« PreviousContinue »
British India the area of Government forests at 70,000,000.
No data are available for estimating the forest area in the
demand the systematic teaching of forestry in England. THE TEACHING OF FORESTRY.
In the German Empire the total forest area only mea
sures 34,346,000 acres, of which 11,243,000 acres belong to A Vanual of Forestry. By William Schlich, Ph.D. the State. Yet there are no less than nine forest schools
Vol. I. (London: Bradbury, Agnew, and Co., 1889.) in the different States for educating the superior officers
cognized in England that forestry is a profession in wood managers in private estates. The books published the sense in which we speak of the profession of law or on the subject of forestry in all its branches during the of medicine. And it is a bold step to publish a manual of three years 1886-88 amounted to 177, or fifty-nine a year forestry for English readers in a systematic and strictly on an average. Besides these, there are ten periodicals technical form. This is the task which Dr. Schlich has un- on forestry, some quarterly, most monthly. One general dertaken, and the volume before us is the first instalment association of German foresters meets annually, and ten of a large work, which, when completed, will be the first local societies hold their meetings either annually or once comprehensive manual of forestry in the English lan- in two years. And all these associations publish their guage.
transactions. Perhaps it will be urged that this large and Before going out to India in 1866, Dr. Schlich had daily-growing forest literature is not necessarily an adpassed the examinations for the superior forest service in vantage ; that German foresters had better attend to the his own country (Hesse Darmstadt), he had been the management of their forests instead of writing books. As pupil of one of the most eminent Professors of Forestry in a matter of fact, however, the management of the German Germany, the late Gustav Heyer, and he held a distin- forests, public as well as private, is excellent, and is imqushed place among his fellow students. At the com- proving steadily. The best proof of this is the large and mencement of his career, the changes which had taken steadily growing income derived from these estates by the place in Hesse Darmstadt in consequence of the Austrian Government, by towns and villages, and by private prowar were believed to affect injuriously the chances of pro- prietors, and, more than that, the improved condition and motion for the younger members of the forest service. the increased capital value of these properties. This induced him to accept the offer of an appointment A commencement, however, of forest literature has in India. Here he was designated at an early date been made in the English language. The Transactions for important positions, and thus, after he had served of the Royal Scottish Arboricultural Society have attained several years in Burmah, he was sent to Sind, where, their twelfth volume, and they frequently contain papers wader completely different conditions of climate and of considerable importance. The Indian Forester, comforest, he did excellent work. He served successively as menced as a quarterly by Dr. Schlich in 1875, is now a Conservator of Forests in Lower Bengal and in the i monthly magazine, of which fifteen volumes have apPanjab, until he rose to the post of Inspector-General of peared. In addition to these a number of valuable Forests. In 1985 he consented to relinquish his import publications on different branches of forestry might be ant position in India, in order to become Professor of named that have been published within the last twentyForestry at the Forest School which it had been decided five years. to lori in connection with the Royal Indian Engineering German forest literature, though it has attained such College at Coopers Hill.
large dimensions, is of comparatively recent origin. The volume before us contains the general and intro- During the eighteenth century sylviculture and the ductory part; in a second volume the author proposes to management of forestry had made great progress in many set forth in detail the different sylvicultural operations; parts of the country, but the methodical and scientific while the protection of forests, the utilization of timber treatment of the subject dates from the labours, during and other forest produce, the systematic arrangement of the first thirty years of the present century, of Hartig in the plans for working, and the financial aspect of forest Prussia, Cotta in Saxony, and Hundeshagen at Giessen. masagement, will complete the work. Not the least of Scientific forestry in England must necessarily be built the advantages which will be gained by the publication upon what has been accomplished in this respect in of this manual will be to settle the English forest termino-' Germany, and with becoming modesty Dr. Schlich logy. The technical terms which had been tentatively, acknowledges that the principal German works have used since methodical forest management was begun in been his guide in the preparation of the present book. India may now be expected to receive general currency, ' Great Britain does not stand alone in this respect. In and will be more correctly understood than before. France also the development of scientific forestry has to
The primary object of the Coopers Hill Forest School ' a great extent been based upon the progress previously is the training of officers for the Indian Forest Service, made in Germany. The same may be said of forestry in but others also may attend the forestry classes in order to , Italy, Russia, Scandinavia, and other European countries. qualify for the management of forests and woodlands in Part I. of the manual treats of the utility of forests, Great Britain and in the colonies. It may therefore be directly in producing wood and other forest produce, and hoped that Dr. Schlich's manual will eventually promote indirectly in influencing the climate, in the distribution of the good management of forests in many parts of the rain-water, in the preservation of the soil on sloping ground, world. In Great Britain and Ireland the author states in the binding of moving sands, and in affording shelter the area of woods and forests at 2,790,000 acres, and in against winds. All these matters are clearly and ex
VOL. XLI.- No. 1050.
