Wmm^ lilliliiriiiilim "•' h. 17 Noon 50° 29-68 „ 48-5° Sunset 29-70 „ 48-0° „ I& Noon 46° 29-90 „ 50-5° Sunset 29-90 ., "^^'"■l .. 19 9 a.m. 29-90 „ 52-0° Noon 42° 29-86 „ Sunset 2988 „ 48-0° „ 20 10 a.nh 38° 20' 29-88 „ Sunset 29-83 „ S4-o° Favoured by clear weather, we occasionally had glimpses of projecting headlands on the Patagonian coast, and especially on the 19th, when we made out the promontory of San Josd on the south side of the wide and deep Bay of San Matias, and later in the same day sighted some hills on the north side of the same gulf near the mouth of the Rio Colorado, the chief of Patagonian rivers.* As far as I could * It is unfortunate that the Spaniards who had the naming of so large a part of the American continent should have shown so little inventive faculty. When they did not adopt a native name for a river, they rarely got beyond Red River, Black River, or Big River, and wherever we turn we encounter a Rio Colorado, a Rio Negro, or a Rio Grande. ESTUARY OF LA PLATA. 277 discern, the sea-birds that approached the ship were the same species which had visited us on the Pacific coast, cape pigeons being as before the most numerous and persevering. At sunrise on the shortest day we were approach- ing the city of Monte Video. Covering a hill some three hundred feet in height, and spreading along the shore at its base, the town presents a rather imposing aspect. It looks over the opening of the vast estuary of La Plata, fully sixty miles wide, into which the great rivers of the southern half of the continent discharge themselves. From the detritus borne down by these streams the vast plains that occupy the larger part of the Argentine territory have been formed in recent geological times, but the alluvial deposits have not yet filled up the gulf that receives the two great streams of the Parana and the Uruguay. It would seem, however, that that consummation is rapidly approaching. Extensive banks, reaching nearly to the surface at low water, occupy large portions of the great estuary, and the navigable channel is so shallow that large ships are forced to anchor twelve or fourteen miles below Buenos Ayres, and even at Monte Video cannot approach nearer, than two miles from the landing-place. A small steam-tender came off to convey passengers to the city, and, with very little delay at the custom- house, I proceeded to the Hotel de la Paix, a French house, to which I was recommended. In spite of the irregularity of the ground, the city is laid out on the favourite Spanish chess-board plan, in quadras of nearly equal size. The main streets run parallel to 278 NVTES OF A NATURALIST. the shore, and, being nearly level, are well supplied with tramcars ; but the cross streets are mostly steep and badly paved. The flat roofs of the houses, en- joying a wide sea-view, are the favourite resort of the inmates in fine weather, and many of them have a 'mirador, roofed in and windowed on all sides, whence idle people may enjoy the view sheltered from sun' or rain. A stranger is at once struck by one marked difference between the towns on the Atlantic coast and those on the western side of South America. Here people live free from the constant dread of earthquakes, and do not shrink from making their town houses as high as may be convenient ; but the towns become more crowded, and one misses the charming /«^«oj of the better houses of Santiago and Lima. To a traveller fresh from Peru and Chili and Western Patagonia, the region which I now entered, with its boundless spaces of plain and its huge rivers, appears by comparison tame and unattractive to the lover of nature. It is true that the industrial develop- ment of the last quarter of a century has been almost as rapid here as in the great republic of North America. The great 'plains are now traversed by numerous lines of railway, and steamers ply on the greater rivers and several of their tributaries. A naturalist may now accomplish in a few weeks, and at a trifling cost, expeditions that formerly demanded years of laborious travel. The southern slopes of the Bolivian Andes, stretching into the Argentine States of Salta, Oran, and Jujuy, are easily reached by the railway to Tucuman ; and yet easier is the journey by CLIMATE OF URUGUAY. 279 the Paraguay river steamers that carry him over seventeen hundred miles of waterway to Cuyaba, in Central Brazil, the chief town of the great province of Matto Grosso. But the time at my disposal was strictly limited, and the coming glories of Brazil haunted my imagination, so that I had no difficulty in deciding to make but a brief halt in this part of the continent, limiting myself to a short excursion on the river Uruguay and a glimpse of Buenos Ayres. Of three days passed at Monte Video a consider- able portion was occupied by the English newspapers, full of intelligence of deep and chiefly of painful interest ; but I twice had a pleasant walk in the country near the city. Some heavy rain had fallen before my arrival, and the roads, which are ill kept, were deep in mire ; but the winter season in this region is very agreeable, and the favourable impression made during my short stay was confirmed by the general testimony of the residents as to the salubrity of the climate. The winter temperature is about the same as in the same latitude on the Chilian coast, but the summers are warmer by 9° or 10° Fahr., and the mean temperature of the year fully 5° higher, being here about 62° Fahr. We are, however, far removed from the great contrasts of temperature that are found on the eastern side of North America. At Monte Video the difference between the means of the hottest and coldest months is 22°, while in the same latitude on the coast of North Carolina the difference is fully 35°. On the whole, the climate most nearly resembles that of places on the coast of Algeria, especially that of Oran, save that in the latter place 28o NOTES OF A NATURALIST. the winters are slightly colder and the summer months somewhat hotter. The town is surrounded by country houses belong- ing to the merchants and other residents, each with a quinta (garden or pleasure-ground), in which a variety of subtropical plants seem to thrive. Comparatively few of the indigenous plants showed flower or fruit, certainly less than one is used to see in winter nearer home on the shores of the Mediterranean. But a small proportion of the ground is under tillage, and beyond the zone of houses and gardens one soon reaches the open country, which extends through nearly all the territory of the republic. The English residents have adopted the Spanish term (campd), which is universally applied in this region of America to the open country whereon cattle are pastured, and the stranger does not at first well understand the question when asked whether he is " going to the camp." The only fences used in a region where wood of every kind is scarce are posts about six feet high, connected by three or four strands of stout iron wire. These are set at distances of some miles apart, and serve to keep the cattle of each estancia from straying. It is said that when these fences were first introduced, many animals were killed or maimed by running at full speed against the iron wires, but that such cases have now become rare. The more intelligent or more cautious individuals avoided the danger, and have transmitted their qualities to a majority of their off- spring. At the hospitable table of the British minister, Mr. Monson, I met among other guests Mr. E — — , one SIGNOR BARTOLOMEO BOSS/. 281 of the principal English merchants, whose kindness placed me under several obligations. On the follow- ing day he introduced me to an enterprising Italian, whose name deserves to be remembered in connection with modern exploration of the coasts of Patagonia and Tierra del Fuego. Signor Bartolomeo Bossi, who emigrated early in life to South America, seems to be a born explorer, and whenever he has laid by sufficient funds for the purpose he has forsaken other pursuits to start upon some expedition to new or little known parts of the continent. In a small steamer of 220 tons, fitted out at his own cost, he has in two expeditions minutely explored the intricate coasts of the Fuegian Archipelago and a great portion of the Channels of Patagonia. Several of the discoveries interesting to navigators made in the course of the first of these voyages were published in the Noticias Hidrograficas of the Chilian naval department for 1876, and Signor Bossi asserts that the chief motive that determined the English admiralty in despatching the surveying expedition of the Alert was to verify the announce- ments first made by him. I have not seen any reference to Signor Bossi in the interesting volume, "The Cruise of the Alert" by Dr. Coppinger ; but it appears certain that many of the observations re- corded in the Santiago Noticias have been accepted, and are embodied in the most recent charts. In this part of America the Republic of Uruguay is commonly designated as the Banda Oriental, because it lies altogether on the eastern bank of that great river. It possesses great natural advantages — 282 NOTES OF A NATURALIST. fine climate, suiificiently fertile soil, ready access by water to a vast region of the continent, along with a favourable position for intercourse with Europe. But these privileges are made almost valueless by human perversity. The military element, which has been allowed to dominate in the republic, is the constant source of social and political disorder. A stable administration is unknown, for each successful general who reaches the presidential chair must fail to satisfy all the greedy partisans who demand a share of the loaves and fishes. After a short time it becomes the turn of a rival, who, with loud promises of reform, and flights of patriotic rhetoric, raises the standard of revolt. If he can succeed in getting enough of the troops to join him, the revolution is made, and Uruguay has a new president, whose history will be a repetition of that of his predecessors. If the pretender should fail, he is summarily shot, unless he be fortu- nate enough to make his escape into the adjoining territories of Brazil or Argentaria. On the day after my arrival the news of a rising headed by a popular colonel reached the capital, and troops were sent ofif in some haste to suppress the revolt. In each case the existence of the Government depends on the uncertain contingency whether the troops will remaijti faithful or will hearken to the fair promises of the new candidate for power. It is obvious that a country in a chronic condition of disorder is a very inconvenient neighbour, and Uruguay would long have ceased to exist as a separate government, if it were not for the jealousy of the two powerful adjoining states. Brazil and NIGHT IN THE ESTUARY. 283 Argentaria * are each ready and willing to put down the enfant terrible, but neither would tolerate the annexation by its rival of such a desirable piece of territory. The prospect of a long and sanguinary war has hitherto withheld the Governments of Rio and Buenos Ayres, and secured, for a time, immunity to Uruguayan disorder. I had arranged to start on the 24th of June, in the steamer which plies between Monte Video and the Lower Uruguay. That day being one of the many festas that protect men of business in South America from the risk of overwork, banks and offices were closed, and but for the kindness of Mr. E I should have found it difficult to carry out my plan. I went on board in the afternoon, and found a small crowded vessel, not promising much comfort to the passengers, but offering the additional prospect of safe guidance which every Briton finds on board a ship commanded by a fellow-countryman. The sun set in a misty sky as we left our moorings and began to advance at half speed into the wide estuary of La Plata. As night fell the mist grew denser, and during the night and following morning we were immersed in a thick white fog. It was in reality a feat of seamanship that was accomplished by our captain. The great estuary of La Plata, gradually narrowing from about sixty miles opposite * The constant inconvenience of employing such cumbrous expressions as Argentine Confederation or Argentine territory for a state of such vast extent and such yearly increasing importance must be felt by eveiy one who has occasion to speak or write about this region of America. I trust that I shall be forgiven if in this book, as well as elsewhere, I have taken the liberty of applying a single name, which has nothing about it so strange as that it should not long since have come into use. 284 NOTES OF A NATURALIST. Monte Video to about sixteen at Buenos Ayres, is almost everywhere shallow and beset by sand or mud- banks, between which run the navigable channels. According to their draught, the ships that conduct the extensive trade between Buenos Ayres and Europe are spread over the space below the city, the larger being forced to anchor at a distance of fourteen miles. To avoid the banks, and to escape collision with the ships in the water-way, in the midst of a fog so dense was no easy matter. It is needless to say the utmost caution was observed. We crept on gently through the night, and at daybreak approached the anchorage of the large ships. Our captain seemed to be perfectly acquainted with the exact position of every one of the.m, and, as with increasing light he was able to recognize near objects, each in turn served as a buoy to mark out the true channel. Soon after sunrise we reached the moorings, about two miles from the landing-place, and lay there for a couple of hours, while the Buenos Ayres passengers and goods were conveyed to us in a steam-tender. It was a new experience to know one's self so close to a great and famous city without the possibility of distinguishing any object. At about ten a.m. we were again under steam and making for the mouth of the Uruguay on the northern side of the great estuary. The fog began to clear, and finally disappeared when, a little before noon, we were about to enter the waters of the mighty stream, which is, after all, no more than a tributary of the still mightier Parana.* Just at this point, signals and * The Parank, with its great tributary the Paraguay, drains an area THE URUGUAY RIVER. 285 shouts from a very small steamer induced our captain to slacken speed. The strangers urgently appealed to him to take on board some cargo for a place on the river, the name of which escaped me. To this request a polite but very decided refusal was returned, the prudence of which we afterwards appreciated. The cargo in question doubtless consisted of arms, ammu- nition, or other stores for the use of the revolutionary force supposed to be gathered at Mercedes, not far from the junction of the Rio Negro with the Uruguay, and it clearly behoved the steamboat company to avoid being involved in such enterprises. At its mouth the Uruguay has a width of several — probably seven or eight — miles, and at the confluence of the Rio Negro, some fifty miles up stream, the breadth must be nearly half as much. The water at this time was high, as heavy rain had fallen in the interior, and the current had a velocity of about three miles an hour. I believe that it is only exceptionally, during unusu- ally dry seasons, that tidal water enters the channels of the Parana or the Uruguay. I was struck by the frequent passage of large green masses of foliage that floated past as we ascended the river. Some consisted of entire trees or large houghs, but several others ap- peared to be formed altogether of masses of herbaceous vegetation twined together or adhering by the tangled roots. It can easily be imagined that, where portions of the bank have been undermined and fall into a stream, the soil is washed away from the roots, and the whole may be floated down the stream and even of more than 1,100,000 square miles; the basin of the Uruguay is reckoned at 153,000 square miles. 286 NOTES OF A NATURALIST. carried out to sea. The efficacy of this mode of transport as one of the means for the dispersion of plants is now generally recognized, and, considering that the basin of the Parani covers a space of over twenty-one degrees of latitude, we must admit the pro- bability that it has had a large part in the diffusion of many tropical and subtropical species to the southern part of the continent. The Rio Negro, which drains about half the terri- tory of the republic, is the chief affluent of the Uruguay. At the junction we met a small steamer which plies to and fro on the tributary stream, and some time was lost in effecting the exchange of passengers and cargo. From some new-comers we gathered rather vague reports as to the attempted revolution. The chief was a certain Colonel Maximo Perez, already well known in Uruguayan political life. I have already explained that the term in this country means the effort to use the soldiery to upset the existing administration, or, if you happen to be in power, to employ the same agency to make short work of your rivals. It was generally thought that Perez had made the mistake of raising the standard too soon, and must fail. This anticipation was soon verified, and before I left the country two reports, each equally authentic, reached the capital — the one that he had made his escape, the other that he had been shot. To the community it was a matter of indifference which story might be true : in the one case, he would appear again to renew the revolt ; in the other, some new adventurer would take his place. A few miles above the confluence of the Rio Negro ISLANDS OF THE URUGUAY. we reached Fray Bentos, the great factory where " Liebig's Extract of Beef" is prepared and sent to Europe. Whatever prosperity exists in the Banda Oriental depends altogether on beef To the raising of horned cattle the greater part of the soil of the republic is devoted, and in caring and guarding them most of the rural population is employed. The saladeros, where the animals are slaughtered and the various parts converted to human use, are the chief, almost the only, industrial establishments, and it is their produce that supports the trade and navigation. Though the channel is narrower above the junction of the Rio Negro, the Uruguay was still a mighty river, from one to two miles in width, with numerous islands, all covered with trees and seemingly unin- habited. The trees on the islands and along the banks are mostly small, about thirty feet in height, but on some of the islands they must certainly surpass fifty feet. It was impossible for a passing stranger to identify the unfamiliar forms of these trees, which seemed to present considerable variety, the more so as the majority appeared to be deciduous, and but a few withered leaves remained on the nearly bare branches. Paisandu, the place of my destination, is about a hundred and fifty miles from the mouth of the i-iver, and the steamer often accomplishes the distance in fourteen hours. I was led to hope that we should arrive soon after midnight, but as night fell a dense fog spread over the river. Further progress was impossible, and we dropped anchor in mid-channel. 288 NOTES OF A NATURALIST. With sunrise the fog quickly melted away, and the turning of the screw soon announced that we had resumed our journey. Up to this point the banks of the river on either side had been absolutely flat, but at an early hour on the 26th we for the first time were relieved by the appearance of some rising ground on the east side of the river. There was nothing deserving to be called a hill, but so impatient is human nature of the monotony of dead-level, that even a rise of a couple of hundred feet is a welcome alleviation. A house on the summit, which must command a vast range of view, appeared to be the only desirable residence I had yet seen in this region. The dead-level soon resumed its place on the eastern bank ; but a few miles farther we began to descry a range of low hills on the opposite, or Argentine, bank of the stream. We had hitherto held no communica- tion with the territory on that side, but before noon we dropped anchor opposite to the landing-place for the town of Concepcion. This is one of the chief places in the state of Entrerios, which, as the name implies, fills the space between the two great rivers, Parana and Uruguay, and extends northward about two hundred and forty miles from the estuary of La Plata. The town stands on a low bill about two- miles from the river. Some passengers went ashore, a few were taken in their place, and after a short delay the screw was again in motion and the voyage was resumed. About two p.m. we were at length opposite to Pai- sandu, a name known to most English readers only by the ox-tongues prepared at the neighbouring saladeros. PAISANDU. One of the peculiarities of this region arises from the fact that in the estuary and along the lower course of the great rivers the banks shelve so gradually that boats are seldom able to approach the shore. Else- where the inhabitants would make provision by con- structing long jetties carried far enough to enable boats to draw alongside. But suitable timber is said to be scarce and very dear, and, besides, such constructions would deprive a part of the population of their means of gaining a livelihood. Carts with a pair of enormous wheels, seven or eight feet in diameter, are driven into the water till it reaches nearly to the shafts, and passengers scramble as best they may into or out of the boats. In this novel fashion I reached the shore, with one or two other passengers. Paisandu has the aspect of a thriving country town, with streets and buildings of plain aspect, but looking clean and well cared for. It stands on rising ground, which is not a hill, but merely the river-ward slope of the flat country through which the Uruguay has here scooped a broad trench about a hundred feet below the general level. I found a very fair country inn kept by an Englishman, and at once proceeded to deliver a note of introduction to Dr. French, an English physician who enjoys considerable local reputation. The days being short at a season corresponding to our European Christmas, it was already too late for an excursion to the neighbouring country, which was postponed till the following morning ; and I passed the greater part of the afternoon and evening in the agreeable society of Dr. French, whose range of general information, and thorough acquaintance with the U 290 NOTES OF A NATURALIST. country which he has made his home, rendered his conversation interesting and instructive. Many Englishmen seem to imagine that, at least as regards material progress, distant countries, with the possible exception of the United States, are much less advanced than we are at home. I was led to an opposite conclusion as far as the more advanced states of South America are concerned, and I was struck by one illustration of the fact that I encountered at Paisandu. In the course of my long conversation with Dr. French, we were three times interrupted by the tinkling of a little bell connected with telephone wires carried into his sitting-room. I learned that a wire was carried from each of the chief estancias and saladeros within a circuit of eight or ten miles from the town. On each occasion advice was sought and obtained as to some case of sickness or accident, and it was impossible not to be struck by the great addi- tion thus made to the usefulness of a skilful medical adviser in country districts. With regard to this and other applications of the telephone and the electric telegraph, our backward condition may be explained by the extraordinary fact that the English people have tolerated the existence of a Government monopoly, which, in many cases, acts as a prohibition ; but in other matters, such as electric lighting, our relative inferiority must be set down to the extreme slowness with which new ideas germinate and reach maturity in the English nature. I was much interested by the information given to me by Dr. French as to the frequent occurrence of the fossil remains of large extinct mammalia in this FOSSIL REMAINS IN URUGUAY. 