I02 



NA TURE 



\JSIov. 29, I ( 



that is, the practice of setting fire to the trees in order to 

 clear the ground, is still carried on extensively. The 

 clearing away of the woods is to prepare the ground for 

 agriculture, but as much or more by the preparation of 

 the soil as by obtaining space for the cultivation contem- 

 plated, and this is the peculiarity of the usage. The trees 

 growing on the spot selected are burned, and the seed is 

 sown on the soil thus manured with the ashes of the trees. 

 The effects of sartagc in other European countries, in 

 India, and in North America, are brought under notice 

 and discussed at some length. In France it is a practice 

 recognised both in forest science and in forest manage- 

 ment, but whereas it was formerly resorted to largely it is 

 now adopted only in special circumstances. It is there 

 found that the oak, particularly a hardy variety known as 

 the rotivre, of all forest trees sustains best the treatment 

 of sarlaoe. In the Ardennes the coppice woods oirouvre, 

 which are so treated, yield excellent firewood and char- 

 coal. The burning is carried out in August and Septem- 

 ber, and, at the proper time for sowing cereals, rye or 

 buckwheat is scattered over the ground and covered with 

 a light hoe. After the crop is reaped the young tree- 

 shoots begin to grow rapidly, but it is often necessary in 

 order to insure perpetuity of good growths to plant out 

 seedlings, and this is especially the case with the oak. 



At the present time there are in Finland districts in 

 which sartage is now prohibited, others in which it is 

 carried on under restrictions, and others in which it is 

 tolerated and apparently freely practised. Should the 

 cleared ground not be retained permanently under agri- 

 culture, it is likely to become covered again with a crop of 

 self-sown trees, of the same kind as those destroyed, or 

 of a kind of higher pecuniary value. On the banks of 

 the Saima See, for example, fir trees have been replaced 

 either by firs or by birch. The fir or pine may be of 

 more value for building purposes, but the birch supplies a 

 better firewood, and for this there is and probably will 

 long continue an ever-increasing demand in St. Peters- 

 burg, to which it can be sent from most places in Finland 

 by water. 



When a crop of trees after destruction is not replaced 

 by another crop, the proximate effect upon the climate is 

 generally considered to be beneficial to agriculture. But 

 in .Sweden in many districts in which the forests have 

 been cleared away it is remarked that spring now begins 

 a fortnight later than it did in the last century, and this 

 is attributed to protracted frost due to diminished humidity 

 of the atmosphere. 



The improved forest economy of France dates from 

 the issue of the celebrated Forest Ordinance of 1669, if 

 not from a much earlier period. But in Finland all im- 

 provements in forest economy have been effected since 

 1809, and particularly during the last twenty-five years. 

 Though formerly an independent country, Fmland was 

 for a long time a province of Sweden, and in 1809 it was 

 annexed to the dominions of Russia as a Grand Duchy, 

 with the enjoyment of pre-existing privileges and of 

 government under its own laws issued in accordance with 

 its Constitution. In 1848 were sent out Imperial Instruc- 

 tions relative to the management of the Crown forests, 

 along with regulations respecting projected surveys, and 

 in 1858 new arrangements for the management of these 

 forests were made. 



The forest administration of Finland is now in the 

 hands of well-trained officers, and much of the lavish 

 waste of former days has ceased. By giving more atten- 

 tion to considerate thinning, by more skilful conservation 

 and more scientific exploitation, it was felt that the " pro- 

 duce and the products of the forests might be equalised 

 approximately, if not perfectly," and one object aimed at 

 in the inspection of forests is to prevent the removal of 

 trees being effected more rapidly than the re-growth. As 

 has been remarked, Finland has a constant market for 

 firewood and timber ia St. Petersburg, where firewood is 

 now more expensive than coal brought from Britain. 



It is to its School of Forestry at Evois that Finland 

 looks for its supply of trained forest conservators. This 

 school was opened in 1859, and intending students were 

 required to produce before admission a university diploma, 

 or a first class certificate of the completion of the course 

 of study at a gymnasium. Closed after a time from lack 

 of students, it was reorganised and reopened in 1874. The 

 course of study occupies two years, and the subjects are 

 forest science, surveying, engineering, rural economy, 

 legal economy, and drawing. In July and August the 

 pupils are required, for the sake of practice, to measure 

 fields and woods, and to estimate the quantities of stand- 

 ing timber. We observe that under forest science is 

 included " the science of hunting,'' whereat many an 

 English youth would no doubt be inclined to say " Happy 

 Finlanders ! " Officered by men trained in this school, 

 the Finnish forest administration is now in a position to 

 attain objects identical with thoee of the advanced forest 

 economy of Europe : first, to secure a sustained produc- 

 tion from the forests ; secondly, to secure along with this 

 an amelioration of their condition ; and thirdly, a repro- 

 duction of them by self-sown seed when felled. 



Readers who are interested in forest conservancy will 

 find much valuable information in the middle section of 

 Dr. Brown's work. The subject is one which must ere 

 long force itself on the attention of political economists. 

 The reckless clearances that have been eftected in our 

 Canadian territories are approaching a limit ; the most 

 cautious estimates do not allow a longer period than 

 fifteen years for the exhaustion of our Canadian timber 

 lands at the present rate of consumption, and one very 

 trustworthy and experienced authority limits it to seven 

 years. W. Fream 



LETTERS TO THE EDITOR 



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Optical Phenomena 



The phenomenon described a; " Cluud-Glow " by your cor- 

 respondent, Mr. F. A. R. Rus-ell, in Nature of the I5lh inst. 

 (p. 55)i ^"d by Mr. J. J. Walker in your last issue (p. 77), was 

 observed here by me ; as, however, the time my observatiun com- 

 menced (s p.m.) W.1S three-quarters of au hour later than the 

 time given by Mr. Russell (4.18 p.m.) it is probable that many 

 of the features described by him had faded before the pheno- 

 menon came under my notice. As seen by me, the appearance 

 consisted of an arc-like mass of glowing vapour of a ruddy hue^ 



