930 REPORT — 1900. 



of the science whose servants we are, let us not forpjet, on the one hand, to do 

 honour to those whose lifework it was to make the way straight for us, and whose 

 conquests have become our peaceful possession ; nor, on the other, that it lies with 

 us so to carry on the good work that when this Section meets a hundred years 

 hence it may be found that the achievements of the twentieth century do not 

 lag behind those of the nineteenth. 



The following Reports and Papers were read : — 



1. Report on Experimental Investigation of Assimilation in Plants. 



See Reports, p. 569. 



Report on Fertilisation in the PhcEophycecB. — See Reports, p. 569. 



3. British Sylviculture. By Samuel Margerison. 



Former supplies and high quality of British oak, &c. Recent supplies largely 

 consist of foreign timber. Native timbers still required in large quantities and 

 likely to be more in demand, because of lessening of stocks and enlarged home 

 consumption in the countries now supplying us. The period covered by the life 

 of a timber-tree fruitful in economic changes. We have much land at present 

 unproductive, or only slightly productive, suitable for growing a native supply of 

 timber, but owners and nation comfortably apathetic in the matter, content with 

 present abundant supply. Sportsmen are groundlessly fearful of their pleasures 

 being disturbed. It is really a national matter, calling for Government aid and 

 supervisioti, or good private ' working plans,' which cannot be disturbed by changes 

 of individual management. 



Comparison of results of Continental sylviculture with ours ; their crops 

 treble and quadruple of ours. Natural conditions here not less favourable, but 

 management generally inferior. 



Differences arise in details : 



Growing the Crop. — Thick planting and careful thinning (preserving an overhead 

 canopy and encouraging lengthy growth) ; making sport secondary to sylviculture, 

 whilst still providing abundance of it. 



Harvesting the Crop. — Gradual thinning ; reserving the thriving trees ; partial 

 conversion on the spot ; savings in haulage, again keeping sport secondary ; 

 reasonable cost of railway carriage. Forestry schools, with opportunities for 

 detailed research and teaching, with equipment, scientific and practical, worthy of 

 the subject. 



4. The Great Smoke-Cloud of the North of England and its Influence on 

 Plants. By Albert Wilson. 



The widespread eflect of smoke insufficiently realised. Dwellers in towns 

 often so hardened to it as to be almost oblivious of its presence. The great smoke- 

 producing district of the North of England ; its extent ; miserable condition of 

 vegetation in some parts of the area. Variation in amount of smoke according to 

 the season. Efl:ect in reducing air transparency, dimness of sky and landscape. 

 Distance to which smoke travels. Smoke often mistaken for haze. Red sunset*? 

 in South-east Yorkshire. Atmosphere of the North of England. North of the 

 smoke area never brilliant with southerly winds. The smoke from Barrow-in- 

 Furness, an isolated town ; long distance at which this is noticeable ; comparison 

 of its volume with that from the great smoke area. The characteristic smell from 

 certain large works, and the distance at which it can be detected. Discoloration 

 of rainwater ; ' black rain.' Influence of smoke on sunshine and air temperature 

 in calm summer weather, and in anticyclonic weather during autumn or winter ; 