291 district. Complete skeletons are, of course, not commonly found ; but large bones in good condition are, as I learned, easily procured. My stay was necessarily so short that I could not expect to obtain any, but I entertained a hope, not yet realized, that through the kind intervention of Dr. French, some valuable specimens might be obtained for the Cam- bridge University Museum. But to complete our knowledge of the very singular extinct fauna of this region of America, prolonged research on the spot, conducted by experienced palaeontologists, is a necessary condition. These plains are the cemeteries in which myriads of extinct creatures lie entombed. We probably have got to know the majority of the larger species, but it is probable that many others have as yet escaped the notice of naturalists. The steamer in which I had travelled ascends the river as far as Salto, about sixty miles above Paisandu ; but at that placp the navigation is interrupted by rapids, and travellers pursue their journey by land until they reach the steamers that ply on the upper waters of the Uruguay. I should have wished to visit Salto, but the steamer was to arrive at night and to depart on the return voyage next morning. By stopping at Paisandu I secured the opportunity for seeing a little of the country and the vegetation. By way of seeing something of the natives. Dr. French took me to one of the best houses in the town, and introduced me to one of his patients, an old lady ninety years of age. She did much credit to the skill of her medical adviser, as I found her full of life and activity, conversing freely and intelligently on the 292 NOTES OF A NATURALIST. topics of the day. In the garden surrounding her house were a number of orange trees in full bearing, and, amongst other exotics, the largest tree of Euca- lyptus globulus that I have yet seen, though planted, as the old lady assured me, only twenty years before. It was announced that the return steamer was due at two p.m. on June 27, so I arranged, in the lan- guage of this region, to go for an excursion to the camp as early as possible in the morning. In com- pany with a young Englishman to whom Dr. French had introduced me, I started in a carriage, and, after passing through the belt of gardens and fields sur- rounding the town, soon reached a rather wide stream running between muddy banks. I now understood why all the vehicles here are hung upon such ex- tremely high wheels. The horses take to the water as easily as if they were amphibious, and we got across the stream without taking in water, but not without a severe tug to get the carriage through the deep mud. We next approached a large saladero ; but I had no curiosity to see the process of slaughter, nor the various stages by which a live animal is speedily converted into human food. We made a circuit round the saladero and the adjoining enclosures, and before long reached the open country. The general aspect reminded me of what I have seen at the corresponding season in the less inhabited parts of Northern Africa, especially near Tunis, although the plants, as, might be expected, are not only different, but in great part belong to different natural families. Open spaces covered with herbaceous vegetation alternate with patches of low bushes, mostly FLORA OF THE CAMP. 293 evergreen, and here and there with shrubs under ten feet in height ; but there was nothing deserving to be called a tree. The indigenous trees of this region seem to be confined to the banks and islands of the great rivers. Among the bushes were four species of Baccliaris, a Composite genus characteristic of South America, three species of Solatium, a Lrcium, etc. But the commonest bush, which extends from the Tropic of Capricorn to Patagonia, is Duz-aux dependetis, with crooked branches beset with stout thorns, which has no near ally among European plants. I found several plants stiU in flower — ^two or three pretty species of the mallow tribe, a Buddleia, an Oxalis, and a Verhcn-2 {V. phlogifolid), nearly alUed to the orna- mental species of our gardens. I returned to the town just in time to have all in readiness for the steamer, which arrived punctually at two o'clock, and, after bidding farewell to Dr. French, embarked with the impression that life in a country town on the Uruguay is %-er\- much like life in a country town an\-where in Europe — somewhat dull, but not devoid of interest to one who is content to feel that he has been of some use to fellow-creature-s. The weather had become brighter, and we were spared the annoj-ance of waiting at night for the clearing of the fc^. We held on our course do\vn the stream, and at sunrise were again at anchor opposite to the cit>- of Buenos Ayres, now for the first time become \isible. Seen in the bright morning light, it presented a somewhat imposing aspect, as befits the most populous and important port of the South American continent The advance of the Argentine 294 NOTES OF A NATURALIST. Confederation has been so rapid since public tran- quillity has been assured that the returns of a few years ago are doubtless considerably below the truth. Those of the five years from 1870 to 1874 show a yearly average of about ten millions sterling of im- ports, and nearly seven and a half millions of exports ; but these figures, especially the latter, should now be much increased. Of the whole commercial movement more than eighty per cent, belongs to Buenos Ayres, and the extension of railways must further increase its supremacy. I went to the Hotel de Provence, a French estab- lishment fairly well kept, and, after confinement in the little den on board the river steamer, enjoyed the novel sense of occupying a spacious room. A good part of the day was spent in wandering about the town. It is built on the regular chess-board plan, with quadras of equal dimensions. The streets are narrow and ill-paved, most of them traversed by tram- cars, which are the only convenient vehicles ; but the whole place is pervaded by an air of activity which seems strange in Spanish America, reminding one rather of the towns of the United States. I was directed to an exhibition of the natural pro- ducts and manufactures of the states * of the Argentine Confederation, which appeared to make a creditable show, but of which I felt myself to be no competent judge. I was chiefly interested by the large collections of native woods from Corrientes and the mountain regions of Tucuman, Salta, and the adjoining states. * The term provinces, commonly applied to the federated States, is misleading, and should be laid aside. ARGENTINE FORESTS. 295 We know at present very little as to the extent of the Argentine forests, and still less as to the proportion in which the more valuable species are distributed ; but it is obvious that in these forests there exist important sources of wealth, which, however, must require good management for their future develop- ment. Many of the largest and most valuable trees belong to the family of LeguminoscB, and may be found to rival in importance those of Guiana. Speaking of the forests of the northern states, the late Professor Lorentz writes that they are exclusively confined to the eastern slopes of the mountains on which the winds from the Atlantic deposit their moisture, while the western slopes remain dry and bare of trees. He dwells on the need for an efficient forest law, as the result of the carelessness of the sparse population is that in the neighbourhood of in- habited places much valuable timber is ruthlessly destroyed. It may be feared that, under a constitution which, for such purposes, leaves practical autonomy to fourteen different states, it may be very difficult to obtain the enactment of an efficient law, and still more difficult to secure its enforcement. The chief architectural boast of Buenos Ayres is the Plaza Mayor, one side of which is occupied l^ the cathedral, a very large pile in the modern Spanish style, which is not likely to serve as a model for imitation. The day being a festa, there was a ceremony in the afternoon, which attracted a crowd of the female population. The great church was ablaze with thousands — literally thousands — of wax candles, and the entire pavement was covered with 296 NOTES OF A NATURALIST. costly carpets of the most gaudy colours. The be- haviour of the congregation did not convey to a stranger the impression of religious feeling. It is doubtful, however, to what extent we are right in applying in such .matters the standard derived from a different race and different modes of feeling. A severer style of worship would have no attractions for a people who thirst for satisfaction to the eye and ear ; and they would certainly not be the better, in their present condition of progress, if the scepticism of the age were to close this avenue of escape from the sordid cares of daily life. On June 29, my second day at Buenos Ayres, I made a short excursion to the Boca, on the shore of the Rio de la Plata, only about three miles from the city. I had an illustration of the careless way in which, from want of sympathy or want of imagination, most people give directions to strangers. Being in- formed that the tramcars plying to La Boca were to be found in a certain street, I proceeded thither to look out for a vehicle going in the right direction. After a few minutes a vehicle appeared, coming from La Boca. After ten minutes more a second arrived from the same direction, and after ten minutes more a third, but not one in the opposite sense. At last I went into the shop of a German chemist near at hand, when the mystery was explained. The cars enter the town by one street, make a short circuit, and return by a different street. The Boca does not offer much to interest a stranger. I could have fancied myself somewhere in the out- skirts of Leghorn, so frequent were the familiar sounds SAGITTARIA MONTEVIDENSIS. 297 of the Italian tongue, save that in Italy it would be difficult to find a spot where the horizon is unbroken by a near hill, or by the distant outline of Alp or Apennine. Having paid a short visit to Mr. Schnyder, the newly appointed Professor of Botany, I strolled through the adjoining fields with the hope of finding some remains of the autumnal vegetation. The low flat country is intersected by broad ditches, and much reminded me of Battersea fields as they existed half a century ago, when I first began to collect British plants. Seeing in a ditch the remains of a fine Sagittaria, I filled a bit of paper with the minute seeds, and from these has sprung a plant which has for several seasons been admired by the visitors to Kew Gardens. It is the Sagittaria Montevidensis, which is not uncommon in Argentaria and Uruguay, but, so far as I know, does not extend to Brazil — a singular fact, considering that the seeds must be readily transported by water-birds. In its native home it grows to a somewhat larger size than the European species, but is not very conspicuous. Culti- vated at Kew, in a house kept at the mean temperature of about 78° Fahr., it has attained gigantic propor- tions, rising to a height of over six feet, and the petioles of the leaves attaining the thickness of a man's arm. I had arranged to take my passage to Brazil in the steamer Neva, of the Royal Mail Company, and at this season I felt no regret at quitting this region of South America, which offers comparatively slight attractions to the tourist. I was led, however, fron^ 298 NOTES OF A NATURALIST. all the information that I collected, to form a high estimate of the advantages that it offers to European settlers. At the present time the chief source of profit is from the rearing of cattle ; but, though long neg- lected, agriculture promises to become the most important element of national prosperity. Until the middle of this century there were none but wooden ploughs of the type used by the aborigines, and corn was imported from abroad to feed the townspeople. There are now numerous agricultural colonies formed by foreign settlers, especially in the state of Santa Fe, and the results have been eminently successful. Large crops of grain, especially wheat, of excellent quality, are easily raised. The vine prospers, even as far south as Bahia Blanca, and in the northern states cotton, olives, tobacco, and other subtropical products appear to thrive. These agricultural colonies have been chiefly formed by Italian, Swiss, and German immigrants, and one of the most recent, composed of Welshmen, has been established so far south as the river Chubat in Patagonia. It may be feared that, owing to the deficient rainfall of that region, the prospects of the settlement are somewhat uncertain. The Argentine Government has shown its wisdom in promoting immigration by the extraordinary liberality of the terms offered to agricultural settlers from Europe. With a territory as large as the whole of continental Europe, exclusive of Russia, and a population of scarcely two millions, immigration is the indispensable requisite for the development of re- sources that must render this one of the most im- portant nations of the earth. The law, which, as I EMIGRATION TO ARGENT ARIA. 299 believe, is still in force, offers to settlers wishing- to cultivate the national lands which are under the control of the Central Government the following terms : — An advance of the cost of the passage from a European port to Buenos Ayres, with conveyance from that city to the location selected ; a free gift of a hundred hectares (about 247 acres) to each of the first hundred families proceeding to a new settlement ; an advance, not exceeding a thousand dollars per family, to meet expenses for food, stock, and outfit, repayable without interest in five years ; the sale of additional Government land at two dollars per hectare, payable in ten annual instalments ; and, finally^ exemption from taxes for ten years. To the class of settlers who hold themselves above farming work other careers are open. Many young Englishmen who enjoy life in the saddle have done well as managers of estancias, for the raising of horses and cattle. The chief advice to be given to those who have some capital at their disposal is not to purchase property until they have gained practical experience. The Argentines show a laudable anxiety for the spread of education, and there is a considerable demand for teachers and professors, which has been mainly supplied from Germany, many of the professors from that country being men who have established a merited reputation. One of the attractions of this region for European settlers is the excellence of the climate. Though not quite so uniform as that of Chili, it is free from the extremes of temperature that prevail in the United States. In the low country the difference between 300 NOTES OF A NATURALIST. the mean temperature of the hottest and coldest months is from 22° to 25° Fahr., while in the middle states of the northern continent the difference is nearly twice as great — from 40° to 45°. The mean summer temperature is here about the same as in places six or eight degrees farther from the equator in eastern North America. The rainfall, which is of such vital importance to agriculture, appears not to be subject to such great annual irregularities as it is in the United States and Canada. The average at Buenos Ayres is about thirty-five inches annually, and in ascending the Parana this increases to fifty-three inches in Corrientes,. and eighty inches in Paraguay. It is only in some parts of the interior — e.g. about Mendoza — and in Patagonia, that the cultivator is, in ordinary seasons, exposed to suffer from drought. Apart from the economic results of the great influx of immigration, the large recent admixture of European blood is effecting important salutary consequences. I have seen no recent returns, but it appears * that in the six years ending 1875, the number of immigrants from Europe exceeded 284,000, or about 47,500 annually ; and I believe that this average has been exceeded since that date. Of the whole number fully one-half are Italians, and I found unanimous testi- mony to the fact that they form a valuable element in the population. With the exception of a small * Much information, respecting this country is to be found in a volume entitled, "The Argentine Republic," published in 1876 for the Cen- tenary Exhibition at Philadelphia. It contains a series of papers pre- pared by Mr. Richard Napp, assisted by several German men of science.. PHOGIiESS OF ARGENTARIA. 301 proportion from the Neapolitan provinces, it is ad- mitted that, whether as agricultural settlers or as artisans in the cities, the Italians are an orderly, industrious, and temperate class. The Germans and Swiss are not nearly so numerous, but form a useful addition to the orderly element in their adopted country. It may be hoped that experience and education have not been thrown away on the native Argentine, and that the memory of the forty years of intestine disorder which followed the final establish- ment of independence may serve as a warning against renewed attempts at revolution ; but assuredly the foreign element, which rapidly tends to become pre- dominant, will be found an additional security against the renewal of disorder. Although a majority of the large commercial houses at Buenos Ayres are English, and the trade with this country takes the first place in the statistical returns, the predominance is not so marked as it is on the western side of South America. Next to England, and not far behind, France has a large share in the trade, and although Germany has only lately entered the field, it appears that the business operations with that country are rapidly extending. Here, and at several other places in South America, I heard com- plaints that German traders palm off cheap inferior goods, having forged labels and trade-marks to imitate those of well-known English manufacturers. It is true that charges of a similar nature have been recently brought against some English houses. One asks if the progress of civilization is to lead us back to caveat emptor as the only rule of commercial ethics. If so. 302 NOTES OF A NATURALIST. some further means must be discovered to enable the innocent purchaser to protect himself. The most serious difficulty in the way of the increasing foreign trade of Argentaria is that arising from the shallowness of the great estuary of La Plata, which prevents large vessels from approaching the ports. In the course of ages nature will remedy the defect, when the present shoals are raised by deposits of fresh silt so as to confine the volume of water brought down by the great rivers, which would then scour out navigable channels. Whether the process may not be hastened by human skill and enterprise is a question which I am unable to answer. At present I believe that the only point where vessels of moderate burthen can approach the shore is at Ensenada, about fourteen miles below Buenos Ayres. It is now con- nected by railway with the capital, and promises to become an important trading port. EMBARCATION AT BUENOS AY RES. 303 CHAPTER VI. Voyage from Buenos Ayres to Santos — Tropical vegetation in Brazil — Visit to San Paulo — Journey from San Paulo to Rio Janeiro — Valley of the Parahyba do Sul — Ancient mountains of Brazil — Rio Janeiro — ^Visit to Petropolis — Falls of Itamariti — Struggle for existence in a tropical forest — The hermit of Petropolis — Morning view over the Bay of Rio — A gorgeous flowering shrub — Visit to Tijuca — Yellow fever in Brazil — A giant of the forest — Voyage to Bahia and Pernambuco — Equatorial rains — Fernando Noronha — St. \'incent in the Cape de Verde Islands — Trade winds of the North Atlantic — ^Lisbon — Return to England. About midday on June 30, I took my departure from Buenos Ayres. The operation was not altogether simple or to be quickly accomplished. Jolting heavily over the ill-paved streets, a hackney coach carried me and a fellow-traveller with our luggage to the river- bank. The sight was very strange. It was a busy day, and there were literally hundreds of high-wheeled carts engaged in carrying passengers and goods out to the boats, which lay fully half a mile from the shore. When, after a delay that seemed excessive, we were installed in a boat, this was pulled in a leisurely fashion to the steam-tender, which lay more than a mile farther out. When the hour fixed for the 304 NOTES OF A NATURALIST. departure of the tender was long past, we at length got under way, and finally reached the Neva steamship of the Royal Mail Company, about fourteen miles below the city, at five o'clock. With iron punctuality dinner was served at the regular hour, although none of the passengers were ready, and the luggage was not brought on board till after dinner. There was, in truth, no reason for haste, as we were appointed to call at Monte Video on the following morning. My chief business at that place was to recover possession of the chest containing my botanical collections, which I had deposited at the custom-house. Impressed with the attractions of Brazil, and feeling the strict limits of time to which I was bound, I asked myself if I should not have done better to have omitted a visit to the Plata region, and saved nine days by proceeding direct to Brazil in the Iberia, which started on the 22nd of June. I should certainly recommend that course to any naturalist travelling under similar circumstances at the same season ; but I am sure that, if I had done so, I should have felt regret at having missed an opportunity, and should have fancied that I had lost new and interesting experiences. At four p.m. on the ist of July the big ship began to move from her moorings opposite Monte Video, and for about sixty miles kept a due easterly course. Somewhere near the port of Maldonado we passed a bright light on an island which shows as a bold head- land. I was told that this is known as Cape Frio, because of the cold often encountered here by those arriving from Brazil. It may be supposed that the VOYAGE TO SANTOS. 305 force of the south-west wind which prevails in winter is more felt as the wide opening of the great estuary- is reached. During my own short stay, the wind never rose beyond a gentle breeze, and the temperature on land was no more than agreeably cool, usually between 55° and 60° Fahr. during the day. The distance from Monte Video to Santos, which is reckoned at 970 sea miles, was accomplished in about three days and eighteen hours. The voyage was uneventful. On the 3rd we approached the Brazilian coast, but the land lay low, and no objects could be distinguished. The weather was all that could be desired by the most delicate passengers, the barometer remaining almost stationary at about 30'2 inches,* and the temperature by day rising gradually from 57° at Monte Video to 62° in lat. 25" south. Before sunrise on the morning of July 5, we entered the bay through which the Santos river discharges itself into the Atlantic, and found ourselves in a new region. The richness of the green and the luxuriance of the foliage recalled the aspect of the coast at Jacmel, in Hayti, and as the morning advanced, while we slowly steamed towards the head of the bay, I had no difficulty in deciding on a course which had already suggested itself to my mind. I knew that Santos is connected by railway with SSo Paulo (better known in the form San Paulo), the chief town of this part of Brazil, and that the railway between that place and the capital was also completed ; and I accordingly * Dr. Hann (" Klimatologie," p. 657, et seq.) has discussed the causes of the prevalent high barometric pressure on both coasts of temperate South America, and has shown that in winter the area of maximum pressure moves northward towards tlie Tropic of Capricorn. X 3o6 NOTES OF A NATURALIST. determined to leave the steamer, and find my way by land to Rio Janeiro. Santos is an ancient place which had long remained obscure, until the great development of coffee-cultiva- tion in South Brazil, and the construction of a railway to the interior, have made it the most advantageous port for the shipment to Europe of that important product. It lies at the mouth of an inconsiderable stream that enters the head of the bay. Seen from the sea, it appears to be backed by a range of lofty, flat-topped hills, but, in truth, these are no more than the seaward face of the great plateau which extends through a considerable part of the province of San Paulo. Although Santos is placed a few miles south of the Tropic of Capricorn, the aspect of the vegetation is completely tropical ; and if a stranger were in doubt, the fringe of cocoa-nut palms on the shores of the bay would completely reassure him. Although the thermometer on board ship did not rise above 6y°, the air seemed to us, arriving from the south, very warm, and we were surprised to hear the com- pany's agent, when he came on board, complain that he had found the water in his bath uncomfortably chilly. I landed with a young German fellow-traveller who, like myself, intended to proceed to San Paulo ; and, as we found that the train was not to start for three hours, we occupied the time in ascending the nearest hill. It was now nearly three months since I had enjoyed a glimpse of true tropical vegetation in the forest of Buenaventura, and the interest and delight of this renewed experience can never be forgotten. TROPICAL VEGETATION AT SANTOS. 307 It was clear that on the slopes about Santos the native forests had been cleared, but on all the steeper parts, not reclaimed for cultivation, the indigenous vegeta- tion had resumed the mastery. Trees and shrubs in wonderful variety contended for the mastery, and maintained, as they best could, a precarious struggle for existence with a crowd of climbers and parasites. So dense was the mass of vegetation that it was impossible to penetrate in any direction farther than a few yards, and there was no choice but to follow the track that led to the summit of the slope, on which stood a pretty house with an adjoining coffee-planta- tion. Among the many new forms of vegetation here seen, the most singular was that of the Tillandsia* Long, whitish, smooth cords hang from the branches of the taller trees, and at eight or ten feet from the ground abruptly produce a rosette of stiff leaves, like those of a miniature pineapple, with a central spike of flowers. But the most brilliant ornament of this season was a species of trumpet-flower {Bignonia venusta, Ker = Pyrostegia ignea, Presl), which, partly supporting itself, and partly climbing over the shrubs and small trees, covered them with dense masses of brilliant orange or flame-coloured flowers. Laden with specimens, I returned to the town just in time for the afternoon train to San Paulo. The railway was constructed by an English company, and is so far remarkable that a somewhat difficult problem has been solved in an efficient and probably economical fashion. The object is, within a distance of a few * The species common here is allied to T. stricta, but is not, I think, identical. 3o8 NOTES OF A NATURALIST. miles, to raise a railway train about 2500 feet. This is done by four stationary engines. The line is laid on four rather steep inclines, with nearly level inter- mediate spaces, each ascending train being counter- poised by one descending in the opposite direction, and the loss of time in effecting the connections is quite inconsiderable. On every map of Brazil that I have seen, the Serra do Mar, which we were here ascending, is represented as a range of mountains running parallel to the coast, and extending from near Rio Janeiro to the Bay of Paranagua in South Brazil, apparently dividing the strip of coast from the low country of the interior. Most travellers would probably have expected, as I did, that on reaching the summit we should descend considerably before reaching San Paulo, and it was with surprise that from the summit I saw before me what appeared to be a vast level plain, with some distant hills or mountains in the dim horizon. It is true that the drainage of the whole tract is carried westward and ultimately reaches the Parana ; but the slope is quite insensible, and I do not think that, in the space of about sixty miles that lay between us and San Paulo, the descent can exceed two or three hundred feet. There was a complete change in the aspect of the vegetation, and open tracts of moorland recalled scenes of Northern Germany. Night had closed before we reached the station at San Paulo. There was a difficulty about a carriage to convey us to the hotel. Perhaps the demands were unreasonable, or perhaps we were too unfamiliar with the coinage of Brazil, which is that of the mother GERMAN COMMERCIAL TRAVELLERS. 