356 KANSAS CITY REVIEW OF SCIENCE. 



Another advantage is that it shows immediately the degree of humidity, for 

 a table, inscribed on the semi-circumference of the .circle, gives in a moment the 

 equivalent of the degrees of the hygrometer in the fractions of saturation of the 

 air. 



By this method we can make most interesting comparisons of the humidity 

 of the fogs and mists that are. encountered on the mountains and in the vicinity of 

 elevated lakes. 



It is easy to see the utility of the compass, which shows the position of the 

 country, and is especially useful to the traveler, when exploring an unknown 

 place or surrounded by a heavy fog. The direction of the wind can also be 

 easily ascertained by tying a piece of ribbon to the ring at the top of the instru- 

 ment, and so making it still more useful — La Nature. 



TREE CULTURE ON WASTE LAND. 



Hitherto the abundance of natural timber in this country has made it easy 

 to dispense with timber culture, and for the most part our land owners have 

 taken little interest in such slow-growing crops. This state of things, however, 

 is rapidly passing away. The demand for special woods for manufacturing pur- 

 poses is steadily and rapidly increasing, while the natural supply is diminishing, 

 and must ultimately become quite inadequate. Meantime there are millions of 

 acres of land suitable for timber culture and for nothing else, except poor pastur. 

 age that our land owners are allowing to lie waste and idle for lack of a little 

 forethought, and too frequently our would-be thritt farmers will risk their surplus 

 means in wild-cat speculations, promising, but never yielding, large and speedy 

 returns, when the same money, spent in planting timber, would soon convert 

 their worthless swamps and stony places into valuable properties. 



A correspondent of the Scientific Neivs, writing from Wisconsin, tells of a 

 piece of land that was planted with walnut twenty-three years ago. The land 

 was flooded every spring and summer, and was unfit for ordinary cultivation. The 

 trees are now from 1 6 to 20 'inches through, and have been sold for $27,000. 

 No particulars have been given as to the cost of planting the grove, or the amount 

 of attention it has had during the years of growth. There can be little doubt, 

 however, that the investment was small m comparison with the return, and the 

 land would otherwise have remained entirely unproductive. To the country the 

 timber crop was so much clear gain. It is clear that our national resources might 

 be enormously increased by a similar utilization by timber culture of lands which 

 are now left unused and unproductive; and the planters would find their groves 

 a surer investment for the security of their family possessions than any savings 

 bank deposit. 