haustively treated, and in regard to the climatic influence certainty to say what yield of timber may be expected of forests the author gives a most useful summary of the from plantations made in a certain locality, researches which have been made to determine the effect The second chapter deals with the shape and developof forest growth upon the temperature of air and soil, ment of forest trees, but we can refer only to what the rainfall, humidity, and evaporation, in Germany, Switzer- author says regarding height-growth. Building again land, and France, mainly by the establishment of parallel chiefly upon researches made in Germany, Dr. Schlich stations, one being situated inside a fully stocked forest explains how the different species have a different mode and the other at some distance in the adjoining open of height-growth. On p. 163 an instructive diagram will country.
be found exhibiting the relative height-growth of spruce, Part II. sets forth the fundamental principles of sylvi- , silver fir, beech, and Scotch pine, in a locality of the first culture. The author maintains, with justice, that the quality. At the age of 50 years the mean height attained principles of sylviculture hold good all over the world, by each species is as follows :but adds that the illustration of these principles must be
64 feet taken from a limited area. For this purpose he has
Beech chosen the timber trees of Western Europe on the
55 2 50th degree of north latitude, and the countries im
108 1 102
Silver fir mediately to the north and south of it-in other words, · At a later age spruce and silver fir take the lead, while the forest trees of England, Northern France, and the beech and Scotch pine remain behind in the race; and greater part of Germany. These species the author does when 120 years old the order of the species stands as not attempt to describe ; he assumes that his readers are follows :familiar with them. The first chapter dwells upon the ex
118 feet ternal conditions which influence the development of
Silver fir forests. He says :-
97 “Soil, including subsoil, and atmosphere are the media which act upon forest vegetation, and they together are in Scotch pine and beech therefore make the principal sylviculture called the locality. The active agencies, or height-growth during the first period of their life, whereas factors, of the locality depend on the nature of the soil spruce and silver fir continue to grow vigorously in height and the climate, the latter being governed by the situation. to a much greater age, spruce more so than silver fir. The sum total of these factors represents the quality or The progress of height-growth of the different species is yield-capacity of the locality. The forester requires to be well acquainted with the manner in which soil and much affected by the character of the soil, by elevation, climate act on forest vegetation, in order to decide in the more or less crowded state of the wood, and other each case which species and method of treatment are best circumstances, but under otherwise similar conditions it adapted, under a given set of conditions, to yield the will always be found that deep, fresh fertile soil produces most favourable results.”
much taller trees than shallow, dry, or rocky soil. Every forester knows that on good soil, and under
In the third chapter, which deals with the character conditions otherwise favourable, a timber crop is heavier and composition of woods, the author points out that the than one of equal age grown under less favourable con object of sylviculture is not to rear isolated trees, but conditions. In the concluding section of this chapter the siderable masses of trees, forming more or less crowded author shows how one may use this fact in order to woods. Pure woods consist of one species only, or of one assess the quality of a locality. Numerous measurements species with a slight admixture of others, whereas mixed of woods of different species and ages, grown under dif- woods contain a mixture of two or more species. The ferent conditions, have been made in Germany on a syste- advantages of mixed woods are clearly set forth, and the matic plan, and from the data thus obtained yield tables author's remarks on this subject may be specially recomhave been calculated, showing the volume of timber pro- mended to the attention of proprietors and managers of duced at different ages on a given area by the principal woodlands in Great Britain. species oa localities of different quality classes. Using
The last and most important chapter deals with the the yield tables published for the Scotch pine by Wilhelm sylvicultural systems--that is, the different methods under Weise, now Professor at the Forest School of Karlsruhe, which the creation, regeneration, tending, and utilization the author shows that at the ages of 50 and 120 years the of woods are effected. The three well-known classes volume per acre of timber only, not including faggots, in are: first, high forest, originating in seedlings, either localities, which according to their yield-capacity are self-sown or artificially raised ; second, coppice, which classed as first, second, and third class, is as follows: regenerates itself from coppice shoots; and third, coppice
with standards, a combination of seedling and coppice 1. II. III.