309 country ; but on hearing from the driver a demand for several thousand rees, we indignantly resolved to walk, and engaged a man to convey our luggage to the hotel. We were favourably impressed by the appearance of this provincial capital. In the space of a mile we passed through several good streets, well lighted with gas, and better paved than any I had seen in South America. Many handsome houses with adjoining gardens were passed on the way, and, on reaching the Grand Hotel, nice clean rooms, and good food provided for the evening meal, further conduced to favourable first impressions of Brazil. My young German companion, a traveller for a com- mercial house, was returning from a visit to the interior of Brazil. By steamer on the Parana and Paraguay he had gone from Buenos Ayres to Cuyaba, the capital of the province of Matto Grosso, a vast region with undefined boundaries, probably larger than most of the European states. I have often been struck by the results of superior education among Germans engaged in business, as compared with men of the same class in other countries. It is not that they often merit the designation of intellectual men, and still more rarely do they show active interest in scientific inquiry ; but they retain a respect for the studies they have abandoned, are ready to talk intelligently on such subjects, and, as a rule, have a regard for accuracy as to facts which is so uncommon in the world, as much because the majority are too ignorant to appreciate their importance as owing to deliberate disregard of truth. I did not learn much as to the progress of inner Brazil, but my fellow-traveller 3IO NOTES OF A NATURALIST. mentioned a few particulars that had struck him as singular. He found the civil population of Cuyaba solicitous in their adherence to European fashions in dress, and, as a special note of respectability, the men always appearing in what are vulgarly called chimney- pot hats. The current coin in all but small transac- tions consisted in English sovereigns, but he was unable to explain how these have reached a region which can have so few commercial relations with this country. He departed on the following morning, while I resolved to spend a day in visiting the neigh- bourhood of the city. Although San Paulo lies exactly on the southern tropic, the winter climate is positively cool, and at sunrise on July 6 the thermometer stood at 58° Fahr. On a rough estimate from a single barometric obser- vation it stands, about 2400 feet above the sea. Its appearance was altogether unlike that of all the towns seen in Spanish America. The somewhat wearisome monotony of regular square blocks gave place to the irregular arrangement of some of the provincial towns in England, several streets running out into the country and ending in detached villas. The general impression was that of comfort and prosperity. Several well-appointed private carriages were seen in the streets, and the shops were as good as one commonly sees in a European town of the same class. I was much interested by the short country excur- sion, which occupied most of the day, and by an aspect of vegetation entirely new to me. The plants, with scarcely an exception, belonged to genera pre- vailing in tropical America, many of them now seen FLORA OF THE BRAZILIAN PLATEAU. 311 by me for the first time ; but the species were nearly- all different from those of the coast region, and the general aspect of the flora still more markedly different. There was no trace of that luxuriance which we commonly expect in tropical vegetation ; monocotyledonous plants, except grasses, were very few, and, in place of the large ferns that abounded at Santos, I found but a single Gleichenia, allied to a species that I had gathered in the Straits of Magellan. Although a fair number of plants were still in flower, I soon came to the conclusion that night frosts must be not unfrequent at this season, and that a considerable proportion of the vegetation must be annually renewed. I found several groups of small trees, chiefly of the laurel family, and for the first time saw \!s\^ Araucaria brasiliensis, possibly in a wild state ; but none of the trees attained considerable height, and I doubt whether in a state of nature this plateau has ever been a forest region. I was rejoiced to see again, growing in some abundance, the splendid Bignonia veitusta, and was led to doubt whether its real home may not be in the interior, and its appear- ance at Santos due to introduction by man. We possess a fair amount of information as to the climate of the Brazilian coasts, but our knowledge of the meteorology of the interior provinces is miserably scanty. I was led to conjecture that, although the district surrounding San Paulo is not divided by a mountain range from the neighbouring coast region, the climate must be very much drier, and that the rainfall is mainly limited to the summer season. In the course of my walk, I unexpectedly ap- 312 NOTES OF A NATURALIST. proached a country house about three miles from the town, and was somewhat surprised by meeting a carriage with ladies on their way to the house. As far as my experience has gone in the country parts of Portugal or Spain, such an encounter would there be regarded as a very unusual phenomenon. The railway from San Paulo to Rio Janeiro appears to be a well-managed and prosperous concern, paying to its shareholders dividends of from ten to twelve per cent. The distance is about 380 miles, and the trains perform the distance in about thirteen and a half hours. Leaving my hotel in the dark, I found at the station a crowd of passengers contending for tickets ; but good order was maintained, and we started punctually at six o'clock. For some way the line is carried at an apparent level over the plain, with occasional distant views of high hills to the north, arid crosses two or three inconsiderable streams, whose waters run to the Parang. A slight but con- tinuous ascent, scarcely noticed by the passing traveller, leads to the watershed which, in this direc- tion, limits the vast basin of the Parana. After a long but very gentle descent, we reached a stream flowing westward. I at first supposed it, like those already seen, to be a tributary of the Parana which made its way through some depression in the low ridge over which we had passed ; but I soon ascer- tained that this was an error. Near the spot where the railway crosses it, the stream makes a sharp turn, and thenceforth proceeds in a direction little north of east for about four hundred miles, till it falls into the Atlantic at SSo Joao da Barra, north-east of Rio GEOLOGY OF EASTERN BRAZIL. 313 Janeiro. This is the Rio Parahyba do Sul, not to be confounded with the Rio Parahyba north of Per- nambuco, nor yet with the more important river Paranahyba in the province of Piauhy. For the greater part of the way to Rio the railway runs parallel with the river. As laid down on the maps, the valley lies between a mountain range called the Serra da Mantiqueira on the left, and a minor range, which divides the upper course of the river from the middle part, where it flows in the opposite direction. The appearance of the country through which I now passed forcibly suggested to me views respecting its geological history, which were confirmed and extended by what I afterwards saw in the neigh- bourhood of Rio, and by all that I have since been able to learn on the subject. I had already been struck by what little I had seen of the plateau region of the province of San Paulo. Beneath the superficial crust of vegetable soil, the plateau appears to be formed of more or less red arenaceous deposits, such as would result from the erosion and decomposition of the gneiss or granite which is the only rock I had seen in the country. In the valley of the Parahyba, the connection was un- mistakable. Every section in the valley showed thick beds of the same coarse-grained, red arenaceous deposits, and on the slopes the same material lay at the base of whatever masses of granite we approached." But what especially struck me were the forms and appearance of the mountains on either hand, if that designation could properly be given to them. I saw nothing that would elsewhere be called a mountain 314 NOTES OF A NATURALIST. range. The outlines were in most places rouncjled and covered with vegetation, but at intervals occurred steep conical masses, of the same general type as the sugar-loaf peaks surrounding the Bay of Rio Janeiro. However steep, the rocks nowhere showed angular peaks or edges, these being always more or less rounded. It would be rash to generalize from the partial observations of a passing traveller; but the broad outlines of the geology of Brazil, or, at least, of the eastern provinces, have now been well traced,* and some general conclusions may safely be drawn. It is true that large districts of the interior have been but partially explored, and remain blanks on the geological map ; but the eastern half of Brazil is undoubtedly ancient land, presenting no trace of secondary strata except in small detached areas near the coast, and where more recent tertiary deposits are to be found only in a portion of the great valley of the Amazons. A mountain range, having various local designations, but which may best be called the Serra da Manti- queira, extends from the neighbourhood of San Paulo to the lower course of the Rio San Francisco, for a distance of twelve hundred miles, and this is mainly composed of gneiss, sometimes passing into true granite, syenite, or mica schist ; and the same may be said of the Serra do Mar, a less considerable range ' lying between the main chain and the coast. The * The best general account of the geology of Brazil that I have seen is contained in a short paper by Orville A. Derby, entitled, " Physical Geography and Geology of Brazil. " It was published in the Rio News, in December, 1884, and, through the kindness of Mr. Geikie, I have seen a reprint in the library of the School of Mines. DISINTEGRATION OF GRANITE. 315 southern limits of the Serra do Mar do not appear to be well-defined, but we may estimate its length at from five to six hundred miles. The other mountain systems of the empire are less well known ; but I believe that the ranges dividing the province of Minas Geraes from Goyaz, and the so-called Cordillera Grande of the province of Goyaz, lying between the two main branches of the great river Tocantins, are largely formed of ancient sedimentary rocks of the Laurentian and Huronian groups. The granite of the Serra da Mantiqueira and Serra do Mar is coarse-grained, with large crystals of felspar, and is therefore much exposed to disintegration. So far as I know, the vast masses of detritus forming the plateaux of this region show no other materials than such as would be produced by the disintegration of the crystalline rocks, and there is strong reason to believe that these have never been overlaid by sedimentary deposits. Let us now consider what must have been the past history of a region formed of such materials, exposed, during a large part of the past history of the earth, to the action of the elements. In such an inquiry one of the chief points for consideration is the amount of rainfall. The direct effect, both mechanical and chemical, of rain falling on a rock surface is perhaps not the most important. Still more essential is its action in removing the disintegrated matter, and thereby exposing a fresh surface to renewed action. The difference in the absolute result due to abundant or deficient rainfall would be found, if we could cal- culate it accurately, to be enormous. In a nearly 3i6 NOTES OF A NATURALIST. rainless country, such as Egypt or Peru, we see a slope covered with debris, and are apt to conclude that the rock is being rapidly disintegrated ; but, in truth, what we see is the work of many, perhaps many hundred, centuries, which remains in situ because there is no agency to remove it. In a land of heavy rainfall the debris is speedily carried to lower levels, and the work of destruction is constantly renewed. We have scarcely any observations of rainfall in the mountain districts of Brazil. The only reliable return that I have seen is that of one year's rainfall at Gongo Seco, in Goyaz, which amounted to more than a hundred and thirty inches ; but we may safely conclude that it is everywhere very great. It is also important to note that if, as most geologists now believe, the Atlantic valley has existed since an early period of the earth's history, Eastern Brazil must always have been a land of heavy rainfall. A great mountain range on the eastern side of the continent might have created a desert region in the interior, but would have received in the past as much aqueous precipitation as it does at the present time. We have, therefore, to consider what must have been the ancient condition of a region subjected throughout vast periods of geological time to the utmost force of disintegrating agencies applied to a rock very liable to yield to them, and where, without reckoning the large proportion which must have been carried by rivers to the sea, we see such vast deposits of the disintegrated materials formed out of the same matrix. To my mind the conclusion is irresistible that ancient Brazil was one of the greatest mountain RUINS OF THE ANCIENT MOUNTAINS. 317 regions of the earth, and that its summits may very probably have exceeded in height any now existing in the world. What we now behold are the ruins of the ancient mountains, and the singular conical peaks are, as Liais has explained, the remains of some harder masses of metamorphic gneiss, of which the strata were tilted at a high angle. As the same writer has remarked, although the crystalline rocks are for the most part easily disintegrated, some por- tions are formed of much more resisting materials, and these have to some extent survived the incessant action of destructive forces. We are far from possessing the materials for a rational estimate of the probable extent and elevation of the ancient mountain ranges of Brazil. In the first place, we have a plateau region occupying a large part of the upper basin of the Parana, with an area of fully 100,000 square miles, covered with detritus to an unknown, but certainly considerable, depth. In addition to this, it cannot be doubted that the finer constituents carried down by that river, and its tributary the Paraguay, from the same original home, have largely contributed to the formation of the Argentine pampas and Paraguay, including the northern portion of the Gran Chaco. Borings and chemical analysis of the soil may hereafter give us reliable data ; but in the mean time we may safely reckon that an area of 200,000 square miles has been mainly formed from the materials derived from the ancient mountains whose importance I endeavour to point out. In addition to all this, we should further reckon the soluble matter and fine silt carried to the 3i8 NOTES OF A NATURALIST. ocean during the long course of geological history,, and take into account that the same great mountain region also furnished materials to streams which flowed northward and eastward. In attempting to speculate on the past history of this region it is important to remark that, so far as evidence is available, there is reason to believe that Brazil has undergone less considerable changes of level than most other parts of the earth's surface. Even if we go back to the period of the earlier secondary rocks, there is no evidence to show that movements of elevation or depression have exceeded a few hundred feet. I have attempted elsewhere* to give a sketch of the views which I hold as to the probable origin of the chief types of phanerogamous vegetation. I there pointed out that, at a period when physical conditions in the lower regions of the earth's surface were widely different, and the proportion of carbonic acid gas present in the atmosphere was very much greater than it has been since the deposition of the coal measures, it was only in the higher region of great mountain countries that conditions prevailed at all similar to those now existing. I further argued that, if the early types of flowering plants were confined, as I believe they were, to the high mountains, we could not expect to find their remains in deposits formed in shallow lakes and estuaries until after the probably long period during which they were gradu- ally modified to adapt them to altered physical con- ditions. * Proceedings of the Royal Geographical Society for 1S79, p. 564. VALLEY OF THE PARAHYBA. 319 A general survey of the South American flora shows, along with elements derived from distant regions, a large number of types either absolutely peculiar to that continent, or which, in some cases, appear to have spread from that centre to other areas. Of these peculiar types some may probably have originated in the Andean chain, but as to the majority, it seems far more probable that their primitive home was in Brazil ; and it is precisely on the ancient mountains of this region that I should look for the ancestors of many forms of vegetation which have stamped their character on the vegetation of the con- tinent. I should be the first to admit that the views here expressed have no claim to rank as more than pro- bable conjectures ; but I hold that these, when resting on some positive basis of facts, are often serviceable to the progress of science, by stimulating inquiry and leading observers to co-ordinate facts whose connec- tion had not previously been apparent. In following the valley, in places where the siliceous soil supported only a scanty vegetation, I was struck by the singular appearance of scattered piles, usually about four feet in height, having much the appearance of rude milestones, occurring here and there in some abundance, but never very near each other. I was often able to avail myself of the short halts of the train at wayside stations to secure specimens of in- teresting plants, but I was not able to approach near to these unknown objects. I have no doubt, how- ever, that they were habitations of termites, or, as they are commonly called, white ants. I have never been 320 NOTES OF A NATURALIST. able to conjecture the origin of the instinct that induces so many species of termites in different parts of the world to construct dwellings in this form, nor what advantage they can derive from it. As the Parahyba appeared to be a rapid-flowing stream, it is probable that in following the valley the railway descends considerably before it reaches the point, about eighty miles north of Rio, where it abruptly turns away from the river to make its way to the capital. The appearance of the vegetation announced a change of climate, but I did not notice any palms by the way. The country between the Parahyba valley and the coast appears to be an irregular moun- tain tract, nowhere of any great height, with projecting summits rising here and there of the same general character as those already described, and the railway follows a sinuous course so as to select the lowest depressions between the neighbouring bosses of granite. As we wound to and fro, constantly changing our direction amid scenes of increasing loveliness, night closed with that suddenness to which one becomes accustomed in the tropics, and the last part of the way was unfortunately passed in darkness. The approach to Rio must be surpassingly beautiful, but, beyond the fantastic outlines of the surrounding mountains, little could be discerned save the lights of the city, visible for many miles before we reached the railway station. After a long drive through paved streets, I reached the English hotel (Carson's), and was curtly informed that the house was full. The next in rank is the Fonda dos Estrangeiros, to which I proceeded, and THE BAY OF RIO JANEIRO. 321 found quarters in a rather shabby room, not over- clean. The general style of the establishment and the food provided answered the same description. It is generally admitted that the accommodation for strangers in the capital of Brazil does not come up to the reasonable expectations of travellers. By quitting the steamer at Santos, and travelling to Rio \iy land, I had gained some slight acquaintance with a new region, but I was well aware that I had suffered a considerable loss. The view on first enter- ing the Bay of Rio Janeiro is one of those spectacles that leave an ineffaceable impression even on persons not very sensitive to natural beauty, and one on which my fancy from early youth onwards had most often dwelt. The pursuits of a naturalist, besides their own fascination, offer additional rewards to all who worship in the temple of Nature, but they also sometimes exact a sacrifice. Sallying forth on the morning of July 8, a little under the impression of the unattrac- tive quarters of the night, I had but very moderate expectations as to what might be enjoyed of the scenery in the midst of a large city and its surround- ings, but I was speedily disabused. Man has certainly done little to set off the unequalled fascinations of the place, but he has been powerless to conceal them. I passed a delightful day, partly strolling much at random on foot, and occasionally availing myself of the street-cars, which are frequented by all classes, and afford a stranger the best opportunity for seeing some- thing of the very mixed population. The famous Bay of Rio Janeiro may properly be described as a salt-water lake, so completely is it Y 322 NOTES OF A NATURALIST. landlocked and cut ofif from the open sea. About thirty miles long and twenty in breadth, it is large enough to allow of spacious views, yet not so large as to lose in distance the marvellous background that is presented in every direction by the fantastic peaks that surround it. Numerous islands stud the surface, the larger telling their history in piles of huge blocks, either simulating rude Cyclopean architecture, or lying in wild confusion — granite pinnacles, half- decayed or fallen into utter ruin. The shores are everywhere a maze of coves and inlets, in which land and water are interlaced ; and over all — the mainland and the islands alike — the wild riot of tropical vege- tation holds its sway, defying the efforts of man to tame it to trimness. Even within the limits of the city, which stretches for about four miles along the shore, four or five coves present a ceaseless variety of outline. Of necessity the plan is completely irregular. Where a space of level ground opens out between the shore and the rocks, the city has spread out ; where the rocks approach the water's edge, it is narrowed in places to a single street. In architecture, since the great era of Alcobaga and Batalha, the Portuguese have not achieved much, and their descendants in South America have done little to adorn the capital of their great empire. The largest building, the imperial palace, might easily be taken for a barrack. Nature has undertaken the decoration of the city, and, amid the palms, and under the shade of large-leaved tropical trees in the public walks and gardens, the absence of sightly buildings is not felt. The suburb of Botafogo, which is the fashionable THE AVENUE OF PALMS. 323 quarter, lies on the shores of the most beautiful of the coves round which the city has grown up. It mainly consists of a range of handsome villas facing the sea, each with a charming garden, and, in this season, must be a delightful residence. But it is generally admitted that the climate of Rio is debilitating to European constitutions. As compared with most coast stations in the tropics the heat is not excessive — the mean temperature of the warmest month (Feb- ruary) is not quite 80° Fahr., and that of the coldest (July) about 70° ; but most Europeans, and especially those of Germanic stock, require to be braced by intervals of cold, if they are to endure a hot climate with impunity. The annual appearance of yellow fever in the city supplies a still stronger motive to many of the foreign residents for fixing their abode amongst the hills. The chief resort, which in summer is frequented by most of the wealthier classes, is the well-known Petropolis, in the Organ Mountains, or Serra dos Orgaos, that rise beyond the northern shores of the bay. From Botafogo I directed my steps towards the Botanic Garden, and, as usual among people of Portuguese descent, found great readiness in giving information to strangers. Following a road that turned away from the shore, I seemed to have left the city far behind, and be quite in the country ; but pre- sently another beautiful dark blue cove opened out before me, and again turning inland I reached the garden. I must confess to a feeling of something like disappointment at the famous avenue of palms. It has been correctly described as reproducing the 324 NOTES OF A NATURALIST. effect of the aisie of a great Gothic cathedral, and the defect, as it. seemed to me, is that the reproduction is too faithful. The trees of Oreodoxa regia, which are about a hundred feet in height, are all exactly of the same form and dimensions, so much alike that they appear to have been cast in the same mould, and it is difficult to persuade one's self that they are not artificial productions. It may not be easy to say why the same uniformity which satisfies the eye in a con- struction of stone, should fail to do so when similar forms are represented by natural objects. I suppose the fact to be that in all aesthetic judgments the mind is unconsciously influenced by trains of association. Our admiration is aroused not merely by given com- binations of colour or form — by the mere visual image formed on the retina — but is controlled by our sense of fitness. We should resent as a caprice of the architect an irregularity in a vista of arches : among objects endowed with life we expect some manifesta- tion of the universal tendency to variation. With an intention, never fulfilled, to make a second visit to the garden, and, under the guidance of the director. Dr. Glaziou, to make nearer acquaintance with some of the vegetable wonders there brought together, I returned to my hotel. Before reaching Rio, I had decided to devote most of my short re- maining time to a visit to the Organ Mountains, and to make Petropolis my head-quarters. As there was no especial reason for delay, I started for that place on the morning of the following day, July 9. I shall make no attempt to describe the beauties of the bay as they were successively unfolded during the THE ORGAN MOUNTAINS. 