Slike stranica
PDF
ePub

MERCATOR'S PROJECTION.

on a Mercator's projection, when taken from the graduated meridian with the middle latitude between the two plans as a centre, the same degree of accuracy cannot be attained on the conical projection; and the general distance scale given on such maps, if the area included is

30°

-Azores

02

Madeira

Canary Is

PARIC

AFRICA

[blocks in formation]

different angle, thereby rendering it a much more complicated matter to accurately lay down a track, or to take from it the bearing of one place from another. And again, while the distances can be accurately measured

[blocks in formation]

7821-284

Madeira

extensive, is only an approximate. I may mention in this connection that I have measured distances on the Admiralty charts, which are all on Mercator's projection, between distant points, for determining the length of telegraphic cables; and when these distances were afterwards actually measured, by the number of miles of cable laid, I have never found them to be in error. At any great distance from the Equator, Mercator's projection greatly exaggerates the lengths of the degrees of latitude and longitude, and therefore gives a false notion of relative areas, and for this reason a modification of the conical projection may be preferred in some cases, but by the well-known system of "squaring in the work on the Mercator's projection can be transferred to another map, where it will be shown in its true proportions. Time will not permit me to dwell further on this subject, or I could give other reasons for my preference, for rough survey work, for this useful projection.

I have now brought my paper to a conclusion. I have endeavoured to touch, however lightly, on the art of observing as it should be practised by travellers, and in this connection I would remark that it is greatly to be deplored that many of the well-educated and intelligent men who visit little-known countries, fail to make themselves acquainted with the manner in which observations, for fixing their positions, should be taken and recorded, the consequence being that, instead of contributing valuable information to geographers, they have frequently nothing more to tell us than that they have made big bags of game, and have seen lakes, rivers, and mountains, the positions of which on the map they can only assign by guess-work. As regards two of the instruments to which I have referred, the plane table and the compass, I feel sure that surveying in the field with them would form a valuable branch of instruction in our schools, and, would give pupils a more perfect knowledge of the manner in which maps are made, and surveys are carried on, than they can gain in any other way.

ON ACCLIMATISATION.

BY ROBERT W. FELKIN, M.D., F.R.S.E., ETC.

(Read at Meeting of British Association, 1891.)

FOR many reasons the subject of acclimatisation is an important one, and its interest increases yearly. New areas are coming under European influence, and statesmen are naturally anxious to know of what use they will prove; whether they will only be useful in a strictly commercial sense, or whether colonisation will be possible, and if so, where and to what extent? Again, the World's population is rapidly increasing, and, according to the paper which the President of this Section, Mr. E. G. Ravenstein, read before this Association in Leeds last year, unless some great catastrophe happen, we may look forward to a time in the comparatively

near future when the population of the World will be so great that it will be almost impossible to obtain subsistence, even should the whole area of the World become inhabited by an evenly distributed population.

During the last few years the subject of acclimatisation has been frequently referred to. I would call to mind the paper read by Dr. A. Oppler before this Association in 1887; Mr. Ravenstein's paper on "The Lands of the Globe still available for European Settlement," read in 1890; a paper read by Sir W. Moore before the Epidemiological Society in January this year, "Colonisation of Central Africa by Europeans;" a paper I myself read on the same subject at Birmingham in 1886; a paper published by Professor Virchow in the Zeitschrift für Ethnologie 1885, accompanied by an important discussion in which Bastian and Fritsch took part; a communication on the "Acclimatisationsfähigkeit der Europaer in Asien," by Professor A. Sprenger, published in the same journal. The subject of acclimatisation is also referred to by Herr Joest in a paper on his journey in Africa in 1883 (ibid.); and in 1886 various other important communications were published in the Zeitschrift für Ethnologie, viz. :—a paper by Dr. Beyfuss on "Die Acclimatisation der Europaer in Niederlandisch-Indien;" one by F. Jagor on "Der Sterblichkeit der Eingeborenen und Europaer in Ost-Indien," which was followed by a discussion; and a very important paper by Dr. August Hirsch on "Acclimatisation and Colonisation." These are all I need mention.

I find it, therefore, very difficult to say anything fresh on the subject. This is my misfortune, not my fault: I would not myself have chosen to introduce this discussion; but, having been requested to do so, I will endeavour to indicate what acclimatisation is, and what the difficulties of acclimatisation are, and I must apologise if I only echo much that has been said before.

When we look at the opinions that have been expressed on the subject of acclimatisation, we find that we can divide them into two schools of thought-one regarding acclimatisation as impossible, which view is supported by Virchow, Hirsch, Fritsch, Ravenstein, and others. Without going into detail, they hold that Europeans can never become acclimatised in the full sense of the word in Tropical regions, thinking that the deterioration, caused by climatological factors and endemic diseases will invariably either kill off the emigrants, or at any rate render their ultimate existence impossible. Others, as De Quatrefages, hold that Europeans can become acclimatised anywhere. They, however, allow that the process of acclimatisation will be accompanied by severe loss, and will only occur after several generations. Others again are far more sanguine, such as Livingstone and the late Bishop Hannington, who thought that rapid acclimatisation in Tropical regions is possible for Europeans. I may state at once my own view of the subject. It is that, although we have at the present day examples of nations who have become acclimatised in areas far from their original habitat, hundreds of years have been required, and an immense mortality has accompanied their migrations, and it has only been by a process of the survival of the fittest that this acclimatisation has been possible at all. I believe, however, that our increased knowledge of climatology and of hygiene has rendered the problem more easy of solution.