forest. The modifications of these three main systems are Cubic feet at the age of 50 years 5060 3940 2700
numerous, and particularly the treatment of high forest 9060 6950 5340
has developed in a great variety of ways. On this subject The figures of these yield tables Dr. Schlich has we must refer the reader to the manual. These art found to a certain extent to be applicable to Scotch pine matters which can hardly be fully understood without forests in England. They can therefore be used in order to opportunities for obtaining practical experience of forests assess the yield-capacity of any locality stocked with treated under the various systems described. Such Scotch pine. Eventually, similar yield tables will doubt- opportunities may, to some extent, be found in Great Jess be prepared for the Scotch pine and other forest trees Britain. The high forests of larch and Scotch pine m in Great Britain, and it will then be possible with Scotland, raised by planting, are excellent, and in some
districts Scotch pine woods are regenerated by self-sown surface soil. Gradually, small and then large ravines and seedlings. The oak woods of the Forest of Dean, and the torrents were formed, which have torn the hill range into beech woods on the chalk downs of Buckinghamshire, the most fantastic shapes, while the débris has been 280 instances of high forests with different character and where the torrents emerge into the plain, fan-shaped
carried into the plains, forming, commencing at the places different method of treatment. Most instructive, again, accumulations of sand which reach for miles into the are the natural oak forests in Sussex--coppice, with a plain, and which have already covered and rendered large proportion of standards. So are the coppice woods sterile extensive areas of formerly fertile fields. Indeed, of ash and sweet chestnut for the production of hop-poles one of these currents or drifts of sand has actually carried la Kent, and the osier beds on the banks of the Thames. away a portion of the town of Hushiarpur. The evil has The difficulty is, that the treatment of these woods is measures are not adopted at an early date, the progress
by no means reached its maximum extent, and if curative estrely empirical, and that, without authentic statistical of transporting the hill range into the plain will go on, fata regarding yield in timber, regarding income and until the greater part of the fertile plain stretching away putlay, no forest can properly be used for purposes of from its foot has been rendered sterile." instruction. If the student wishes fully to understand this and other portions of the excellent manual before us, The author might have added the denuded hills, and be must study the forests of Germany, public and private. the rivers, formerly navigable, but now silted up, in the This may be a disadvantage, but under the circumstances Ratnagiri district of Western India, and other similar of the case it cannot be helped.
instances. Appended to the first part of the book are two treatises That a country so populous as India requires immense which will be read with interest by those who may not quantities of timber, bamboos, and firewood, goes withare to study the more technical portion of the manual. out saying. Among other articles of forest produce, They deal with forestry in Great Britain and Ireland and cattle fodder is an important item. In the drier portions in British East India. The physical configuration of of the country the supply of grass, particularly during Indis, its climate and rainfall, the distribution of the seasons of drought, is more plentiful under the shelter of forests, and the forest policy pursued by the Government trees than out in the open. In times of scarcity, grain
India during the last thirty years, are clearly set forth, can easily be carried long distances to provide food for The protection and systematic management of its forests the people, while cattle fodder cannot be so easily carried. are matrers of the utmost importance for the welfare of As a matter of fact, where forests have been formed and the millions inhabiting the British Indian Empire, of in- protected in the drier parts of India, they have proved a finitely greater importance than good forest management great help in enabling the people to maintain their cattle is for Germany or other rountries of Europe. Enthusiastic in times of drought and scarcity. foresters in India have long maintained that, by improving In India the duty of taking action necessarily devolved the condition of existing forests, so as to make them more upon the State. The result has been the formation of dense and compact, by extending their area, and by extensive forest estates, called