325 short passage to and from Petropolis. From early youth the Bay of Naples has ever appeared to me so perfectly beautiful that I was very reluctant to admit the pretensions of a rival. Even now I can well understand that some may find the pictures presented to the eye on the.charmed coasts of our Mediterranean bay more complete, and the tints of the shores and sea and sky more harmonious ; but there could be no doubt as to the gorgeous vesture that everywhere adorns this land. The vegetation of the Mediterranean coasts seems but poor and homely after the eye has dwelt on the luxuriance of tropical life, as though one were to compare a garb of homespun with trappings of velvet and embroidery. The islands of the bay present a ceaseless variety. Some are mere rocks, on which sea-birds of unknown aspect stood perched. Many of the larger are inhabited, and one, as I heard, has a population of thirteen hundred souls, and several charming villas showed it to be a favourite resort. In about an hour and a half from the city, the little steamer ran alongside of a wooden jetty at a spot on the northern side of the bay facing the bold range of the Organ Mountains, which extend for over twenty miles in an easterly direction. Between the northern shore and the foot of the mountains is a level swampy tract, evidently filled up by the detritus borne down by the numerous streams, and beyond this the mountain range rises very abruptly from the plain. Somewhat to my disappointment, I ascer- tained that Petropolis lies at a considerable distance from the higher part of the Organ range to which 326 NOTES OF A NATURALIST. my attention had hitherto been directed. It is towards its eastern extremity that the Serra shows that remarkable series of granitic pinnacles of nearly equal height, appearing vertical from a distance, that suggested the likeness to the pipes of an organ whence these mountains obtained their name. The height of the loftier part has been estimated at 7500 feet above sea-level. I do not think that any of the summits near Petropolis can surpass the level of 5000 feet. A short train with a small locomotive carried pas- sengers for Petropolis across the low tract to the point where the ascent abruptly commences, a distance of nine or ten miles. The marshy plain is doubtless fever-stricken, and we passed very few houses on the way to the terminus, which is appropriately named Raiz da Serra. The construction of a railway on the slope leading thence to Petropolis, up which trains should be drawn by a wire rope, had been commenced, but at the time of my visit passengers were conveyed in carriages, each drawn by six or eight mules. A well-kept and well-engineered road — by far the best mountain road that I have seen in any part of America — leads to the pass or summit of the ridge that divides Petropolis from the Bay of Rio. The views during the ascent, especially in looking back over the bay, were entrancing, and new and strange forms of vege- tation showed themselves at each turn of the road. From the summit, a gentle descent of a couple of miles leads to the main street of Petropolis. The place lies about 2900 feet above the sea, in a basin or depression amidst forest-covered hills. ATTRACTIONS OF PETROPOLIS. 327 The abundant rains of this region have carved the surface into a multitude of httle dells and recesses, separated by hills and knolls of various size and height, leaving in their midst one comparatively broad space, where most of the buildings are grouped. The streamlets that issue from every nook in the mountains are finally united in two streams that flow in opposite directions, but both, I believe, ultimately find their way northward to the Parahyba. The streamlets have been turned to account by the inhabitants, for on each side of the main streets a rivulet of crystal water serves to maintain the vigour of a line of trees supplying the one need of the long summer — shelter from the vertical midday sun. In the present season (mid-winter) only one hotel was open ; but in summer, when all who can do so escape from the oppressive heat of Rio, two or three others are generally crowded. It is at once apparent that PetropoHs is a place for rest and enjoyment, not for business. The few shops and hotels are all in the main street, Rua do Im- perador; the other streets, or roads, lie between ranges of detached villas, each with a garden, and here and there some more secluded habitation is with- drawn into some nook on the margin of the forest. The large majority of the trees and shrubs of this region have persistent leaves, but a few lose their foliage annually in winter, and a few others, I believe, during the heat of summer. The only prominent reminder of the fact that we were in winter was the appearance of the Bombax trees that line the main street, now completely bare of foliage. The tree commonly planted in this part of Brazil is, I believe. 328 NOTES OF A NATURALIST. the Bofnbax pubescens of botanists. The fruit, with its copious silky appendage to the seeds, alone remained at this season ; but when covered with a mass of large white flowers, it must have a gorgeous appearance. I cannot feel sure that every naturalist will approve of the resolution, which I very soon formed, to remain as long as was possible at Petropolis. To reach the higher summits of the Organ Mountains would have required at least three or four days' travel, and at this season I could expect to see very little of the vegetation of the higher zone. In the mean time, I found in the immediate neighbourhood, within a radius of four or five miles, an unexhausted variety of objects ■of interest, and the attractions of the place were doubtless heightened by the fortunate circumstances in which I found myself. It is certain that the ten days that I spent at this fascinating spot remain in my memory as the nearest approach to a visit to the terrestrial paradise that I can expect to realize. Besides the British minister, Mr. Corbett, I was for- tunate enough to make the acquaintance of two English families, whose constant kindness and hospi- tality largely contributed to the enjoyment of my stay. To find in the midst of the marvels of tropical nature the charms of cultivated society, was a com- bination that I had not ventured to promise to myself Although I never went farther than five or six miles from my head-quarters, the variety of delightful walks in every direction seemed to be inexhaustible ; go where one would, it seemed certain that one could not go wrong. I soon ascertained, indeed, that it is useless to attempt to penetrate the forests, except by THE STRUGGLE FOR EXISTENCE. 329 following a road or cleared path. My first lesson was on the slope of a little hill some three hundred feet in height that overlooks the town. I was told that there was a path on the farther side, but, seeing the ground partly open, with trees of small stature not much crowded together, I resolved to follow the straight course. The ascent cost me over two hours of hard work, and I accomplished it only with the help of a sharp knife, by which to cut through the tangle of vegetation. In the midst of this I was surprised to find tall fronds of our common English bracken {Pteris aquilina), a fern that has been able to adapt its constitution to all but the most extreme climates of the world. The little hill that cost me so much labour had been completely cleared ten years before, so that all the trees and shrubs had grown up since that time. The first excursion recommended to every stranger at Petropolis is that to the Falls of Itamariti. I went there twice, varying somewhat my course — the first time with a horse, which I found quite unnecessary and rather an incumbrance ; the second time alone. The falls are not very considerable. A stream so slender that it can be passed by stepping-stones falls over two ledges of granite rock, together about forty feet in height ; but, framed in a mass of the most luxuriant tropical vegetation, the whole forms a lovely picture. For some reason which I did not learn, the forest on the slopes of the lower part of the glen below the falls had been felled just before my visit, and its beauty had vanished, but fortunately the arm of the destroyer was arrested before reaching the falls 330 NOTES OF A NATURALIST. As happens to every stranger in a tropical forest, I was bewildered amidst the great variety of trees that struggle for supremacy, the one condition for victory being to get a full share of the glorious sunshine over- head. By vigorous tugging at one of the lianes that hung like a rope from a branch sixty feet above my head, I succeeded in breaking off a fragment, and identifying one of the larger trees as a species of fig, with large, ov^l, leathery leaves somewhat like those of a magnolia. It is needless to say that each tree is invaded by a host of enemies — parasites that fatten on its substance, comparatively harmless epiphytes that cling to the branches, and hosts of climbing lianes that mount to the topmost branches, robbing them of their share of sunlight, and hang down, often twined together, and in the deep shade are generally mere bare flexible stems. It was strange to observe that one of the deadliest enemies, a small parasite, fixing itself near the ground on the trunks of the larger trees, is a species of fig, belonging to the same genus as some of the giants of the forest, and doubtless tracing its descent from a common ancestor. It is in the tropical forest that one feels the force of Darwin's phrase " struggle for existence," as applied to the vegetable world. In our latitudes it is by an effort of the imagination that we realize the fact that in our fields and woodlands there is a contest going on between rival claimants for the necessary conditions of life. Here we see ourselves in the midst of a scene of savage warfare. The great climbers, like monstrous boas, that twine round and strangle the branch, remind one of the Laocoon ; the obscure parasite that eats THE HERMIT OF PETROPOLIS. 331 into the trunk of a mighty tree till a great cavity- prepares its downfall, testifies to the destructive power of an insidious enemy. 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 Melastomacecz were every- where 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 assist- ance 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 332 NOTES OF A NATURALIST. especially those of the Lepidopterous insects — butter-, flies 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 pre- served 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 bom 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 A SEA OF MIST. 333 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 dis- appearance of mist as seen from a height in early morning must be familiar to every genuine moun- taineer, 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 334 NOTES OF A NATURALIST. from the scene of action, but, though watching atten- tively, 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 suc- cession gave direct evidence to that effect. During the first five days of my visit the weather at Petropolis was perfectly enjoyable. The tempera- ture varied from about 6o° 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 i6th of July the sky became overcast, and some rain fell in the afternoon, the ther- mometer 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. THE DEVELOPMENT OF INDOLENCE. 335 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 dis- position, 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 butter- flies in the forest near his home, to earning ten times as much by walking to a distance, especially if ex- pected 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 bridfe to a 336 NOTES OF A NATURALIST. 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 oflf a branch from the nearest plant. It belonged, as I suspected, to the family oi Melastomacem, 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 Melastomacecs having brilliant flowers, and it seems improbable that the same species which I found THE EMPEROR DOM PEDRO. 337 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 excep- tional 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 efi"ect. 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 Z 338 NOTES OF A NATURALIST. 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 incon- siderable ; 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 2 1 St, 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 in- variably 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 TREATMENT OF YELLOW FEVER. 339 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 visita- tion of yellow fever and the best method of treatment. I was especially struck by the experiences of the youngest of the party, who had cotae out from Eng- land a few years before to superintend some consider- able new works for the drainage of Rio. For two years he lived altogether in the city, constantly requir- ing 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 340 NOTES OF A NATURALIST. 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 ;£^i8o. 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 en- countered 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. VEGETATION OF TIJUCA. 341 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 beep unable to identify it. The vegeta- tion 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 ap- peared to be certainly indigenous. Of flowering 342 NOTES OF A NATURALIST. plants the family of MelastomacecB 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 charac- ter as those described by M. Liais* as frequent in Brazil. The crystalline rocks are of very unequal hardness, and while some portions are rapidly dis- integrated, 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 * See his valuable work, " Climats, Geologie, Faune et Geographie Botanique du Brcsil." A GIANT TREE. 343 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 344 NOTES OF A NATURALIST. 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 1 80 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 Moun- tains 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 I SO 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 after- noon. 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 Com- pany, 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 Eng- land is as nearly as possible direct. The coast of Brazil from Rio to Pernambuco runs from south- WINDS OF THE ATLANTIC. 345 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 through- out 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 predomi- nated, 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 hemi- sphere ; 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 346 NOTES OF A NATURALIST. the rapid condensation of large masses of vapour, such as occurs at each heavy fall of rain, may deter- mine temporary currents in the air in directions opposed to the general and ordinary march of the vi^inds. 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 possi- bility 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 dis- appointment. 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 Sao Salvador ; but the concurrent practice of foreigners has established the name now in general use. The steamer lay in the roadstead nearly a mile COAST CLIMATE OF BRAZIL. 347 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 water- proof 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 oscilla- tions 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 y6° to 78° Fahr. on this and the following day, when we called at Maceio, •348 NOTES OF A NATURALIST. 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 pre- ceding 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 pro- SUN-STROKE. 349 tected 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. Hann * 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 con- cerned, 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 * "Klimatologie,'' p. 382. 350 NOTES OF A NATURALIST. 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. PERNAMB UCO. 3 5 1 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 com- parison 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 plaqe within eight degrees of the equator, of being remark- ably 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, 352 NOTES OF A NATURALIST. 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 irt 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 manceuvres 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 sei-ve 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 THE ANEROID BAROMETER. 353 residence, either as artisans or as agricultural settlers, in Brazil. My command of the language is un- fortunately 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"o6 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 2 A 354 NOTES OF A NATURALIST. mercurial barometer is not indicated on the face of the instrument. Assuming that the aneroid is com- pensated 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 read- ing of the aneroid corresponds. For scientific pur- poses 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'o6 inches at the temperature of 84° Fahr. would (neg- lecting 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 com- parison 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 FERNANDO NORONHA. 355 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.* 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 * Darwin's estimate of the height was one thousand feet, wliile Professor Moseley gives double that amount. I incline to think that the lower figure is nearer to the truth. 3S6 NOTES OF A NATURALIST. extinction owing to competition from species intro- duced by settlers, it may be hoped that the explora- tion 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 atten» tion 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 ^6°, and the effect of being surrounded by a body of cool water when the skin was in the con- dition usual in the tropics was felt by nearly all the passengers. M. GEORGES CLARAZ. 357 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 re- mained 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, belong- ing 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 care- ful 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 358 NOTES OF A NATURALIST. 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 Linncean Society for 1884. As I trust that the great store of information col- lected 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 in- teresting 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 compara- tively recent period, and that the tradition of its presence is preserved in the stories and songs of the natives. Early on July 3 1 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'S°. 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. ISLAND OF ST. VINCENT. 359 In the afternoon of August 4 we made out the picturesque outline of the Cape Verde Islands, and before sunset entered the channel between St. Vincent and St. Antao, finally dropping anchor for the night in the outer part of the fine harbour of St. Vincent. Having been selected as a coaling station, this has become the chief resort of steamers plying between Europe and the Southern Atlantic, and we were led to expect that the operation would take up great part of the following day. Here a fresh disappointment awaited me. I had confidently reckoned upon spend- ing several hours ashore, and seeing something of the curious vegetation of the island, which includes a scanty representation of tropical African types, with several forms allied to the characteristic plants of the Canary Islands. I had not duly taken account of the perverse temper of the officers of health, whose chief object in life seems everywhere to be to make their authority felt by the needless annoyance they cause to un- offending fellow-creatures. We had left Rio with a clean bill of health ; not a single case of yellow fever had occurred for months before our departure ; but Brazil is regarded as permanently " suspected," and quarantine regulations were strictly enforced in our case. I am far from believing that in certain conditions, and as regards certain diseases, judicious quarantine regulations may not be effective ; but, reckoning up all the loss and inconvenience, and the positive damage to health, arising from the sanitary regula- tions now enforced, I question whether it would not 36o NOTES OF A NATURALIST. be better for the world if the system were entirely abolished. The view of St. Vincent, backed by a bold and stern mountain mass, on which scarcely a trace of vegetation is visible from a distance, was for some time sufficiently interesting ; but as the day wore on, and the sun beat down more fiercely, life on board became less agreeable. To keep out the penetrating coal dust all the ports were closed, and, with the thermometer at 90°, the air below was stifling, and the passengers generally preferred to remain on deck, and breathe the hot air mixed with the coal dust that arose from the open bunkers. I offered two of the boatmen who hung about the ship three milreis if they would land on an un- inhabited part of the bay, which I pointed out to them, and collect for me every plant they found growing, and I was well pleased when, after two or three hours, they returned with a respectable bundle of green foliage. Under the vigilant eyes of the officers of health the specimens were hauled up to the deck, while the three dollars were thrown into the boat. It is remarkable that coin is nowhere supposed to convey contagion. When I came to examine it, I found to my disgust that the bouquet included only the leaves of two species, with no trace of flower or fruit. One was most probably Nicotiana glauca, introduced from tropical America ; the other a leguminous shrub, possibly a Cassia, but quite uncertain. The rest of the passengers spent most of the day in bargaining with the hucksters who flocked round ATLANTIC TRADE WINDS. 361 the ship. Ornaments made from palm leaves, sweet- meats of very suspicious appearance, photographs, and tobacco in various forms, were the chief articles of traffic, and the main object seemed to be to prolong the chaffering and bargaining over each article so as to kill as much time as possible. More attractive in appearance were the tropical fruits, of which those suitable to a dry climate grow here in perfection. In spite of persevering efforts, I have never developed much appreciation of the banana as an article of diet, but I thought those obtained here much the best that I have anywhere eaten. General satisfaction was felt when, the work of coaling being finished, the ship was again in motion, with her head set towards Europe. On returning to the channel between the islands, and still more when we had got well out to sea, we encountered a rather strong breeze right ahead, which with varying force continued for the next four days. This was, of course, the regular trade wind of the North Atlantic, and had the agreeable effect of lowering the temperature, which at once fell to 78°. Along with the trade wind, the sea-current apparently travels in the same direc- tion. It is certain that the temperature of the water was here much lower. Before reaching St. Vincent we found it between 80° and 81° Fahr., while after leaving the islands it had fallen to 74°. This tem- perature remained nearly constant for three days, but on the evening of the 9th, in about 27° north latitude, we abruptly encountered another current of still cooler water, in which the thermometer fell to 69°. The force of the wind never, I think, exceeded 362 NOTES OF A NATURALIST. what seamen describe as a fresh breeze, but it sufficed to cause at times considerable disturbance of the surface ; and on the afternoon of the 6th we shipped some heavy seas, so that it was found expedient to slacken speed for a time. I have alluded in a former page to the ordinary- observation that in the track of the trade winds the breeze usually falls off about sunset. It is more difficult to account for the opposite phenomenon, which we experienced on three successive evenings from the 7th to the 9th of August, when the force of the wind increased in a marked degree after nightfall. I was also struck by the fact that the temperature of the air throughout the voyage from St. Vincent to the mouth of the Tagus seemed to be unaffected either by the varying force of the wind or by [the fall in surface-temperature of the sea, to which I have above referred. On board ship in clear weather it is very difficult to ascertain the true shade-temperature when the sun is much above the horizon, but the observations made at sunrise and after nightfall from the evening of the Sth to the morning of the nth varied very slightly, the utmost range being from 77-5" to 73°. Some points in the Canary Islands are often visible in the voyage from Brazil to Europe, especially the lofty peak of Palma ; but we passed this part of the course at night, and nothing was seen. As we drew near to Europe, the wind, through keeping the sam direction, gradually fell off to a gentle breeze, and the surface of the water became glassy smooth, heaving gently in long undulations. The relative effect of THE TOWER OF BELEM. 363 smooth or rough water on the speed of steamers is remarkable, and was shown by the fact that during the twenty-four hours ending at noon on the nth of August the Tagus accomplished a run of 295 knots, while three days before, with only a gentle breeze but rougher water, the run to noon was only 240 knots. Early in the afternoon of the nth, the Rock of Lisbon at the mouth of the Tagus was distinctly visible, and we slowly entered the river and cast anchor at the quarantine station below Belem. Our captain, after the experience of St. Vincent, did not expect to obtain pratique at Lisbon, and with more or less grumbling the passengers had made up their minds to remain on board, when, after a long deliberation, the unexpected news, "admitted to pratique," was rapidly spread through the ship, and we moved up to the anchorage opposite the picturesque old tower of Belem, which the true mariner must always regard as one of his holy places. It marks the spot wherefrom Vasco de Gama and his companions, after a night spent in prayer in the adjoining chapel, embarked on their memorable voyage, and here, after years of anxious uncertainty. King Manuel greeted the sur- vivors on their return to their country. The sun was sinking when such passengers as wished to see something of Lisbon took the oppor- tunity for going ashore, while others, like myself, preferred to remain on board. Hoping to receive letters at the post-office, I landed early next morning, and found a tramcar to carry me to the centre of the town. Early hours are not in much honour at Lisbon. I found the post-office closed, and, after several vain 364 NOTES OF A NATURALIST. efforts, was informed that letters could not be delivered until ten o'clock, the precise hour fixed for our de- parture from the anchorage at Belem. The voyage from Lisbon along the coasts of Portugal and Galicia is usually enjoyed, even by fair-weather sailors. The case is often otherwise with the Bay of Biscay, but on this occasion there was nothing of which the most fastidious could complain. I have sometimes doubted whether injustice has not been done to that much-abused bay, which, in truth, is not rightly so called by those bound from the north to the coast of Portugal. It is simply a part of the Atlantic Ocean, adjoining the coast of Europe between latitudes 43° 46' and 48° 28'. 