366 ANNUAL KECOKD OF SCIENCE AND INDUSTRY. 



trees are cut down. In general, the wood felled when the 

 sap is not running has a decided pre-eminence as to its dura- 

 bility, strength, and density. The heat given out in burning 

 wood felled in December and January is also, according to 

 these experiments, greater than for woods cut in February 

 and March. 7 (7, XL, 123. 



THE DESTKUCTIOX OF FORESTS. 



The rapid and improvident destruction of our forests, and 

 the prevailing indiflerence displayed on the subject of their 

 conservation and cultivation, has become an almost stereo- 

 typed theme of warning and regret. It is demonstrable 

 that the immediate consequences of this improvidence are an 

 inconstancy and diminution of the rainfall, and a general de- 

 terioration of climate, to say nothing of a host of more re- 

 mote and complex evils that follow inevitably in its train in 

 course of time. These consequences have been abundantly 

 realized in the desolation that has overwhelmed once fertile 

 districts of Europe, and has stimulated the enactment and en- 

 forcement of wise laws which our lawgivers would do well to 

 imitate. Councilor Wex, at the recent yearly meeting of the 

 Geographical Society of Vienna, gave an able review of this 

 most important subject as it affected the water supply of 

 Central Europe. From the facts adduced in his paper, Herr 

 Wex demonstrated a fall in the level, since fifty years, of 17 

 inches in the Elbe, 24.8 inches in the Rhine, 17 inches in the 

 Oder, 26 inches in the Vistula, and in the Danube at Orsova 

 as much as 55 inches. Accompanying this fall in level, which 

 means so much of a decrease in the volume of these rivers, 

 there was also shown to be a constantly increasing diminu- 

 tion of the discharge from springs. It would be instructive 

 to have trustworthy data upon this subject from that portion 

 of the United States east of the Rocky Mountains where the 

 destruction of timber land has been for years going on on a 

 scale of unparalleled magnitude. 



CULTIVATION OF THE BAMBOO IX FEANCE. 



A peculiar variety of bamboo has been sent to the Accli- 

 matization Society of Paris, which it is believed will readily 

 adapt itself to the climate of France, and may prove of very 

 great value. It is said, indeed, that the French growth has 