reserved forests, which creating forests where none exist at present, the rainfall at present, the author states, aggregate 33,000,000 in seasons of drought might be increased, and famines acres, or three times the area of State forests in the tnight thus be averted. Dr. Schlich fully discusses this German Empire. Jf forest matters in India continue to subject, and states several cases in which the presence of be properly managed, these estates will not only secure dense forest growth seems to accompany an increased the well-being of the people, but will be an important rainfall; but at the same time he fully explains the source of strength to the Government, financially and reasons why a final conclusion does not seem justified. otherwise. As yet, the revenue which they yield is inThe result is that, though the local influence of forests significant in relation to their extent. But it is growing in lowering the temperature and preserving moisture is steadily. Dr. Schlich shows that during the three years undeniable, we are not justified in hoping for an improve- 1864-67 the average annual net revenue from the Government of the Indian climate. The favourable influence of ment forests amounted to £106,615, and during the five forests ia India upon the irrigation from wells and tanks years 1882-87 to £384,752 ; and he states it as his is, however, beyond doubt, and this is a vital question. opinion that, twenty-five years hence, the net surplus will
To illustrate the effect of forest growth in protecting be four times the present amount. More important, lanse soil on hill-sides, the author mentions the Siwalik however, than the annual revenue is the steadily increashills at the foot of the North-West Himalaya. We quote ing capital value of these Government forest estates. his words :
In Great Britain the aspect of affairs is different. The
small area of the Crown forests, burdened as they are Anyone who has ever stood on the hills behind with prescriptive rights, cannot reasonably be expected Hoshiarpur in the Punjab, and looked down upon the materially to help the development of systematic forest plain stretched out towards the south-west, has carried away an impression which he is not likely to forget. In management. But there are over 2,500,000 acres of that part the Siwalik range consists of an exceedingly woods and forests in the hands of private proprietors, and friable rock, looking almost like sand baked together. there are 26,000,000 acres of barren mountain land and Formerly, the range was covered with a growth of forest waste, a portion of which might be planted up. Provegetation, but a number of years ago cattle owners prietors, as a rule, desire to augment their income and to settled in it, and under the combined attacks of man, increase the capital value of their estates. In many cases while the tread of the beasts tended to loosen the soil. this might be effected by a more systematic management The annual monsoon rains, though not heavy, soon com- of their woodlands, and by the planting up of waste lands. menced a process of erosion and of carrying away the The chief obstacle to progress in this direction is the low
price of timber and the high rent at present obtained by all they require in such modern works as Sprung's the letting of grouse moors and deer forests.
“Lehrbuch der Meteorologie," and Ferrel's "Recent Upon data which cannot be gain said, Dr. Schlich has Advances in Meteorology," the high merit and originality based important calculations, which will be found on of which last are somewbat veiled under its more obtrupp. 17-19. Space forbids the discussion of details, but sive title-" Part 2 of the Report of the Chief Signal the result is that Scotch pine forests cannot be expected Officer of the [U.S.] Army for 1885." But these works are to yield more than 25 per cent. on the capital invested hardly suited for popular instruction; and for that large (the value of the land and of the growing crop).
class of students whose mathematical acquirements are “ All land, therefore, which can be let for the raising of the movements and internal changes of the atmosphere,
more limited, but who nevertheless desire to understand field crops, for shooting, or other purposes, at a rental equal to, or upwards of, 25 per cent of the capital value of and to interpret them rationally in accordance with me the land, had better be so let. On the other hand, land chanical and physical laws, there has hitherto been little which would realize a rental of less than 25 per cent of guidance, save such as they may obtain from casual its value, may with advantage be planted with Scotch references to them in works devoted to the general pine or other similarly remunerative trees."