1 1 have not been able to ascertain that the wind blows harder, or that the sea runs higher there than elsewhere in the same latitudes, and am inclined to rank the prejudice against that particular tract of sea-water among vulgar errors. The adventurer who has attempted to open up a trade with some distant region is accustomed, as he returns home, to count up the profits of his expedi- tion ; and in somewhat the same spirit the man who pursues natural knowledge can scarcely fail to take stock of the results of a journey. It is his happy privilege to reckon up none but gains, and those of a kind that bring abiding satisfaction. He may feel some regret that outer circumstance or his own short- coming have allowed opportunities to escape, and lessened the store that he has been able to accumu- late ; but as for the positive drawbacks, which seemed but trivial at the time, they absolutely disappear in the recollection of his experiences. Thinking of these PSEUDO-PESSIMISM. 365 things as the journey drew to a close, I could not help feeling how great are the rewards that a traveller reaps, even irrespective of anything he may learn, or of the suggestions to thought that a voyage of this kind cannot fail to bear with it How much is life made fuller and richer by the stock of images laid up in the marvellous storehouse of the brain, to be summoned, one knows not when or how, by some hidden train of association — shifting scenes that serve to beautify many a common and prosaic moment of life! Often during this return voyage my thoughts recurred to an article in some periodical lent to me by my kind friends at Petropolis, wherein the writer, with seeming gravity, discussed the question whether life is worth living. My first impression, as I well remember, was somewhat contemptuous pity for the man whose mind could be so profoundly diseased as even to ask such a question, as for a soldier who, with the trumpet-call sounding in his ear, should stop to inquire whether the battle was worth fighting. When one remembers how full life is of appeals to the active faculties of man, and how the exertion of each of these brings its correlative satisfaction ; how the world, in the first place, needs the daily labour of the majority of our race ; how much there is yet to be learned, and how much to be taught to the ignorant ; what constant demand there is for the spirit "of sympathy to alleviate suffering in our fellows ; how much beauty exists to be enjoyed, and, it may be, to be brought home to others ; — one is tempted to ask if the man who halts to discuss whether life is worth living can have a 366 NOTES OF A NATURALIST. mind to care for truth, or a heart to feel for others, or a soul accessible to the sense of beauty. Recurring to the subject, as I sometimes did during the homeward voyage, it seemed to me that I had perhaps treated the matter too seriously, and that the article I had read was an elaborate hoax, by which the writer, while in truth laughing at his readers, sought merely to astonish and to gain repute as an original thinker. However the fact may be, when taken in connection with the shallow pessimism which, through various channels, has of late filtered into much modern literature, there does appear to be some real danger that the disease may spread among the weaker portion of the young generation. A new fashion, however absurd or mischievous, is sure to have attractions for the feebler forms of human vanity. It is true that there is little danger that the genuine doctrine will spread widely, but the mere masquerade of pessimism may do unimagined mischief The better instincts of man's nature are not so firmly rooted that we should wish to see the spread of any influence that directly allies itself with his selfish and cowardly tendencies. To any young man who has been touched by the contagion of such doctrines, I should recommend a journey long enough and distant enough to bring him into contact with new and varied aspects of nature and of human society. Removed from the daily round of monotonous occupation, or, far worse, of monotonous idleness, life is thus presented in larger and truer proportions, and in a nature not quite worthless some chord must be touched that will stir RETURN TO ENGLAND. 367 the Springs of healthy action. If there be in truth such beings as genuine and incurable pessimists, the stern believer in progress will be tempted to say that the sooner they carry out their doctrine to its logical result the better it will be for the race. Their con- tinued existence, where it is not merely useless, must be altogether a mischief to their fellow-creatures. On the morning of the i6th of August, all but com- pleting five months since I quitted her shores, the coast of England was dimly descried amid gusts of cold wind and showers of drizzling rain. My winter experiences in the Straits of Magellan were forcibly recalled to my mind, and I fell some partial satisfac- tion in the seeming confirmation of the conclusion which I had already reached — that the physical differ- ences between the conditions of life in the northern and southern hemispheres are not nearly so great as has generally been supposed. APPENDIX A. ON THE FALL OF TEMPERATURE IN ASCENDING TO HEIGHTS ABOVE THE SEA-LEVEL. The remarkable features of the climate of Western Peru referred to in the text seem to me to admit of a partial explanation from the local conditions affecting that region. The most important of these are the prevalence of a relatively cold oceanic current, and of accompanying southerly breezes along the Peruvian coast. These not only directly affect the temperature of the air and the soil in the coast-zone, but, by causing fogs throughout a considerable part of the year, intercept a large share of solar radiation. It has been found in Northern Chili, some fifteen degrees farther south than Lima, but under similar climatal conditions, that, although the land rises rather rapidly in receding from the coast, the mean temperature increases with increasing height for a considerable distance. It is stated on good authority* that at Potrero Grande, a place about fifty miles distant, and 850 metres above the sea, the mean annual temperature is higher by 2-5° C. than at Copiapo, or at the adjoining port of Caldera. It is probable that in the valley of the Rimac the mean temperature at a height of 1000 metres is at least as high as it is at Lima. Taking the mean temperature of the lower station at I9'2° C, and that of Chicla at i2'2° C, that would give a fall of 7° for a difference of level of 2724 metres, or an average fall of 1° for 387 metres, instead of 1° for 512 metres, as given in the text. A further peculiarity in the climate, which tends to diminish * I borrow this statement from the excellent " Lehrbuch der Klimato- logie," by Dr. Julius Hann. Stuttgart, 1883. 2 B 370 NOTES OF A NATURALIST. below the normal amount the rate of decrease of temperature, is the comparative absence of strong winds, and the feebleness of the sea-breezes which are usually so conspicuous in the tropics. For reasons that will be further noticed, the fall in temperature in ascending mountain ranges is largely due to currents of air carried up from the lower region. In mountain countries an air-current, encountering a range transverse to its own direction, is mechanically forced to rise along the slopes, and thus raises large masses of air to a higher level ; the same effect in a less degree occurs with isolated peaks. But in the Peruvian Andes, as well as in many other parts of the great range, although storms arise from local causes on the plateau, westerly winds from the ocean are infrequent and feeble ; and the sea-breezes, due to the heating of the soil by day, much less sensible than usual in warm countries. Making full allowance for the operation of the two causes here specified, it yet appears that the difference of temperature between the coast and the higher slopes of the Peruvian Andes is exceptionally small. It is not merely due to the abnormal cooling of the coast-zone, but to the exceptionally high tempera- ture found in the zone ranging from 3500 to 4000 metres. I should not have attached much importance to the few observa- tions of the thermometer that I was able to make during a hurried visit, if the conclusion which they suggest had not been strongly confirmed by the character and aspect of the vegetation. When I found that the table given by Humboldt, which has been copied and adopted by so many writers on physics, in which the mean temperature at a height of 2000 toises, or 3898 metres, in the Andes of Ecuador, close to the equator, is set down at 7°, while at Chicla, thirteen degrees of latitude south, at a height less only by 174 metres, there is reason to believe that we find a mean annual temperature of not less than 12°, I was led to enter more fully into the subject. The result of somewhat careful study has been to convince me that, while the physical principles involved in the attempt to discover the vertical distribution of temperature in the atmo- sphere prove the problem to be one of extreme complexity, the results hitherto obtained from observation are altogether in- sufficient to guide us to an approximate law of distribution. I may remark that the problem has not merely a general interest APPENDIX. 371 in connection with the physics of the globe, but has a direct bearing on two practical applications of science. The observa- tions of the astronomer and the surveyor require a knowledge of the amount of atmospheric refraction, by which the apparent positions of the heavenly bodies, or of distant terrestrial objects, are made to differ from the true direction ; and to determine accurately the amount of refraction we should know the temperature of the successive strata of air intervening between the observer and the object. In determining heights by means of the barometer, or any other instrument for measuring the pressure of the air, it is equally necessary for accuracy to know the variations of temperature in the space between the higher and the lower station. Three different opinions have prevailed among physicists as to the law, or supposed law, of the rate of variation of tempera- ture in ascending from the sea-level. The simplest supposition, and the most convenient in practice, is that the fall of tempera- ture is directly proportional to the height, and this has been adopted in several physical treatises. In English works the rate has been stated at a fall of 1° Fahr. for 300 feet of ascent, and by French writers the not quite equivalent rate of 1° C. for 170 metres has been adopted. The formula proposed by Laplace for the determination of heights from barometric ob- servations, which has been very generally adopted by travellers and men of science, implicitly assumes that the rate of decrease of temperature is more rapid as we ascend to the higher regions than it is near the sea-level, and this opinion was explicitly affirmed by Biot in his memoirs on atmospheric refraction. A third hypothesis may be said to have originated when, in 1862, Mr. Glaisher made his report of the results of the famous balloon ascents effected by him and Mr. Coxwell,* and among others exhibited a table showing the average decline of tempera- ture corresponding to each successive thousand feet increase of elevation from the sea-level to a height of 29,000 English feet. As Mr. Glaisher's tables showed a gradual decline in the rate of fall of temperature with increasing height, they clearly did not accord with the ordinary assumption of an uniform rate, * See Reports of the British Association for the Advancement of Hcience ioT 1882, pp. 451-453. 372 NOTES OF A NATURALIST. and still less with the hypothesis of Laplace and Biot. In February, 1 864, Count Paul de St. Robert, of Turin, communi- cated to the Philosophical Magazine a short paper, in which he showed the incompatibility of Mr. Glaisher's results with the ordinary formulae for the reduction of barometric observations, and proposed a new formula based on a law of decrement of heat based upon Mr. Glaisher's tables. In the following June, M. de St. Robert published in the same journal a further paper, in which, still accepting Mr. Glaisher's results as accurate, he investigated the subject in a masterly manner, as well with reference to the measurement of heights, as in its connection with the determination of the amount of atmospheric refraction. The formula proposed by M. de St. Robert, and the tables subsequently published by him for its adaptation to use, appearing to be at once the most accurate and the most convenient, have been adopted by myself and by many other travellers ; * but it is evident that their value depends on the correctness of the results, above referred to, deduced by Mr. Glaisher, and their conformity with observation in mountain countries. Before we inquire into the conclusions to be drawn from observation, it may be well to point out how incomplete is our knowledge of the physical agencies which regulate the distri- bution of temperature in the atmosphere. The primary source of temperature is solar radiation, and its effect at any given point on the earth's surface depends on the absolute amount of heating power in the sun's rays, irrespective of absorption, commonly designated the solar constant, and on the proportion of heat which is lost by absorption in passing through the atmosphere. The temperature of the air at any point will, in the first place, depend on the amount of solar radiation and of heat radiated from terrestrial objects directly absorbed, and next on the heating of the strata near the surface by convection. The amount of heat received from the sun, directly or indirectly, varies of course with the sun's declination * It is remarkable that there is no reference to the investigations of M. de St. Robert, and the formula deduced from them, in the article on the "Barometrical Measurement of Heights," in the new edition of the Encyclopedia Britannica. APPENDIX. 373 at the time, and the length of the day at the place of observa- tion. When the sun is below the horizon the air loses heat by radiation, and still more, in the strata near the surface, by convection to surfaces cooled by radiation. It was until lately believed that the experiments of Herschel and Pouillet had given an approximate measure of the absolute intensity of solar radiation, and that the proportion absorbed by the atmosphere at the sea-level at a vertical incidence might be estimated at about one-fourth of the whole. It is not too much to say that the recent researches of Mr. Langley, especially those detailed in his Report of the Mount Whitney expedition* have completely revolutionized this department of physics. It now appears that the true value of the solar constant is not much less than twice as great as the previous estimate, and that rather more than one-third is absorbed by the atmosphere before reaching the sea-level. Mr. Langley has further proved that the absorptive action of the atmosphere varies with the wave-length of the rays, and that, omitting the " cold bands " which correspond to the dark bands in the visible spectrum, it diminishes as the wave-length increases. It further appears highly probable that the larger part of the absorptive action of the atmosphere is due to the aqueous vapour, the carbonic-acid gas, and the minute floating particles of solid matter, which are present in variable proportions. Allowing for the probable extension of our knowledge by further research, it is yet evident that, even if we had not to take into account the further elements of the problem next to be specified, the distribution of heat in the atmosphere, as dependent on solar radiation, is a question of extreme complexity. The action of winds has an important effect in modifying the temperature of the air. It is not possible to draw a distinct line between the great air-currents, which affect large areas, and slight breezes, depending on local causes, and limited to the lower strata of the atmosphere ; but in relation to the present subject it is necessary to distinguish between them. There is a general circulation in the aerial envelope covering the earth, caused by unequal heating of different parts of the surface. * Published by the War Department, United States Army, Pro- fessional Pafers Jof the Signal Service, No. XV. 374 NOTES OF A NATURALIST. Heated air rises in the equatorial zone, and its place is filled by currents from the temperate and subtropical zones. The heated air from the equator flows at first as an upper current towards the poles, but as it gradually loses its high temperature, it becomes mixed with the currents setting from the poles towards the equator, causing the atmospheric disturbances and variable winds characteristic of the cooler temperate zones. As a rule, bodies of air of different temperatures do not very quickly mix, but tend to arrange themselves in layers or strata in which masses of unequal temperature are superposed. It is obvious that in such a condition, where a layer of colder air lies between two having a higher temperature, the whole cannot be in a state of equilibrium. But in nature we constantly find that equilibrium is never attained. There is a continual tendency towards equilibrium, along with fresh disturbances which alter the conditions. As Professor Stokes remarks in a letter on this subject with which he favoured me, " to know the temperature of the succes- sive strata as we ascend in a balloon, we should know the biographies of the different strata." Those which are now superposed may have been hundreds of miles apart twenty-four hours before. It follows that without a knowledge of the course and velocity of the higher currents existing in the atmosphere, we cannot expect to learn the vertical distribution of temperature. Apart from the effects of the great movements of the air, there is another effect of air-currents to be considered, which tends especially to modify the temperature found at or near the earth's surface. The heating of the surface by day, and the cooling by night, determine the existence of local currents of ascending or descending air. In rising, the air encounters diminished pressure, and therefore expands, and in so doing overcomes resistance. The molecular work involved in dilatation is performed at the expense of the other form of molecular work which we call heat. In other words, the air in ascending loses heat. It is found that the amount of decrement of temperature due to the ascent of a body of air is nearly exactly i° C. for loo metres. As a general rule, ascending currents arise from the surfaces exposed to the sun during the day, and must largely contribute to produce the rapid decrement of heat which is found in the lower strata near the surface, as compared with APPENDIX. 375 the rate of change in the higher regions ; but it will be obvious that the amount of effect produced by this cause is subject to continual variation from changes in local conditions. The nature of the soil, the extent and character of the vegetation, the form of the surface, are all elements virhich modify the amount of disturbance in the equilibrium of the surrounding atmosphere. As above remarked, in discussing the climate of Western Peru, prevailing winds which impinge upon a range of mountains may indirectly affect the temperature of the higher region by mechanically forcing masses of air to rise along the slopes, and ultimately, by expansion, to be cooled much below the temperature which they possessed when they originally flowed against the slopes. One of the most important agencies affecting the distribution of temperature in the atmosphere arises from the presence of aqueous vapour. In its invisible condition it affects the absorp- tive power of the air on the solar rays, and, when condensed in the form of cloud, it acts as a screen, intercepting most of the calorific rays which would otherwise reach the earth. But it is especially through the large amount of heat consumed in con- verting water into, vapour, and set free when vapour returns to the fluid state, that the temperature of the air is largely modified. When we consider that in converting a given volume — say, one cubic metre — of water into vapour, enough heat is consumed to lower about 1,650,000 cubic metres of air by 1° C. in temperature, and that the same amount of heat is liberated when the vapour so produced returns to the liquid state, we perceive how power- fully the ordinary processes of evaporation and condensation must affect the temperature of the air. It is needless to analyze further the several agencies which, sometimes co-operating, and sometimes in mutual opposition, determine the vertical distribution of temperature in the atmo- sphere. It is but too obvious that no approach to uniformity can be expected, and it might even be anticipated that any approximation to a regular law of distribution that should be found under one set of conditions — ^as, for instance, in serene weather by day — would be altogether inapplicable under dif- ferent conditions, such as exist in stormy weather, or by night. The need for practical application of some empirical rule, or law, of vertical distribution has made it necessary to appeal to 376 NOTES OF A NATURALIST. the results of observation, and for this object the only existing materials are to be found in the records of balloon ascents, and in the observations made on high mountains. In balloon ascents the temperature at any considerable height is free from the disturbances caused by the vicinity of the earth's surface, and the results might be expected to contribute to the more accurate determination of the amount of atmospheric refraction. For the measurement of heights by the barometer, it would appear safer to rely on such information as may be gleaned from mountain observations. Of balloon ascents by far the most important are those achieved in 1862 by Messrs. Glaisher and Coxwell, to which I have referred in a preceding page. Mr. Glaisher has given in his report a full record of the actual observations made in the course of his eight ascents, and has explained the processes by which he constructed the successive tables, from which he deduced as the final result a continuous decline (unbroken save in a single instance) in the rate of decrement of temperature found in passing through each successive zone of 1000 feet, in ascending from the sea-level to a height of 29,000 English feet. I am not aware that the processes employed by Mr. Glaisher in obtaining these results have ever been subjected to such close scrutiny as their importance demands, and as I have found on careful examination that his results are not borne out by the actual observations, I am forced to express my dissent from his conclusions. The admiration due to the courage, skill, and perseverance displayed by Mr. Glaisher throughout these memorable ascents will not be lessened if we should find it necessary to modify the inferences which he has drawn from them. The full discussion of Mr. Glaisher's observations involves an inconvenient amount of detail, and such readers as may be disposed to enter more fully into the subject I must refer to an article in the London, Edinburgh, and Dublin Philosophical Magazine. The general conclusions to which I have arrived from the observations made under a clear or partially clear sky is, that the average results show a rapid fall of temperature in the zone extending to about 5000 feet, or 1500 metres, above the earth's surface, and that, within that limit, the rate of fall diminishes APPENDIX. 377 as the height increases. Above the height specified the observations prove that in each ascent the balloon passed through successive strata of air whose temperature varied in a completely irregular manner, the fall of temperature being sometimes very rapid for an ascent of a few hundred feet, and sometimes very slight in a much longer interval. In each of the higher ascents we even find instances in which the thermo- meter rose in ascending from a lower to a higher station, reversing the ordinary progression. These alternations occurred at various heights from 5000 to 25,000 or 26,000 feet above the sea-level.* It seems to me very doubtful whether any safe con- clusions can be drawn from averages deduced from separate series of observations so discordant, but, in any case, I may confidently assert that the results of actual observations do not bear out the conclusions deduced by Mr. Glaisher. I desire further to point out that these balloon ascents were all executed by day, in summer, and in weather as serene as can ordinarily be found in our climate. If they did authorize us to derive from them an empirical law regulating the vertical distribution of temperature, this might, at the best, serve to approximate to the true amount of atmospheric refraction found by day in geodetical observations, but would be no guide to the conditions obtaining by -night, which are those important to the astronomer. Mr. Glaisher has not failed to notice the great difference shown by the observations made when the sky was overclouded as compared with those under a clear or partially clear sky, and has given a table showing that the mean results up to a height of 4000 feet above the sea show a nearly uniform decline of 1° Fahr. for each 244 feet at ascent. The numerical results of observations made under, or amidst, cloud appear to me of no practical value, as they depend upon conditions which are subject to constant variation. If it be true that observations in balloon ascents, which are free from the disturbances caused by the vicinity of the earth's * Air nearly saturated with vapour is lighter than air relatively dry ; and hence it may happen that, when a current of moist air meets one relatively dry, it will flow over the latter if they are nearly at the same tempera- ture, but if the drier current be much warmer, it may flow beneath it. 378 NOTES OF A NATURALIST. surface, have hitherto failed to lead to any general results indicating a normal rate of decrea:se of temperature with in- creasing elevation, it could scarcely be hoped that observations on mountains should contribute farther to enlighten us. From what has been already said, it is apparent that the fact that the place of observation is close to the surface causes disturbances the nature and amount of which must vary with each particular spot, and with the season and the condition of the atmosphere at the moment of observation. The intensity of solar radiation increases rapidly with in- creasing elevation,* so that when the sky is clear surfaces exposed to the sun are heated much above the normal tempera- ture. Owing to its slight absorptive power the free atmosphere is little affected ; but the strata nearest the surface are heated by convection, while a contrary effect follows when the surface is no longer exposed to the sun, and radiates freely to the sky. The air in mountain countries is rarely at rest. Even when there is no sensible breeze, the unequal heating of the surface causes ascending and. descending currents, which lose or gain heat by expansion or contraction. More commonly winds are experienced which, by impinging on the inclined surfaces, force bodies of air to higher elevations, and thereby directly cause a fall of temperature. All these causes of disturbance ai'e complicated by the action of aqueous vapour, which, in most mountain countries, is sup- plied from the surface, as well as borne upwards by ascending currents. Besides the effect of raising the temperature where condensation takes place, and lowering it where clouds are dissolved in strata of dry air, the amount of aqueous vapour present at a given place affects the intensity of solar radiation, and the consequent amount of heating of the surface. In spite of these obstacles to the attainment of accurate numerical results from which to infer the distribution of temperature in the atmosphere, we are yet, for the larger part of the earth, forced to rely on mountain observations as the only * On this subject see Handbuch der Klimatologie, by Julius Hann, pp. 141, et seq. See also Tables I. and II. in a report on theimo- metric observations in the Alps, by J. Ball,, in Reports of the British Association for the Advancement of Science for 1862, pp. 366-368. APPENDIX. 