instrument by Casella, whose performance was very satisfactory, and which in a very short time returned to its normal indication after exposure to diminished pressure in the Andes; but it had the defect, which, so far as I know, is common to the aneroid instruments by the best makers, that the temperature at which the scale is originally laid down by comparison with a standard mercurial barometer is not indicated on the face of the instrument. Assuming that the aneroid is compensated for variations of temperature, and I have found this to be the case within ordinary limits in good instruments, there remains the question to what height of mercury at what temperature a given reading of the aneroid corresponds. For scientific purposes it is customary to reduce the reading of the mercurial barometer to the temperature of the freezing-point of water, and it is often supposed that the aneroid reading corresponds to that figure. But we may feel pretty confident that the maker, in laying down the scale, did not work in a room at freezing-point. I have been accustomed to assume 15° Cent., or 59° Fahr., as about the probable temperature with instruments made in our climate.

In the present case, the barometer-reading of 30·06 inches at the temperature of 84° Fahr. would (neglecting the small correction for capillarity) be reduced by about fourteen-hundredths of an inch, in order to give the correct figure at freezing-point; but for comparison with an aneroid, supposed to have been laid down at 59° Fahr., the correction would be a fraction over seven-hundredths of an inch. As a matter of fact, my aneroid marked at four p.m. 29·89 inches, or, allowing for the correction, just one-tenth of an inch less than the ship’s mercurial barometer, and, as I believe, was more nearly correct.

As the sun was declining on the evening of July 30, we sighted the remarkable island of Fernando Noronha. It lies about four degrees south of the equator, and more than two hundred miles from the nearest point of the Brazilian coast. The outline is singular, for the rough hills which cover most of the surface terminate at the western end of the island in a peak surmounted by a column, in the form of a gigantic lighthouse, which must rise over a thousand feet above the sea-level.48 Although Darwin passed some hours on the island in 1832, it remains to the present day one of the least known of the Atlantic islands, so far as regards its natural productions. A fellow-passenger who had landed there assured me that he had found granite; but I have no doubt that the island is exclusively of volcanic origin, for such is the opinion of the few scientific men who have visited it.

The island has been converted by the Brazilian Government into a convict station, and in consequence access by strangers has become very difficult. Such information as we possess is mainly to be found in Professor Moseley’s account of the voyage of the Challenger. On landing there with Sir G. Nares, he at first obtained permission from the governor to visit the island and to collect natural objects; but the permission was very soon retracted, and he was unable to obtain specimens of several singular shrubs that abound and give the island the appearance of being covered with forest.

Now that the attention of naturalists has been directed to the especial interest attaching to the fauna and flora of oceanic islands, and their liability to extinction owing to competition from species introduced by settlers, it may be hoped that the exploration of this small but remarkable island will before long be undertaken by a competent naturalist. For that purpose it would be, in the first place, necessary to obtain the permission of the Brazilian Government, and to secure the means of existence during a stay of ten or twelve days on the island. The most effectual means would be through direct personal application to the emperor, who is well known to take a lively interest in all branches of natural science.

With the thermometer standing about 82°, the passengers naturally preferred the upper deck to the close air of the saloon, and were resting in their ship-chairs between nine and ten p.m., when suddenly there came an outburst of coughing and sneezing, followed by demands for muffling of every kind. There was no sensible movement in the air, but I found that the thermometer had fallen to 79° Fahr., and there was a feeling of chilliness which was not easily explained by that slight fall of temperature.

The mystery was explained on consulting the chief officer, who throughout the voyage paid much attention to the temperature of the sea. Since leaving Pernambuco, the thermometer in buckets brought up from the surface had varied only between 82° and 83°. On this evening we had abruptly encountered a relatively cold current, with a temperature somewhat below 76°, and the effect of being surrounded by a body of cool water when the skin was in the condition usual in the tropics was felt by nearly all the passengers.

With slight variation, this comparatively cool current must have extended over a large area on both sides of the equator, as the temperature of the water remained nearly the same for about forty-eight hours.

Throughout the voyage from Brazil to Europe, I was fortunate in enjoying the society of a man of remarkable intelligence, who has been a diligent and accurate observer of nature in a region still imperfectly known. M. Georges Claraz, by birth a Swiss, belonging to a family of small proprietors in the Canton of Fribourg, had gone out as a young man to improve his fortune in South America. He had received a fair scientific education, having followed the lectures of the eminent men who have adorned the Polytechnic School at Zurich; but, what is much more rare, he appeared to have retained everything that he had ever learned, and to have had a clear perception of the scientific value of the observations that a stranger may make in a little-known region. After passing some time in the state of Entrerios, he had settled at Bahia Blanca, close to the northern border of Patagonia. He had established friendly relations with the Indians, and made frequent excursions in the interior of Patagonia and southward as far as, and even beyond, the river Chubat.

During the entire time, although engaged in the work of a settler, M. Claraz seems to have made careful notes of his observations—on the native Indians and their customs; on the indigenous and the domestic animals; on the plants and their uses; on the mineral structure of the country, not omitting to take specimens of the mud brought down by the different rivers; and on general physics. Of his large collections I trust that the greater part have safely reached Switzerland. A considerable collection of dried plants, sent home while he resided at Bahia Blanca, was unfortunately lost. He was good enough, after his return, to send me a smaller collection remaining in his hands, of which I gave an account in the Journal of the Linnæan Society for 1884.

As I trust that the great store of information collected by M. Claraz will before long be given to the world, I should not wish to anticipate the appearance of his work, but I may say that among many interesting particulars, several of which I noted at the time, I was especially struck by the evidence collected among the Indians, which seemed to prove that the Glyptodon survived in Patagonia down to a comparatively recent period, and that the tradition of its presence is preserved in the stories and songs of the natives.

Early on July 31 we passed the equator, but it was not till ten p.m. on the following day that we escaped from the area of cool water and found the ordinary equatorial temperature of 82·5°. During the three following days the weather was hot and relaxing, the thermometer ranging by day between 84° and 85°. For some hours on the 2nd of August the wind came from south-south-east, but before evening it backed to west, and blew from that point rather freshly at night. On the following day we appeared to have met the north-east trade-wind, which was, however, a gentle breeze, and occasionally veered to the north-west.