teaching of these sciences. It is perhaps in consequence These conclusions are based upon circumstances as of this divorce of the deductive from the inductive treatthey exist at the present time. But a change of circum- ment of meteorological subjects that the contributions of stances is not impossible. The author points out that English observers to the science of meteorology bear 6,000,000 loads of timber are imported annually into the but an insignificant proportion to the labour expended on United Kingdom from Europe and North America, and observational work, and that so much of this work is that only a small portion of the forests which furnish this abortive, and practically of little value, owing to the large supply are under systematic management and con- absence of guiding and suggestive theoretical knowledge trol. It may be regarded as certain that the supply from
It is, then, with no ordinary degree of satisfaction that Sweden and Norway and from North America, amounting we hail the publication of Prof. Ferrel's treatise, the title at present to nearly 4,000,000 loads a year, will continue of which heads this notice. As the originator and disto diminish, and, under the circumstances of the case, the coverer of many of the most important problems dealt necessary result of such diminution will eventually be a with in these pages, no one could be better fitted to rise in the price of timber. Again, if proprietors of wood- explain them in terms suited to general comprehension. lands in England and Scotland were in a position to offer and this task he has performed with a completeness and large quantities of home-grown țimber of good quality for lucidity which leave but little to be desired. The work sale, regularly at stated seasons, timber traders would is, as it professes to be, a "popular” treatise, but popular make their arrangements accordingly, and in many cases only in the higher sense of the word. A system of movebetter prices would be obtained. Firewood is at presentments so complex as those of the earth's atmosphere almost unsaleable in the United Kingdom, but if-and cannot be made clear to anyone who is not capable of this may happen-the price of coal should rise consider- following a chain of close reasoning, or who is not preably, firewood would in some districts become an article pared to bring to the study that concentrated attention of general consumption, as it was 150 years ago, and that is requisite to master any problem in deductive to some extent this would improve the money yield of science. But, these being granted, no further demand is woodlands.
made on the student than some familiarity with the It is not too much to say that the publication of Dr. elements of algebra, and the simplest conceptions of Schlich's manual will give a powerful impetus to sys- plane trigonometry and kinetics. The action of the tematic forest management in the United Kingdom, in mechanical and physical forces that determine and India, and in the vast colonies of the British Empire-in regulate the wind system of the globe is clearly exfact, wherever the English language is spoken.
plained in the first two chapters of the work. D. BRANDIS.
The most important and original portion of the book is that which deals with the general circulation of the
atmosphere, in relation to which the cyclones and antiFERREL'S THEORY OF THE WINDS.
cyclones that cause the vicissitudes of local weather are
but matters of subordinate detail. The magnitude of the A Popular Treatise on the Winds. Comprising the work achieved by Prof. Ferrel in this field has hitherto
General Motions of the Atmosphere, Monsoons, been recognized only by the few. It is not too much to Cyclones, Tornadoes, Waterspouts, Hailstorms, &c. say that he has done for the theory of atmospheric circuBy William Ferrel, M.A., Ph.D., &c. (New York : lation that which Young and Fresnel did for the theory of John Wiley and Sons. London : Macmillan and Co. light; and that the influence of his work is not more 1889.)
generally reflected in the literature of the day, must be NUM JUMEROUS as are the popular treatises on various attributed to the want of some popular exposition of the
branches of phenomenal meteorology that have theory. appeared during the last quarter of a century, English Starting with the fundamental conditions of a great literature has hitherto been singularly deficient in ele- temperature difference between equatorial and polar mentary works treating of the physical and mechanical regions and a rotating globe, and pustulating in the first processes of the atmosphere from a theoretical point of instance a uniform land or water surface, it is shown view, and suited to the capacity of the average student. how the convective interchange of air set up by the Those versed in the higher mathematics may indeed find former must result in producing two zones of maximum
pressure in about lat. 30° in both hemispheres, two prin- the ideal system, the chief of which is the mutual intercipal minima at the poles, and a minor depression on the action of expanses of land and sea. The general excelequator, together with strong west winds in middle and lence of these demonstrations is indisputable, but we high latitudes, and an excess of easterly winds in equa- bave marked one or two passages which appear to us to be torial regions. The two tropical zones of high pres- of doubtful validity, and which we recommend to the resare determine the polar limits of the trade winds, and consideration of the author when the time comes, as we the whole system oscillates in latitude with the changing doubt not it will ere long, for the issue of a second edition declination of the sun. Further, as a consequence of the of his work. fact that the great mass of the land is restricted to the The first point to which we would take exception is northern hemisphere, whereas the southern hemisphere what seems to us the too great influence ascribed to presents a comparatively uninterrupted sea surface, on mountain-chains in deflecting the great atmospheric curwhich the retarding friction is less than in the northern rents. That they deflect the surface winds, like other hemisphere, the west winds of middle and high latitudes irregularities of the surface, and in proportion to their are much stronger in the latter than in the former, and magnitude, is, of course, a matter of universal experience ; by their lateral pressure cause a slight displacement of but, in the absence of other causes operating to produce the tropical zones of high pressure and the equatorial a diversion of the greater currents, their action in this one of low pressure to the north of their normal positions respect appears to us to be merely local. As an instance on a hypothetical uniform terrestrial surface.