379 available source from which any indications of a law of distri- bution can be gleaned. Balloon observations have hitherto, so far as I know, been confined to a few places in Europe ; and, even if the results were more conclusive than they have hitherto been, we should not be entitled to infer that they held good for all parts of the earth. In countries where the course of the seasons is more uniform, and the direction and force of the winds less inconstant, it might be expected that the distribution of temperature would exhibit some nearer approach to uni- formity ; and the possibility of making observations at mountain stations by night might enable us to form some conjecture as to a condition of the atmosphere very different from that which obtains when the influence of the sun is present. It cannot be said that the observations hitherto made on mountains have done as much as they might do, if properly conducted, to contribute to our knowledge ; but a few leading facts may be derived from them, and it is worth while to point them out. The most important of these is, perhaps, the influence ot plateaux of elevated land in raising the temperature of the adjacent air. This is established by observation in all parts of the world, and it would appear that the rapid fall of temperature in the strata near the surface which is found at or near the level of the sea, is equally marked when we ascend from a plateau to an isolated summit. Both these conclusions, how- ever, apply only to observations made in the summer of temperate regions, or in the warmer parts of the earth. Apart from this effect of a relatively heated surface which appears to extend above the surface to a height of about 1500 metres, or, in round numbers, 5000 English feet, mountain observations give but slight confirmation to the belief that the rate of de- crease of temperature, in normal conditions of the atmosphere, diminishes as the elevation increases. In endeavouring to use the available materials one difficulty arises from the fact that, in comparing the temperature of the upper with the lower stations, observers have rarely been supplied with simultaneous observations at the lower station, or that, when these have been available, the distance has been so great that the results throw little light on the probable condition of a vertical column of air near the higher station. In parts of the 38o NOTES OF A NATURALIST. world where the daily range of temperature near the coast is very slight, we may with small risk of error use the mean temperature of the season at the lower station as the element of comparison, and, in places near the equator, the mean annual temperature. For this reason, observations in the Andes of Ecuador, Peru, and Bolivia present great advantages, and I think it may be useful to discuss the results so far as they are now available. It is scarcely necessary to examine critically the results of the earlier explorations. Humboldt has given in the " Recueil des Observations Astronomiques," etc., and in the " Memoires de la Socidtd d'Arcueil," vol. iii. p. 579, and elsewhere, the observa- tions made by himself in Mexico, Colombia, and Peru, and also those of Caldas and Boussingault, and has derived from them a table which, with more or less modification, has been adopted in many physical treatises. It exhibits the mean differences of temperature found in successive zones differing in height by 500 toises, the interval corresponding to 974'6 metres, or very nearly 3000 English feet. Height in toises. Mean temperature. Number of metres corresponding to a Number of metres corresponding to a fall of i" C. between the sea-level. successive zones of 500 toises. Sea-level 27 '5 _ _ 500 21-8 171 171 1000 18-4 216 287 1500 14-3 221 238 2000 7-0 190 "33 2500 i-S 187 177 The first remark to be made about this table is that the observations on which it is founded are not properly comparable, being partly single observations made during an ascent, and partly the mean of numerous observations made at certain places, such as Mexico, Quito, etc. It may further be remarked that many of the heights determined by Humboldt have been considerably modified by the results obtained by more recent travellers, and cannot now be regarded as correct. The influence of plateaux is, however, very apparent, as nearly all the observa- APPENDIX. 381 tions from which the estimated temperatures for 1000 and 1500 toises were derived were made at places situated on open elevated valleys or plateaux. At the utmost, the results can be regarded merely as rough approximations to the truth. By far the most important available observations in the Andes are those of Mr. Whymper, miade during his remarkable explorations in 1880 ; but, unfortunately, the details have not yet been given to the world, and, in endeavouring to make use of them, I have been forced to content myself with the brief summary published in the Proceedings of the Royal Geographical Society for 1881. Mr. Whymper was able to secure a register of the temperatures observed at Guayaquil during his stay in Ecuador, which will doubtless be published along with the record of his own observations ; but it does not appear that he was able to obtain observations at Quito during his ascents to the higher peaks ; and it seems that, in comparing the tempera- tures for the purpose of reducing his barometrical observations, he was forced to assume for Quito a mean temperature of 57-9 Fahr., or I4'4 C, obtained from a series of thermometric obser- vations made during his stay at that place. There is reason to believe that the daily range of the thermometer at Quito is very moderate ; and at the equator the differences of season are comparatively slight ; nevertheless, the absence of simultaneous observations at that place diminishes the value of the results shown in the following table, in which Mr. Whymper's results are reduced to metrical measure. I have adopted the heights determined by Mr. Whymper as those deserving most confidence. They agree very well with those published by MM. Reiss and Stubel, so that the limits of error from this cause are inconsiderable. 1 have also adopted the height assigned to Quito— 9350 feet, or 2848 metres. Where Mr. Whymper remained long enough on any summit to observe notable variations in the reading of the thermometer, I have taken the mean of the observed temperatures ; but I have entered separately the results of the ascents of Chimborazo, one being made in January, the other in July, and in a separate line I have entered the mean results of the two. In the following table I have entered in the first column the names of the peaks ascended by Mr. Whymper ; in the second, the height of each as given by him ; in the third, the observed 382 NOTES OF A NATURALIST. temperature in degrees Centigrade ; in the fourth, the difference between the.observed temperature and 27° C. — that assumed for Guayaquil ; in the fifth, the average number of metres corre- sponding to a fall of 1° C. in rising from the sea-level to the higher station ; in the sixth, the difference between the observed temperatures and that assumed for Quito — 14-4° ; and in the seventh, the average number of metres corresponding to a fall of 1° C. in rising from Quito to the higher station. It is obvious that the more rapid the fall the less will be the number in columns 5 and 7. . , h 2 S-s I-. d *i • 111 Name of mountain. 2£ £2 Sfil gti g B §.§1 11 S p. C § 0) ir tat eg a°- ^E" OS, I Chimborazo (Jan.) 6253 - 6-1 33'i 189 20-5 166 2 Chimboraz'o 0uly) 6253 - 8-o6 3506 178 22-46 15" 3 Mean of (l) and (2) 6253 - 7-o8 34-08 183-5 21-48 158-5 4 Cotopaxi 5959 - 8-4 35-4 168 22-8 136-5 S Antisana 5870 + II-I 15-9 369 3-3 916 6 Cayambe 5852 + 2-5 24-5 239 II-9 252 7 Cahihuairazo 5035 + 4'44 22 '56 223 9-96 220 8 Cotocachi 4965 + 2-2 24-8 202 12-2 i73'5 9 Pichincha ... 4851 + 777 19-23 255 6-63 302 10 Corazon 4837 + 4'44 22-56 214 9-96 200 II Sara Urcu 4718 + IO-0 17-00 284 4-4 425 It will at once be seen that the temperatures observed on Antisana, Pichincha, and Sara Urcu were altogether exceptional, probably due to rapid condensation of vapour ; and these may best be excluded from any discussion of the general results. The temperatures noted in the second ascent of Chimborazo were probably below the mean, or at least below the mean for the hours at which most of the other observations were made. But, as opinions may differ on that point, I have also given below the results of comparison with the mean for the two ascents of Chimborazo. For a similar reason 1 regard the figures for Cotopaxi, where Mr. Whymper remained for twenty-six hours on the summit, as giving too low a temperature, while that APPENDIX. 383 observed on Cayambe is certainly too high. The mean result for these two summits is probably a near approximation to the average for that height. In attempting to draw conclusions from the above table, we must first remark that, in consequence of its position on a plateau, the temperature of Quito is considerably higher than it would probably be if the higher peaks descended with an uniform slope to the sea-level. The difference between the means for that place and Guayaquil is only I2"6° C. ; whereas, on the supposition of an uniform decrease in ascending from the sea-level, it should be I4"2°, and still greater if we supposed that the rate of fall of temperature gradually diminishes as the elevation increases. Omitting altogether the results for numbers 5, 9, and II in the above table, we perceive that the observa- tions fall into three groups : (i) those for Chimborazo, at 6253 metres ; (2) those for Cotopaxi and Cayambe, with a mean height of 5905 metres ; (3) those for Cahihuairazo, Cotocachi, and Corazon, whose mean height is 4950 metres. To these it may be well to compare the mean of the results for the entire series, and also the rate of decrease between the sea-level and Quito. I shall designate observations included hereunder by numbers corresponding to the lines in the preceding table. The number of metres of ascent corresponding to a fall of 1° C. gives the most convenient measure of the rate of decrease. s£ ■oS S2 "ss ■E ■si si £■3 •sO' 3^ g 8S Jjrt c S S3 PS. So Quito 2848 12-6 226 Mean of 1, 4, 6, 7, 8, and 10 5483-5 27-19 201-5 14-59 180 -6 „ 3, 4, 6, 7, 8, and 10 5483-5 27-35 200-5 14-75 178-7 „ 7, 8, and 10 4946 23-37 212 10-77 195 ,, 4 and 6 5905 29-95 197 17-35 176 We see from this table that, in ascending from the coast to the highest peaks of Ecuador, the average fall of the ther^ 384 NOTES OF A NATURALIST. mometer was, in round numbers, i° C. for every 200 metres of ascent, while in ascending from the sea-level to the plateau of Quito the fall was proportionately less, being at the rate of 1° C. for 226 metres. On the other hand, the fall of temperature was more rapid in ascending from Quito to the higher peaks. On an average of all the ascents, we may reckon the rate of 1° for 180 metres. But it is remarkable that, taking the average of the three peaks which rise about 2000 metres above the level of Quito, the temperature fell only at the rate of 1° for 195 metres, while in ascending to peaks higher by nearly 1000 metres, the rate of fall was 1° for 176 metres, and if we take the still higher summit of Chimborazo we may reckon the rate of fall at about 1° for 160 metres. The apparent increase in the rate of decline of temperature in the higher region is still more clearly shown if we compare the mean of the three peaks whose average height is 4946 metres, with that of the two whose average height is 5905. For a difference in the mean height of 959 metres, we find an average fall of 6-58° C, or a fall of 1° for 145 metres. Taking the first ascent of Chimborazo as giving the most probable results, we find that between this peak and the mean of the three lower summits, with a difference in height of 1307 metres, the difference of temperature is 973°, or a fall of 1° for 134 metres. Again, comparing Chimborazo with the mean of Cotopaxi and Cayambe, we find, for a difference of height of 348 metres, a difference of temperature of 3"i5°, or a fall of 1° for 1 10 metres. I am fully aware that these observations are not numerous enough to lead to any safe general conclusions ; the com- paratively high temperatures found at the height of about 5000 metres may be due to exceptional local conditions, such, for instance, as the ordinary formation of clouds at about that level ; but, so far as they go, the observations tend to negative the supposition that in the tropics the rate of decrease of temperature diminishes as we ascend to the higher regions of the atmosphere. MM. Reiss and Stubel made numerous observations in the Andes of Ecuador and Peru, during a prolonged visit to that region. Lists of heights obtained by reduction from their observations have appeared in various German scientific periodicals, and more fully in the American Journal of Science, APPENDIX. 38s vol. ii. pp. 268, 269 ; but, so far as I can ascertain, the record of their observations of the barometer and thermometer has never been given to the world. In " Copernicus,'' vol. iii. p. 193, et seg., Mr. Ralph Copeland has published a summary of the results of a series of meteoro- logical observations made by him at various stations on the line of railway connecting Mollendo on the Pacific coast with Puno in Bolivia, near the lake of Titicaca, and also at La Paz and at Tacna. Two series of observations were made at Vincocaya, the summit station of the railway, 4377 metres above the sea. All the other stations are either on elevated plateaux, or on open slopes inclining gently towards the coast. The temperatures are partly derived from numerous observations and partly by taking the mean of the maxima and minima, with corrections for each station, the reasons for which are assigned by Mr. Copeland. In most of these I am inclined to concur, but there are two from which 1 am fo:;ced to dissent. In re- ducing Mr. Copeland's tables to metrical measure, I have there- fore ventured to make some corrections, which do not, however, much alter the results. I give below the heights above the sea, in metres, with the corrected mean temperature for each place, and the dates for each set of observations. Places. Latitude. Height. Dates of observation. Mean temperature, corrected. Mollendo Tacna Arequipa Hotel, Arequipa railway station Vincocaya, I. ... , IL ... Puno, I ,11 La Paz 17° 2' 54" 18° 1' 21" 16° 25' 20" 15° S3' 56" 15° so' 2" 16° 27' 0" 20 560 2346 2300 4377 3840 364s July 2 July 7-10 Feb. 2-8' June 29-30 Feb. 28-Marcli 4 June 6-27 March 20-April 4 April 1 5- June 2 Feb. 12-25 167° c. 14-2° 16 -2° 9-o° 2-83° — 2 '2° 9-2° 7-8° 107° Without entering into minute details, or discussing the small corrections for changes in the sun's declination to be allowed for latitude and for the dates of observation, we perceive that 2 C 386 NOTES OF A NATURALIST. on the western slope of the Cordillera the rate of decrease of temperature in this region is much below the ordinary average. Estimating the mean temperature of MoUendo at 22° at the beginning of February, we find between MoUendo and Arequipa a difference of 5-8'' C, or a fall in summer of 1° for an ascent of 4.01 metres ; while in mid- winter we obtain a difference of 77°, showing that an ascent of 364 metres is necessary to cause a fall of 1°. This abnormal condition is, no doubt, mainly due to the exceptionally low temperature of the coast-zone. Between Arequipa and Vincocaya we may reckon the fall of temperature on the 1st of March at i4'2° for an ascent of 2031 metres, giving the proportion of 1° to 143 metres ; but in winter the decrease is less rapid, as we have at the end of June a difference of about ii'5° for an ascent of 2077 metres, or about 181 metres for a fall of 1°. A remarkable contrast is shown when we compare the temperature at Vincocaya with that of places on the plateau surrounding the great lake of Titicaca. From Mr. Copeland's observations we may estimate the mean annual temperature of Vincocaya at 1° C, that of Puno at 8'S°, and that of La Paz at 8'8°. These figures would give a mean difference of 7'5° for a difference in height of 537 metres between Vincocaya and Puno, or a decrease of 1° for 72 metres. Between Vincocaya and La Paz we have a difference of 7 '8° for a difference in height of 732 metres, or a fall of 1° for 94 metres. The mean of the two comparisons gives a fall of 1° for 83 metres, or about twice as rapid a change as the average of the comparison between Arequipa and Vincocaya. I am not disposed to attribute this remarkable difference of atmospheric conditions exclusively to the influence of plateaux in raising the mean temperature. In my own shght experience in the Peruvian Andes, in ascending from Chicla, at about 3700 metres, to Casapalta, at about 4200 metres, I observed so complete and rapid a change in the character and aspect of the vegetation as to satisfy me that the difference in the annual mean temperature must be even greater than that observed by Mr. Copeland for a some- what greater difference of height between Vincocaya and Puno. It may be that, in this comparatively dry region of the Andes, the higher stations receive more frequent, though not copious, falls of rain or snow, the evaporation of which main- APPENDIX. 387 tains a constant low temperature in the surface and the sur- rounding air. In comparing observations in Peru, Bolivia, or Chili with those made in the Andes of Ecuador, it must not be forgotten that the climatal conditions are essentially different. Owing to the fact that in the latter the range of the Andes is much narrower, and on one side the main valleys descend in a nearly due easterly direction, the hot, vapour-laden, easterly winds reach the plateaux still charged with moisture, and at all seasons rain is frequent and abundant. Farther south, the winds from the Atlantic have deposited the greater part of their moisture before they arrive at the western side of the main range, and the annual rainfall must be comparatively trifling. I have sought in vain in the records of mountain observations in other parts of the world for materials from which any pro- bable inference may be drawn as to a law regulating the ratio of decrease of temperature with increasing height above the sea-level. There is reason to admit that isolated peaks of no great height show a more rapid decrease as compared with the plain than do considerable mountain masses. Of mountains exceeding the height of 3000 metres in the tropics, the most rapid rate of decrease is that recorded for Pangerango in Java, being 1° for 178-5 metres. The greater mountain masses in or near the tropics show nearly the same rate of decrement, by comparison with the sea-level, that I have been led to infer from the observations in Ecuador. The average rate for the Himalayas is about 1° for 194 metres of ascent, and for the less lofty peaks of Mexico Humboldt's observations show a decrease of 1° for 188 metres. The great irregularities due to local conditions make it impos- sible to derive any positive conclusions as to the comparative rate of decrease in successive zones of elevation. In Europe and North America comparisons between the temperatures at mountain summits and the sea-level give rates of decrease varying between 1° for 160 metres, and 1° for 170 metr-es ; but it must be remarked that the averages are mainly founded on observations made in summer, and it is certain that the rate of decrease is much slower in winter. Where the difference of height is not very great, it not uncommonly happens that in winter the phenomenon is reversed, and that 388 NOTES OF A NATURALIST. we experience an increase of temperature in ascending above the plain. The same result on a small scale may often be remarked on clear cold nights, when the temperature rises for a distance of some hundred feet in ascending isolated eminences, the effect being due to the cooling effect of radiation from the surface. It seems most probable that in the winter of the temperate and polar zones the distribution of temperature in the atmo- sphere is subject to conditions widely different from those prevailing in summer ; and, if that be true, we should have intermediate conditions in the spring and autumn ; so that even if we could arrive at comparatively accurate results for one season of the year, these would not be applicable at other periods. The general result to which I have arrived is that to ascertain the distribution of temperature in the atmosphere in successive zones of elevation is a problem of extreme complexity, towards which the existing materials do not furnish even an approximate solution. I hold, however, that it ought to be possible to obtain much more definite knowledge than we now possess by means of properly conducted observations in various parts of the world. Foremost of these I would suggest the importance of well- conducted balloon ascents within the tropics. In selecting stations for such ascents we are somewhat restricted by local considerations, especially the extension of forests in many regions, such as the greater part of tropical Brazil. In British India there would be no difficulty in selecting suitable stations, and there would be additional value in comparing the results obtained from ascents in Bengal, and in the very different climate of the North-west Provinces. Elsewhere in the tropics we might expect valuable results from ascents in Queensland, and from the llanos of Venezuela. It seems not impossible that, with a considerably smaller outlay, useful results may here- after be obtained by means of improved self-recording instru- ments sent up in captive balloons ; but in most countries such a record would be liable to interruption owing to storms. The next desideratum is to obtain for a series of years simul- taneous observations at successive stations, at vertical intervals of 500 or 600 metres, situated on the flanks and at the summits of high mountains to be chosen for the purpose. Some APPENDIX. 389 of these might with advantage be chosen on islands, and among these the following may be suggested : — ^the Peak of TeneriflFe, Mauna Kea in the Sandwich Islands, Fusiyama in Japan, the Piton de Neige in the island of Reunion, and Etna in Sicily. It would add much to the value of these observations if in each case there were a double series of stations, one series being on the windward, the other on the leeward side of the mountain. It would also be important to obtain observations at similar series of stations in continental regions, removed from the im- mediate influence of the sea. Pike's Peak in Colorado, which already possesses an observing station at the summit, and Mount Whitney in California, which Mr. Langley has selected as eminently suited for an observatory, both offer many advan- tages for the desired purpose. Another desirable station might easily be found in the Caucasus, or in Armenia, and one or more could be selected on the southern declivity of the Hima- layes. In South America, where railways have been carried to such great heights, it may be hoped that regular observations may at some future time be secured at the successive railway stations. It would be worthy of the enlightened governments of Chili and Argentaria to make a commencement, by providing for such a series being obtained at the stations on the railway now in course of construction over the Uspallata Pass. For the realization of most of these desires, as well as many others affecting the progress of human knowledge, and the general welfare of our race, we must be content to await the advent of a happier era, when the fruits of industry, and the efforts of rulers, shall no longer be mainly devoted to the maintenance and development of the arts of destruction. While awaiting such additional knowledge as may hereafter be obtained, it is necessary in the mean time to form some provisional hypothesis on which to base the formula for deter- mining the difference of heights of two stations, by barometric observations, and for ascertaining the amount of atmospheric refraction; and the subject might with advantage be discussed at a congress of scientific men. I have no authority to decide on a question of such difficulty, nor do I pretend to be thoroughly versed in the somewhat voluminous literature of the subject. I may remark, however, that in one of the fullest and most elaborate works by recent writers, Dr. Riihl- 390 NOTES OF A NATURALIST. mann * has proposed a formula for the reduction of barometric observations which implicitly assumes that the rate of decrement of temperature in ascending mountains is uniform, inasmuch as he takes the mean of the temperatures observed at the higher and lower stations as the value of the mean tempera- ture of the column of air between the two stations. It would appear that his adoption of the hypothesis of an uniform rate of decrease is merely due to the apparent impossibility of discover- ing a more satisfactory hypothesis. Following on a line of inquiry first suggested by the late M. Plantamour and M. Charles Martins, Dr. Riihlmann has analyzed a series of two- hourly observations of temperature made during six years at the hospice of the Great St. Bernard and at the Geneva Observatory. Treating the mean temperature of the column of air between the levels of those places as the unknown quantity, and neglecting, as unimportant, the corrections for the tension of aqueous vapour and for gi-avity, he has deduced the " true temperature," as he styles it, of the intermediate column from the equation of condition between the pressures, the heights, and the temperatures of the two stations, for the average of the two-hourly periods of observation for each month. He has shown that, while on the average of the entire year the mean " true temperature " of the intermediate column of air agrees pretty well with the mean of the yearly observations at the two extreme stations, the means for the separate hours and those for the separate months usually differ widely from the so- called " true temperatures " for the corresponding periods. From this investigation Dr. Riihlmann has shown that during the warm hours of the day, and the summer months, the " true mean temperature" is lower than the mean of the observed temperatures at the two extreme stations, while at night, and during winter, it exceeds that mean to a rather greater extent. It may be objected that the cause of the apparent discrepancy lies in the fact that, in thermometric observations, we obtain, not the true temperature of the surrounding air, but that of the thermometer, and that, however carefully screened, the thermo- meter cannot be completely freed from, the effects of radiation * See "Die Barometrischen Hohenmessungen und ihre Bedeutung fiir die Physik der Atmosphare," Leipzig, 1870, by R. Riihlmann. APPENDIX. 