Given picked individuals, and the careful selection of tropical areas in which to colonise, I see no reason why, with precautions, Europeans should not colonise even in the Tropics; if he

"... Study well the clime,

Mould to its manners his obsequious frame,
And mitigate those ills he cannot shun."

I may mention in passing that a very careful selection would need to be made, and that persons with a tendency to gout or rheumatism, diabetes or albuminuria, those with a nervous or alcoholic family history, or those suffering from either acquired or hereditary syphilis, should certainly be rejected.

When speaking of the subject of acclimatisation with reference to Europeans, we are very apt to fall into the error of imagining that all Europeans can be acclimatised or will resist acclimatisation in any given area equally. This is undoubtedly a mistake, for a marked difference obtains between northern and southern Europeans in this respect, and not only the climatology of their original residence must be taken into account, but also their habits and customs and their psychical peculiarities; and if these factors have to be considered with regard to the adaptability of a nation for emigration, so too with regard to the individuals of any nation. It is a fact that selected individuals from nearly every European nation may thrive almost all over the world. It has been denied that environment influences the human species, and it has been said that nations seek out that environment which is best suited for them. These statements I feel bound to deny, and I would say that environment definitely influences not only individuals but nations. This Herbert Spencer has shown in his Principles of Biology, where he demonstrates that every organ and every function of living beings undergoes a certain and definite modification within certain limits under the stimulus of new conditions ; and he further opines that this modification is almost always such as to produce an adaptation to a new environment.

Broadly speaking, it must be admitted that Europeans can only become readily acclimatised in the Temperate Zone, that is to say, where climatic and other conditions are approximately akin to their present habitat. We may say too that the people who inhabit the Temperate Zone become more easily acclimatised in countries towards the north of their present habitation; and this is shown by the fact, if we are to credit it, that during the past 2000 years the Aryans have penetrated from the Tropics to the region of ice and snow within the Arctic Circle. Apart from this, however, as Mr. Ravenstein has shown, "if the white man is ever to occupy permanently the Tropical parts of the world, it will have to be done by stages, each stage making a generation of men. We well know that the peoples of southern Europe, such as the Italians and southern Frenchmen, can better bear the climate of sub-Tropical Africa than can northern Europeans. A steady stream of migration is, in fact, setting in that direction. Germans and Belgians are pouring into France, Frenchmen are going to Algeria, the Arabs from the shores of the Mediterranean have found their way, into the Sudan, whilst the Sudanese are pushing forward into VOL. VII. 2 z

Bantu Africa. A similar movement is going on in southern Africa. The descendants of those Dutchmen who, a couple of hundred years ago, first settled at the Cape, have made their way to the Transvaal, and European migration, favoured by geographical features, is being pushed even within the Tropics towards the Zambezi." With this I quite agree, and would once more call attention to the fact that wholesale, immediate acclimatisation for Europeans in Tropical regions is entirely out of the question.

There is little doubt that southern European nations would be able to colonise in the Tropics were the physical constitution alone to be taken into account; but temperature also plays a definite rôle in the possibility of prolonged existence in a given region, and it is a quality which especially requires time to be modified to new conditions of life. Hereditary temperament and capacity of mind variously characterise all nations, and differences of intellectual and moral power are well-marked factors in the possibility of acclimatisation. It is these factors which to a great extent limit the power of southern Europeans to thrive in the Tropics, whereas northern Europeans, though physically less able to withstand Tropical influences, are yet in possession of a more stable temperament, and greater strength of character, which will go far to enable them to overcome the difficulties incident to a sojourn or a settlement in the Tropics.

The acclimatisation of Europeans in the Tropics can only be successful if migration occurs step by step; and in estimating the possibilities of acclimatisation we must count by generations rather than by years. In 1861, it is true, Dr. Hunt denied this, saying that "time is no agent," and "if there is no sign of acclimatisation in one generation there is no such process." This, however, cannot be accepted, because there are many instances to prove the contrary.

What happens with regard to animals? We know that they can be acclimatised, and we know how their bodily structure is modified in order to enable them to adapt themselves to a new environment. It is not necessary to quote instances, they are so well known, but the following quotation from the last edition of the Encyclopædia Britannica shows the practical way in which an animal or plant may be acclimatised in a country very dissimilar from that of its native habitat, and where it has been experimentally proved that the species in question cannot at once live and maintain itself:—

"1. We must transport as large a number as possible of adult healthy individuals to some intermediate station, and increase them as much as possible for some years. Favourable variations of constitution will soon show themselves, and these should be carefully selected to breed from, the tender and unhealthy individuals being rigidly eliminated.

"2. As soon as the stock has been kept a sufficient time to pass through all the ordinary extremes of climate, a number of the hardiest may be removed to some more remote station, and the same process gone through, giving protection if necessary while the stock is being increased, but as soon as a large number of healthy individuals is produced, subjecting them to all the vicissitudes of the climate."

It is obvious that we cannot deal with men exactly in this way, yet

« PrethodnaNastavi »