we will take the case of the Western Ghats of India, an The great modification and extension of Hadley's escarpment from 3000 to 7000 feet in height, running theory thus introduced by Prof. Ferrel depends mainly on athwart the direction of the summer monsoon of the : 0 points of the first importance. By all previous writers Arabian Sea. The wind charts of the Arabian Sea, issued it was assiimed that a mass of air at rest relatively to the by the Indian Meteorological Office, show no appreciable earth's surface on the equator, if suddenly transferred to deflection of the monsoon wind on the windward face of some higher latitude-say, e.g., 60°—would have a relative this range ; and if the same cannot be asserted of the easterly movement in that latitude equal to the difference corresponding wind in the north of the Bay of Bengal, of rotary relocities on the equator and on the both where it impinges on the coast range of Arakan, it is parallel, ar about 500 miles an hour, the difference being evident that the defection of this current to north, and proportional to that of the cosines of the latitudes. This, eventually to north-west, is caused by the indraught however, would be true only in the case of rectilinear towards the heated plains of Northern India. motion. In reality, as Prof. Ferrel was the first to demon We believe that a similar explanation will be found to strate, the mass of air would obey the law of the preserva- hold good in all the more conspicuous cases cited by tion of areas, like all bodies revolving under the influence Prof. Ferrel. Thus, at p. 183 he says :of a central force, and its relative eastward velocity in latitude 6o* would be 1500 miles an hour, being as the
"The air of the lower strata of the atmosphere in the
trade-wind zone of the North Atlantic, having a westerly difference of the squares of the cosines. If
, on the other motion, and impinging against the high table-lands and hand, any mass of air at rest in latitude 60° were suddenly mountain-ranges of Mexico, is deflected around towards transferred to the equator, it would have a relative westerly the north over the south-eastern States, and up the Mismovement of 750 miles an hour, and any mass of matter
sissippi valley into the higher latitudes, where it comwhatever moving along a meridian is either deflected-or
bines with the general easterly flow of these latitudes,
and adds to its strength. This completely breaks up the if, like a railway train or a river between high banks, it continuity of the tropical calm belt and dry zone, so that, 19 not free to yield to the deflecting force, presses-to the instead of a dry region with scanty rainfall, such as is right of its path in the northern, and to the left in the found in North Africa, Arabia, Persia, Beloochistan, and southern hemisphere.
Cabul, we have on the same parallels in the southern The second point first established by Prof. Ferrel is
and eastern United States a region of abundant rainfall, that, in virtue of centrifugal force, this deflection or
and all the way up the Mississippi valley and in the in
terior of the continent there is much more rain than in pressure to the right in the northern, and to the left in
the interior of Asia.” the southern, hemisphere is suffered in exactly the same degree by bodies moving due east and due west, or along Taking this passage as it stands, or only together with a parallel of latitude, and therefore also in all intermediate the immediate context, it might be understood to imply azimuths.
that the author ascribes this great diversion of the winds From the first of these principles it will be readily seen
of the Gulf of Mexico, together with all the rainfall they why the west winds of middle latitudes are so much bring to the southern States of America, solely to the stronger than the easterly winds of the equatorial zone; influence of the comparatively low mountain-chain of and from the second, how these opposite winds, by their Central America. That such, however, is not his meanmutual pressure, produce the tropical zones of high ing is evident from his subsequent remarks on p. 215, barometer and the polar and equatorial regions of low where, in describing the monsoons of North America, barometer.
after noticing the high temperature of the land area in in subsequent chapters are discussed the modes in summer, he says :which the general circulation of the globe affects the climates of different latitudes by determining the distri- tion with the
deflection referred to [in the passage quoted
“On the southern and south-eastern coast, in connecbution of rainfall in wet and dry zones, and inequalities above], it causes the prevailing winds to be southerly and of temperature through the agency of marine currents. south-easterly, instead of north easterly, as they would Also the causes that modify and disturb the regularity of otherwise be in these trade-wind latitudes.”