668 THE POPULAR SCIENCE MONTHLY. 



by being applied to softened steel plates produced almost indefinite 

 multiplication of the original engraved plate. For commercial pur- 

 poses this invention proved of immense value in the production of 

 bank-notes, receipts, and postage-stamps. 



To ignore the exertions of the Society of Arts in the direction of 

 agriculture, and especially arboriculture, would be to omit an impor- 

 tant page in its history. The introduction of new varieties of grasses 

 and roots was sedulously encouraged, while drill-ploughs, the drainage 

 of land, root-slicers, chaff-cutters, scarifiers, reaping-machines, and 

 means of harvesting hay and corn in wet seasons, were all subjects of 

 premiums. Big things and little things came in for their share of 

 attention. In the early days of the Society sheep were marked with 

 tar, to the great loss of wool-growers. The Society sought strenu- 

 ously to modify and improve the mode of marking sheep, and mean- 

 while instituted a crusade against that bold invader, the Norway rat, 

 who had recently overrun the country. 



The preservation of timber was an object of earnest solicitude. 

 In this age, when coal has effectually displaced wood as a heat-pro- 

 ducer, and iron has been successfully applied to the construction of 

 houses and ships, it is difficult to realize the anxiety of our forefathers 

 at seeing whole forests destroyed for smelting purposes. For a long 

 time past the work of destruction had been going on, when the Society 

 of Arts stepped in to advocate the planting of trees on a large scale. 

 The production of oak was a special object of the Society's attention, 

 the planting of acorns was carried on to a very large extent, and gold 

 medals for raising that description of timber were awarded to many 

 noblemen and gentlemen, among whom were the Earl of Wilton, the 

 Marquis of Tichfield, Mr. Morse, Mr. Curwen, and others. The culti- 

 vation of the ash for which the Bishop of Llandaff received a gold 

 medal of the Scotch fir and larch, and of fruit-trees generally, re- 

 ceived active encouragement. Under the auspices of the Society 

 millions of trees were planted, to the enrichment and adornment of 

 many previously-barren slopes. It is worthy of remark that to a neg- 

 lect of these precautions is assigned an actual change of the climatic 

 conditions of parts of Italy, and that the reduction of the Arno to an 

 insignificant stream is ascribed to the reckless denudation of the moun- 

 tains among which that historic river takes its rise. Travelers in 

 Switzerland also have not failed to observe in the side valleys many 

 relics of ancient mines, deserted, at last, because all the wood within 

 carrying distance had been recklessly destroyed without any attempt 

 being made to replace it by planting. 



Considerable effort was devoted to encouraging the introduction 

 and culture of spices into the British possessions. The cinnamon-tree 

 was introduced into Jamaica; the nutmeg-plant into St. Vincent; the 

 clove-tree into Trinidad ; the mango and the bread-fruit tree were also 

 planted in the West Indies. Attention was also directed toward such 