391 to and from surrounding objects. This remark applies especially to the observations at the St. Bernard, which lies at a consider- able distance from Geneva, and where the temperature is unduly depressed by surrounding masses of snow. I do not, however, attach much importance to these sources of error ; and I have no doubt that under the most favourable condition^ the discrepancy shown by Riihlmann will be found to a greater or less extent, but I differ from that writer in the inference that he has drawn from the facts. If I have not misunderstood his remarks, Dr. Riihlmann concludes that the true temperature of the successive strata of air in the zone between the base and the summit of a mountain is but slightly affected by the diurnal changes that are exhibited in the range of the thermometer, and to a moderate extent only by the changes of season as shown by the range of the monthly means. He has not adverted to the fact that the differences disclosed in his tables may be the result of changes in the rate of decrement of temperature in ascending from the lower to the higher station. He shows that, on the mean of the July obser- vations, the mean temperature of the air between the levels of Geneva and the St. Bernard is lower than the mean difference of the temperatures observed at those places by i'57° C. But this is not inconsistent with the supposition that the thermo- meters have recorded the true air temperature at each station, but that the rate of decrement of temperature in ascending, ai that season, diminishes rapidly in the successive vertical zones. In the same manner the fact that the true mean temperature in January is higher than the mean of the observed thermometers by I '83° C, might be accounted for by supposing that in winter the rate of decrement is smaller in the lower strata, and increases in ascending above the surface. It is equally true that, in both cases, the facts may be consistent with such an irregular dis- tribution of the atmosphere in successive layers, or strata, of very unequal temperature as was apparent in most of Mr. Glaisher's balloon ascents. What is completely proved is that it is only under exceptional conditions that the hypothesis of an uniform rate of decrement of temperature, directly proportional to height above the sea-level, is approximately correct for observations in the temperate zone, where there is a considerable diurnal and annual range of the thermometer. 392 NOTES OF A NATURALIST. My own impression, as the result of such study as I have been able to give to the subject, is that, in the present state of our knowledge, the reduction of barometric observations for the height of mountains made by day, and in summer, in temperate latitudes, may best be effected by the formula proposed by M. de St. Robert ; while for observations made at other seasons, and in the tropics, I should prefer the formula proposed by Mr. Ruhlmann. Before closing these remarks, I may refer to an ingenious suggestion made by M. de St. Robert in a paper pubhshed in the journal Les Mondes in Paris, in 1864, the substance of which is to be found in the Atti delV Academia delle Scienze di Torino for 1866, p. 193. Impressed with the difficulty of approximating in practice to a correct knowledge of the distribution of tempera- ture in the air between the summit of a mountain and a lower station, the author sought to escape from it by seeking a phe- nomenon, susceptible of observation, which should give a direct measure of the mean density of the air in the space between the two stations. He pointed out that the velocity of sound supplies such a measure, and that, given the barometric pressures at the higher and lower stations, the angle of elevation of the former, measured by a theodolite and corrected for refraction, and the exact time required for sound to traverse the interval between them, the height is given with a near approximation to accuracy by a simple formula. The error arising from air currents, which increase or diminish the velocity of transmission, would be readily eliminated by discharging a fire-arm simultaneously at both stations, observing the interval between the light reaching the eye and the report becoming audible, and taking the mean of the intervals observed at both stations. M. de St. Robert does not disguise the practical difficulty of measuring the time interval with the requisite accuracy, but he thinks that it may be obtained within a fifth of a second. The error in the result is inversely proportionate to the time required to traverse the distance, and where the stations are as distant as is compatible with the sound being audible, its amount for an error of a fifth of a second is inconsiderable. This suggestion has not received the attention which it seems to deserve. It possesses the advantage that the observations may readily be repeated with little trouble or cost, and that the APPENDIX. 393 risk of error may be much diminished by taking the mean of the observed intervals of time. A comparison between observa- tions between stations whose height is known, made under different conditions, by day and night, and in different states of weather, might, I think, contribute to diminish our ignorance as to the variable conditions of the atmosphere at different heights above the surface. APPENDIX B. REMARKS ON MR. CROLL'S THEORY OF SECULAR CHANGES OF THE earth's climate. Most scientific readers are familiar with the theory respecting the influence of changes in the eccentricity of the earth's orbit on the climate of the globe, which has been sustained with remarkable ability by Mr. James CroU. The views originally advanced in various scientific periodicals were presented to the public in a connected form in the volume entitled " Climate and Time," wherein the author has brought a wide knowledge of the principles of physics, and of the whole field of geological science, to the support of his theory. Even those who have not given especial attention to the subject are also acquainted with the conclusions which Sir Charles Lyell drew from the discussion of Mr. Croll's arguments, and which are contained in the thirteenth chapter of the tenth edition of his " Principles of Geology," and also with the more recent examination of the subject which is to be found in Mr. Alfred Wallace's important work, " Island Life." I need not say that a theory so important in. its bearing on some of the most obscure problems of geology has been dis- cussed, in more or less detail, by many other writers. To most of the objections presented to his theory, Mr. CroU has replied with his usual ability ; and I believe that at present the prevail- ing tendency among geologists is towards a partial acceptance of his views, subject to the limitations assigned by Mr. Wallace. 394 NOTES OF A NATURALIST. The latter author holds, in common with Sir Charles Lyell, that geographical causes, arising from the varying distribution of land and sea, have mainly controlled the distribution of tempera- ture over the earth's surface ; but he is disposed to go farther than Lyell in admitting the influence of periods of high eccen- tricity in causing those great accumulations of snow and ice which were requisite to produce the phenomena of a glacial period, whenever a sufficient area of elevated land in high latitudes coincided with the period of high eccentricity. It would probably be of little avail, even if I were to under- take the task, that I should attempt any thorough discussion of this vast and difficult problem ; and it would certainly require far more space than can here be given to it. I may, however, venture to make a few remarks upon some points which have not, to the best of my knowledge, been much noticed in the discussion. In reading Mr. Croll's work, which charmed many an hour during the voyage to and from South America, I found it very difficult to discover any flaw in the chain of close reasoning by which he supports his conclusions. Most of the facts on which he relies are warranted by observation, and have been accepted as well established by writers of the highest authority ; and his inferences as to the results of altered conditions appeared to be in strict conformity with admitted physical principles. Never- theless, when I reflected on the anomalies which are found at the present time in respect to the climate of many spots in the world, and the complexity of the causes which determine its actual condition, I felt a doubt whether, in his attempt to trace the result of possible changes, Mr. Croll may not have over- looked some of the elements of the problem. Let me briefly state the leading propositions of Mr. CroU's theory in order to make intelligible the succeeding remarks. Estimating approximately the mean distance of the earth from the sun at ninety-one and a half millions of miles, and the eccentricity* of the sun's place in the orbit at one and a half million, it follows that at one period of the year, which happens to be about the winter solstice of the northern hemisphere, the earth receives from the sun a quantity of heat greater than that * I use the term "eccentricity" in the popular sense, to express the distance of the focus from the centre of the ellipse. APPENDIX. 395 which reaches it in the opposite part of its orbit, in the propor- tion of 93^ to 90^, or about as 1000 to 936. Midsummer of the southern hemisphere is the season when the earth is nearest to the sun ; the winter of the southern and the summer of the northern hemisphere occur when the earth is farthest from the source of heat. The conclusion seems inevitable — the southern hemisphere must have hotter summers and colder winters than our hemisphere, where the heat of summer is tempered by the greater distance, and the cold of winter mitigated by the com- parative nearness, of the sun. The next point to be considered is the effect of ocean-currents, and especially of the Gulf-stream, in modifying the climatal conditions of some parts of the earth. Following in the track of the late Captain Maury and Principal Forbes, Mr. Croll has especially insisted on the importance of the great current which, issuing from the Gulf of Mexico, and flowing northward between Florida and the Bahamas, extends across the Atlantic towards the western shores of Europe. He calculates that by this current alone an amount of heat equal to that received on the entire surface of the earth in a zone thirty-two miles in breadth on each side of the equator is carried from the tropics to the cooler regions of the northern hemisphere. Mr. Croll has, I think, victoriously replied to several of the objections opposed to this portion of his argument. His estimate of the volume of water transferred by the Gulf-stream from the tropics to the northern part of the Atlantic, which he reckons at the annual amount of about 166,000 cubic miles, is, I think, in no degree exaggerated ; and I also think that he is warranted in estimating the mean initial temperature at about 65° Fahr. I am, however, persuaded that in assuming 40° Fahr. as the temperature to which, on an average, this vast body of water is reduced before it returns to the equatorial zone, Mr. Croll has gone beyond the probable limit. A large part of the stream is diverted eastward about the latitude of the Azores, and is never cooled much below 55° Fahr. before the waters enter the return current on the eastern side of the Atlantic basin ; and I believe that, if we allow the water of the Gulf-stream to undergo an average loss of temperature of 20° Fahr., we shall be more likely to exaggerate than to underrate the amount of cooling. In insisting on the importance of the Gulf-stream in modify- 396 NOTES OF A NATURALIST. ing the climate of Europe and the adjacent parts of the arctic zone, Mr. CroU agrees with many preceding writers ; but, so far as I know, he was the first to suggest that in consequence of the greater persistency of the south-east trade- winds, which ordinarily extend up to, and, at some seasons, even north of, the equator, the warm waters of the Northern Atlantic derive a large share of the heat which is carried to the temperate and arctic zones from the southern hemisphere. Applying the same reasoning to the currents of the Pacific Ocean, Mr. CroU arrives at the general conclusion (" Climate and Time," p. 94) that " the amount of heat transferred from the southern hemisphere to the northern is equal to all the heat falling within fifty-two miles on each side of the equator." I do not believe that the facts on which Mr. CroU bases this essential portion of his theory are sufficiently established. With regard to the Atlantic, I have expressed in the text (p. 344) an opinion, derived from conversations with practical seamen, that in the Atlantic the trade-winds of the northern are stronger than those of the southern hemisphere. That opinion, I am disposed, on further examination, to regard as incorrect. I believe that the north-east trade-winds often blow with greater force ; but, taking the average of the entire year, I now think there can be no doubt that the south-east trade-winds extend over a wider area in the equatorial zone. However this may be, our knowledge of the currents of the Atlantic does not, I think, authorize us to conclude that the portion of heated water carried from the southern to the northern hemisphere is nearly so large as Mr. CroU has estimated. If the heat of the Gulf- stream were mainly supplied, as Mr. CroU contends, from that source, there should be a marked difference in the volume and temperature of the current, between the season when the north- east trade-winds approach the equator and that in which the south-east trades prevaU to the north of the line, for which there is no evidence. As regards the currents and winds of the Pacific, in spite of one considerable exception, to which I shall further allude, I think that the balance of evidence points to a greater prevalence of the south-east trade-winds, and to the probable transference of some portion of the equatorial waters from the southern to the northern hemisphere. APPENDIX. 397 For the present discussion it is best to accept Mr. Croll's estimate, and to compare the amount of heat which he supposes to be transferred from one hemisphere to the other with the total amount which is received annually from the sun on each hemisphere. For this purpose I have taken the known areas of the torrid, temperate, and frigid zones respectively, and, following Mr. CroU, I have adopted Mr. Meech's estimate of the average amount of he^t, per unit of surface, received from the sun in each zone, irrespective of absorption by the atmo- sphere. To estimate the proportion of heat which actually reaches the surface, I have adopted Pouillet's measure of the proportion of solar radiation cut off at vertical incidence, which is 24 per cent. I assume 28 per cent, to be the average loss in the torrid zone, 50 per cent, in the temperate zone, and 75 per cent, in the frigid zone.* The resulting figures, showing the proportional amount of heat annually received on the surface of each zone, and on the entire hemisphere, are as follows : — Torrid zone ... ... ... ... 337° Temperate zone ... ... ... 2304 Frigid zone ... ... ... ... 112 Whole hemisphere ... ... ... 5786 Calculating, on the same basis, the amount received on a zone one mile wide at the equator, allowing a loss of 25 per cent, from atmospheric absorption, and multiplying the result by 104, I obtain the number 233'i, or rather more than one twenty- fifth part of the entire heat annually received from the sun by each hemisphere. To trace the results of such a transfer of heat from one hemisphere to the other, I shall adopt a mode of reasoning, sanctioned by the great authority of Sir John Herschel, to which Mr. Croll frequently resorts. It is by solar heat that the surface of the earth is raised above the temperature of space, which is assumed to be 239 degrees below the zero of Fahrenheit's scale. Adopting Ferrel's estimate, I take the mean temperature of the northern hemisphere at 59-5° Fahr., or 298^ degrees above the temperature of space. To maintain this temperature, it * Viewed in the light of Mr. Langley's recent researches on solar radiation, all these numerical determinations are probably far from the truth ; but the errors do not much affect the present argument. 398 NOTES OF A NATURALIST. receives one-half of the amount of solar radiation which reaches the earth, and in addition, on Mr. CroU's hypothesis, one twenty- fifth part of that which reaches the southern hemisphere. It follows that the heat available to raise the southern hemisphere above the temperature of space stands to that which is received by the northern hemisphere in the ratio of 24 : 26, and that the mean temperature of the southern hemisphere should be 298'5 X ^, or 275'5° above the temperature of space ; so that, in ordinary language, the mean temperature of the southern hemisphere should be 36-5° Fahr. If the fact corresponded with this result of theory, it would not be necessary to invoke in- creased eccentricity of the earth's orbit to account for the extreme cold of one hemisphere, seeing that the actual con- ditions would suffice to completely alter their relative tempera- tures. It occurs to me, however, that, on further consideration, Mr. CroU would reduce his estimate of the volume of heated water transferred from the southern to the northern hemisphere ; but even if that estimate were reduced by one-half, we ought to find in the southern hemisphere a mean temperature of 47"8° Fahr., or nearly 12 degrees lower than that of our hemisphere. We have already seen that, so far as climate depends on the relative position of the earth and the sun, we ought to find in the southern hemisphere climates of a more extreme character, with hotter summers and colder winters, than those to which we are accustomed. If it be true that through the agency of ocean-currents a considerable amount of heat is transferred to the northern hemisphere, that circumstance might serve to account for the fact that the summers of the southern are not generally hotter than those of the northern hemisphere ; but it would, at the same time, tend to aggravate the severity of the southern winters. At the time of the publication of Mr. Croll's earlier memoirs, there existed a general belief that the southern hemisphere was in fact notably cooler than our portion of the globe, and he naturally referred to the supposed fact as harmonizing with the general conclusions drawn by him from theory. But, imperfect as our knowledge of the southern hemisphere still is, a good deal of information has been obtained of late years. The only stations south of the fiftieth degree of latitude from which we APPENDIX. 399 possess continuous observations are those mentioned in the text (p. 273) ; but we also know with sufficient accuracy the climates of two widely separated islands lying about 50° south ; and from these we derive results widely different from those to which we were led by theoretical considerations. The fol- lowing table gives approximately the mean temperatures, on Fahrenheit's scale, for the year and for the hottest and coldest months of the places referred to in the southern hemisphere, and the means for corresponding latitudes in the northern hemisphere : — •R V 1 as 0,'-' I 1^ If en s 15 12; Kerguelen Land 49° 17' 44-3° IS-l" 3Q-6° 63-3° 22-0'' ^2-0° Auckland Island 5°° 30' ,o-2" ss-fi" 44-6" fiz-i" 19-0° 4i'i° * Falklands (Stanley) I. 51° 41' 4q-6" ^6-," 43-o" 61 -6" T7-T° 3n-R° FalklandsII 52° 5' SS-P" 17-4" 47-3" 5i-3" 16-40 3Q-3" Falklands, mean of I. and II. ,2-7" 37-0" 45-1" 6r-," 16-7° 3n-fi° Punta Arenas 53° =S' SI -4" 34-7" 43-°" 6o-6° 14-2° 37 '7° t Ushuaia ... .,. 54° 53' 53-2" 31-8" 41-9" 59-6'' 12 -O" 36-2» If we compare the mean results of these five stations with those for corresponding latitudes in the northern hemisphere, we find that the summers are cooler and the winters very much milder, and that in the latitudes between 50° and 55° the mean annual temperature is notably higher. In Kerguelen Land alone the mean annual temperature is lower than the normal for the same latitude north of the equator ; but that island is evidently exposed to exceptional conditions. * The observations at Stanley Harbour, which are those adopted by Dr. }ia.mi(Klimatoli>gie, p. 697), show temperatures notably lower than those recorded for a place in the islands lying farther south, which are given in the Zeitschrift der CEsterreichischen Gesellschaftfur Meteorologie, vol. T. p. 369. The mean of the two is probably nearly correct. t These figures are derived from the tables given in the Anales de la Oficina Meteorologica Argentina, by B. Gould, vol . iii. The figures show a considerable amount of annual variation. The monthly means of the six months from February to July, 1879, exceed those of the same period in 1878 by more than 2° Fahr. 40O NOTES OF A NATURALIST. The differences between the mean results given above are shown by the following table, in which the signs show the excess or deficiency of the southern as compared with the northern hemisphere : — Warmest month. Coldest month. Annual mean. - 1 1-1° Fahr. + i8-i° Fahr. + 4'2° Fahr. Dr. Hann has carefully discussed the question as to the com- parative mean temperatures of the two hemispheres in a paper published in the proceedings of the Vienna Academy, the substance of which is given in his KUmatologie, pp. 89, et seq.j and it is difficult to refuse assent to his conclusion that so far as the available evidence goes, it shows that the mean tempera- ture of both hemispheres is equal. I find, then, that the same train of reasoning by which Mr. CroU has sought to explain the occurrence of glacial periods by changes in the eccentricity of the earth's orbit, and the pre- cession of the equinoxes, leads us to conclusions respecting the climatal condition of the different parts of the earth, at the present amount of eccentricity, which are altogether opposed to the results of observation ; and I am driven to the conclusion that the causes which he has adduced have not the predominant influence which he has attributed to them, and that there must be other agencies to which he has not assigned their due importance, but which are adequate to counteract the efficiency of those which, as observation proves, fail to achieve the effects anticipated from them. I am far from pretending to be able to analyze completely the complex agencies which, by their mutual action, determine the chmate of different parts of the earth, but I may briefly refer to two of them. Foremost of these is the relative distribution of land and sea, for a due appreciation of which we are indebted to the great work of Sir Charles Lyell. It is unnecessary here to discuss how far his view of the probable amount of change in past geological epochs may, in the present state of our knowledge, be subject to limitation. Mr. Wallace, who is the most strenuous supporter of the modern doctrine of the per- manence of the present continents and ocean basins, recognizes the theoretical correctness of Lyell's views, and admits that changes of level great enough to cause profound modifications APPENDIX. 401 of climate have actually occurred. Notwithstanding recent objections, it appears to me that Darwin's hypothesis as to the subsidence of a great tract in the Southern Pacific is that which best accounts for the existence of the countless coral islands in that region ; nor is the probability of a nearly continuous barrier of volcanic islands across the Atlantic to be completely dis- missed. That such changes would have largely affected the climate of the earth cannot, I think, be doubted. If I may venture to express my own view on this difficult subject, I must say that, although it has not been overlooked by the able men who have discussed it, the paramount importance of aqueous vapour as an agent for modifying climate has not yet been fully recognized. Mr. Croll has constantly discussed the phenomena of ocean-currents, as if their chief function were to affect climate by heating or cooling the surrounding air, which is thence diffused over the land surfaces, and he has devoted little attention to the effects of evaporation from the sea, and the subsequent condensation in some other region of the vapour produced. When we remember that as much heat is consumed in the conversion of one cubic mile of water into vapour as would raise the temperature of nearly ninety-seven cubic miles of water by 10° Fahr., we get some measure of the vast power of vapour as a vehicle of heat. Admitting, as I am disposed to do, that 166,000 cubic miles of water are annually conveyed northward by the Gulf-stream, and suffer an average loss of 20° Fahr. before returning to the torrid zone, I must point out that the entire heat requisite to maintain this great volume of water at the higher temperature would be consumed in the conversion of 3433 cubic miles of water into vapour. In point of fact, I believe that more than one-half of the quantity specified is expended in evaporation, and that the cooling of the waters of the Gulf-stream is mainly due to this agency. To follow the vapour thus produced, to ascertain where it is condensed, and where the heat disengaged in the act of condensation becomes available to raise the temperature of the air, is a task which is beyond our present resources ; but it is one which must be performed before we can reason with any confidence as to the ultimate distribution of the heat carried by the Gulf-stream or any other ocean-current. Whatever part of the vapour produced by evaporation from the Gulf- 2 D 402. NOTES OF A NATURALIST. stream goes to supply the rainfall of Western Europe, or to form snow in the arctic regio'ns, acts as a vehicle to transfer heat from the tropics to the temperate and frigid zones. But it is more than probable that a large part of the vapour in question is carried back to the torrid zone, and that some of it is even restored to the southern hemisphere. The south-eastern branch of the Gulf-stream flows, at least partially, into the area of the north-east trade-winds. These winds reach the lower region as cold and very dry winds. As they advance towards the equator, and are gradually warmed, their capacity for aqueous vapour constantly increases, and there can be no doubt that in both hemispheres the trade-winds bear with them a large share of the vapour which goes to supply the heavy rainfall of the tropics. In the Pacific region we have direct evidence to this effect, in the fact that in Hawaii, and elsewhere, the side of the islands exposed to the trade-winds is that of heavy rainfall, and is generally covered with forest. No sufficient data exist for estimating the amount of vapour thus carried back to the tropics from high latitudes on both sides of the equator, nor the amount of heat set free by its condensation ; but we may form some conception of its probable amount by considering that at the moderate estimate of a mean annual rainfall of seventy-two inches for the portion of the globe between the tropics, this amounts to a yearly fall of 88,737 cubic miles, and that we can scarcely reckon the share of this great volume of water supplied by evaporation from the same part of the globe at more than one-half Still less is it possible to calculate the amount of vapour annually transferred from the northern to the southern hemisphere, which goes to neutralize the apparent effect of the diversion of portions of the equatorial waters to the north side of the line. In the Atlantic basin it is probable that the larger part of the rainfall in the region including and surrounding the Gulf of Mexico and the Caribbean Sea is supplied by vapour carried from the temperate zone by the north-east trade-winds. There is some reason to believe that a portion of the rainfall of the great basin of the Amazons, south of the line, is also supplied from the same source. Several travellers report that during the rainy season the prevailing winds are from the west and north-west, the latter being especially predominant at APPENDIX. ' 403 Iquitos, about 4° S. latitude, and 1600 miles from the mouth of the river. In tropical Australia the rainy season falls during the pre- valence of the north-west monsoon, and we cannot doubt that this is mainly supplied by vapour carried from the northern hemisphere. Another region wherein the same phenomenon is exhibited on a large scale is the central portion of Polynesia, extending from the Feejee to the Society Islands over a space of at least twenty degrees of longitude. Over that wide area, as far as about twenty degrees south of the line, the regular south-east trade-wind prevails only in the winter of the southern hemisphere, while during the rest of the year, especially in summer, north and north-east winds have the predominance. Taking the mean of three stations in the Feejee Islands, of which the returns are given by Dr. Hann, I find in round numbers the very large amount of 150 inches for the mean annual rainfall, of which 105 fall during the seven months from October to April, while the five colder months from May to September supply only forty-five inches of rain. There can be little doubt that the larger part of the 105 inches falling during the warm season is derived from the northern hemisphere. I by no means seek to account fully for the apparent con- tradiction between the results of theory, as developed by Dr. CroU, and the actual distribution of heat over the earth as proved by observation ; but I venture to think that I have shown reason to doubt the possibility of drawing absolute conclusions as to the results of astronomical changes until we shall have fuller knowledge than we now possess of all the agencies that regulate climates. Before concluding these remarks, I will notice one other branch of the argument in regard to which I am unable to concur with Mr. CroU. As we have seen, the essential point in his theory as to the modus operandi of changes of eccentricity, and the relative position of the poles, on the distribution of temperature, is that the currents of the equatorial zone are driven towards the pole which has the summer in aphelion, and that the cause of this shifting of the currents depends on the greater strength of the trade-winds in the hemisphere which has the winter in aphelion ; the strength of the trade-winds in turn depending on the amount of difference of temperature 404 NOTES OF A NATURALIST. between the equatorial and the colder zones. Taking the surface of the earth generally, the trade-winds of the southern are probably stronger than those of the northern hemisphere, and, if it were true that the south temperate and frigid zones were colder than those of the other hemisphere, it would be allowable to argue that the greater difference of temperature as compared with the equatorial zone was the cause of the greater strength of the trade-winds. But we now certainly know that the southern hemisphere between latitudes 45° and 55'^ is con- siderably warmer than the corresponding zone of the northern hemisphere, and we have good grounds for believing that the mean temperature of the whole hemisphere south of latitude 45° is higher, and certainly not lower, than that of the same portion of the northern hemisphere. We are therefore not justified in explaining the greater strength of the southern trade-winds by a greater inequality of temperature between the equator and the pole. In my opinion the cause of this predominance of the southern trade-winds is to be sought in the fact that the southern is mainly a water hemisphere, while the northern is in great part a land hemisphere. In the south, the great currents of the atmosphere flow with scarcely any interruption, except that caused by Australia, where, in fact, the trade-winds are irregular, and lose their force. In the northern hemisphere the various winds originating in the unequal heating of the land surface interfere with the normal force of the trade-winds, and weaken their effect. In connection with this branch of the subject, I may remark that the belief in the greater cold of the southern hemisphere mainly rests on the fact that all the land hitherto seen in high latitudes has been mountainous, and is covered by great accumulations of snow and ice. But this does not in itself justify the conclusion that the mean temperature is extremely ow. It is true that the fogs which ordinarily rest on a snow- covered surface much diminish the effect of solar radiation during the summer in high latitudes, but this is compensated by the great amount of heat liberated in the condensation of vapour. The only part of the earth which is now believed to be covered with an ice-sheet is Greenland, but the mean of the observations in that country shows a temperature higher by at APPENDIX. 405 least 10° Fahr. than that of Northern Asia, where the amount of snowfall is very slight, and rapidly disappears during the short arctic summer. If there be, as some persons believe, a large tract of continental land surrounding the south pole, I should expect to find that the great accumulations of snow and ice are confined to the coast regions. In that case the mean tempera- ture of the region within the antarctic circle would probably be lower than it would be in the supposition, which appears to me more probable, that the lands hitherto seen belong to scattered mountainous islands. If, from any combination of causes, one pole of the earth has ever been brought to a mean temperature much lower than that now experienced, I should expect to find that the phenomena of glaciation would be exhibited towards the equatorial limit of the cold zone, rather than in the portions near the pole. The formation of land-ice depends on the condensation of vapour, and before air-currents could reach the centre of an area of extreme cold the contained vapour would have been condensed. This consideration alone suffices, to my mind, to make the supposition of a polar ice-cap in the highest degree improbable. Mr. Wallace (" Island Life," p. 142) cites, as conclusive evidence of the effect of winter in aphelion in producing glaciation, the facts, to which attention was first directed by Darwin, as to the depression of the line of perjjetual snow, and the consequent extension of great glaciers, on the west coast of Southern Chili. I have adverted to this subject in the text (p. 229), and I may further remark that if winter in aphelion be the cause of the depression of the snow-line in latitude 41° S., it can scarcely fail to produce some similar effect in latitude 34° S. Yet we find on the southern limit the snow-line much lower, and at the northern much higher, than it has ever been observed in corresponding latitudes in the northern hemisphere, the line being depressed by more than 8000 feet within a distance of only seven degrees of latitude. The explanation, as I have ventured to maintain, is altogether to be found in the extra- ordinary rainfall of Southern Chili ; and to the same cause we must attribute the fact that, in spite of the greater distance of the sun, the winter temperature is higher than in most places in corresponding latitudes in the northern hemisphere. At Ancud in Chiloe, in latitude 41° 46', the temperature of the coldest 4o6 NOTES OF A NATURALIST. month is lower by less than three and a half degrees of Fahrenheit than it is at Coimbra in Portugal, one and a half degree nearer the equator, in the region which receives the full warming effect of the Gulf-stream. I should have expressed myself ill in the preceding pages if I should be supposed to deny that, in his writings on this subject, Mr. CroU has made an important contribution to the physics of geology. He has, in my humble opinion, been the first to recognize the full importance of one of the agencies which, under possible conditions, may have profoundly affected the climate of the globe during past epochs, although I do not believe that, in the present state of our knowledge, we can safely draw those positive inferences at which he has arrived. Even those who are unable to accept any portion of his theory as to the causes of past changes of climate must feel indebted to his writings for numerous valuable suggestions, and for the removal of many popular opinions which his acute criticism has shown to be untenable. INDEX. Acacia Cavenia, 157 Aconcagua, 192 valley, vegetation of, 195 Ades7nia, 182 Agassiz, Professor Alexander, 342 AjuUa, Promontory of, 5 1 Albatross, 215 Alligators, 41 Alpine zone ii) Andes, 91 Amancais, 71 Amatapi, Sierra, 52 Ancud, 14s Andean Flora, Alpine zone, 104 , divisions of the, 104 , European genera common to, lOI Andean railways, 63 Andes, 49 , Alpine zone in, 91 , cactoid plant in, 92 , Chilian, view of, 183 , climate of Peruvian, 99 , Compositce in, 102 , cosmopolitan weeds in, loi Aneroid barometers, 353, 354 Angol, 213 Antarctic beech, 256 Flora, range of, 219 ArUhofterus Wardii, 34 Anticosti, 273 Apoquinto, baths of, 188 Araucanian Indians, 212 , language of, 213 Araucaria Brasiliensis, 311 Argentaria, climate of, 300 , emigration to, 298, 299 , forests of, 295 , progress of agriculture, 298 , frontier of Chili and, 258 Arica, vegetation of, 121 Armeria maritima, var. andina, 263 Artichoke, wild, 168 Atacama, desert of, 124, 131 Atlantic, colour of, 7 ■ , summer temperature of, 362 , temperature of, 5 , winds of, 345 Ayacttcho sXtzxashvp, 118 Azores, 5 B Baccharis, 157 Bahia Blanca, 298, 357, 358 Bahia de Todos Santos, 346 Baillonia spartioides, 202 Balmacedo, Don F., 191 Banda Oriental, 281 , vegetation of, 293 Barbadoes, absence of venomous snakes in, 14 , black population of, 1 1 harbour police, 9 planters, 13 , productiveness of, S Barometer, high, 4 , tables for, 4 Beagle Channel, 273 Belem, Tower of, 363 4o8 INDEX. Berberis buxifolia, 263 empetnfolia, 263 ilicifolia, 263 Berberry, 225 Bentos, Fray, 287 Bio-Bio river, 213 Black-fish, 7 Blue Mountains, Jamaica, 17 Bombax pubescens, 328 Borya Bay, 241 Bossi, Signer Bartolomeo, 281 Botafogo, 322 Bove, Lieutenant, 252 Bramble in Chili, 150 Brazil, ancient mountains of, 317 , coffee-planting in, 341 , geology of, 313, 314 , glacial deposits in, 342 ■ -, rainfall in coast region of, 334 Brazilian physicians, their fees, 340 Bridges, suspension, in the Andes, Buenaventura, 32 Buenos Ayres, 293-295, 299 Cabo Blanco, 43 San Lorenzo, 37 Santa Elena, 38 Cachapoal river, 178 Cactoid plant in Andes, 92 Caldera, 133 Callao, 61 , quarantine at, 57 Canary Islands, 362 Cape Fro ward, 243 Farinas, 44 -^— pigeon (DapHon capensis), 214 Pillar, 238 Verde Islands, 359 Capricorn, Tropic of, 132 Cardoon, 164 Casapalta, 91 Catamarans, 352 Cathartes atratus, 112 Caudivilla, 109 Cauquenes, Morro de, 182 , town of, 169 Cauquenes Baths, 172 , railway to, 163 Celery, wild, 221 Cereus Quisco, 151, 176 Cerro de Pasco, 72 • del Roble, 151 Chacao, Canal de, 216 Chagres river, 22 Chaneral, 133 . Channels of Patagonia, 222, 223 Chicla, hotel at, 80 ■. , scenery at, 84 , vegetation of, 98 Chili and Argentaria, frontier of, 258 and Peru, naval war of, 58 , bramble in, 150 , Central, flora of, 141 , climate of, 143-145 , rainfall in, 144 , European plants in, 164 , physical geography of, 170 , Southern, glaciers of, 229 , rainfall of, 229 Chilian elections, cumulative vote, 191 mines, 161 Chiliotrichium amelloides^ 234 Chiloe, island of, 215 Chimborazo, 38 Chonos Archipelago, 216 Chosica, 73 Chuquiraga spinosa, 91 Churches in Lima, 62 Chusquea, 152 Cigars, Guayaquil, 41 Cinnamon tree, 10 Claraz, M. Georges, 357, 358 Clarence Island, 243 Climate, effects of tropical, 39 Ctticus lanceolaius, 164 Cobeja, 131 Coffee-planting in Brazil, 341 CoUetia spinosa, 177 Colomba, 214 Colon, 21, 22, 27 Commercial travellers, German, 309 CompositcE in Andes, 102 Concepcion del Uruguay, 288 Condor, 87, 93 Condors, captive, 185 Copiap6, 133 , Rio de, 133 INDEX. 409 Coquimbo, vegetation of, 136, 138 Corbett, Mr., 328 Cordillera de la Costa, zi8 Cordillera Grande, of Goyaz, 315 Cordillera Pelada, 218, 219 Cordillera in Peru, 49 Corrientes, 294, 300 Cosmos Line, German steamers of, 205 Cousino, Madame, 207 Crab, red, 227 Croll, Dr. James, 271 , remarks on his theory of secular changes of climate, 393 Cryptocarya Peumus, 160 Cuyaba, 279, 310 D Dandelion {Taraxacum lavigatiim], 263 Daption capensis, 214 Darwin, Mount, 267, 270 Dawson Island, 245 Desfontainea spinosa, 225 Desolation, Land of, 235, 241 Diomedea exulans, 215 fuliginosa, 215 Don, Royal Mail steamer, 2 Doterel, wreck of the, 267 Drimys Winteri, 147 Drummond-Hay, Mr., 148 Dungeness, 271 Duvaua dependens, 293 Earthquake-waves, 122 Eccremocarpus scaber, 199 Ecuador, 36, 40 Eden haibour, 224 Education, Chilian zeal for, 265 Elections, Chilian, cumulative vote, 191 Enceha canescens, 134 Engler, Dr., 34, 106 English Narrows, 223 English the lingua franca of Ame- rica, 88 Ensenada, 302 Entrerios, 288 Equator, cold current near, 356 , path of the sun, 37 Equatorial rains, 352 vegetation, 33 Erodium cicutarium, 165 Escallonia, 181 Espiritu Santo, Cape, 271 Eucalyptus globulus, 160, 292 Evergreen beech (Fagus betuloides), 225 Existence, struggle for, 330 Eyre Sound, 228 Fagus betuloides, 225 obliqua, 151 Falkland Islands, 247, 273 Fayrer, Sir Joseph, 349 Fenton, Dr., 250, 262, 269 Fernando Noronha, 354, 355 Feuillee, Father, 184 Fluit, Mr., 153 Flowering plants, origin of, 3 1 Flying-fish, S of Pacific, S3 Fogs on Peruvian coast, 54 Francoa sonchifolia, 210 French, Dr., 289, 291 Fruit-sellers, migratoiy, 42 Fuegians, 233, 242, 260, 261 Gallinazo, 87 , scavenger bird, 112 Galvesia limensis, 45 Gillies, Captain, 344 Glacial deposits in Brazil, 342 Glaciers in South Patagonia, 239 of Southeirn Chili, 229 Glaziou, Dr., 324 Gleichenia, 226, 311 Glyptodon, 358 Gongo Seco, 316 Gordontown, Jamaica, 18 , cool climate of, 19 Graham, Mr. J. R., 67 Granite, disintegration of, 315 Grisebach, 34, 14S Gualtro, 168 4IO INDEX. Guanacos, 131, 253 Guano Islands, 53 Guayaquil cigars, 41 Guayaquil, city of, 40, 41 , Gulf of, 38, 40 Guayas river, 38, 41, 42 Gynopleura linearifolia, 157 H Hale Cove, 220 Hann, Dr. Julius, 144, 305, 349 Hanover Island, 236 Hayti, island of, 15 , cannibalism in, 16 Haze, opacity of, 158 Heights above sea-level, fall of temperature in ascending to, 369 Henderson's Inlet, 231 Hess, Mr., 163 Hippeastrujii equestre, 19 Hopedale, in Labrador, 273 Huanillos, 127 Humboldt current, 50 Humming-birds, 209 Hura crepitans, 10 Hymenophylla, 226 Iberia steamship, 269 Ice-axe, 226 Ice, floating, 228 lUiluk, 274 Immigrant plants, Darwin's view of, 166 ■ , checks on their extension, 167 Indians, Araucanian, 212 , Patagonian, 260 Iquique, 121 , sea-fight at, 127 Isla de Santa Maria, 211 Islay steamship, 29 Itamariti, Falls of, 329 Jamaica, 16 , black population of, 20 , vegetation of, 18 Jacmel harbour, 15 K Kageneckia oblonga, 175 Kingston, Jamaica, 16 Lapageria rosea, 209 La Plata, estuary of, 277, 283 Las Condes, 163 La Serena, 136, 145 Lavapie Promontory, 211 Liais, M., 342 Libocedrus, 235 Lichens, 221 Lima, 61 , a dinner-party at, 108 , ancient beaches near, 113 , meteorological observations at, 99 Liriodendron, 344 Lisbon, Rock of, 363 Llaillai, 150 Llama in Peru, 95 Loa river, 127 Lobelia gigantea, 184 Lobelia tupa, 184 , poisonous species of, 76 Lobos de tierra, 53 de afuera, 53 Lomaria magellanica, 226 Lombardi, Signor M., 109 Lombardy poplar, 160 LorantAus, 176, 202 Lord Nelson Strait, 236 Lota, coal deposits of, 207 , parque of, 208 iynch, Don Patricio, 67 , his administration, 68 M Maceio, 347 Magellan, Straits of, 238, 239, 367 , forests in the, 240 , variable climate in, 240, 254 Maipo river, 134 Maldonado, 304 Malesherbiacea, 157 Mango tree, 10 Mapocho river, 157 ' INDEX. 411 Markham, Captain Albert, 135 MarrubiuTn vulgare, 138 Matto Grosso, 279 Matucana, San Juan de, 76 Mayne Channel, 237 Maytenus mageUanica, 263 Meiggs, Mr., 65 Mejillones, 132 Memory, lapses of, 26 Mendoza, 300 Mercator's projection, 30 Messier's Channel, 220, 231 Mist, clearing of, 333 Mitraria coccinea, 225 Molina, 175 Mollendo, 119 , a bad port, 120 Monkeys, domesticated, 332 Monson, Mr., 280 Montana of Eastern Peru, 97 Monte Video, 277, 279 Morro de Cauquenes, 182 Mountain-sickness, 81 Mulinum, 189 Mutida, 111 Mutisiacece, 102 Myzodendron punctulatum, 256 N Napp, Mr. Richard, 300 Nation, Mr. W., 70, 108 Naval war of Chili and Peru, 58 New Granada, 32 Nicotiana glauca, 360 Nikolaiewsk, 273 North Atlantic, trade wind of, 361 Northern hemisphere, temperature of, 273, 274 O O'Higgins, General, 154 Olfactory nerve, fugitive impres- sions, 190 Oreodoxa regia, 324 Organ Mountains, 325 Oroya railway, 64 , spiral tunnel of, 79 , viaducts of, 74 Ostrich, South American., 261 Uxalis Mat a, 146 Pacific coast-steamers, 31 Pacific, colour of water of, 31 , first view of, 25 , flying-fish of, 53 , high seas in Southern, 211 steamer, delay of, 269 Paisandu, 288, 289 Palms, avenue of, 323 Panama, 21 Bay, birds in, 29 Grand Hotel, 27 ■ railway, 25 ship-canal, 23 , vegetation of, 24 Paraguay river-steamers, 279 Parana, 317 , basin of the, 312 river, 284 Paranagua, Bay of, 308 Paranahyba, 313 valley, 320 Parasites and climbers, 330 Patagonia, 300 Channels, scenery of. 222, 227 , vegetation of, 225, 235 , women of, 253 Patagonian coast, winter climate, - 276 Patagonian Indians, 260 Payta, climate and vegetation of, 45 Peckett Harbour, 262, 270 Pedro, Dom, Emperor of Brazil, 337 Pelicans, black, 59 Penas, Gulf of, 218 Pernambuco, 351 Pernettya, 2,2,'^ Peru, 44 and Chili, naval war of, 58 , climate of Northern, 47 , future of, 117 Peruvian coast, fogs on, 54 , low temperature of, 55 sugar-plantation, no Pessimism, 365, 366 Petrel, giant, 215 Petropolis, 326, 327, 335 , hermit of, 331 , winter climate of, 334 412 INDEX. Peumo tree, 159, 175 Philippi, Dr., 154 , Professor Federigo, 155, 219 Physicians, Brazilian, their fees, 340 Pierola, Dictator of Peru, 117 Pietrabona, Commander, 257 Pimento tree, 10 Pisagua, 123 — ; — , white roclcs at, 125 Pisco, 119 Plantago maritima, 263 Pleroma arboreum, 342 granulosum, 336 Podocarpus nubigena, 235 Poncho, 179 Porliera hygrometrica, 199 Port Famine, 24^, 250 Gallant, 241 Potato, wild, in Andes, 93 Prado, General, 36 Prosopis Hmensis, 46 Proustia Baccharoides, 195 Pteris aquilina, 329 Puente Infernillo, 78 Puerto Bueno, 233 Punta Arenas, 145, 246, 273 Puya, 151 Quadras in Santiago, 153 Quarantine at Callao, 57 at St. Vincent, 359 Quaresma, 336 Queen Adelaide Island, 236, 238 Quillaja saponaria, 175 Quillota, Valley of, 150 Quinta Normal at Santiago, 155 Railways, Andean, 63 , Oroya, 64 , spiral tunnel of, 79 , viaducts of, 74 Rancagua, 168 Reed, Mr. Edwin, 204 Reilly, Mr., 210 Resguardo del Rio Colorado, 20Q. Rhamses, the, 205 Rhea Darwinii, habits of, 261 Rimac, valley of the, 71 , ancient terraces in, 75 , Compositee in, 76 , effects of sea-breeze in, 98 Rio Claro, 171 Colorado, 276 — — Janeiro, Bay of, 321, 322, 325 , Parahyba do Sul, 313 San Francisco, 314 Rocks, disintegration of, 115 , ice-action on, 228 Rumex acetosella, 263 Sagittaria Montevidensis, 297 Saladeros, 287 Salix Humboldtiatm, 77 Salta, 294 Salto, 291 Sambucus Peruviana, lOl Sampayo, Don Francisco, 257 San Bartolome, 73 Cristobal, Cerro, 156 Sand-box tree {Hura crepitans), 10 Sandy Point, 246, 250 , burnt forest at, 256 , mutiny of convicts at, 251 , the hotel at, 249 , vegetation of, 255, 263 San Felipe, 192 Sanitary rules, neglect of, 87 San Jos^, Promontory of, 276 volcano, 164 San Lorenzo, island of, 59 San Matias, Bay of, 276 San Paulo, 308-310 and Rio Janeiro railway, 312 , railway from Santos to, 307, 308 San Ramon, Salto de, 190 Santa Clara, 72 Santa Cruz settlement, 246 Santa Lucia, Rock of, 162 Santa Rosa de los Andes, 193, 196 Santiago, 145, 153, 156, 161 , railway to, 149 „ sunset at, 186 INDEX. 413 Santos, 305, 306 , tropical vegetation at, 307 Sao Joao da Barra, 312 Sao Salvador, 346 Sarmiento Channel, 231 Sarmiento, Mount, 243, 244, 267, 270 Scavenger bird, H2 Schinus niolle, 77 Sea-sickness, 217 Seaweed, bands of, 6 Senecio, the genus, 268 Serra da Mantiqueira, 313, 314 Serra do Mar, 308, 314 Shannon, Captain, 269 Simpson, Captain, 207 Sitka, 274 Smyth's Channel, 231, 237 Solanum Tnanimosum^ 33 Soroche, mountain-sickness, 81 Soto, Don Olegario, 171 South America, tropical, origin of flora, 35 , rainless zone of, 48 South Brazil, plateau of, flora, 311 South Patagonia, glaciers in, 239 Southern Atlantic, climate of, 305 Southern Cross, 7, 253 Southern hemisphere, temperature of, 272-274 Spanish-Americans, indolence of. Species, groups of incomplete, 181 Staten Island, 252, 258 St. Antao Island, 359 Steamers, Pacific coast, 31 Straits of Magellan, 270 Sunstroke, causes of, 349, 350 Surco station, 75 Swinburne, Don Carlos, 154 Taforo, Dr., 191 Tagus steamship, 344 Talca, 14S Taltal, 133 Tamar, Cape, 240 Tambo de Mora, 119 Tarapaci, 125 Taraxacum Icevigatum, 263 Telephone, use of, in South America, 290 Tierra del Fuego, 245, 267 Tijuca, 338 , giant tree near, 343 , vegetation of, 341 Tillandsia, 307 Titicaca, Lake of, 63, 66 Tocantins river, 315 Tocopilla, 128, 133 , scenery of the moon, 129 Trade wind, north-east, 6 Trescott, Mr., 60 Tres Montes, Cape, 218 Trinidad, Gulf of, 231 Triumph, the ship, 135 Tropaolum. tuberosum, 78 Trumpet-flower (Bignonia venusta), 307. 3" Tucuman, 294 Tumaco, 36 Tumbez, 43 Tupa Berterii, 184 secunda, 184 Tupungato, the Peak of, 153 U Ucayali river, English settler at, 96 Unalaschka, 274 Uruguay, climate of, 279 , fossil remains in, 291 , islands of the, 287 Republic of, chronic disorder, 282, 284, 285 Ushuaia, mission station at, 260 Ushuaja, 273 Uspallata Pass, 200 Utricularia, 33 V Valdivia, 145 Valparaiso, 138, 145 , danger of earthquakes at, 139 Vegetation, equatorial, 33 Verbena family, 201 Viaducts, Oroya railway, 74 414 INDEX. Vicuna Mackenna, Don Benjamin, Villages, remains of ancient Peru- vian, 73 Viiia del Mar, 149 Vincent, St., aspect of, 360 • , quarantine at, 359 Vinciguerra, Signer, 252 Virgenes, Cape, 271 Volcano de Ghana, 219 W Wellington Island, 222 Willsen, Captain, 205 Winter's bark (Drimys Wintert), 147 Y Yellow fever, treatment of, 339 NOTE ON THE MAP OF SOUTH AMERICA. In the annexed map an attempt has been made to represent the probable course of the isothermal lines — lines denoting equal temperature — in the South American continent. The black lines indicate the mean temperature for the entire year ; the red lines that for January, the hottest month ; and the green lines that of July, the coldest month. The numbers placed over each line in corresponding colours indicate the temperature in degrees of the Centigrade scale. We possess a fair amount of information as to the meteorology of the coasts of the continent ; but of the interior our knowledge is miserably deficient, and is nearly limited to several stations in Argentaria, and a few in the basin of the Amazons. As a result, the course of the isothermal lines in the interior is to a great extent conjectural. As in all similar maps, no account has been taken of the relief of the surface ; when a line crosses a mountain range, the tempera- ture indicated is that which would be found, as is assumed, if the height were reduced to the sea-level. No attempt has been made to show the variations of temperature with the season in the part of the continent near the equator. These are very slight, and depend mainly on local conditions, the mean temperature of the year varying from 25-5° to 28° C, or from about 78° to 82° Fahr. ; the hottest seasons near the equator, apart from local conditions, being those of the equinoxes. The chief interest of the map to the physical geographer arises from the remarkable effect of the southern, or Humboldt, current, in lowering the temperature of the western coast between the fifth and the fortieth degrees of south latitude. This is,, of 4i6 NOTE ON THE MAP OF SOUTH AMERICA. course, most apparent in the isothermal for January. Itwill beseen that at that season the temperature of Northern Peru is about the same as that of Buenos Ayres, lying thirty degrees farther from the equator. In midwinter (July) the effect is far less apparent, and in the south of the continent the isotherms for that season nearly correspond with the parallels of latitude. The lines indicating mean annual temperature naturally assume a course intermediate between those for the extreme seasons. PRINTED UY WILLIAM CLOWES AND SONS, LIMITED, LONDON AND BECCLES. 30" L A jsr T I c Iflf Jicnti^/n ; KcQan FauL, Trctwh & Co. f:diviHV^;it:r Wlh